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Using frequency analysis to determine wetland hydroperiod

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Title:
Using frequency analysis to determine wetland hydroperiod
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English
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Foster, Lisa D
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University of South Florida
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Hydrology
Time series
Frequency analysis
Spectral analysis
Power spectrum density
Dissertations, Academic -- Engineering Science -- Masters -- USF   ( lcsh )
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bibliography   ( marcgt )
theses   ( marcgt )
non-fiction   ( marcgt )

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Abstract:
ABSTRACT: Wetlands are nominally characterized by, vegetation, presence of saturated soils and/or period and depth of standing water (inundation). Wetland hydroperiod, traditionally defined by the period or duration of inundation, is considered to control the ecological function and resultant plant community. This study seeks to redefine "hydroperiod" to incorporate both surface and subsurface water-level fluctuations, to identify predominant hydroperiod of different wetland types, and to find the range of the water-level fluctuations during the predominant hydroperiod durations. The motivation being that wetland ecological condition is controlled not just by the period of inundation but also by the proximity and depth to water-table and period of water-level fluctuation. To accomplish this, a frequency distribution analysis of water-table and stage levels in wetlands is performed. The conclusions of this study suggest a need to rethink current definitions and methodologies in determining hydroperiod. Redefining wetland hydroperiod taking into consideration depth to water-table, namely water-level periods and depths below ground surface, may also aid in the understanding of how fluctuations in water-levels in a wetland affect plant ecology.
Thesis:
Thesis (M.S.)--University of South Florida, 2007.
Bibliography:
Includes bibliographical references.
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by Lisa D. Foster.
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Title from PDF of title page.
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Using Frequency Analysis to Determine Wetland Hydroperiod by Lisa D. Foster A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Engineering Science Department of Civil and Environmental Engineering College of Engineering University of South Florida Major Professor: Mark A. Ross, Ph.D. Mahmoud Nachabe, Ph.D. Kenneth Trout, Ph.D. G. Ladde, Ph.D. Date of Approval: March 26, 2007 Keywords: hydrology, time series, frequency analysis, spectral analysis, power spectrum density Copyright 2007, Lisa D. Foster

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i Table of Contents List of Tables.................................................................................................ii List of Figures................................................................................................iii Abstract......................................................................................................viii Chapter One: Introduction..............................................................................1 1.1 Introd uction.........................................................................................1 1.2 Background Information.........................................................................2 1.2.1 Wetland Hydrology...........................................................................................2 1.2.2 Water Budget....................................................................................................3 1.2.3 Hydroperiod......................................................................................................5 1.3 Objective of Study.................................................................................7 Chapter Two: Methodology.............................................................................9 2.1 Study Area...........................................................................................9 2.2 Data Co llection....................................................................................13 2.3 Method ology.......................................................................................27 2.3.1 Discrete Fourier Transform............................................................................28 2.3.2 The Periodogram............................................................................................30 2.3.2.1 Spectral Leakage.....................................................................................31 2.3.2.2 Spectral Estimates..................................................................................31 2.3.3 Application of the Method..............................................................................32 Chapter Three: Resu lts and Discussion...........................................................33 3.1 Over view............................................................................................33 3.2 Temporal Characteri stics of Hydroperiod.................................................36 3.3 Hydroperiod WaterLevel Fluctuations....................................................41 3.4 Comparison of Findings........................................................................52 Chapter Four: Conclusions............................................................................56 Refere nces..................................................................................................59 Appendices.................................................................................................63 Appendix A: Time Series Figures.................................................................64 Appendix B: Annual Observed Water-Level Time Se ries..................................76 Appendix C: Spectral Analysis Figures..........................................................88 Appendix D: Wate r-Level Tables................................................................105

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ii List of Tables Table 1: Observation Wells and Physiograp hic Regions......................................15 Table 2: Observation Wells with Corresponding FLUCCS and Wetland Type...........16 Table 3: Observation Wells and Respective Wellfields........................................24 Table 4: Wetland Observ ation Well A ttributes...................................................25 Table 5: Power Spectral Density Peak Periods for all Observation Wells................39 Table 6: Power Spectral Density Semi-Annual Peak Periods for all Observation Wells.............................................................................................40 Table 7: Average Wetland WaterLevel Magnitudes and Ranges..........................49 Table 8: Qualitative Hydroperiod Defi nitions as Defined by Mitsch and Gosselink 2000...............................................................................52 Table 9: Hydroperiod Durations and Wate r-Level Magnitudes and Ranges for All Wetlan d Types............................................................................53 Table 10: Annual Wetland WaterLevel Magnitudes and Ranges.........................105

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iii List of Figures Figure 1: SWFWMD Domain: West-Cen tral Florida Study Area Counties...............10 Figure 2: Physiographic Regions of West-Central Florida (Modified from White, 1970)...........................................................................................12 Figure 3: Location of Observation Wells...........................................................14 Figure 4: Observation Wells by We tland Type...................................................17 Figure 5: Orthophotographic Aerials of Wetland Observation Wells 2062 and 2064, Respectively Located in Mixe d Forest and Cypress Wetlands........21 Figure 6: Observation Wells and Wellfields.......................................................23 Figure 7: Observed Water-Level Time Se ries for Four Wetlands: Bottomland (1969), Wet Prairie (10896), Mixe d (1980), and Cypress (1929)...........33 Figure 8: Annual Water-Level Obse rvations for (a) Mixed (1980) and (b) Cypress ( 1929) Wetl ands...........................................................35 Figure 9: Spectra of the Water-Leve l Record for Well Numbers (a) 1980, Located in a Mixed Forest Wetlan d and (b) 1929, Located in a Cypress Wetland............................................................................37 Figure 10: Probability Densities of the Winter/Spring and Summer/Fall Hydroperiod Phases of (a) NonWellfield Cypress (1929), (b) Wellfield Cypre ss (10965), and (c) Non-Wellfield Wet Prairie (1946) Wetl ands...........................................................................42 Figure 11: Probability Densities of Water-Levels for Non-Wellfield Cypress Wetland Wells 1989, 1961, and 1918, Which are Respectively Located in the Lake Upland, Western Valley, and Gulf Coastal Lowlands.....................................................................................44 Figure 12: Probability Densities of Water-Levels for Non-Wellfield Cypress Wetland Observation Wells Located in all Physiographic Regions..........45 Figure 13: Probability Densities of Water-Levels for Non-Wellfield Wet Prairie Wetland Observation Wells Located in all Physiographic Regions..........45 Figure 14: Probability Densities of Wate r-Levels for Cypress (1944) and Mixed (1946) We tlands...........................................................................46 Figure 15: Probability Densities of Wate r-Levels for Wellfield Cypress (10965) and Wellfield Bottoml and (598) Wetlands.........................................47

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ivFigure 16: Probability Densities of Water-Levels for Gulf Coastal Lowlands, Cypress Wetland Observation Wells 10958, Located in a Wellfield, and 1944, Not Locate d in a Wellfield................................................48 Figure 17: Proposed Relationships Between Species Richness of Woody Vegetation in Swamps Relative to the Hydroperiod (Source: After Ewel, 1990)..................................................................................54 Figure 18: Average Duration and Dept h of Inundation from 2004 through 2006 for All Wetl and Types.....................................................................55 Figure 19: Observed Water-Level Ti me Series for We tland Well 598....................64 Figure 20: Observed Water-Level Ti me Series for Wetland Well 1021...................64 Figure 21: Observed Water-Level Ti me Series for Wetland Well 1918...................64 Figure 22: Observed Water-Level Ti me Series for Wetland Well 1929...................65 Figure 23: Observed Water-Level Ti me Series for Wetland Well 1932...................65 Figure 24: Observed Water-Level Ti me Series for Wetland Well 1935...................65 Figure 25: Observed Water-Level Ti me Series for Wetland Well 1938...................66 Figure 26: Observed Water-Level Ti me Series for Wetland Well 1944...................66 Figure 27: Observed Water-Level Ti me Series for Wetland Well 1946...................66 Figure 28: Observed Water-Level Ti me Series for Wetland Well 1954...................67 Figure 29: Observed Water-Level Ti me Series for Wetland Well 1959...................67 Figure 30: Observed Water-Level Ti me Series for Wetland Well 1960...................67 Figure 31: Observed Water-Level Ti me Series for Wetland Well 1961...................68 Figure 32: Observed Water-Level Ti me Series for Wetland Well 1966...................68 Figure 33: Observed Water-Level Ti me Series for Wetland Well 1969...................68 Figure 34: Observed Water-Level Ti me Series for Wetland Well 1977...................69 Figure 35: Observed Water-Level Ti me Series for Wetland Well 1978...................69 Figure 36: Observed Water-Level Time Series for Wetland Well1980...................69 Figure 37: Observed Water-Level Ti me Series for Wetland Well 1981...................70 Figure 38: Observed Water-Level Ti me Series for Wetland Well 1987...................70 Figure 39: Observed Water-Level Ti me Series for Wetland Well 1988...................70 Figure 40: Observed Water-Level Ti me Series for Wetland Well 1989...................71 Figure 41: Observed Water-Level Ti me Series for Wetland Well 1990...................71

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vFigure 42: Observed Water-Level Ti me Series for Wetland Well 1991...................71 Figure 43: Observed Water-Level Ti me Series for Wetland Well 1992...................72 Figure 44: Observed Water-Level Ti me Series for Wetland Well 1995...................72 Figure 45: Observed Water-Level Ti me Series for Wetland Well 2060...................72 Figure 46: Observed Water-Level Ti me Series for Wetland Well 2062...................73 Figure 47: Observed Water-Level Ti me Series for Wetland Well 2064...................73 Figure 48: Observed Water-Level Ti me Series for Wetland Well 2066...................73 Figure 49: Observed Water-Level Ti me Series for Wetland Well 2159...................74 Figure 50: Observed Water-Level Ti me Series for We tland Well 10896.................74 Figure 51: Observed Water-Level Ti me Series for We tland Well 10958.................74 Figure 52: Observed Water-Level Ti me Series for We tland Well 10965.................75 Figure 53: Annual Observed Water-Le vel Time Series for Wetland Well 598..........76 Figure 54: Annual Observed Water-Le vel Time Series for Wetland Well 1021........76 Figure 55: Annual Observed Water-Le vel Time Series for Wetland Well 1918........76 Figure 56: Annual Observed Water-Le vel Time Series for Wetland Well 1929........77 Figure 57: Annual Observed Water-Le vel Time Series for Wetland Well 1932........77 Figure 58: Annual Observed Water-Le vel Time Series for Wetland Well 1935........77 Figure 59: Annual Observed Water-Le vel Time Series for Wetland Well 1938........78 Figure 60: Annual Observed Water-Le vel Time Series for Wetland Well 1944........78 Figure 61: Annual Observed Water-Le vel Time Series for Wetland Well 1946........78 Figure 62: Annual Observed Water-Le vel Time Series for Wetland Well 1954........79 Figure 63: Annual Observed Water-Le vel Time Series for Wetland Well 1959........79 Figure 64: Annual Observed Water-Le vel Time Series for Wetland Well 1960........79 Figure 65: Annual Observed Water-Le vel Time Series for Wetland Well 1961........80 Figure 66: Annual Observed Water-Le vel Time Series for Wetland Well 1966........80 Figure 67: Annual Observed Water-Le vel Time Series for Wetland Well 1969........80 Figure 68: Annual Observed Water-Le vel Time Series for Wetland Well 1977........81 Figure 69: Annual Observed Water-Le vel Time Series for Wetland Well 1978........81 Figure 70: Annual Observed Water-Le vel Time Series for Wetland Well 1980........81

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viFigure 71: Annual Observed Water-Le vel Time Series for Wetland Well 1981........82 Figure 72: Annual Observed Water-Le vel Time Series for Wetland Well 1987........82 Figure 73: Annual Observed Water-Le vel Time Series for Wetland Well 1988........82 Figure 74: Annual Observed Water-Le vel Time Series for Wetland Well 1989........83 Figure 75: Annual Observed Water-Le vel Time Series for Wetland Well 1990........83 Figure 76: Annual Observed Water-Le vel Time Series for Wetland Well 1991........83 Figure 77: Annual Observed Water-Le vel Time Series for Wetland Well 1992........84 Figure 78: Annual Observed Water-Le vel Time Series for Wetland Well 1995........84 Figure 79: Annual Observed Water-Le vel Time Series for Wetland Well 2060........84 Figure 80: Annual Observed Water-Le vel Time Series for Wetland Well 2062........85 Figure 81: Annual Observed Water-Le vel Time Series for Wetland Well 2064........85 Figure 82: Annual Observed Water-Le vel Time Series for Wetland Well 2066........85 Figure 83: Annual Observed Water-Le vel Time Series for Wetland Well 2159........86 Figure 84: Annual Observed Water-Le vel Time Series for Wetland Well 10896......86 Figure 85: Annual Observed Water-Le vel Time Series for Wetland Well 10958......86 Figure 86: Annual Observed Water-Le vel Time Series for Wetland Well 10965......87 Figure 87: Spectral Analysis of We tland Well 598 Water-Level Time Series...........88 Figure 88: Spectral Analysis of We tland Well 1021 Water-Level Time Series.........88 Figure 89: Spectral Analysis of We tland Well 1918 Water-Level Time Series.........89 Figure 90: Spectral Analysis of We tland Well 1929 Water-Level Time Series.........89 Figure 91: Spectral Analysis of We tland Well 1932 Water-Level Time Series.........90 Figure 92: Spectral Analysis of We tland Well 1935 Water-Level Time Series.........90 Figure 93: Spectral Analysis of We tland Well 1938 Water-Level Time Series.........91 Figure 94: Spectral Analysis of We tland Well 1944 Water-Level Time Series.........91 Figure 95: Spectral Analysis of We tland Well 1946 Water-Level Time Series.........92 Figure 96: Spectral Analysis of We tland Well 1954 Water-Level Time Series.........92 Figure 97: Spectral Analysis of We tland Well 1959 Water-Level Time Series.........93 Figure 98: Spectral Analysis of We tland Well 1960 Water-Level Time Series.........93 Figure 99: Spectral Analysis of We tland Well 1961 Water-Level Time Series.........94

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viiFigure 100: Spectral Analysis of We tland Well 1966 Water-Level Time Series........94 Figure 101: Spectral Analysis of We tland Well 1969 Water-Level Time Series........95 Figure 102: Spectral Analysis of We tland Well 1977 Water-Level Time Series........95 Figure 103: Spectral Analysis of We tland Well 1978 Water-Level Time Series........96 Figure 104: Spectral Analysis of We tland Well 1980 Water-Level Time Series........96 Figure 105: Spectral Analysis of We tland Well 1981 Water-Level Time Series........97 Figure 106: Spectral Analysis of We tland Well 1987 Water-Level Time Series........97 Figure 107: Spectral Analysis of We tland Well 1988 Water-Level Time Series........98 Figure 108: Spectral Analysis of We tland Well 1989 Water-Level Time Series........98 Figure 109: Spectral Analysis of We tland Well 1990 Water-Level Time Series........99 Figure 110: Spectral Analysis of We tland Well 1991 Water-Level Time Series........99 Figure 111: Spectral Analysis of We tland Well 1992 Water-Level Time Series.......100 Figure 112: Spectral Analysis of We tland Well 1995 Water-Level Time Series.......100 Figure 113: Spectral Analysis of We tland Well 2060 Water-Level Time Series.......101 Figure 114: Spectral Analysis of We tland Well 2062 Water-Level Time Series.......101 Figure 115: Spectral Analysis of We tland Well 2064 Water-Level Time Series.......102 Figure 116: Spectral Analysis of We tland Well 2066 Water-Level Time Series.......102 Figure 117: Spectral Analysis of We tland Well 2159 Water-Level Time Series.......103 Figure 118: Spectral Analysis of We tland Well 10896 Water-Level Time Series.....103 Figure 119: Spectral Analysis of We tland Well 10958 Water-Level Time Series.....104 Figure 120: Spectral Analysis of We tland Well 10965 Water-Level Time Series.....104

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viiiUsing Frequency Analysis to Determine Wetland Hydroperiod Lisa D. Foster ABSTRACT Wetlands are nominally characterized by, vegetation, presence of saturated soils and/or period and depth of standing water (inundation). Wetland hydroperiod, traditionally defined by the pe riod or duration of inundati on, is considered to control the ecological function and resultant plant community. This study seeks to redefine hydroperiod to incorporate both surface an d subsurface water-level fluctuations, to identify predominant hydroperiod of different wetland types, and to find the range of the water-level fluctuations during the predominant hydroper iod durations. The motivation being that wetland ecological condition is controlled not just by the period of inundation but also by th e proximity and depth to water-table and period of waterlevel fluctuation. To accomplish this, a frequency distribution analysis of water-table and stage levels in wetlands is performed. The conclusions of this study suggest a need to rethink current definitions and methodologies in determining hydroperiod. Redefining wetland hydroper iod taking into consideration depth to water-table, namely water-level periods and depths belo w ground surface, ma y also aid in the understanding of how fluctuations in water-levels in a wetland affect plant ecology.

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1 Chapter One: Introduction 1.1 Introduction Wetlands are a significant factor in the health and existence of other natural resources of the state, such as inland la kes, groundwater, wild life, and designated Florida Outstanding Waters. Florida's we tland statute recognizes many benefits provided by wetlands includ ing: flood and storm control by the storage capacity of wetlands; wildlife habitat by providing breeding, nestin g, and feeding grounds and cover for many forms of wildlife and wate rfowl; protection of subsurface water resources and recharging groundwater supp lies; pollution treatment; and erosion control by serving as sedimentation areas and filtering basins. Wetlands are also beneficial to recreation and tourism in Florida, thus improving the economy. Wetlands occur where surface water co llects and/or groundwater interacts with land, inundating the area for extended periods of time (Tiner, 1996). The Clean Water Act defines the term wetlands as those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circum stances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. For an area to be considered a wetland under this definition, that area must contain: water at or near the surface for a period of time (wetland hydrology), wetland plants (hydro phytic vegetation), and periodically anaerobic soils caused by prolonged inundation (hydric soils) (Dennison and Berry, 1993; Tiner, 1996). The hydrological regime of each wetland

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2 differs in frequency and magnitude of high water, duration, timing, and temporal sequences of high and lo w water (Zedler, 2001). 1.2 Background Information 1.2.1 Wetland Hydrology Many studies have shown that wetlands reduce flooding, augment low flows, and/or recharge groundwater. Conversely there are also many examples showing that wetlands increase floodin g, reduce low flows, and/or act as a barrier to recharge (Bullock and Acreman, 2003). Differences in hydroperiod, fire frequency, accumulation of organic ma tter, and source of water can explain the range of structural and function al diversity of Florida wetlands Floridas combination of high fire frequency, low topography, high su rficial groundwater-tables, and seepage to/from deep groundwater aquifers has pr oduced an unusually diverse array of wetlands (Ewel, 1990). In the past, vegetation was used exclusively in the identification of wetlands and their boundaries. More current appr oaches, however, take into account vegetation, soil, and hydrolog ic characteristics for the identification and delineation of wetlands (Tiner, 1991). To assist in the identification of wetlands in the United States, the Soil Conservation Service developed a list of hydric soils and the U.S. Fish and Wildlife Service prep ared a list of wetland plants (Tiner, 1996). In addition, the National Wetlands Inventory, conducted under the direction of the U.S. Fish and Wildlife Service, devised a hierarchical wetland classi fication system based on hydrologic, geomorphologic, chemical, and biological characte ristics (Ewel, 1990). There is, however, no single, correct, indisputable, ecologically sound definition for wetlands, primarily because of the di versity of wetlands and because the

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3 demarcation between dry and wet environm ents lies along a co ntinuum (Cowardin et al., 1979). 1.2.2 Water Budget Wetlands exert a strong influence on the hydrologic cycle, however, the relationship between wetland type and the specific hydrol ogic functions they perform is complex (Bullock and Acreman, 2003). Hydrology remains a component of wetland ecosystems that has not been extensively investigated, though the importance of hydrologic conditions to the structure an d function of wetlands has long been recognized (Shaffer et al., 2000). Wetland ve getation and function depend upon the frequency, duration, and depth of the wate r, whether it be surface or groundwater (Marble, 1992). Hydrology leads to a unique vegetation composition but can limit or enhance species richness (Mitsch and Gosse link, 2000). Hydrology, therefore, plays a critical role in the functional ability and health of a wetland. The major components of a wetlands water budget are precipitation, evapotranspiration, and over bank flooding in riparian wetlands; surface flows, groundwater fluxes, and tides in coasta l wetlands (Mitsch and Gosselink, 2000). Rainfall is the ultimate source of fresh water in central Florida. Most of the precipitation is, however, recycled back to the atmosphere by evapotranspiration (Clemens et al., 1984). Some precipitation is also retained by the overlying canopy, too. This is referred to as interception. This water is not lost in relation to the water budget, however, as it ma y reduce transpiration losses (Mitsch and Gosselink, 2000). When sufficient precipitation does over come losses to evap otranspiration and hydrostatic capillary retention in the uns aturated zone, the remaining water can percolate to the water-table, and recharge the aquifer system. Wh en the infiltration capacity of the soil is exceeded by pr ecipitation rates or the ground becomes

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4 saturated, excess water becomes surface runoff (OReilly, 2004). Hydraulic inflows and outflows, such as precipitation, surface runoff, and groundwater inputs, together with wetland storage characte ristics, control water dept h, flow patterns, stage, duration, and frequency of flooding in we tlands (Mitsch and Go sselink, 2000). Mitsch and Gosselink (2000) expressed the gene ral balance between water storage and inflows and outflows as: T G S ET G S P t Vo o i i n where V = volume of water storage in wetlands V/ t = change in volume of water storage in wetland per unit time Pn = net precipitation (precipitation-interception) Si = surface inflows, including flooding streams Gi = groundwater inflows ET = evapotranspiration So = surface outflows Go = groundwater outflows T = tidal inflow (+) or outflow (-) Mitsch and Gosselink (2000) sugested that the average water depth at any time could be described as: A V d where A = wetland surface area. Although these are the major components of a wetland water budget, the terms vary in importance according to the type of wetland (Mitsch and Gosselink, 2000.) The hydroperiod of a wetland ultimately results from the time variability of all of these components of the water budget. Relatively small changes in the water cycle over

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5 extended time periods can drastically effe ct the hydrperiod and this can in turn change the biotic and abiotic stabilit y of a wetland (Den nison and Berry, 1993) 1.2.3 Hydroperiod The ecological characteristics of a we tland are controlled by the presence and duration of saturated soils or standing water for part of the year (Ewel, 1990), known as the hydroperiod. The hydroperio d is the result of the balance between inflows and outflows of water, wetland stor age, and the subsurface soil, geology, and groundwater conditions (Mitsch and Gosselink, 2000). Hydroperiod refers to frequency, duration, and depth of the wate r within the wetland. The periodicity of inundation, permanent, seasonal, or interm ittent, is the ecological and functional control for many wetlands. For those wetl ands sustained by seepage, subsurface waterlogging or watertable rise, however, it is the periodicity of water-table fluctuations with respect to the root zone that maintains the wetland (Semeniuk and Semeniuk, 1997). Hence, the water budget an d the storage capacity of the wetland (above and below ground) ul timately define the hydrop eriod. Because the storage capacity of the wetland plays a critical role in defining hydroperiod, fluctuations in the depth to water-table must be taken into consideration. It is still not known exactly how fluctuations in the hydroperiod of a wetland affect plant and animal communities (Zedler, 2001). Hydroperiod affects soil aeration, which in turn influences the ability of plants to survive and reproduce. During prolonged inundation, oxygen in the r oot zone is depleted and concentrations of soluble iron, manganese, and even hydrogen sulfide increase, thereby creating stressful conditions on roots (Ewel, 1990). Only a small portion of the thousands of species of vascular plants on Earth have adapted to survive in waterlogged soils (Mitsch and Gosselink, 2000). Wetl ands, therefore, are inhabi ted by only a particular

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6 subset of plant species. Wetlands with longer hydroperiods may, consequently, contain fewer species and serve unique func tions. Species richness is also dependent on fire frequency and depth of organic matter accumulation, because these factors create variations in water depth, residence time, and quality in wetlands with similar hydroperiod (Ewel, 1990). Water-levels in most wetlands fluctuat e seasonally, daily or semi-daily, or unpredictably. Wetland hydroperiods that va ry greatest between high and low waterlevels are often caused by flooding pulses which occur seasonally or periodically (Junk et al., 1989). Pulsing hydroperiod and flowing conditions enhance primary productivity and other ecosystem function s, which are frequently depressed by stagnant conditions (Mitsch and Gosselink, 2000). De Steven and Toner (2004) found that while wetland vegetation integrates the influence of many ecological factor s, wetland hydrologic regime was most strongly correlated with vegetation type. Statistical methods of classification have been increasingly used in the characterization of plant communities including wetland plant communities. Traditionally, however, the classification of wetlands follows simple schemes, which are based on a comb ination of characteristics, such as geomorphism, hydroperiod, location, physiognomy, species dominance, salinity, or topography (Pinder and Rosso, 1998). Althou gh used for characterization of plant communities, use of statistical methods for the analysis of wetland hydroperiod have not gained popularity. Water-level variability in wetlands is important to biological and hydrological function. It is, therefore, of keen interest to quantify the time scale and magnitude of the water-level fluctuations in order to fully understand hydroperiod. Because the variability is also periodic and recurring, it lends itself to a time series investigation in

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7 the frequency domain. This study attempts to quantify hydroperiod using spectral analysis of observed water-level data from various wetlands in West-Central Florida. 1.3 Objective of Study Wetlands exhibit episodic (storm events), seasonal, and yearly patterns of fluctuation in surface and su bsurface water (Dennison and Berry, 1993). West-Central Florida wetlands are influenced by a sha llow and rapidly fluctuating water-table and regular high intensity rainfa ll events, yet depth to the water-table is not typically included as a parameter in the definition of hydroperiod. There is little information regarding the influence of the depth to the water-table in the classification of wetlands. Because wetland ecological condition is controlled not just by the period of inundation, but also by the proximity and depth to the water-table (controlling the dry periods), there is a need to thoroughly define hydroperiod incorporating the depth to water-table. Mi tsch and Gosselink (2000) observed a wet and dry season for Big Cypress Swamp near the Florida Everglades, however, to date an attempt to quantify hydroperiod as a whole has not been done. This study seeks to analyze wetland hydroperiod using Fo urier Transformation and Time Series analysis considering the frequency domain of observed water-levels, both above and below the land surface, in order to quantify and more accurately define hydroperiod. Spectral analysis of the individual water-level time series data can provide an invaluable insight into the temporal and pe riodic behavior of hy drological processes (Hegge and Masselink, 1996). For this reason, spectral analysis will be used in an attempt to identify dominant frequencies (spectral peaks) in observed water-level time series. The dominant frequencies are representative of the significant components of the hydroperiod through the entire range of water-level fluctuations. Hence, spectral analysis provides a powe rful tool to evaluate hydroperiod. By

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8 incorporating the perspective of water-tabl e depth, and therefore the complete range of wetland water-level fluctuations, this approach should more fully quantify hydroperiod. Specific objectives of this study were to: (1) redefine and quantify wetland hydroperiod, incorporating both surface and subsurface water-level fluctuations using standard frequency analysis (2) identi fy predominant hydroperiods of different wetlands, (3) find the range of the wate r-level fluctuations associated with predominant hydroperiods, (4)investigate wh ether hydroperiod can be associated to a given type of wetland, and (5) very simply investigate whether the effects of pumping can be observed in the re sultant hydroperiod of a wetland.

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9 Chapter Two: Methodology 2.1 Study Area The study area chosen is contained wi thin a typical coastal plain environment incorporating parts of Pasco, Pinellas, Hillsborough, Polk, Lake, and Sumpter counties, which are located in the Southwest Florida Water Management District (SWFWMD) domain in West-Central Florida (Figure 1). The District is approximately 10,400 square miles encompassing 16 countie s with a population of 3.1 million people. The climate of West central Florida is classified as humid subtropical. A strong climatic cycle of a cool, dry season and a warm, rainy season exists, however, spatial and temporal changes in daily te mperature ranges can exceed the average annual ranges (Chen and Gerber 1990). The mean annual temperature is 73F. The long-term average annual precipitation of the region is 52 inches per year, but precipitation shows substantial spatial an d temporal variability (Clayback, 2006; Scott, 2006). On average, the driest months of record are November and April, with the wettest being July and August (NO AA, 2006). The mean annual open-water evaporation rate for the region is 50-52 in ches per year (Clayback, 2006; Ruskauff et al., 2003). Floridas unique geologic history ha s produced a sculptured topography. Several distinct physiographic features have been identified in this region. These features reflect interactions between the geology and both the surfaceand groundwater systems over geologic time. Paleos horelines that separa te several marine plains or terraces, reco gnized by Cooke (1945) an d MacNeil (1950), generally correspond to the physiographic bound aries (Schmidt, 199 7; Lewelling, 1998).

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10 Figure 1: SWFWMD Domain: West-C entral Florida Study Area Counties

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11 The primary physiographic features with in the study area counties are (1) the Northern and Southern Gulf Coastal Lowl ands, (2) the Western and Central Valleys, (3) the Marion, Polk, and Lake Uplands, (4) the Brooksville, Lakeland, Winter Haven, and Lake Wales Ridges, and (5) the TsalaApopka and Osceola Plains (White, 1970; SWFWMD, 2000). A map of the physiography wi thin the counties of interest, adapted from White (1970), is shown in Figure 2. The physiographic regions of particular interest in this study include (1) the Gulf Coastal Lowlands, (2) the Western Valley, and (3) both the Polk and Lake Uplands. The Gulf Coastal Lowlands province co nsists of scarps and marine terraces of aeolian sands. The terraces range from near sea level to 100 ft NGVD. The Gulf Coastal Lowlands lie to the west of the Brook sville Ridge. Included is the area of the Big Cypress Swamp, as well as the extens ive lowland lakes region in northwest Hillsborough County and south-central Pasco County. Soils are uniform fine sand, with little organic material and the landscape contains extensive flatwood pine, oak, and saw palmetto (SWFWMD, 1996; SW FWMD, 2000; Armstrong et al., 2003). The Western Valley physiographic region lies to the south of the Brooksville Ridge and to the east of the Gulf Coastal Lowlands. It runs alon g the eastern borders of Pasco and Hernando Counties and up th rough the middle of Sumter County. The area is an erosional basin with sluggish surface-water drainage and many karst features. The region contains Karst limestone, which is overlaid with a thin layer of sand and clay. Springs and sinkholes are common. Elevations range from 10 to 140 feet, with poorly drained swamps and ma rshes in the lower elevations and pine flatwoods in the higher elevations (SWFWMD, 1996; SWFWMD, 2000; Armstrong, 2003).

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12 Figure 2: Physiographic Regi ons of West-Central Florid a (Modified from White, 1970)

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13 Moderate water-table depths and la nd-surface elevations and relief are characteristic of the upland physiographic regions. They contain numerous shallow lakes and closed-basin lakes, which can become connected during high water. Surface water can sometimes take many w eeks to drain following extended periods of heavy rainfall due to the poor drai nage (Knowles et al., 2002). The upland physiographic regions of interest are the Polk and Lake Uplands. White (1970) classified th e region of central or mid-peninsular Florida as the Polk Uplands and the Lake Wales Ridge physiographic regions. The Polk Uplands region lies to the east of the coastal lowlands in Hillsborough County and to the west of the Lake Wales Ridge in Polk County. The area extends north through Eastern Hillsborough and Western Polk Counties to the Western Valley and the Lake Upland, respectively. Land surface elevations ar e typically between 100 and 130 feet above sea level, The Polk Upland is characterize d by flatwoods, wetlands, and lakes that occupy a poorly drained plat eau, underlain by deeply weathered sand and clayey sand (Lewelling, 1998; Brook s, 1981; White, 1970). Br ooks (1981) described the region as an extensive erosional basin f illed with phosphatic and clayey sands. The Lake Upland area extends northward from the Polk Upland in Polk County to Central Lake County where it meets the Central Valley region. The region contains gently rolling hills with el evations ranging from 50 to 200 ft. above sea level (White, 1970; Knochenmus and Hughes, 1976). 2.2 Data Collection Water-level data used in this study were obtained from thirty-four wells in the four described physiographic regions. Eleven of the observation wells are located in the Gulf Coastal Lowlands, two are in the Polk Upland, one well is in the Lake Upland,

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14 and the remaining 20 are located in the Western Valley (Figure 3). Table 1 lists all of the observation wells by ID number and their respective phys iographic regions. Figure 3: Location of Observation Wells

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15 Table 1: Observation Wells and Physiographic Regions Observation Well ID Physiographic Region 598 Gulf Coastal Lowlands 1918 Gulf Coastal Lowlands 1929 Gulf Coastal Lowlands 1932 Gulf Coastal Lowlands 1935 Gulf Coastal Lowlands 1938 Gulf Coastal Lowlands 1944 Gulf Coastal Lowlands 1946 Gulf Coastal Lowlands 2159 Gulf Coastal Lowlands 10958 Gulf Coastal Lowlands 10965 Gulf Coastal Lowlands 1989 Lake Upland 1990 Lake Upland 10896 Polk Upland 1021 Western Valley 1954 Western Valley 1959 Western Valley 1960 Western Valley 1961 Western Valley 1966 Western Valley 1969 Western Valley 1977 Western Valley 1978 Western Valley 1980 Western Valley 1981 Western Valley 1987 Western Valley 1988 Western Valley 1991 Western Valley 1992 Western Valley 1995 Western Valley 2060 Western Valley 2062 Western Valley 2064 Western Valley 2066 Western Valley The Florida Land Use, Cover and Form s Classification Sy stem (FLUCCS) was used to further distinguish the observations wells by location within a specific wetland type (Figure 4). The FLUCCS is a standardized numeric code developed by the Florida Department of Tran sportation for the classifica tion of land use and plant

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16 communities (Florida Department of Transp ortation, 1999). The wetlands of interest in this study include: (1) Cypress, (2) Hardwood, (3) Marsh, (4) Wet Prairie, and (5) Stream and Lake Swamps (Figure 4). Ta ble 2 lists each observation well, the respective code and corr esponding wetland type. Table 2: Observation Well s with Corresponding FL UCCS and Wetland Type Well ID FLUCCS Wetland Type 598 615 Stream and Lake Swamps; Bottomland (Bot) 1021 615 Stream and Lake Swamps; Bottomland (Bot) 1969 615 Stream and Lake Swamps; Bottomland (Bot) 1918 621 Cypress Isolated (Cyp) 1929 621 Cypress Isolated (Cyp) 1932 621 Cypress Isolated (Cyp) 1935 621 Cypress Isolated (Cyp) 1938 621 Cypress Isolated (Cyp) 1961 621 Cypress Isolated (Cyp) 1978 621 Cypress Isolated (Cyp) 1987 621 Cypress Isolated (Cyp) 1988 621 Cypress Isolated (Cyp) 1989 621 Cypress Isolated (Cyp) 1990 621 Cypress Isolated (Cyp) 1991 621 Cypress Isolated (Cyp) 1992 621 Cypress Isolated (Cyp) 2064 621 Cypress Isolated (Cyp) 2159 621 Cypress Isolated (Cyp) 10958 621 Cypress Isolated (Cyp) 10965 621 Cypress Isolated (Cyp) 1944 621 Cypress Lake fringe (Cyp) 1946 630 Wetland Forest Mixed (Mix) 2062 630 Wetland Forest Mixed (Mix) 1980 630 Wetland Forest Mixed (Mix) 1995 630 Wetland Forest Mixed (Mix) 1954 641 Marsh Isolated (Msh) 1959 641 Marsh Isolated (Msh) 1960 641 Marsh Isolated (Msh) 1966 641 Marsh Isolated (Msh) 2060 641 Marsh Isolated (Msh) 2066 641 Marsh Isolated (Msh) 1977 643 Wet Prairie (WP) 1981 643 Wet Prairie (WP) 10896 643 Wet Prairie (WP)

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17 Figure 4: Observation Wells by Wetland Type

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18 Three of the observation wells used in this study are classified as FLUCCS 615, stream and lake swamps. This community is often referred to as bottomland or stream hardwoods. Bottomland usually occurs on flooded soils along stream channels and in low spots within river, creek, and la ke floodplains or overflow areas. This category has a wide variety of predominan tly hardwood species, of which some of the more common components include red ma ple, river birch, water oak, sweetgum, willows, tupelos, water hi ckory, bays, and water ash and buttonbush. Associated species include cypress, slash pine, loblolly pine and spru ce pine. The dominant trees in bottomlands, however, are usually buttr essed hydrophytic trees such as cypress and tupelo. The understory and ground cover are generally very sparse (FNAI, 1990; FDOT, 1999). Periods of inundation in stream and lake swamps are typically very short, except in floodplain depressions co ntaining clay and organic matter, which retain water for more exte nded periods (Ewel, 1990). Eighteen of the thirty-four wells were located in FLUCCS code 621, cypress. Cypress, a conifer, is the most common wetland tree in Florida. Cypress swamps occur in a variety of physiographic areas rang ing from isolated basins to broad, flat floodplains. Cypress trees are usually th e dominant species in swamps with fluctuating water-levels. Tolerances to varying water-levels, anaerobic sediments, and nutrient conditions allow for wide distribution through much of the southeastern and south-central portions of the U.S. Cypress swamps typically experience a recognized seasonally fluctuating water regime, however, intermittent droughts, resulting in dry swamp conditions, can last for several months. Seasonal or periodic drydowns are important, though, as cy press seeds require nonflooded soil to germinate. Taller trees tend to occur towa rd the center of these swamps due to a longer period of inundation (Ewe l, 1990; Dennison and Berry, 1993).

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19 The cypress community is composed of either pure or predominant pond cypress or bald cypress. In the case of pond cypress, common associates are swamp tupelo, slash pine an d black titi. Common associates of bald cypress include water tupelo, swamp cottonwood, red maple, Amer ican elm, pumpkin ash, Carolina ash, overcup oak and water hickory. On drier site s, bald cypress may also be associated with laurel oak, water oak, sweetgum and sweetbay. It remains unresolved, however, whether the two vari eties of cypress are taxonomically different (Dennison and Berry, 1993; FDOT, 1999). Four of the wells are classified as FLUCCS code 630, we tland mixed forest. This category includes mixed wetlands forest communities in which neither hardwoods nor conifers achieve a 66 percent dominance of the crown canopy composition (FDOT, 1999). Examples of ha rdwoods that are common in mixed forest wetlands are Black Gum, Water Tupelo, Oaks, Willows, and Melaleuca. Confers may include cypress, pines, and ce dars (Ewel, 1990; FDOT, 1999). Six of the observation wells are FL UCCS 641, fresh water marsh wetlands. Fresh water marshes, found in both palustrine (isolate d) and floodplain environments, are comprised of relatively uniform herb aceous, usually emergent, plants. The communities included in the fresh water marsh category are characterized by having one or more of the following predominant species: Sawgrass Cattail, Arrowhead, Maidencane, Butto nbush, Cordgrass, Giant Cutgrass, Switchgrass, Bulrush, Needlerush, Common Reed, and Arrowroot. Marsh vegetation is well adapted to water-level fluctuations. Annual species, for example, sprout during dry periods and are succeeded by perennials during periods of inundation (FDOT, 1999; Dennison, 1993). Water in inland fresh water marshes comes from rainwater, surface runoff, and groundwater. Palustrine marshes may not become inundated seasonally or may

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20 seldom become inundated in dry years. Surf ace water may not, therefore, be present at all times. The permanence of flooding, hydroperiod, and hydropattern decisively affects the character of the palustrine marsh ecosystem (Dennison, 1993). Floodplain marshes, on the other hand, are hydraulically connected to rivers and, therefore, hydroperiod also depends on their elevation relative to the river. Three wells were located in wet prairi es, FLUCCS code 643. A wet prairie is characterized as a treeless plain with a sparse to de nse ground cover composed predominately of grassy vegetation on hy dric soils. Both shallow and deep-water areas of wet prairies are ty pically dominated by grasses and sedges. Wet Prairies are distinguished from marshes by having less water, usually less than a foot at the deepest point, and shorter he rbage. These communities are predominated by one or more of the following species: Sawgrass, Maidencane, Cordgrasses, Spike Rushes, Beach Rushes, St. Johns Wort Spiderlily, Swamplily, Yellow-eyed Grass, Whitetop Sedge. (FNAI, 1990; FDOT, 1999; Southwest Florida Water Management District and Tampa Bay Water, 2005). Data collection for the study consisted of two elements, water-level elevation time series and spatial geographic data. All of the data was acquired from SWFWMD and are available at www.swfwmd.state.fl.us Water-level elevations were recorded in feet above National Geodetic Vertic al Datum 1927 (NGVD). The land surface elevation, also in feet ab ove NGVD, was then subtracted from the water elevation data to obtain water-levels with respect to land surface. A Geographic Information System (GIS) was used to evaluate spatial geographic data files. Shapefiles for landuse classification, lo cation of observation wells, ph ysiographic cla ssification, and wellfields were used. Orthophotographic aerial s were used to verify observation well placement within wetlands and site conditions (Figure 5).

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21 Figure 5: Orthophotographic Aerials of Wetland Observation Wells 2062 and 2064, Respectively Located in Mixed Forest and Cypress Wetlands

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22 The SWFWMD-maintained wells chosen for this analysis met several study criteria. Each observation well was (1) a surficial aquifer well and (2) located entirely within a wetland. In addition, each wetlan d well time series ha d to (1) be derived from a continuous recording device, which provided daily (or more frequent) waterlevel measurements; (2) include a minimum of two consecutive years of records between January 2000 and November 2006, and (3) had no more than 40 consecutive days of missing data. Wells and associated time series that did not meet these criteria were omitted from this study. The observation wells selected were then classified by (1) physiographic region, (2) the type of wetl and at well location, and (3) location within a wellfield. Physiographic regions were identified from the shapefile of physiographic regions as defined in The Geomorphology of the Florida Peninsula by W. A. White, Florida Geological Survey Bulletin 51, 1970. The wetland classi fication was established based on the most recent (2004) land-use classification shapefile. The 2004 land use/cover features are categorized accord ing to the Florida Land Use and Cover Classification System (FLUCCS). Using the wellfield shapefile, Figure 6 was created to show the location of the wells relative to wellfields in the study area. Observation wells were classified as wellfield wells if they were located entirely within or on the wellfield boundary. Table 3 lists all of the observation wells by ID number and their respective wellfield, if present. A compilation of the wells used in this study with their respective attributes is shown in Table 4.

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23 Figure 6: Observation Wells and Wellfields

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24 Table 3: Observation Wells and Respective Wellfields Well ID Wellfield 598 Cypress Creek 1021 None 1918 None 1929 None 1932 None 1935 Starkey 1938 Starkey 1944 None 1946 None 1954 None 1959 None 1960 None 1961 None 1966 None 1969 None 1977 None 1978 None 1980 None 1981 None 1987 None 1988 None 1989 None 1990 None 1991 None 1992 None 1995 None 2060 None 2062 None 2064 None 2066 None 2159 None 10896 None 10958 Starkey 10965 Starkey

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25 Table 4: Wetland Observation Well Attributes Well ID Wetland Name Period of Record Records Physiographic Region FLUCCS Wetland Type Wellfield 598 CCWF TMR-3 Shallow 1/28/03-10/23/06 1358 Gulf Coastal Lowlands 615 Bot Cypress Creek 1021 Hills State Park Pkng 1/6/04-10/21/06 1019 Western Valley 615 Bot None 1918 Pine Ridge 10/10/02-11/7/06 1489 Gulf Coastal Lowlands 621 Cyp None 1929 J.B. Starkey #1 10/24/02-11/7/06 1475 Gulf Coastal Lowlands 621 Cyp None 1932 STWF "FF" 10/22/03-11/7/06 1112 Gulf Coastal Lowlands 621 Cyp None 1935 STWF Eastern #1 10/8/02-11/7/06 1491 Gulf Coastal Lowlands 621 Cyp Starkey 1938 STWF Central 10/8/02-11/7/06 1491 Gulf Coastal Lowlands 621 Cyp Starkey 1944 Lake Armistead 10/26/03-10/18/06 1079 Gulf Coastal Lowlands 621 Cyp None 1946 Mertz Riverine 3/14/02-11/8/06 1700 Gulf Coastal Lowlands 630 Mix None 1954 MBWF Trout Creek Marsh 10/18/02-10/19/06 1462 Western Valley 641 Msh None 1959 MBWF East Cypress Marsh 9/13/02-10/19/06 1497 Western Valley 641 Msh None 1960 New River Marsh 10/16/01-11/2/06 1843 Western Valley 641 Msh None 1961 New River Cypress 10/16/01-11/1/06 1842 Western Valley 621 Cyp None 1966 Green Swamp Marsh 11/24/03-10/9/06 1050 Western Valley 641 Msh None 1969 UHFDA Riverine #1 3/1/02-11/1/06 1706 Western Valley 615 Bot None 1977 UHFDA Wet Prairie 5/22/02-10/18/06 1610 Western Valley 643 WPr None 1978 Alston Cypress #2 8/14/02-10/24/06 1532 Western Valley 621 Cyp None 25

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26 Table 4: (Continued) Well ID Wetland Name Period of Record Records Physiographic Region FLUCCS Wetland Type Wellfield 1980 Alston Bay 11/21/02-10/25/06 1434 Western Valley 630 Mix None 1981 Alston Wet Prairie 3/8/02-10/25/06 1692 Western Valley 643 WPr None 1987 Green Swamp #1 10/11/03-10/9/06 1094 Western Valley 621 Cyp None 1988 Green Swamp #2 5/6/03-10/9/06 1252 Western Valley 621 Cyp None 1989 Green Swamp #3 5/9/03-10/10/06 1250 Lake Upland 621 Cyp None 1990 Green Swamp #4 8/14/03-10/9/06 1152 Lake Upland 621 Cyp None 1991 Green Swamp #5 12/19/03-10/9/06 1026 Western Valley 621 Cyp None 1992 Green Swamp #6 5/9/03-8/4/06 1085 Western Valley 621 Cyp None 1995 Green Swamp Bay 12/19/03-10/10/06 1026 Western Valley 630 Mix None 2060 Cypress Cr. ELAPP marsh 6/18/02-10/19/06 1584 Western Valley 641 Msh None 2062 Cypress Cr. ELAPP riverine 6/18/02-10/19/06 1584 Western Valley 630 Mix None 2064 Cypress Cr. ELAPP Cypress 6/14/02-10/19/06 1588 Western Valley 621 Cyp None 2066 Blackwater Cr. ELAPP marsh 2 4/4/03-11/6/06 1312 Western Valley 641 Msh None 2159 Pheasant Run 4/11/03-11/13/06 1311 Gulf Coastal Lowlands 621 Cyp None 10896 ROMP 55 Surf 1/1/01-10/22/06 2120 Polk Upland 643 WPr None 10958 STWF 2A East Surf 8/24/01-11/6/06 1900 Gulf Coastal Lowlands 621 Cyp Starkey 10965 STWF 3A Central Surf 1/1/01-11/7/06 2136 Gulf Coastal Lowlands 621 Cyp Starkey 26

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27 2.3 Methodology Various methods, such as the semi -variogram (Davis, 1986), harmonic analysis (Godin, 1972), higher order non-Fo urier techniques (Kay and Marple, 1981), and spectral analysis (Bendat and Piersol, 1986) can be used to examine frequency components of a time series. Unlike othe r methods, spectral analysis does not strictly require a stationary time series (Hegge and Masselink, 1996). Hence, spectral analysis can be successfully a pplied to natural time series such as hydrologic time series data to derive attributes of periodicity. Spectral analysis is widely used to analyze the frequency constituents of time series by numerous scientists from variou s disciplines (Chatfield, 2004). It has been applied, for example, in investigations of annual temperature variations (Craddock, 1956), ocean waves (Kinsman, 1984), and o scillatory currents (Hardisty, 1993). Spectral analysis can be highly beneficial, as it allows for fine-scale resolution of the range of frequency components. It can be used to de-convolute multiple processes to derive the relative importance of each. The analysis can be further extended to analyze linear and non-linear relationships between different observed time series. Traditional spectral analysis is, in essenc e, an adaptation of Fourier analysis. The Fourier transform is efficient in the co mputational sense, robust, and produces reliable results for an array of time series. This method, th erefore, is one of the most popular for the analysis of frequency components in a time series exhibiting periodicity (Hegge and Masselink, 1996; Chat field, 2004), and is ubiquitous in the analysis of wave theory.

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28 2.3.1 Discrete Fourier Transform Typically, hydrometeorological observ ations are not made continuously through time. Observation taken only at specific times, usually equally spaced, results in a discrete time se ries. The Fourier transform of a discrete time series n x with a finite lengthN, sampled at a uniform sampling frequencys f, can be expressed as: N n k i N ne n x k X/ 2 1 0 1 ,..., 1 0 N k (1) where k X is the discrete Fourier series. Substituting Eulers formula into Equation 1 results in: 1 02 sin 2 cosN nN n k i N n k n x k X 1 ,..., 1 0 N k (2) where k X is composed of a real cosine part and an imaginary sine element. The discrete Fourier series is of the same length N as the original time series n x. Redefining Equation 2 in terms of the Fourier cosine k a and sine k b coefficients yields: k b i k a k X 1 ,..., 1 0 N k (3) where 1 02 cosN nN n k n x k a (4)

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29 1 02 sinN nN n k n x k b (5) The length of the series N and the sampling frequency s f is used to determine the kth Fourier coefficient: N f k fs k (6) The Fourier transform enables a time series to be represented by a series of cosines and sines whose frequencies are multiples of N fs, which is the frequency resolution, also refe rred to as binwidth. 0 X will be zero if the data is detrended prior to calculating the discrete Fourier transform. The next elemen t in the discrete Fourier series 1 X is the lowest frequency that can be determined from the time series using Fourier techniques. This frequency is referred to as the fundamental frequencyff. The highest frequency yielding meaningful information from a data set is called the Nyquist frequency cf, which is a real number located in the center of the discrete Fourier series 2 / N X. All Fourier coefficients beyond the Nyquis t frequency are complex conjugates of the first half of the series. Th ese complex conjugates repres ent negative frequencies, which have no physical meaning and, therefore, do not provide additional information (Hegge and Masselink, 1996; Chatfield, 2004). The Nyquist frequency can be determined directly from the sampling frequency: N f fs c (7)

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30 Unfortunately, aliasing (i.e. the inclusion of the variance of oscillations with frequencies higher than the Nyquist frequency) occurs as a result of excluding complex conjugates from the discrete Four ier series. To minimi ze the effects of aliasing, a sufficiently small sampling frequency should be used to ensure oscillations greater than half the sampling frequency ar e reduced. Alternativ ely, the series can be filtered to eliminate high-frequency components (Hegge and Masselink, 1996; Chatfield, 2004). 2.3.2 The Periodogram A periodogram is a plot of the intens ity (i.e. wave energy of a water-level fluctuation) or a multiple of the intensity against frequency for the wave components of a periodic functi on represented by a Fourier seri es (Kendall and Ord, 1990). After calculating the Fourier coefficients the periodogram can be computed: N f k b k a k Ps 2 2 2 0 N k (8) N f k b k a k Ps 2 22 1 2 ,..., 1 N k (9) This is the first step in the determinatio n of the auto-spectrum, which provides a representation of the amount of variance of the time series as a function of frequency. Because the Fourier coeffici ents beyond the Nyquist frequency are complex conjugates, they are not included in the calculation of the periodogram. Instead, the first half of the Fourie r coefficients, with the exception of 0 Pand 2 / N P, are doubled for compensation. k P is also referred to as variance-spectral

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31 density, power-spectral density, and ener gy-spectral density (Hegge and Masselink, 1996). 2.3.2.1 Spectral Leakage Most of the hydrometeorological time series data are of finite length. Distortion of the calculated spectral density function caused by the discontinuities at the two endpoints is referred to as spectral leakage. Spectral leakage causes small amounts of spectral energy to leak into adjacent frequencies, thereby skewing the spectral estimates of re spective frequencies. In order to minimize leakage, one of the most popular methods is the Hann taper method (Hegge and Masselink, 1996; Chatfield, 2004). The application of Hann taper involves multiplying the original time series by the taper n w: 1 2 cos 1 5 0N n n w N n ,..., 2 1 (9) Applying a taper prior to calculating th e periodogram has been shown to greatly improve the distinction of the power spectral density peaks. 2.3.2.2 Spectral Estimates The periodogram obtained from the observ ed time series is a manifestation of the original time series. It may, therefore, change if a time series encompassing a different period of record is used, especially if either record is not fully representative of the full reoccurring periodicity. To improve the reliability (i.e. reduction in variance) of the spectral estimates, different statistical methods can be used. For this particular study, the segment averagin g method, proposed by Welch (1967), was used.

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32 The Welch method involves dividing the time series into several small segments with an underlying assumption th at the adjacent segments are statistically independent. A periodogram is calculated for each of the segm ents. The resultant periodograms are then averaged over resp ective frequency bins to obtain more accurate estimates of the power spectral densities. The confidence interval level is directly proportional the number of segments used. To obtain a near maximum reduction of variance, a fi fty percent overlap between adjacent segments is recommended (Welch, 1967; He gge and Masselink, 1996) 2.3.3 Application of the Method The MATLAB function, psd, estimates the power spectral density of a signal using the modified Welch periodogram techni que. MATLAB applies the specified antileakage window to successive detrended se ctions of the time series. Using the specified window size, a fast Fourier tr ansform, FFT, of each section is then computed. The function calculates a peri odogram by obtaining the square of the magnitude of each transform to form the power spectral density estimation of the time series. Specifically, a Welch spectrum object wi th an FFT length equal to the length of the time series was defined in MATLAB The time series was then detrended by removing the series mean. A Hann taper wi ndow of length equal to the number of records was then applied in order to minimi ze spectral leakage. The psd function was then called using the spectrum objec t defined above and the detrended time series to generate a power spectral densit y graph. The process was repeated for all the 37 wetland observation wells. A 95% confidence interval on the spectral estimates was defined by MATLAB.

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33 Chapter Three: Results and Discussion 3.1 Overview A simple plot of the time series allowed for visual identification of trends and illustrated obvious periodicity in the series. Figure 7 is a plot of the observed waterlevel time series between 2/1/03 and 10/ 15/06 for four wells, representative of different wetland characteristics, which exist in the wetlands analyzed in this study. Observation wells 1969, 10896, 1980, and 1929 are respectively located in a western valley bottomland, an upland we t prairie, a western valley mixed forest wetland, and a gulf coastal lowlands cypr ess wetland. Graphs of observed waterlevel for all of the observation well time series from 1/1/2001 through 12/31/2007 can be found in Appendix A. -8.00 -6.00 -4.00 -2.00 0.00 2.00 4.00 6.002/1/ 2 003 8/2/ 2 003 2/ 1 / 2 004 8/ 1 / 20 04 1 / 31/2 0 0 5 8 / 1 / 20 0 5 1 /3 1/2 0 0 6 8 / 1 / 20 0 6Water Level (ft) Wetland Well 1969 Wetland Well 10896 Wetland Well 1980 Wetland Well 1929 Figure 7: Observed Water-Level Time Series for Four Wetlands: Bottomland (1969), Wet Prairie (10896), Mixed ( 1980), and Cypress (1929)

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34 From inspection of the hydrographs, it can be observed that one or more predominant seasonal fluctuations are identifiable. In addition, smaller event-driven fluctuations are ubiquitous; however, the event fluctuations occur at a lower magnitude and inconsistent duration (period). Although these wells are located in different physiographic regions as well as distinct type s of wetlands, it can be seen that the timing of the minimum and maxi mum water-levels in the wetlands is consistent. They do, however, differ in relative water depths, as well as in the overall range of the water-level fluctuations. The observed water-level data in a mixed (1980) and cypress (1989) wetland are superimposed from January 1st through December 31st over all years of record in Figure 8 (a) and (b). Both wetlands ex hibit similar seasonal behavior, not only to each other, but also from year to year. In addition, it is evident that there are two distinct inter-annual periods of water-level fluctuation. From the observations, there appears to be a winter/spring cycle, whic h generally occurs from December through May, and a summer/fall cycle that takes place from June through November each year. It is also observed that the range of water-level fluctuation varies both between wetlands and from year to year. Although the magnitud e of the water-level varies, its pattern remains consistant. Change s from year to year are expected, too, as hydroperiod varies statistically according to climate and antecedent conditions (Mitsch and Gosselink, 2000). Th e annual graphs of observed water-level for all of the observation well time series from 1/ 1/2001 through 12/31/2007 can be found in Appendix B. Both the temporal cycles and the ma gnitude and duration of water-level fluctuations during these inter-annual cycl es appear to be of obvious importance when describing wetland hydroperiod. Spectral analysis is useful in determining the overall temporal characteristics of periodic ity and thus, hydroperiod. What is also

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35 derived from spectral analysis and is very important for deterministic modeling comparisons, is the relative importance and magnitude of storm event periodicity versus seasonal fluctuations. The range of water-level fluctuations and accumulated durations, on the other hand, can be quantified with probability density histograms. -2 -1 0 1 2 31-Jan 3 1-Jan 2Ma r 1Ap r 1Ma y 3 1May 3 0 -Jun 3 0J ul 2 9 -Aug 28-Sep 28-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 (a) -5 -4 -3 -2 -1 0 1 2 31J a n 31-J a n 2 Ma r 1-Ap r 1-May 31-Ma y 30 J un 30-Jul 29 A ug 28-Se p 28 Oct 27-Nov 27 DecWater Level (ft) 2002 2003 2004 2005 2006 (b) Figure 8: Annual Water-Level Observatio ns for (a) Mixed ( 1980) and (b) Cypress (1929) Wetlands

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36 3.2 Temporal Characteristics of Hydroperiod To further investigate the distinct inter-annual periodicity of water-level fluctuation observed in the time series plots, spectral estimates were plotted. Frequency was converted to period (days) prior to plotting. Di stinct peaks can be clearly observed upon inspection of the plo tted spectral analysis graphs (e.i. Figure 9 for cypress (1929) and mixed (1980) wetland wells). Results for all other wells are shown in Appendix C. The spectral peaks indicate presence of dominant waveforms representative of the temporal component of hydroperiod and encompass the entire range of water-level fluctuations. A pattern of generally decrea sing energy with decreasing time period can al so be seen. This behavior is typical of natural systems (Hegge and Masselink 1996). It can also be seen from the spectr al analysis plots, that for time periods of less than 20 days spectral energy effe ctively becomes zero. This justifies that the sampling frequency of 1 day was sufficiently high to minimize the effects of aliasing (Hegge and Masselin k 1996). More importantly, it quantifies the obvious observation that storm event water-level fluctuations are much less intense than the dominant summer/fall and winter/spring water-level fluctuation. The spectral density function for mi xed (1980) and cypres s (1929) wetlands are plotted in Figure 9. These wells are re presentative of the di verse collection of observation wells. From Figure 8, it is observed that the mixed (1980) wetland exhibited a primary peak period of about 365 days, while the cypress (1929) wetland had a primary peak of 180 days. It is no ted, however, that the secondary interannual peak is approximately 180 days fo r the mixed (1980) we tland. Also, both display a tertiary peak near 240 days. The annual spectral peak was expected, as there is a strong annual periodicity in rainfall pattern in West-Central Florida. The semi-annual periodicity was, however, more significant than the annual cycle in approximately half of the wetlands.

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37 (a) (b) Figure 9: Spectra of the Water-Level Record for Well Numbers (a) 1980, Located in a Mixed Forest Wetland and (b) 1929, Located in a Cypress Wetland

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38 The inter-annual peaks are of particular interest in this study. All of the water-level records analyzed, regardless of contributing wetland attributes, contained either a primary or secondary inter-annual peak in the vicinity of 180 days (Table 5). All wetlands displaying an annual primary peak consistently had a secondary peak of approximately 180 days. Tertiary peaks varied between individual wetlands. Of special note was the relative insignificance of short-period (storm events) water-level fluctuatio ns in the spectral energy. All wetlands, regardless of type, physio graphic region, or wellfield effects, exhibit predominant hydroperiod cycles of an approximately 180 day (semi-annual) seasonality (Table 6). A winter/spring cycl e, occurring from December through May, followed by a summer/fall cycle that takes place from June through November, is prevelant in the data each year. The hydr operiod cycle for a we tland, therefore, incorporates the entire range of water-level fluctuations, including both surface and subsurface water-levels. The magnitude an d range of surface and subsurface waterlevels of different wetlands do, however, vary within the predominant inter-annual hydroperiod cycles.

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39 Table 5: Power Spectral Density Peak Periods for all Observation Wells Well ID Wetland Type Primary Peak Period (days) Secondary Peak Period (days) Tertiary Peak Period (days) 598 Bot 272 170 102 1021 Bot 340 170 142 1969 Bot 213 341 99 1918 Cyp 186 248 123 1929 Cyp 184 369 83 1932 Cyp 371 185 246 1935 Cyp 186 373 111 1938 Cyp 373 186 108 1944 Cyp 360 180 123 1961 Cyp 184 368 96 1978 Cyp 383 170 94 1987 Cyp 365 182 83 1988 Cyp 179 104 153 1989 Cyp 179 89 121 1990 Cyp 384 165 239 1991 Cyp 171 114 54 1992 Cyp 362 181 93 2064 Cyp 318 176 95 2159 Cyp 187 119 82 10958 Cyp 190 119 60 10965 Cyp 356 178 151 1946 Mix 189 340 118 1980 Mix 359 179 124 1995 Mix 171 103 122 2062 Mix 176 122 123 1954 Msh 365 183 122 1959 Msh 374 187 83 1960 Msh 369 184 125 1966 Msh 350 175 93 2060 Msh 317 226 115 2066 Msh 164 109 176 1977 WPr 179 230 122 1981 WPr 188 60 115 10896 WPr 353 193 230

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40 Table 6: Power Spectral Density Semi-Annua l Peak Periods for all Observation Wells Well Wetland Type Primary Inter-annual Period (days) 1021 Bot 170 1969 Bot 213 598 Bot 170 Avg Bot 184 Std dev Bot 25 1918 Cyp 186 1929 Cyp 184 1932 Cyp 185 1944 Cyp 180 1961 Cyp 184 1978 Cyp 170 1987 Cyp 182 1988 Cyp 179 1989 Cyp 179 1990 Cyp 165 1991 Cyp 171 1992 Cyp 181 2064 Cyp 176 2159 Cyp 187 1935 Cyp 186 1938 Cyp 186 10958 Cyp 190 10965 Cyp 178 Avg Cyp 181 Std dev Cyp 7 1946 Mix 189 1980 Mix 179 1995 Mix 171 2062 Mix 176 Avg Mix 179 Std dev Mix 8 1954 Msh 183 1959 Msh 187 1960 Msh 184 1966 Msh 175 2060 Msh 226 2066 Msh 164 Avg Msh 187 Std dev Msh 21 1977 WPr 187 1981 WPr 188 10896 WPr 193 Avg WPr 189 Std dev WPr 3 Avg All 182 Std dev All 12

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41 3.3 Hydroperiod Water-Level Fluctuations The water-level fluctuations during the predominant 180 day semi-annual periods are of great importance in defining hydroperiod. Figure 9 contains histograms of three characteristically different wetlands, which display the probabilities that the water-level lies in sp ecific ranges during the winter/spring and summer/fall hydroperiods over a three year period. It can be observed from the histograms that, the probability density dist ribution for the summer/fall is skewed to the right of the winter/sprin g distribution. This indicate s that, regardless of wetland characteristics, higher water-levels exist in wetlands during the summer/fall hydroperiod. This is expected as, the summer/fall hydroperiod is the semi-annual period during which the peak of the rainy season in West-Central Florida falls. In addition, it is roughly in phase with the peak of the available solar radiation and extreme ET demand. Duration, maxi mum depth, and range between the winter/spring and summer/fall hydroperiods, on the other hand, appear to vary.

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42 (a) (b) Figure 10: Probability Densities of the Winter/Spring and Summer/Fall Hydroperiod Phases of (a) Non-Wellfield Cypress (1929) (b) Wellfield Cypress (10965), and (c) Non-Wellfield Wet Prairie (1946) Wetlands

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43 (c) Figure 10: (Continued) To understand water-table fluctuations with respect to different types of wetlands, wellfiel d stresses, and physiographic re gions, probability distribution histograms of the complete raw well data we re plotted. Wetlands of the same type show similarities in water-level ranges and probability distribution (Figures 9-11). Regardless of physiographic region (Figure 9) the overall water-le vel distribution for non-wellfield cypress wetlands (Figure 10) is skewed towards the positive end and the water-level varies from approximately -4 to +2 feet, relative to land surface. Figure 11 is a compilation of all non-wellfield cypress wetland water-level probability densities, which exhibit similar distributions and water-level ranges, regardless of physiographic region. Due to minimal av ailable data for other wetland types, similarities within other types of wetlands are less apparent. The water-level in wet prairie wetlands (Figure 13), for example, ra nges from about -6 to +3 feet, however, has a somewhat inconsistent distribution. The cypress and wet prairie wetlands

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44 display differences in water-level range, durations, and probability density distributions, thus attesting to hydrolog ic differences between different types of wetlands. Although semi-annual hydroperiod durations exists in different types of wetland, it cannot be expected that different wetlands will also have similarities in water-level fluctuation magnitudes or ranges. Figure 11: Probability Densities of Water-Levels for Non-Wellfield Cypress Wetland Wells 1989, 1961, and 1918, Which are Respec tively Located in the Lake Upland, Western Valley, and Gulf Coastal Lowlands

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45 Figure 12: Probability Densities of Water-Levels for Non-Wellfield Cypress Wetland Observation Wells Located in all Physiographic Regions Figure 13: Probability Densities of Water-Levels for Non-Wellfield Wet Prairie Wetland Observation Wells Located in all Physiographic Regions

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46 From the figures, analogous water-leve l behavior is found to exist between like wetland types, regardless of phys iographic region. Because hydroperiod influences the type of vegetation present in a wetland, it is logical that individual wetlands of the same classifi cation will exhibit similar hy drological behavior. Figure 14 illustrates differing water-level ranges and probability distributions for two different types of wetlands, which are both in the same physiographic region. This difference was characteristic of all wetland type comparisons. This corroborates the popular contention that chan ges in hydrological behavior of a wetland control the resultant plant communities. Figure 14: Probability Densities of Water-Levels for Cypress (1944) and Mixed (1946) Wetlands It is also important to understand the e ffect of wellfield stresses, if any, on water-level fluctuations. Upon analysis of the water-level probability distributions for

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47 wells located within a wellfield, it was found that the water-level was skewed towards the negative side, regardle ss of wetland type (Figure 15). Although both wetland types exhibit predominantly negative wate r-levels, the overall water-level ranges and durations differ between the wetlands The wellfield bottomland (598) wetland water-level ranged from -10 to +2 feet, while the wellfield cy press (10965) ranged from -8 to 0 feet. Figure 15: Probability Densities of Water-Leve ls for Wellfield Cypress (10965) and Wellfield Bottomland (598) Wetlands Wellfield cypress (10958) and non-wellfield (1 944) wetlands are directly compared in Figure 16. The figure clearly demonstrates the effects of pumping on the magnitude of water-levels occurring within inter-annual hydroperiod cycles of a wetland. The water-level probability distribution for the well located within a wellfield, is clearly skewed towards the negative side, while the non-wellfield waterlevel probability distribution is skewed toward the positive side. The wellfield wetland water-level is at approximately -3 feet most of the time, never reaching land surface,

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48 though the water-level fluctuates from 11 to -2 feet. The non-wellfield wetland water-level, on the other hand, fluctuates from -2 (the maximum wellfield wetland water-level) to +4 feet. It can be seen from the histog ram that the water-level is predominantly around land surface for the non-wellfield wetland. Limited wellfield observation points were available for this study. Therefore, conclusions of overall decreased water-level and increased water-level fluctuation can not be fully made. Table 7 contains average water-level magnit udes and ranges for all of the wetlands analyzed in this study over all years of available data. Annual water-level magnitudes, ranges and statistics for all of the wetlands are tabulated in Appendix D. Figure 16: Probability Densities of Water-Levels for Gulf Coastal Lowlands, Cypress Wetland Observation Wells 10958, Located in a Wellfield, and 1944, Not Located in a Wellfield

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49 Table 7: Average Wetland WaterLevel Magnitudes and Ranges Well Water-Level (ft) Well Wetland Type Low High Mean Std dev 1918 Cyp minimum -2.54 -0.66 -1.44 0.79 maximum 1.70 1.80 1.73 0.05 range 2.36 4.34 3.17 0.84 1929 Cyp minimum -3.77 0.77 -0.83 2.08 maximum 2.02 2.14 2.07 0.06 range 1.25 5.79 2.90 2.06 1932 Cyp minimum -3.50 -1.58 -2.33 1.03 maximum 1.64 2.10 1.83 0.24 range 3.34 5.14 4.16 0.91 1944 Cyp minimum -2.06 -0.72 -1.20 0.75 maximum 2.13 3.72 2.82 0.81 range 2.94 4.68 4.02 0.94 1961 Cyp minimum -4.56 0.29 -2.05 2.16 maximum 1.35 2.88 1.94 0.58 range 1.47 5.91 3.99 1.95 1978 Cyp minimum -4.65 -0.10 -2.20 2.34 maximum -1.96 2.38 1.02 2.00 range 1.89 5.59 3.21 1.63 1987 Cyp minimum -4.22 -0.30 -2.87 1.75 maximum 0.63 1.34 1.04 0.30 range 1.46 4.91 3.91 1.65 1988 Cyp minimum -4.38 -0.55 -2.67 1.67 maximum 0.09 2.42 1.67 1.07 range 2.69 5.57 4.35 1.20 1989 Cyp minimum -3.66 -1.87 -2.68 0.74 maximum 0.63 1.98 1.47 0.59 range 3.42 4.71 4.15 0.54 1990 Cyp minimum -2.94 -1.76 -2.35 0.83 maximum 1.72 1.91 1.82 0.13 range 3.67 4.66 4.17 0.70 1991 Cyp minimum -0.83 2.62 0.90 2.44 maximum 2.37 2.58 2.48 0.15 range -0.25 3.41 1.58 2.59 1992 Cyp minimum -3.21 -1.36 -2.22 0.93 maximum 1.55 1.72 1.61 0.09 range 2.93 4.76 3.83 0.92 2064 Cyp minimum -7.77 -3.09 -5.35 1.96 maximum -0.60 1.45 0.82 0.81 range 4.12 6.38 6.17 1.75 2159 Cyp minimum 1.01 1.39 1.21 0.19 maximum 2.44 2.70 2.59 0.13 range 1.20 1.62 1.38 0.22

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50 Table 7: (Continued) Well Water-Level (ft) Well Wetland Type Low High Mean Std dev 1935 Cyp WF minimum -5.32 -2.16 -3.32 1.38 maximum 0.72 0.87 0.79 0.08 range 3.03 6.04 4.10 1.33 1938 Cyp WF minimum -2.58 1.72 0.13 1.87 maximum 1.42 3.51 2.72 1.00 range 1.71 4.00 2.60 1.08 10958 Cyp WF minimum -10.69 -5.13 -7.33 2.32 maximum -2.57 -2.11 -2.33 0.18 range 3.02 6.46 5.00 2.27 10965 Cyp WF minimum -7.78 -1.85 -4.77 2.55 maximum -1.46 0.12 -0.56 0.59 range 1.83 4.65 4.21 2.17 1946 Mix minimum -5.81 -1.33 -3.33 1.98 maximum -0.46 4.27 1.65 1.74 range 2.48 7.61 4.98 2.00 1980 Mix minimum -0.84 1.19 0.30 1.04 maximum 0.88 2.60 1.91 0.91 range 1.41 1.72 1.61 0.18 1995 Mix minimum -0.84 0.29 -0.28 0.57 maximum 0.03 1.84 1.12 0.96 range 0.87 1.79 1.40 0.48 2062 Mix minimum -4.53 0.12 -1.71 2.02 maximum 1.58 4.07 3.11 0.95 range 2.80 7.02 4.83 1.78 1021 Bot minimum -9.63 -8.37 -8.87 0.67 maximum -5.90 0.89 -2.32 3.41 range 3.73 9.51 6.55 2.89 1969 Bot minimum -1.33 1.40 0.23 1.11 maximum 1.78 4.85 3.70 1.16 range 2.90 4.32 3.47 0.68 598 Bot WF minimum -5.76 -4.24 -4.89 0.78 maximum 0.60 1.39 0.91 0.42 range 4.99 6.36 5.80 0.72 1954 Msh minimum -6.64 0.12 -3.87 2.85 maximum 0.12 3.28 2.29 1.46 range 2.88 7.63 6.16 2.22 1959 Msh minimum -4.95 -0.96 -3.37 2.12 maximum 1.35 1.90 1.71 0.31 range 2.84 6.30 5.08 1.94 1960 Msh minimum -3.40 0.88 -0.97 2.15 maximum 2.33 3.14 2.60 0.34 range 1.45 5.56 3.57 2.11

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51 Table 7: (Continued) Well Water-Level (ft) Well Wetland Type Low High Mean Std dev 1960 Msh minimum -3.40 0.88 -0.97 2.15 maximum 2.33 3.14 2.60 0.34 range 1.45 5.56 3.57 2.11 1966 Msh minimum -2.54 -1.19 -2.05 0.75 maximum 0.83 1.70 1.36 0.47 range 2.74 4.24 3.41 0.76 2060 Msh minimum -3.29 0.45 -1.36 1.63 maximum 1.11 2.21 1.87 0.44 range 1.61 4.44 3.23 1.41 2066 Msh minimum -3.75 0.43 -1.56 2.11 maximum 1.59 3.40 2.51 0.75 range 2.21 5.37 4.06 1.56 1977 WPr minimum -6.39 -2.93 -4.56 1.68 maximum 0.05 3.44 1.50 1.38 range 4.57 7.06 6.06 1.09 1981 WPr minimum -4.33 -2.19 -3.08 0.90 maximum 0.58 1.74 1.33 0.44 range 3.68 4.91 4.41 0.57 10896 WPr minimum -5.74 -0.52 -3.75 2.15 maximum -3.15 2.27 -0.83 2.32 range 2.39 4.15 2.92 0.70

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52 3.4 Comparison of Findings Mitsch and Gosselink (2000) recognized that wetland hydroperiod defines the rise and fall of surface and subsurface wate r-level in a wetland an d suggested that it helps characterize each type of wetland. Mitsch and Gosselink (2000) also observed both a wet and dry season, year to year fluctuations, and pulsing water-levels, however, to date, an attempt to quantify hydroperiod as a whole has not been done. Table 8 contains the qualitative hydroperio d definitions as pres ented by Mitsch and Gossekink. From this study, it is seen that all wetlands exhibit a semi-annual hydroperiod and different types of wetlands exhibit varying water-level magnitudes, durations and ranges. The quantitative re sults of hydroperiod durations and waterlevel magnitudes and ranges for all wetland types are in Table 9. Table 8: Qualitative Hydroperiod Definiti ons as Defined by Mi tsch and Gosselink, 2000 Definition Description Permanently Flooded flooded thro ughout the year in all years Intermittently exposed flooded throughout the year except in years od extreme drought Semi-permanently Flooded flooded in the growing season in most years Seasonally Flooded flooded for extended periods during the growing season, but usually no surface water by end of growing season Saturated substrate is saturated for extended periods in the growing season, but standing water is rarely present Temporarily Flooded flooded for brief periods in growing season, but watertable is otherwise well below land surface Intermittently Flooded surface is usually exposed with surface water present for vaiable periods without de tectable seasonal pattern Source: Mitsch and Gosselink, 2000

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53 Table 9: Hydroperiod Durations and Wate r-Level Magnitudes and Ranges for All Wetland Types Cypress Cypress WF Mixed Bottomland Marsh Wet Prairie Avg Hydroperiod Duration (days) 179 185 179 184 187 189 Std Dev Hydroperiod duration (days) 7 5 8 25 21 3 Avg Minimum Water-Level (ft) -1.9 -3.8 -1.3 -4.3 -2.2 -3.8 Std Dev Minimum Water-Level (ft) 1.6 3.1 1.6 6.4 1.2 0.7 Avg Maximum Water-Level (ft) 1.8 0.2 1.9 0.7 2.1 0.7 Std Dev Maximum Water-Level (ft) 0.6 2.1 1.1 4.3 0.5 1.3 Avg WaterLevel Range (ft) 1.3 4.0 3.2 5.0 4.3 4.5 Std Dev Water-Level Range (Ft) 0.7 1.0 2.0 2.2 1.1 1.6 *Wetland well 598 was omitted from this table, as it was the only wellfield bottomland wetland

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54 Also not yet quantified is the duration of inundation, which has been used traditionally to traditiona lly defined wetland hydroper iod. Ewel (1990) suggested hydroperiod durations, defined as period of inundation, for several types of swamps (Figure 17) as a comparison of species ri chness. It is not clear how the duration estimates were derived, though. Inundat ion depths were also not noted. Figure 17: Proposed Relationships Between Species Richness of Woody Vegetation in Swamps Relative to th e Hydroperiod (Source: After Ewel, 1990) Figure 18 shows the averag e duration and depth of inundation from 2004 through 2006 for all wetland types. It can be seen from the figure that there is variability in both average depth as well as duration of inundation within similar wetland types. Due to variability in the location of wells within the wetlands and limited data collection sites, the depth and du ration of inundation needs to be further investigated. It can, however, be said that on average, the water-level fluctuation H y dro p eriod ( months ) Species of Woody Vegetation Low High

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55 above land surface during peri ods of inundation ranges from 0 to +2 feet. The figure clearly shows that neit her period nor average depth of inundation appears to be an obvious characteristic of the various wetland types. 0.00 0.50 1.00 1.50 2.00 0.03.06.09.012.0 Inundation Duration (months)Water-level (ft) Bot Cyp Mix Msh WPr Cyp WF Bot WF Figure 18: Average Duration and Depth of Inundation from 2004 through 2006 for All Wetland Types

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56 Chapter Four: Conclusions Since ecological characte ristics of a wetland ar e controlled by wetland hydroperiod, the periodicity of both inundation and water-table fluctuations should be used in defining hydroperiod and in investigating ecological function. Spectral analysis of wetland water-level time series was used to successfully identify dominant frequencies, which are represen tative of the hydroperiod and encompass the entire range of water-level fluctuations. Spectral estimates of water-level time series from 34 wetland observation wells indicate a distinct semi-annual peak periodicity, found to be significant with a 95% confidence interval. Also, all of the wetlands analyzed, regardless of type, phys iographic region, or wellfield effects, exhibit cyclic behavior of two dominant, 180-day hydroperiods each year. A winter/spring cycle, occurring from Decemb er through May, and a summer/fall cycle that takes place from June through Novemb er occur each year. A strong annual cycle is also exhibited in many of the wetlands, possibly occurring from the combination of the two semi-annual cycles. The hydroperiod cycle for West-Central Florida wetlands incorporates the entire range of water-level fluctuations, including both surface and subsurface water-levels. This cyclic behavior is of great importance in wetland sustainability, as dry to moist, but not saturated conditions are usually required for germination and seedling growth. The relative importance of the winter/spring cycle as compared to the summer/fall cycle is uncertain, though.

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57 It appears, from the spectral analysis, that the hydroperiods of West-Central Florida wetlands are dominated by long te rm hydrologic processes and not by stormevent responses. No wetland investigated had a significant event periodicity. This doesnt mean that a particular hurricane wont change water-levels appreciably; however, for the years investigated, even t periodicity was not exhibited in the spectral analysis. Flooding (elevated water-levels) associ ated with major tropical events is likely resultant from the relative coincidence of thes e storms during the summer/fall hydroperiod peak. These hydrol ogic events are less important from a wave (spectral) energy stan dpoint and perhaps less import ant to the overall health of a wetland. The magnitude and range of surface and subsurface water-levels are not consistent between the 180 day winter /spring and summer/ fall inter-annual hydroperiod cycles for indivi dual wetlands. Wetlands ge nerally exhibit higher and lower water-levels during the summer/fall hydroperiod, but similar storm response. Although the magnitude and range differ, the water-level probability distributions (shape) for the two 180 day semi-annual periods are similar. Analogous water-level behavior does exist between like wetland types, regardless of physiographic region. This is intuitive, as it is generally believed that hydroperiod influences the type of vegetati on present in a wetlan d. Therefore, for a given wetland type, physiogr aphic region does not a ppear to affect wetland hydroperiod. Very interestingly and contrary to qualitative definiti ons, the period and depth of inundation in a wetland appears no t to be a good index of wetland type, as seen in the seemingly random behavior shown in Figure 18. More data is, however, needed to fully conclude this tenuous, but significant observation. The water-level behavior, including probabilit y distribution and magnitud e and range of water-level fluctuation, both between different types of wetlands and from year to year,

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58 however, vary considerably. Comparison of the results from this study to the qualitative hydroperiod definitions sugge st these types of relationships are oversimplistic and unreliable. From the findings, wellfield stress (water-level pumping) can also affect wetland hydroperiod. Wetlands located in wellfields showed considerably lower water-levels than those wetlands not located in wellfields. Wellfield wetlands also exhibited a greater range of water-leve l fluctuation as a group. Water-level fluctuations in cypress wetlands outside of wellfields exhibited typical fluctuation from about -2 to +2 ft, with an average range of 1.3 feet, with a positively skewed (above land surface) water-level probabilit y distribution. Cypress wetlands located in wellfields, however, displayed water-level fluctuations from approximately -4 to +.2 ft, with average ranges of 4 feet. In additi on, the water-level probability distribution for wellfield wetlands is negatively skewed. Further analysis of a greater number of wetlands is required to draw more conclusive observations. One last finding, resulting from this analysis, concerns wetland water-level measurements. Because the important wa ter-level periodicity appears to be seasonal, observations recorded at interval s of several times a month appear to be relatively useful at further elucidatin g wetland hydroperiod characteristics for different wetland types. Less frequent moni toring, however, is probably not useful for this purpose or, in general, monitoring the health of a wetland. Also, any frequency less than daily will not expose the full extreme of water-level fluctuation, which may also be important fo r particular plant communities.

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59 References Armstrong, B., C. Doreen, A.Collazos, and J.L. Mallams. 2003. Doline and AQuifer Characteristics wi thin Hernando, Pasco, and Northern Hillsborough Counties Tampa. Karst Studies in West Central Florida. Karst Research Group, USF: 39-51. Battle, J. M. and S. W. Golladay. 2001. Hydroperiod Influence on Breakdown of Leaf Litter in Cypress-gu m Wetlands. The American Midland Naturalist 146: 128-145. Bendat, J. S. and Piersol, A. G. 1986. Random Data: Analysis and Measurement Procedures. 2/e, Wiley, Chichester, 566 pp. Bourgeau-Chavez, L. L., K. B. Smith, S. B.Brunzell, E.S.Kasisch ke, E.A.Romanowicz, and C.J.Richardson. 1995. Remote Monito ring of Regional Inundation Patterns and Hydroperiod in the Greater Everglad es Using Synthetic Aperture Radar. Wetlands 25(1): 176-191. Brooks, H.K. 1981. Guide to the Ph ysiographic Regions of Florida Institute of Food and Agricultural Services, University of Florida. Gainesville, FL. Brooks, R. T. 2005. A Review of Basin Morp hology and Pool Hydrology of Isolated Ponded Wetlands: Implications for Season al Forest Pools of the Northeastern United States. Wetlands Ecol ogy and Management 13: 335. Bullock, A. and M. Acreman. 2003. The Role of Wetlands in the Hydrological Cycle. Hydrology and Earth System Sciences 7(3): 358-389. Chatfield, C. 2004. The Analys is of Time Series: An Intr oduction. CRC Press. Boca Raton,FL. Chen, E. and J. F. Gerber.1990. Climate. In R. L. Myers and J. J. Ewel ( eds. ). Ecosystems of Florida. University of Central Florida Press Orlando, FL: 11-34. Clayback, K.B. 2006. Investigation of Norma lized Streamflow in West Central Florida and Extrapolation to Ungaged Coastal Fringe Tributaries. Masters Thesis University of South Florida, Tampa, Fl. Clemens, L. A., D. Spangler,and D.J. Patton. 1984. The Hydrologic Cycle. In E. A. Fernald and D. J. Patton ( eds. ). Water Resources Atlas of Florida. Institute of Science and Public Affairs, Tallahassee,FL.

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60 Cooke, C.W. 1945. Geology of Florida. Flor ida Geological Survey Bulletin 29, 339 p. Cowardin, L. M., V. Carter, F.C.Golet, and E.T.LaRoe. 1979. Classification of wetlands and deepwater habitats of the United States, U. S. Department of the Interior, Fish and Wildlife Service, 131 pp. Craddock, J. M. 1956. The Repr esentation of the Annual Te mperature Variation Over Central and Northern Europe by a Two-Term Harmonic Form. Quarterly Journal of the Royal Meteorological Society 82: 275-288. Davis, J. C. 1986. Statistics an d Data Analysis in Geology. John Wiley, New York, 646 pp. Dennison, M. S. and J. F. Berry.1993. Wetlands Guide to Science, Law, and Technology. Noyes Publications. Park Ridge, FL. Ewel, K. 1990. Swamps. In R. L. Myers and J. J. Ewel ( eds. ).Ecosystems of Florida. University of Central Flor ida Press, Orlando: 281-323. FDOT.1999. Florida Land Use, Cover and Fo rms Classification System. State of Florida Department of Transportation: 1-93. FNAI.1990. Guide to the Natural Communities of Florida. Florida Natural Areas Inventory and Florida Department of Natural Resources: 1-120. Godin, G. 1972. The Analysis of Tides. Liverpool University Press, 264 pp. Haag, K. H., T. M. Lee, and D.C.Herndon. 2005. Bathymetry and Vegetation in Isolated Marsh and Cypress Wetlands in the Northern Tampa Bay Area, 20002004. Scientific Investigatio ns Report 2005-5109: 1-49. Hardisty, J. 1993. Time Series Analysis Using Spectral Tec hniques: Oscillatory Currents. Earth Surface Processes and Landforms 18,855-862. Hegge, B. J. and G. Masselink. 1996. Spectr al Analysis of Geomo rphic Time Series: Auto-Spectrum. Earth Surface Proc esses and Landforms 21: 1021-1040. Junk, W. J., P. B. Bayley, and R.E.Sparks. 1989. The Flood Pulse Concept in RiverFloodplain Systems. Journal Of Canadi an Fisheries And Aquatic Sciences 106(Special Issue): 11-127. Kay, S. M. and Marple, S. L. 1981.Spe ctrum analysis-A modem perspective. Proceedings of the IEEE 69: 1380-1419. Kinsman, B. 1984. Wind Wa ves: Their Generation and Propagation on the Ocean Surface. Dover Publications, New York, 676 pp. Knochenmus, D.D., and Hughes G.H. 1976. Hydrology of La ke County, Florida. U.S. Geological Survey Water Resource s Investigation, 76-72, 100 pp.

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61 Knowles, L. J., A. M. OReilly,and J.C. Adamski. 2002. Hydrogeology and Simulated Effects of Ground-Water Withdrawals from the Floridan Aquifer System in Lake County and in the Ocala National Forest and Vicinity, North-Central Florida. Water-Resources Investigat ions Report Tallahassee, Fl, U.S. Geological Survey. Lewelling, B. R., A. B. Tihansky, an d J.L.Kindinger. 1998. Assessment of the Hydraulic Connection between Ground water and the Peace River, WestCentral Florida. Water-Resources In vestigations Report 97-4211, U.S. Geological Survey Tallahassee, FL. MacNeil, F.S. 1950. Pleistocen e shorelines in Florida an d Georgia. U.S. Geological Survey Professional Paper, 221-F: 95-107. Mann, C. J. and R. G. Wetzel. 2000. Hy drology of an Impo unded Lotic Wetland Subsurface Hydrology. Wetlands 20(1): 337. Marble, A. D. 1992. A Guide to Wetland Functional Design, CRC Press LLC., Boca Raton, FL. Mitsch, W. J. and J. G. Go sselink .2000. Wetlands. John Wiley and Sons, Inc. New York, NY. OReilly, A. M. 2004. A Method for Simulati ng Transient Ground-Water Recharge in Deep Water-Table Settings in Central Florida by Using a Simple WaterBalance/Transfer-Function Model. Scientific Invest igations Report 2004-5195. Reston, Virginia. U.S. Department of the Interior and U.S. Geological Survey: 49. Pinder, L. and S. Rosso.1998. Cl assification and or dination of plant formations in the Pantanal of Brazil. Plant Ecology 136: 151. Ruskauff, G., Aly, A., Ewing, J., Jobes, T., Donigan, A., Tara, P., Trout, K., Ross, M., 2003. The Integrated Northern Tampa Ba y Hydrologic Model (INTB). Volume 3, Tampa Bay Water, Tampa, Fl. Semeniuk, V. and C. A. Semeniuk. 1997. A Geomorphic Approach to Global Classification for Natural Inland Wetlan ds and Rationalizat ion of the System Used By the Ramsar Convention A Discussion. Wetlands Ecology and Management 5: 145-158. Schmidt, W. 1997. Geomorphology and Physiography of Florida. In Jones, D.S. and Randazzo, A.F.(eds.). The Geology of Fl orida. University Press of Florida: Gainesville, pp. 1-12. Scott. M.H. 2006. Precipitation Variability of Streamflow Fraction in West-Central Florida. Masters Thesis, University of South Florida, Tampa, Fl. Shaffer, P. W., C. A. Cole, M.E.Kentula, and R.P.Brooks. 2000. Effects of Measurement Frequency on Water-Level Summary Stat istics. Wetlands 20(1): 148.

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62 Southwest Florida Water Management Di strict. 1996. Northern Tampa Bay Water Resource Assessment Project. Volu me 1, Surface water/Groundwater Interrelationships. Southwest Florida Water Management Dist rict. 2000. Hillsborough River Watershed Management Plan. Southwest Florida Water Management Dist rict and Tampa Bay Water. 2005. Wetland Assessment Procedure (WAP) Instruct ion Manual for Isolated Wetlands. Tiner, R. W. 1991. The Concept of a Hy drophyte for Wetlan d Identification. BioScience 41(4): 236-247. Tiner, R. W. 1996. Techni cal Aspects of Wetlands: Wetland Defi nitions and Classifications in the United States. U. S. Geological Survey Water-Supply Paper, Report: W 2425, Reston, VA. Welch, P. D. 1967. The Use of Fast-Fourier Transform fo r the Estimation of Power Spectra: A Short Method Based on Ti me Averaging over Short, Modified Periodograms. IEEE Transactions of Th e Audio And Electroacoustics, AU-L5: 70-13. White, W.A.1970. The Geomorpho logy of the Florida Penins ula. Florida Bureau of Geology Bulletin No. 51, 164 pp. Zedler, J. B. 2001. Handbook for Restor ing Tidal Wetlands. CRC Press, Boca Raton,FL.

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63 Appendices

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64 Appendix A: Time Series Figures Wetland Well 598-10 -8 -6 -4 -2 0 21/ 1/ 2 001 7/ 2/ 2 00 1 1/ 1/ 2002 7/2/2002 1/1/2003 7/2/2003 1/1/2004 7/1/2004 12/ 31/2004 7/ 1/ 2 005 12/ 3 1 / 2005 7/ 1/ 2 006 12/31 / 2006Water Level (ft) Figure 19: Observed Water-Level Time Series for Wetland Well 598 Wetland Well 1021-12 -10 -8 -6 -4 -2 0 21/1/2001 7/2/2001 1/1/2002 7/ 2 /2002 1/ 1 /2003 7/ 2 /200 3 1/ 1 / 2 00 4 7/ 1 / 2 0 04 12/31/2004 7/ 1 / 2 0 05 12/31/2005 7 /1 / 2006 1 2 /3 1 /2006Water Level (ft) Figure 20: Observed Water-Level Time Series for Wetland Well 1021 Wetland Well 1918-3 -2 -1 0 1 2 31 /1 / 2 0 0 1 7/ 2 /20 0 1 1/1/20 0 2 7 /2/2002 1 /1 / 2003 7 /2 / 2 0 0 3 1/ 1 /20 0 4 7/1/2004 1 2/31/2004 7 /1/2005 1 2/ 3 1/2 0 0 5 7/ 1 /20 0 6 12 / 31/2006Water Level (ft) Figure 21: Observed Water-Level Time Series for Wetland Well 1918

PAGE 74

65 Appendix A: (Continued) Wetland Well 1929-5 -4 -3 -2 -1 0 1 2 31/1/2001 7 /2 /200 1 1 /1/ 2 0 0 2 7 /2/ 2 0 0 2 1/1/2003 7 / 2/200 3 1 /1 /200 4 7 /1 /200 4 12/ 3 1 / 2004 7/1/2005 1 2/3 1 / 2 00 5 7 / 1/200 6 12 /3 1 / 20 0 6Water Level (ft) Figure 22: Observed Water-Level Time Series for Wetland Well 1929 Wetland Well 1932-4 -3 -2 -1 0 1 2 31/1/2 00 1 7/2/2001 1/ 1/200 2 7/2/2 00 2 1/1/2003 7 /2/200 3 1/ 1/200 4 7/1/2 00 4 1 2/31/200 4 7 /1/200 5 1 2/31 /2005 7/1/20 0 6 1 2/ 31/2006Water Level (ft) Figure 23: Observed Water-Level Time Series for Wetland Well 1932 Wetland Well 1935-6 -5 -4 -3 -2 -1 0 1 21 /1 /2001 7 /2/ 2 0 01 1 /1/200 2 7 /2/2002 1/1/2003 7 /2 /2003 1 /1/200 4 7 /1/2004 12/31/2004 7 /1 /2005 12/3 1/2 005 7 /1/20 06 12 /3 1/200 6Water Level (ft) Figure 24: Observed Water-Level Time Series for Wetland Well 1935

PAGE 75

66 Appendix A: (Continued) Wetland Well 1938-3 -2 -1 0 1 2 3 41 / 1/2 00 1 7 /2 /2 00 1 1 /1 /2 00 2 7 /2/ 2 002 1/1/2003 7/2/2 0 03 1 / 1/2 0 04 7 /1 /2 00 4 1 2/ 31/ 20 0 4 7 /1/ 2 005 12 / 31/2 0 05 7/1/2 0 06 12/ 3 1/2006Water Level (ft) Figure 25: Observed Water-Level Time Series for Wetland Well 1938 Wetland Well 1944 -4 -2 0 2 4 61/1/2001 7 / 2 / 2 0 0 1 1/1/2002 7 / 2 / 2 0 0 2 1/1/2003 7 / 2 / 2 0 0 3 1/1/2004 7/1/ 2 0 0 4 12/31/2004 7/1/ 2 0 0 5 12/31/ 2 005 7/ 1 / 2 0 0 6 12/31/ 2 006Water Level (ft) Figure 26: Observed Water-Level Time Series for Wetland Well 1944 Wetland Well 1946-8 -6 -4 -2 0 2 4 61/1/ 2 0 0 1 7/2/20 0 1 1/1/20 0 2 7 / 2 / 2 0 02 1 / 1 / 2 0 03 7 / 2 / 2 0 03 1 / 1 / 2 0 0 4 7 / 1 / 2 0 0 4 1 2/31 /20 0 4 7 / 1/2 0 05 1 2/31 / 2 0 05 7 / 1 / 2 0 06 1 2/31 / 2 0 06Water Level (ft) Figure 27: Observed Water-Level Time Series for Wetland Well 1946

PAGE 76

67 Appendix A: (Continued) Wetland Well 1954 -8 -6 -4 -2 0 2 41/ 1/2001 7/2/2001 1/1/2002 7/2/ 2 002 1/ 1/2003 7/2/ 2 003 1/1/2004 7/ 1 / 200 4 12/31/2004 7/1/ 20 05 12/31/2005 7/ 1/2006 12/31/2006Water Level (ft) Figure 28: Observed Water-Level Time Series for Wetland Well 1954 Wetland Well 1959-8 -6 -4 -2 0 2 41/ 1/2001 7/2 / 2001 1/1 / 2002 7/ 2/2002 1/ 1/ 2003 7/ 2/ 2003 1 /1/2004 7/ 1/ 200 4 12 / 31/ 200 4 7/1/2005 12 / 31/ 20 05 7/ 1/2006 1 2 /31/2006Water Level (ft) Figure 29: Observed Water-Level Time Series for Wetland Well 1959 Wetland Well 1960 -4 -3 -2 -1 0 1 2 3 41 / 1 / 2 00 1 7/2/2001 1 / 1 / 2 002 7 / 2 / 2 0 02 1/1/2003 7 / 2 / 2 0 03 1 / 1 / 2 004 7 / 1 / 2 00 4 12/31 / 2 0 04 7 / 1 / 2 005 1 2/31 / 2 0 05 7/1/2006 12 / 3 1 / 2 00 6Water Level (ft) Figure 30: Observed Water-Level Time Series for Wetland Well 1960

PAGE 77

68 Appendix A: (Continued) Wetland Well 1961-6 -4 -2 0 2 41/1 / 2 0 0 1 7/2 / 200 1 1 / 1/ 2 0 0 2 7 /2 / 2 0 0 2 1/1/2003 7/2/2003 1/1 / 2 0 0 4 7/1 / 200 4 1 2 / 3 1 /2004 7 / 1/ 2 0 0 5 12/ 3 1/2 0 0 5 7/1/2006 12/31/2006Water Level (ft) Figure 31: Observed Water-Level Time Series for Wetland Well 1961 Wetland Well 1966-3 -2 -1 0 1 21/1 / 200 1 7/2/ 2 001 1/1/2002 7 /2/ 20 02 1/1/ 2 003 7/ 2/ 20 03 1 /1/ 2 004 7/1 / 200 4 12/31/200 4 7/1 / 200 5 1 2 /31 / 2005 7/1/2006 1 2 /31 /2 006Water Level (ft) Figure 32: Observed Water-Level Time Series for Wetland Well 1966 Wetland Well 1969-2 -1 0 1 2 3 4 5 61/1/20 01 7/2/20 01 1/1 /20 02 7/ 2/20 02 1/ 1/20 03 7/2/2003 1/1/2 0 04 7/1/2 0 04 12/31/2 0 04 7/1/20 0 5 12/31/2005 7/1/20 06 12/31/2 006Water Level (ft) Figure 33: Observed Water-Level Time Series for Wetland Well 1969

PAGE 78

69 Appendix A: (Continued) Wetland Well 1977-8 -6 -4 -2 0 2 4 61/1/2001 7/2/2001 1/1/2002 7/2/2002 1/1/2003 7/2/2003 1/1/2004 7/1/2004 12 /31/2004 7/1/2005 12 /31/2005 7/1/2006 12 /31/2006Water Level (ft) Figure 34: Observed Water-Level Time Series for Wetland Well 1977 Wetland Well 1978-6 -5 -4 -3 -2 -1 0 1 2 31/1/2001 7/2/2001 1/1 / 2002 7/ 2/ 20 0 2 1/ 1/ 20 0 3 7/ 2/ 2 00 3 1 /1/ 2 00 4 7 /1/ 2 00 4 1 2/31/2 0 04 7/1/2005 12/ 3 1/2005 7/1 / 2006 12 /3 1/ 2 00 6Water Level (ft) Figure 35: Observed Water-Level Time Series for Wetland Well 1978 Wetland Well 1980-2 -1 0 1 2 31 / 1/ 2 0 0 1 7 / 2 /2 0 0 1 1/ 1 /2002 7/2/2002 1 / 1/2003 7 / 2/ 2 0 0 3 1/ 1 /2004 7/1/2004 12/3 1 /2004 7 / 1/ 2 0 0 5 1 2 /3 1 / 2 0 0 5 7/ 1 /200 6 12/31/200 6Water Level (ft) Figure 36: Observed Water-Level Time Series for Wetland Well1980

PAGE 79

70 Appendix A: (Continued) Wetland Well 1981-5 -4 -3 -2 -1 0 1 2 31 / 1 / 20 01 7 / 2 / 20 0 1 1/1/2002 7 / 2 / 20 02 1 / 1 / 20 0 3 7/2/2003 1 / 1 / 20 04 7 / 1 / 20 0 4 12/3 1 /2004 7 / 1 / 20 0 5 12 / 31 / 2 0 05 7/1/2006 1 2 / 31 / 2 00 6Water Level (ft) Figure 37: Observed Water-Level Time Series for Wetland Well 1981 Wetland Well 1987-5 -4 -3 -2 -1 0 1 21/ 1 / 200 1 7/ 2 / 200 1 1/1/2002 7/ 2 / 200 2 1/ 1 / 200 3 7/2/2003 1 /1 / 200 4 7/ 1 / 200 4 12/31/2004 7 /1 / 200 5 12/31/ 2 005 7/ 1 /20 0 6 12 / 31/ 2 00 6Water Level (ft) Figure 38: Observed Water-Level Time Series for Wetland Well 1987 Wetland Well 1988-5 -4 -3 -2 -1 0 1 2 31/1/2 001 7/2/2 001 1/1/2 002 7/ 2/ 2 002 1/ 1/ 2 003 7/ 2/ 2 003 1/ 1/ 2 004 7/ 1/ 2 004 12/ 31/ 2004 7/ 1/ 2 005 12/31/ 2005 7/ 1/ 2 006 12/31/ 2006Water Level (ft) Figure 39: Observed Water-Level Time Series for Wetland Well 1988

PAGE 80

71 Appendix A: (Continued) Wetland Well 1989-4 -3 -2 -1 0 1 2 31 / 1/ 2 0 01 7 / 2/ 2 0 01 1 / 1/ 2 0 02 7 / 2/ 2 0 02 1 / 1/ 2 0 03 7/ 2 /2003 1/ 1 /2004 7/ 1 /2004 12 / 31 / 2 00 4 7/ 1 /2005 12 / 31 / 2 00 5 7/ 1 /2006 12 / 31 / 2 00 6Water Level (ft) Figure 40: Observed Water-Level Time Series for Wetland Well 1989 Wetland Well 1990-4 -3 -2 -1 0 1 2 31 / 1 / 2 0 0 1 7 / 2 / 2 0 0 1 1 / 1 /20 0 2 7/2/20 0 2 1/1/2003 7/2/2003 1/1/2004 7/1/2004 12 / 3 1 /2004 7/1/2005 12 / 3 1 /20 0 5 7/1/2 0 06 12 / 3 1 /20 0 6Water Level (ft) Figure 41: Observed Water-Level Time Series for Wetland Well 1990 Wetland Well 1991-4 -3 -2 -1 0 1 2 31 /1/2001 7/ 2 /2 0 0 1 1 /1 / 20 0 2 7 /2/2002 1/1/2003 7/ 2 /2 0 0 3 1 /1 / 2004 7 /1/2004 1 2 /31/2004 7 /1 / 20 0 5 12/ 3 1/ 2 0 0 5 7/1/2006 12/31/2006Water Level (ft) Figure 42: Observed Water-Level Time Series for Wetland Well 1991

PAGE 81

72 Appendix A: (Continued) Wetland Well 1992-4 -3 -2 -1 0 1 21 /1/2 0 01 7/2 /2 00 1 1/1 /2 002 7 /2/2 0 02 1 /1/2 0 03 7/ 2/2 00 3 1/1 /2 004 7/1/2004 1 2 /31/ 2 00 4 7/ 1/2 00 5 12/3 1/ 2005 7/1/2006 1 2 /31/ 2 00 6Water Level (ft) Figure 43: Observed Water-Level Time Series for Wetland Well 1992 Wetland Well 1995-2 -1 0 1 2 31 /1/2 001 7/2/2001 1/1 /2 002 7/2/2002 1/1/2003 7/2/2003 1/1/2004 7/1/2 00 4 12/31/2004 7/1/2 005 12/3 1 /2005 7/1 /2 006 12/3 1 /2006Water Level (ft) Figure 44: Observed Water-Level Time Series for Wetland Well 1995 Wetland Well 2060-4 -3 -2 -1 0 1 2 31/1 /2 001 7/2 /20 01 1/1 /2 002 7/2 /2 002 1/1/2003 7/2 /2 003 1/ 1 /2004 7/1 /2 004 12/31 / 2004 7/1 /2 005 12/31 / 2005 7/1 /2 006 12/31 / 2006Water Level (ft) Figure 45: Observed Water-Level Time Series for Wetland Well 2060

PAGE 82

73 Appendix A: (Continued) Wetland Well 2062-6 -4 -2 0 2 4 61/ 1 /2 0 01 7/ 2/200 1 1 / 1/2002 7/ 2 /2 0 02 1/ 1/200 3 7 / 2/2003 1/ 1 /2004 7/ 1/200 4 12/31/20 0 4 7/ 1 /2005 12 /3 1 /2 00 5 7 / 1/2006 12/31/2006Water Level (ft) Figure 46: Observed Water-Level Time Series for Wetland Well 2062 Wetland Well 2064-10 -8 -6 -4 -2 0 21/ 1 /20 0 1 7 /2 / 2 0 0 1 1/1/2002 7/ 2 /20 0 2 1/ 1 /20 0 3 7 /2 / 200 3 1/1/2004 7/ 1 /20 0 4 1 2 /31 / 2004 7 /1/2005 12/ 3 1/2 0 05 7 /1 /20 0 6 12/31/2006Water Level (ft) Figure 47: Observed Water-Level Time Series for Wetland Well 2064 Wetland Well 2066-6 -4 -2 0 2 41/1/20 0 1 7/2 / 20 0 1 1 / 1 / 20 0 2 7 / 2 / 20 0 2 1 / 1 /200 3 7 /2/2003 1/1/2004 7/1 / 20 0 4 1 2 / 3 1/20 0 4 7 / 1 /200 5 12/31/2005 7/1/2006 12/31/2006Water Level (ft) Figure 48: Observed Water-Level Time Series for Wetland Well 2066

PAGE 83

74 Appendix A: (Continued) Wetland Well 2159-1 0 1 2 31/1/2001 7/2/2001 1/1/2002 7/2/2002 1/1/2003 7/2/2 0 03 1/1/2 0 04 7/1/2 0 04 12 / 31/200 4 7/1/ 20 05 12 / 31/ 2 00 5 7/1/ 200 6 12 / 31/ 2 00 6Water Level (ft) Figure 49: Observed Water-Level Time Series for Wetland Well 2159 Wetland Well 10896-7 -6 -5 -4 -3 -2 -1 0 1 2 31/ 1 / 2 001 7/ 2 /2001 1/1 / 2002 7/2 / 2 00 2 1/ 1 / 2 003 7/ 2 /2003 1/ 1 /2004 7/ 1 / 2 004 12/ 31/200 4 7/1/2005 12/31 / 2005 7 /1 / 2 006 12/ 31/2 006Water Level (ft) Figure 50: Observed Water-Level Time Series for Wetland Well 10896 Wetland Well 10958-12 -10 -8 -6 -4 -2 01/1/ 2 001 7/2/2001 1/ 1/2002 7/2/ 2 002 1/1/2003 7/ 2/2003 1/ 1/20 04 7/ 1 / 2 004 1 2/31/2 004 7/ 1/2005 12/ 31/2 005 7/1/ 2 006 12/31/2 0 06Water Level (ft) Figure 51: Observed Water-Level Time Series for Wetland Well 10958

PAGE 84

75 Appendix A: (Continued) Wetland Well 10965-10 -8 -6 -4 -2 0 21 / 1 / 2001 7/2 / 2001 1 / 1 / 2002 7/2/2002 1 / 1 / 2 0 03 7 / 2 / 2003 1 / 1 / 2 0 04 7 / 1 / 2004 12/31/2004 7 / 1 / 2 0 05 1 2/31/2 0 05 7 / 1 / 2 0 06 1 2 / 3 1 / 20 0 6Water Level (ft) Figure 52: Observed Water-Level Time Series for Wetland Well 10965

PAGE 85

76 Appendix B: Annual Observed Water-Level Time Series Wetland Well 598 -10 -8 -6 -4 -2 0 21-Jan 31 -J an 2-Ma r 1-A p r 1-May 3 1-Ma y 3 0 -Ju n 30-Jul 29-Aug 2 8-Sep 2 8 -Oct 27-Nov 2 7-De cWater Level (ft) 2003 2004 2005 2006 Figure 53: Annual Observed Water-Le vel Time Series for Wetland Well 598 Wetland Well 1021-10 -8 -6 -4 -2 0 21-Jan 3 1-Jan 2-M a r 1-Apr 1-May 31 -M ay 30 -J un 30-Jul 29 -Au g 2 8 -Sep 28-Oct 27-Nov 2 7 -D e cWater Level (ft) 2004 2005 2006 Figure 54: Annual Observed Water-Le vel Time Series for Wetland Well 1021 Wetland Well 1918 -3 -2 -1 0 1 2 31 -Jan 31J an 2 -Mar 1 -A pr 1-Ma y 31-May 30-Jun 3 0-Ju l 29 -A ug 2 8-S e p 28-Oc t 27-Nov 27-DecWater Level (ft) 2002 2002 2003 2004 2005 2006 Figure 55: Annual Observed Water-Le vel Time Series for Wetland Well 1918 Wetland Well 1021

PAGE 86

77 Appendix B: (Continued) Wetland Well 1929 -5 -4 -3 -2 -1 0 1 2 31-Jan 31-Jan 2Mar 1-Apr 1M ay 31-May 30-Jun 3 0Ju l 29-Aug 2 8S e p 28-Oct 27-N ov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 56: Annual Observed Water-Le vel Time Series for Wetland Well 1929 Wetland Well 1932 -4 -3 -2 -1 0 1 2 31 Jan 31-Jan 2M ar 1Apr 1-Ma y 31-M ay 3 0Jun 30 -Jul 29-Aug 28Sep 28-O c t 27Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 57: Annual Observed Water-Le vel Time Series for Wetland Well 1932 Wetland Well 1935 -6 -5 -4 -3 -2 -1 0 1 21J a n 31-Jan 2-Mar 1 A p r 1-May 31-May 30 J u n 30 J u l 29-Aug 28 Se p 28-Oct 2 7N ov 27 De cWater Level (ft) 2002 2003 2004 2005 2006 Figure 58: Annual Observed Water-Le vel Time Series for Wetland Well 1935

PAGE 87

78 Appendix B: (Continued) Wetland Well 1938 -3 -2 -1 0 1 2 3 41-J a n 3 1 -J a n 2-Mar 1 A p r 1-Ma y 31-Ma y 3 0 Jun 3 0 -Jul 2 9 A u g 28-Sep 2 8 -Oc t 27N ov 27 D e cWater Level (ft) 2002 2003 2004 2005 2006 Figure 59: Annual Observed Water-Le vel Time Series for Wetland Well 1938 Wetland Well 1944 -3 -2 -1 0 1 2 3 4 51-Jan 3 1-J a n 2 -M a r 1-A p r 1-May 31 -M ay 3 0Ju n 3 0-J u l 29-Aug 2 8 -Se p 2 8O ct 27 -N ov 2 7 -De cWater Level (ft) 2003 2004 2005 2006 Figure 60: Annual Observed Water-Le vel Time Series for Wetland Well 1944 Wetland Well 1946 -8 -6 -4 -2 0 2 4 61-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 61: Annual Observed Water-Le vel Time Series for Wetland Well 1946

PAGE 88

79 Appendix B: (Continued) Wetland Well 1954 -8 -6 -4 -2 0 2 41-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 62: Annual Observed Water-Le vel Time Series for Wetland Well 1954 Wetland Well 1959 -8 -6 -4 -2 0 2 41-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 63: Annual Observed Water-Le vel Time Series for Wetland Well 1959 Wetland Well 1960 -4 -3 -2 -1 0 1 2 3 41-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2001 2002 2003 2004 2005 2006 Figure 64: Annual Observed Water-Le vel Time Series for Wetland Well 1960

PAGE 89

80 Appendix B: (Continued) Wetland Well 1961 -5 -4 -3 -2 -1 0 1 2 3 41-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 65: Annual Observed Water-Le vel Time Series for Wetland Well 1961 Wetland Well 1966 -3 -2 -1 0 1 21/1 1/31 3/2 4/1 5/1 5/31 6/30 7/30 8/29 9/28 10/28 11/27 12/27Water Level (ft) 2003 2004 2005 2006 Figure 66: Annual Observed Water-Le vel Time Series for Wetland Well 1966 Wetland Well 1969 -2 -1 0 1 2 3 4 5 61-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 67: Annual Observed Water-Le vel Time Series for Wetland Well 1969

PAGE 90

81 Appendix B: (Continued) Wetland Well 1977 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 51-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 68: Annual Observed Water-Le vel Time Series for Wetland Well 1977 Wetland Well 1978 -6 -5 -4 -3 -2 -1 0 1 2 31/1 1/31 3/2 4/1 5/1 5/31 6/30 7/30 8/29 9/28 10/28 11/27 12/27Water Level (ft) 2002 2003 2004 2005 2006 Figure 69: Annual Observed Water-Le vel Time Series for Wetland Well 1978 Wetland Well 1980 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 70: Annual Observed Water-Le vel Time Series for Wetland Well 1980

PAGE 91

82 Appendix B: (Continued) Wetland Well 1981 -5 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 71: Annual Observed Water-Le vel Time Series for Wetland Well 1981 Wetland Well 1987 -5 -4 -3 -2 -1 0 1 21-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 72: Annual Observed Water-Le vel Time Series for Wetland Well 1987 Wetland Well 1988 -5 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 73: Annual Observed Water-Le vel Time Series for Wetland Well 1988

PAGE 92

83 Appendix B: (Continued) Wetland Well 1989 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 74: Annual Observed Water-Le vel Time Series for Wetland Well 1989 Wetland Well 1990 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 75: Annual Observed Water-Le vel Time Series for Wetland Well 1990 Wetland Well 1991 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 76: Annual Observed Water-Le vel Time Series for Wetland Well 1991

PAGE 93

84 Appendix B: (Continued) Wetland Well 1992 -4 -3 -2 -1 0 1 21/1 1/31 3/2 4/1 5/1 5/31 6/30 7/30 8/29 9/28 10/28 11/27 12/27Water Level (ft) 2003 2004 2005 2006 Figure 77: Annual Observed Water-Le vel Time Series for Wetland Well 1992 Wetland Well 1995 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2004 2005 2006 Figure 78: Annual Observed Water-Le vel Time Series for Wetland Well 1995 Wetland Well 2060 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 79: Annual Observed Water-Le vel Time Series for Wetland Well 2060

PAGE 94

85 Appendix B: (Continued) Wetland Well 2062 -5 -4 -3 -2 -1 0 1 2 3 4 51-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 80: Annual Observed Water-Le vel Time Series for Wetland Well 2062 Wetland Well 2064 -10 -8 -6 -4 -2 0 21-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2002 2003 2004 2005 2006 Figure 81: Annual Observed Water-Le vel Time Series for Wetland Well 2064 Wetland Well 2066 -5 -4 -3 -2 -1 0 1 2 3 41-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 82: Annual Observed Water-Le vel Time Series for Wetland Well 2066

PAGE 95

86 Appendix B: (Continued) Wetland Well 2159 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2003 2004 2005 2006 Figure 83: Annual Observed Water-Le vel Time Series for Wetland Well 2159 Wetland Well 10896 -7 -6 -5 -4 -3 -2 -1 0 1 2 31-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2001 2002 2003 2004 2005 2006 Figure 84: Annual Observed Water-Le vel Time Series for Wetland Well 10896 Wetland Well 10958 -12 -10 -8 -6 -4 -2 01-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2001 2002 2003 2004 2005 2001 Figure 85: Annual Observed Water-Le vel Time Series for Wetland Well 10958

PAGE 96

87 Appendix B: (Continued) Wetland Well 10965 -10 -8 -6 -4 -2 0 21-Jan 3 1-Jan 2-Mar 1-Apr 1-May 31-May 3 0-Jun 30-Jul 29-Aug 28-Sep 2 8-Oct 27-Nov 27-DecWater Level (ft) 2001 2002 2003 2004 2005 2006 Figure 86: Annual Observed Water-Le vel Time Series for Wetland Well 10965

PAGE 97

88 Appendix C: Spectral Analysis Figures Figure 87: Spectral Analysis of We tland Well 598 Water-Level Time Series Figure 88: Spectral Analysis of We tland Well 1021 Water-Level Time Series

PAGE 98

89 Appendix C: (Continued) Figure 89: Spectral Analysis of We tland Well 1918 Water-Level Time Series Figure 90: Spectral Analysis of We tland Well 1929 Water-Level Time Series

PAGE 99

90 Appendix C: (Continued) Figure 91: Spectral Analysis of We tland Well 1932 Water-Level Time Series Figure 92: Spectral Analysis of We tland Well 1935 Water-Level Time Series

PAGE 100

91 Appendix C: (Continued) Figure 93: Spectral Analysis of We tland Well 1938 Water-Level Time Series Figure 94: Spectral Analysis of We tland Well 1944 Water-Level Time Series

PAGE 101

92 Appendix C: (Continued) Figure 95: Spectral Analysis of We tland Well 1946 Water-Level Time Series Figure 96: Spectral Analysis of We tland Well 1954 Water-Level Time Series

PAGE 102

93 Appendix C: (Continued) Figure 97: Spectral Analysis of We tland Well 1959 Water-Level Time Series Figure 98: Spectral Analysis of We tland Well 1960 Water-Level Time Series

PAGE 103

94 Appendix C: (Continued) Figure 99: Spectral Analysis of We tland Well 1961 Water-Level Time Series Figure 100: Spectral Anal ysis of Wetland Well 1966 Wa ter-Level Time Series

PAGE 104

95 Appendix C: (Continued) Figure 101: Spectral Anal ysis of Wetland Well 1969 Wa ter-Level Time Series Figure 102: Spectral Anal ysis of Wetland Well 1977 Wa ter-Level Time Series

PAGE 105

96 Appendix C: (Continued) Figure 103: Spectral Anal ysis of Wetland Well 1978 Wa ter-Level Time Series Figure 104: Spectral Anal ysis of Wetland Well 1980 Wa ter-Level Time Series

PAGE 106

97 Appendix C: (Continued) Figure 105: Spectral Anal ysis of Wetland Well 1981 Wa ter-Level Time Series Figure 106: Spectral Anal ysis of Wetland Well 1987 Wa ter-Level Time Series

PAGE 107

98 Appendix C: (Continued) Figure 107: Spectral Anal ysis of Wetland Well 1988 Wa ter-Level Time Series Figure 108: Spectral Anal ysis of Wetland Well 1989 Wa ter-Level Time Series

PAGE 108

99 Appendix C: (Continued) Figure 109: Spectral Anal ysis of Wetland Well 1990 Wa ter-Level Time Series Figure 110: Spectral Anal ysis of Wetland Well 1991 Wa ter-Level Time Series

PAGE 109

100 Appendix C: (Continued) Figure 111: Spectral Anal ysis of Wetland Well 1992 Wa ter-Level Time Series Figure 112: Spectral Anal ysis of Wetland Well 1995 Wa ter-Level Time Series

PAGE 110

101 Appendix C: (Continued) Figure 113: Spectral Anal ysis of Wetland Well 2060 Wa ter-Level Time Series Figure 114: Spectral Anal ysis of Wetland Well 2062 Wa ter-Level Time Series

PAGE 111

102 Appendix C: (Continued) Figure 115: Spectral Anal ysis of Wetland Well 2064 Wa ter-Level Time Series Figure 116: Spectral Anal ysis of Wetland Well 2066 Wa ter-Level Time Series

PAGE 112

103 Appendix C: (Continued) Figure 117: Spectral Anal ysis of Wetland Well 2159 Wa ter-Level Time Series Figure 118: Spectral Anal ysis of Wetland Well 10896 Wa ter-Level Time Series

PAGE 113

104 Appendix C: (Continued) Figure 119: Spectral Anal ysis of Wetland Well 10958 Wa ter-Level Time Series Figure 120: Spectral Anal ysis of Wetland Well 10965 Wa ter-Level Time Series

PAGE 114

105 Appendix D: Water-Level Tables Table 10: Annual Wetland Water-Level Magnitudes and Ranges Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1918 Cyp minimum -1.25 -1.3 -0.66 -2. 54 -2.54 -0.66 -1.44 0.79 maximum 1.72 1.7 1.7 1. 8 1.70 1.80 1.73 0.05 range 2.97 3 2.36 4.34 2.36 4.34 3.17 0.84 1929 Cyp minimum 0.48 -0.8 0.77 -3. 77 -3.77 0.77 -0.83 2.08 maximum 2.08 2.14 2.02 2. 02 2.02 2.14 2.07 0.06 range 1.6 2.94 1.25 5. 79 1.25 5.79 2.90 2.06 1932 Cyp minimum -1.9 -1.58 -3.5 -3.50 -1.58 -2.33 1.03 maximum 2.1 1.76 1. 64 1.64 2.10 1.83 0.24 range 4 3.34 5.14 3.34 5.14 4.16 0.91 1944 Cyp minimum -0.72 -0.81 -2. 06 -2.06 -0.72 -1.20 0.75 maximum 3.72 2.13 2. 62 2.13 3.72 2.82 0.81 range 4.44 2.94 4. 68 2.94 4.68 4.02 0.94 1961 Cyp minimum -3.98 0.29 -0.29 -1.69 -4 .56 -4.56 0.29 -2.05 2.16 maximum 2.04 1.76 2.88 1.68 1. 35 1.35 2.88 1.94 0.58 range 6.02 1.47 3.17 3.37 5. 91 1.47 5.91 3.99 1.95 1978 Cyp minimum -0.1 -0.29 -3.74 -4. 65 -4.65 -0.10 -2.20 2.34 maximum 1.79 2.38 1.85 -1. 96 -1.96 2.38 1.02 2.00 range 1.89 2.67 5.59 2. 69 1.89 5.59 3.21 1.63 1987 Cyp minimum -0.3 -3.57 -3.38 -4. 22 -4.22 -0.30 -2.87 1.75 maximum 1.16 1.34 1.03 0. 63 0.63 1.34 1.04 0.30 range 1.46 4.91 4.41 4. 85 1.46 4.91 3.91 1.65 1988 Cyp minimum -0.55 -2.23 -3.53 -4. 38 -4.38 -0.55 -2.67 1.67 maximum 2.14 2.42 2.04 0. 09 0.09 2.42 1.67 1.07 range 2.69 4.65 5.57 4. 47 2.69 5.57 4.35 1.20 105 Appendix D: Water-Level Tables

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106 Table 10: (Continued) Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1989 Cyp minimum -1.87 -2.73 -2.47 -3. 66 -3.66 -1.87 -2.68 0.74 maximum 1.55 1.98 1.72 0. 63 0.63 1.98 1.47 0.59 range 3.42 4.71 4.19 4. 29 3.42 4.71 4.15 0.54 1990 Cyp minimum -1.76 -2.94 -2.94 -1.76 -2.35 0.83 maximum 1.91 1.72 1.72 1.91 1.82 0.13 range 3.67 4.66 3.67 4.66 4.17 0.70 1991 Cyp minimum -0.83 2.62 -0.83 2.62 0.90 2.44 maximum 2.58 2.37 2.37 2.58 2.48 0.15 range 3.41 -0.25 -0.25 3.41 1.58 2.59 1992 Cyp minimum -1.36 -2.08 -3.21 -3.21 -1.36 -2.22 0.93 maximum 1.57 1.72 1.55 1.55 1.72 1.61 0.09 range 2.93 3.8 4.76 2.93 4.76 3.83 0.92 2064 Cyp minimum -7.77 -3.09 -4.76 -4.15 -6 .98 -7.77 -3.09 -5.35 1.96 maximum 1.08 1.03 1.45 1.13 -0.6 -0.60 1.45 0.82 0.81 range 8.85 4.12 6.21 5.28 6. 38 4.12 6.38 6.17 1.75 2159 Cyp minimum 1.39 1.01 1.24 1.01 1.39 1.21 0.19 maximum 2.7 2.63 2.44 2.44 2.70 2.59 0.13 range 1.31 1.62 1.2 1.20 1.62 1.38 0.22 All Avg Cyp minimum -5.875 -0.636 -1.5893 -1.6807 -4.032 -3.36 -0.49 -1.86 1.41 maximum 1.56 1.75 2.21071 1.79571 0.822 1.12 2.22 1.78 0.50 range 7.435 2.386 3.8 3.47643 4. 854 2.32 4.82 3.64 1.28 106 Appendix D: (Continued)

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107 Table 10: (Continued) Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1935 Cyp WF minimum -2.16 -2.96 -2.82 -5. 32 -5.32 -2.16 -3.32 1.38 maximum 0.87 0.84 0.72 0. 72 0.72 0.87 0.79 0.08 range 3.03 3.8 3.54 6. 04 3.03 6.04 4.10 1.33 1938 Cyp WF minimum 1.72 0.62 0.74 -2. 58 -2.58 1.72 0.13 1.87 maximum 3.5 3.51 2.45 1. 42 1.42 3.51 2.72 1.00 range 1.78 2.89 1.71 4 1.71 4.00 2.60 1.08 10958 Cyp WF minimum -10.69 -5.13 -6.06 -6.02 -8 .77 -10.69 -5. 13 -7.33 2.32 maximum -2.42 -2.11 -2.24 -2.57 -2 .31 -2.57 -2.11 -2.33 0.18 range 8.27 3.02 3.82 3.45 6. 46 3.02 6.46 5.00 2.27 10965 Cyp WF minimum -7.78 -7.17 -1.85 -2 .94 -2.78 -6.11 -7. 78 -1.85 -4.77 2.55 maximum -0.97 -0.53 -0.02 0. 12 -0.51 -1.46 -1. 46 0.12 -0.56 0.59 range 6.81 6.64 1.83 3. 06 2.27 4.65 1.83 4.65 4.21 2.17 All Avg Cyp WF minimum -7.78 -8.93 -1.855 -2.835 -2.72 -5.695 -6 .59 -1.86 -3.82 2.03 maximum -0.97 -1.475 0.56 0.557 5 0.0225 -0.4075 -0 .47 0.60 0.15 0.46 range 6.81 7.455 2.415 3.392 5 2.7425 5.2875 2. 40 5.29 3.98 1.71 1946 Mix minimum -4.73 -1.44 -3.34 -1.33 -5 .81 -5.81 -1.33 -3.33 1.98 maximum 1.15 2.15 4.27 1.15 -0. 46 -0.46 4.27 1.65 1.74 range 5.88 3.59 7.61 2.48 5. 35 2.48 7.61 4.98 2.00 1980 Mix minimum 1.19 0.55 -0. 84 -0.84 1.19 0.30 1.04 maximum 2.6 2.26 0. 88 0.88 2.60 1.91 0.91 range 1.41 1.71 1. 72 1.41 1.72 1.61 0.18 107 Appendix D: (Continued)

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108 Table 10: (Continued) Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1995 Mix minimum 0.29 -0.3 -0.84 -0.84 0.29 -0.28 0.57 maximum 1.84 1.49 0.03 0.03 1.84 1.12 0.96 range 1.55 1.79 0.87 0.87 1.79 1.40 0.48 2062 Mix minimum -1.31 0.12 -2.95 0.1 -4. 53 -4.53 0.12 -1.71 2.02 maximum 3.53 3.48 4.07 2.9 1. 58 1.58 4.07 3.11 0.95 range 4.84 3.36 7.02 2.8 6. 11 2.80 7.02 4.83 1.78 All Avg Mix minimum -3.02 -0.66 -1. 2025 -0.245 -3.005 -3 .01 0.07 -1.26 1.40 maximum 2.34 2.815 3.195 1.95 0.5075 0.51 3.20 1.95 1.14 range 5.36 3.475 4.3975 2.195 3.5125 1.89 4.54 3.21 1.11 1021 Bot minimum -8.62 -8.37 -9.63 -9.63 -8.37 -8.87 0.67 maximum 0.89 -1.95 -5.9 -5.90 0.89 -2.32 3.41 range 9.51 6.42 3.73 3.73 9.51 6.55 2.89 1969 Bot minimum -0.44 1.4 0.53 0.99 -1. 33 -1.33 1.40 0.23 1.11 maximum 3.65 4.3 4.85 3.93 1. 78 1.78 4.85 3.70 1.16 range 4.09 2.9 4.32 2.94 3. 11 2.90 4.32 3.47 0.68 All Avg Bot minimum -0.44 1.4 -4.045 -3.69 -5.48 -5.48 -3 .485 -4.3217 0.88802 maximum 3.65 4.3 2.87 0. 99 -2.06 -2.06 2.87 0.691 2.2873 range 4.09 2.9 6.915 4. 68 3.42 3.315 6.915 5.01267 1.78548 598 Bot WF minimum -4.66 -5.76 -4.24 -5.76 -4.24 -4.89 0.78 maximum 1.39 0.6 0.75 0.60 1.39 0.91 0.42 range 6.05 6.36 4.99 4.99 6.36 5.80 0.72 108 Appendix D: (Continued)

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109 Table 10: (Continued) Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1954 Msh minimum 0.12 -4.35 -4.6 -6. 64 -6.64 0.12 -3.87 2.85 maximum 3 3.28 2.77 0.12 0.12 3.28 2.29 1.46 range 2.88 7.63 7.37 6. 76 2.88 7.63 6.16 2.22 1959 Msh minimum -0.96 -4.19 -4.95 -4.95 -0.96 -3.37 2.12 maximum 1.88 1.9 1.35 1.35 1.90 1.71 0.31 range 2.84 6.09 6.3 2.84 6.30 5.08 1.94 1960 Msh minimum -3.4 0.88 0.68 0.22 -3. 23 -3.40 0.88 -0.97 2.15 maximum 2.71 2.33 3.14 2.49 2. 33 2.33 3.14 2.60 0.34 range 6.11 1.45 2.46 2.27 5. 56 1.45 5.56 3.57 2.11 1966 Msh minimum -2.54 -1.19 -2. 43 -2.54 -1.19 -2.05 0.75 maximum 1.7 1.55 0. 83 0.83 1.70 1.36 0.47 range 4.24 2.74 3. 26 2.74 4.24 3.41 0.76 2060 Msh minimum 0.23 0.45 -2.23 -1.98 -3. 29 -3.29 0.45 -1.36 1.63 maximum 2.03 2.06 2.21 1.93 1. 11 1.11 2.21 1.87 0.44 range 1.8 1.61 4.44 3.91 4. 4 1.61 4.44 3.23 1.41 2066 Msh minimum 0.43 0.07 -2.97 -3. 75 -3.75 0.43 -1.56 2.11 maximum 2.64 3.4 2.4 1. 59 1.59 3.40 2.51 0.75 range 2.21 3.33 5.37 5. 34 2.21 5.37 4.06 1.56 All Avg Msh minimum -1.59 0.18 -2. 09 -2.58 -3.87 -4. 10 -0.05 -2.20 1.94 maximum 2.37 2.38 2.61 2.08 1.20 1. 22 2.61 2.06 0.63 range 3.96 2.20 4. 70 4.66 5.06 2.29 5.59 4.25 1.67 109 Appendix D: (Continued)

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110 Table 10: (Continued) Well Water-Level (ft) Well Wetland Type Water-level Characteristic 2001 2002 2003 2004 2005 2006 Low High Mean Std dev 1977 WPr minimum -6.39 -2.93 -3.62 -3.49 -6 .38 -6.39 -2.93 -4.56 1.68 maximum 0.58 2.36 3.44 1.08 0. 05 0.05 3.44 1.50 1.38 range 6.97 5.29 7.06 4.57 6. 43 4.57 7.06 6.06 1.09 1981 WPr minimum -3.67 -2.19 -2.38 -2.85 -4 .33 -4.33 -2.19 -3.08 0.90 maximum 1.38 1.49 1.74 1.45 0. 58 0.58 1.74 1.33 0.44 range 5.05 3.68 4.12 4.3 4. 91 3.68 4.91 4.41 0.57 10896 WPr minimum -5.68 -5.74 -3.22 -3 .6 -0.52 -5.74 -0.52 -3.75 2.15 maximum -3 -3.15 -0.83 0.55 2.27 -3. 15 2.27 -0.83 2.32 range 2.68 2.59 2.39 4. 15 2.79 2.39 4.15 2.92 0.70 All Avg WPr minimum -5.68 -5.27 -2.78 -3 .20 -2.29 -5.36 -5. 49 -1.88 -3.80 1.58 maximum -3.00 -0.40 1.01 1.91 1.60 0.32 -0. 84 2.48 0.67 1.38 range 2.68 4.87 3.79 5. 11 3.89 5.67 3.55 5.37 4.47 0.79 *Annual Water-Level Minimum, Maximum, and Range for the Summer/Fall Semi-Annual Hydroperiod Cycle for all Wetlands 110 Appendix D: (Continued)


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Using frequency analysis to determine wetland hydroperiod
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by Lisa D. Foster.
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[Tampa, Fla.] :
b University of South Florida,
2007.
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ABSTRACT: Wetlands are nominally characterized by, vegetation, presence of saturated soils and/or period and depth of standing water (inundation). Wetland hydroperiod, traditionally defined by the period or duration of inundation, is considered to control the ecological function and resultant plant community. This study seeks to redefine "hydroperiod" to incorporate both surface and subsurface water-level fluctuations, to identify predominant hydroperiod of different wetland types, and to find the range of the water-level fluctuations during the predominant hydroperiod durations. The motivation being that wetland ecological condition is controlled not just by the period of inundation but also by the proximity and depth to water-table and period of water-level fluctuation. To accomplish this, a frequency distribution analysis of water-table and stage levels in wetlands is performed. The conclusions of this study suggest a need to rethink current definitions and methodologies in determining hydroperiod. Redefining wetland hydroperiod taking into consideration depth to water-table, namely water-level periods and depths below ground surface, may also aid in the understanding of how fluctuations in water-levels in a wetland affect plant ecology.
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Thesis (M.S.)--University of South Florida, 2007.
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Includes bibliographical references.
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Text (Electronic thesis) in PDF format.
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Advisor: Mark A. Ross, Ph.D.
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Hydrology.
Time series.
Frequency analysis.
Spectral analysis.
Power spectrum density.
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Dissertations, Academic
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x Engineering Science
Masters.
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