Remote sensing of mangrove wetlands: Relating canopy spectra to site-specific data
No abstract available.
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Geology topics
Research about Florida
Source-linked reports with geographic coverage including Florida.
First record of an hypopus (Acari: Hypoderatidae) from a jaeger (Aves: Charadriiformes: Stercorariidae)
Thalassornectes (Alcidectes) aukletae, originally described from two species of auklets (Charadriiformes: Alcidae) from maritime eastern Russia, is reported from a third species of pelagic charadriiform (Stercorariidae), the pomarine jaeger, Stercorarius poinarinus (Temminck), from Florida. The specimens from the jaeger are slightly smaller, the genital apodeme is more heavily sclerotized, paired setae gm are twice as long and there are other minor variations in the idiosomal and leg chaetotaxy. These differences are not considered sufficient to warrant taxonomic separation at the species or subspecies level from the nominate species T. (A.) aukletae. The same hypopus occurring across different families of birds is unusual in the Hypoderatidae. The diversity in hosts from several orders of birds, low intensities of infection in the two species from Africa, low prevalences in alcids from Russia, and rarity of these hypoderatids in all surveyed hosts leads us to speculate that the true host affinities of species in the genus Thalassornectes are unknown. The alternative consideration is that these are simply uncommon species that are very host specific.
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Sediment resuspension mechanisms in Old Tampa Bay, Florida
The mechanisms that resuspend bottom sediments in Old Tampa Bay, a shallow, microtidal, subtropical estuary in west-central Florida, were determined by analysing data collected during several periods from 1988 to 1990. Hydrodynamic and suspended-solids concentration data were collected at a relatively deep (4 m) site where a permanent platform was built and at a relatively shallow (1·5 m) site where a submersible instrument package was deployed. Bottom sediments were non-cohesive silts and fine sands. The primary sediment resuspension mechanism at both sites was wind waves, which were generated by strong and sustained winds associated with winter storms and tropical storms. At the platform, waves were depth-transitional, and estimated bottom shear stresses were most sensitive to wave period and water depth. Concentrations of suspended solids at this site corresponded well with wave motion, and non-linear wave-current interaction was small. At the shallow-water site, concentrations of suspended solids were elevated during periods of strong north-easterly winds and large bottom orbital velocities. At both sites, wind direction was an important factor in determining the occurrence and magnitude of sediment resuspension. Resuspended sediments settled within several hours as storm intensity diminished. Winds and waves generated by thunderstorms were more transient than those generated by winter storms and tropical storms. Based on the data collected during this study, thunderstorms are less likely to resuspend bottom sediment than winter storms and tropical storms. Maximum tidal currents at the study sites are usually less than 15 cm s −1 and did not increase observed concentrations of suspended solids.
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The value and vulnerability of small estuarine islands for conserving metapopulations of breeding waterbirds
Compelling arguments for preserving large habitat ‘islands’ have been made for a number of animal groups, but most commonly for terrestrial birds. We argue that, for many species of waterbirds nesting in coastal estuaries, maintaining numerous small islands may be a more effective management strategy than maintaining larger islands or reserves. In this study, the number of great white heron Ardea herodias nests over a 5-year period (1986–91) was negatively correlated with island area in the Florida Keys, USA. Nest densities were highest in the 2–10 ha island size range and lowest for islands larger than 100 ha. These small islands also attract nesting black skimmers Rynchops niger , brown pelicans Pelecanus occidentalis , and several species of terns and gulls. Small estuarine islands are vulnerable to sea level rise, erosion from watercraft, and, for dredge material islands, lack of sufficient maintenance because of competing needs for beach nourishment. Managers need to enforce more buffering and protection of these islands and argue for more dredged material allocations in some areas.
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South Florida Ecosystem Program of the U.S. Geological Survey
Introduction The South Florida Ecosystem Program is one of several study areas within the USGS Ecosystem Program. The Ecosystem Program was established to enable the USGS to enhance its scientific assistance to resource managers who require an improved scientific information base to resolve or prevent complex resource conflicts or environmental problems in specific ecosystem sites. Through 3-5-year efforts in each ecosystem site, USGS intensifies its provision of scientific information tailored to the specific management needs of that ecosystem. The information is designed to have a direct, significant, and immediate impact on management and policy decisions. It addresses regional or subregional issues that involve environmental resources such as water, minerals, and land. The sites may have as their focus such issues as water quality or water supply, environmental effects of mineral or energy use or extraction, effects of alterations in land use or land cover. Initially, the Ecosystem Program focussed on two ecosystems: San Francisco Bay and south Florida. Chesapeake Bay was added in FY 1996. Activities in each site last from three to five years, and additional ecosystem sites will be added as funding becomes available. The program is multidisciplinary and brings together scientists from appropriate disciplines to apply their diverse expertise to common problems. Disciplines in the present suite of ecosystems include land characterization, surface modeling, geospatial database management, ground- and surface-water hydrology, geophysics, ecology, geochemistry, paleontology, hydrologic modeling, and contaminant, sediment, and nutrient dynamics. The South Florida Ecosystem Program is an intergovernmental effort to reestablish and maintain the ecosystem of south Florida. One element of the restoration effort is the development of a firm scientific basis for resource decisionmaking. The U.S. Geological Survey (USGS) is one of the agencies that provides scientific information as part of the USGS South Florida Ecosystem Program. The Program, which was begun in fiscal year 1995, provides multidisciplinary hydrologic, cartographic, and geologic data that relates to the mainland of south Florida, the Florida Bay, and the Florida Keys and Reef ecosystems. The Program complements ongoing USGS work, such as the National Water-Quality Assessment Program , the Federal-State Cooperative Program, Marine and Coastal Geology Program and Regional Geology Program , and topographic mapping and digital cartography .
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Biogeochemical study of the pinelands in Everglades National Park, Florida
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Computation of the time-varying flow rate from an artesian well in central Dade County, Florida, by analytical and numerical simulation methods
To construct a digital simulation of a plume of brackish water in the surficial Biscayne aquifer of central Dade County, Florida, that originated from a flowing artesian well, it was necessary to quantify the rate of spillage and the consequent point-source loading of the aquifer. However, a flow-rate measurement (2,350 gallons per minute) made 2 months after drilling of the well in 1944 was inconsistent with later measurements (1,170 gallons per minute) in 1964, 1965, and 1969. Possible explanations were the: (1) drawdown of the aquifer over time; (2) raising of the altitude at which the water was discharged; (3) installation of 80 feet of 8-inch liner; (4) an increase in the density of the flowing water; and (5) gradual deterioration of the well casing. The first approach to reconciling the measured flow rates was to apply a form of the equation for constant-drawdown analysis often used to estimate aquifer transmissivity. Next, a numerical simulation analysis was made that provided the means to account for friction loss in the well and recharge across vertically adjacent confining layers and from lateral boundaries. The numerical analysis required the construction of a generalized model of the subsurface from the surficial Biscayne aquifer to the cavernous, dolomitic Boulder Zone at a depth of 3,000 feet. Calibration of the generalized flow model required that the moddle confining unit of the Floridan aquifer system separating the artesian flow zone in the Upper Floridan aquifer from the Lower Floridan aquifer (the Boulder Zone) have a vertical hydraulic conductivity of at least 1 foot per day. The intermediate confining unit separating the flow zone from the surficial Biscayne aquifer was assigned a much lower hydraulic conductivity (0.01 foot per day or less). The model indicated that the observed mounding of Upper Floridan aquifer heads along the axis of the Florida Peninsula was related to the variable depth of the freshwater and brackish-water zone overlying deeper saline water. The analyses only partly reconciled the two rates. The second rate was accepted as representative of the conditions prevailing at the time of its measurement. On the basis of flowmeter logging, it was assumed that an additional 230 gallons per minute escaped through the corroded casing at that time. Factors not amenable to analysis, such as the inherent inaccuracy of the method of estimating flow from the well and possible error in estimating losses through the casing, could easily account for the remainder of the difference between the two measured rates.
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Statistical summaries of surface-water hydrologic data collected in the Suwannee River Water Management District, Florida, 1906-93
Since 1906, hydrologic data have been collected systematically on streams and lakes in the Suwannee River Water Management District (SRWMD) by the U.S. Geological Survey (USGS), the SRWMD, and other agencies. Records of stream discharge and stream and lake stage in the SRWMD (fig. 1), collected largely in cooperation with the SRWMD since 1975, have been published for many years in the USGS annual report series "Water Resources Data for Florida." Streamflow and stream and lake elevation statistics are given in this report for sites shown in figure 1. All 27 daily streamflow stations shown are (or were) operated by the USGS in cooperation with the SRWMD; all 18 lake stage stations shown are now (1994) operated by the SRWMD, but were operated until the late 1970’s by the USGS in cooperation with the SRWMD. All unregulated stream stations which have three or more years of continuous record are included in this report. All unregulated lake stations having at least three years of intermittent lake elevation readings are also included. There are many other sites in the SRWMD for which shorter records or miscellaneous measurements are available but are not included because statistical summaries for such stations require interpretive analysis beyond the scope of this report. Basic hydrologic data have long been recognized as fundamental to the analysis of magnitude and frequency of floods, availability of water supplies, potential for reservoir storage, and permitting of waste discharges. Also, in recent times, scientists and water managers have become more aware of the complex relations between flows and water levels and the terrestrial and aquatic plant and animal life in wetland ecosystems. In 1994, the SRWMD and the USGS began a long-term program of cooperative studies designed to better understand minimum and maximum flow and water levels needed to manage the surface and ground water resources of the District and maintain or improve the various ecosystems therein. Information presented in this report, together with frequency analysis of station data, flow regionalization, studies of the relation of salinity to flow in the lower Suwannee River, definition of ground-water surface-water interactions, surface- and ground-water quality studies, and studies of interaction between surface-water bodies and wetlands, will provide the basis for the SRWMD to establish minimum flow and level requirements for streams and lakes in the SRWMD area. This report is a necessary first step in the longterm program of study because it contains basic stream discharge and stream and lake elevation statistics, most of which are not contained in the annual report "Water Resources Data for Florida." These statistics, most of which were generated using a U.S. Geological Survey computer program, ADAPS, Automatic Data Processing System, characterize normal flows and levels and departures from normal due to floods and droughts or seasonal climatic variations. Specifically, the report presents for the period of record of each stream or lake gaging station, as appropriate: Minimum, maximum, and mean of monthly mean stream elevations and discharges in graphical and tabular form. For streams, annual mean discharge, highest and lowest annual mean discharge, highest and lowest daily mean discharge, minimum annual seven-day mean discharge, instantaneous peak discharge and elevation, instantaneous minimum discharge, and basin yield. Duration of annual daily mean stream elevation and discharge. Duration of daily values are shown in both graphical and tabular form. Duration of daily mean stream elevations and discharge, by months, in tables. Minimum and maximum 1-,3-,7-,14-,30-, 60-, 90-,120-, and 183-consecutive day stream elevations and discharges (with rankings) for each year of record. Mean monthly lake elevations and statistics by month, including number of monthly values, mean, variance, standard deviation, skewness, and coefficient of variation. For convenience, a GLOSSARY of commonly used terms related to the collection and reporting of surface-water elevations and discharge is included before the Introduction section of this report. The authors wish to acknowledge Natalie Rackley, formerly of the U.S. Geological Survey, and T.W. Grubbs, U.S. Geological Survey, for their computer assistance in the compilation of station records, and Jim Tomberlin, U.S. Geological Survey, for the mapping of stream and lake gaging stations.
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Potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, September 1994
This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 1994. The map is based on water-level measurements made at more than 900 wells and springs. Ninety-two new wells were added to the September 1994 map--42 in southern Georgia and 50 in Florida. Data on the map were contoured using 5-foot contour intervals in most areas. The potentiometric surface of this karstic aquifer generally reflects land surface topography. Potentiometric-surface highs often correspond to topographic highs, which are areas of surficial recharge to the Upper Floridan aquifer. Springs within topographic lows along with areas of more diffuse upward leakage are natural zones of discharge. Municipal, agricultural, and industrial withdrawals have lowered the potentiometric surface in some areas. The potentiometric surface ranged from 131 feet above sea lvel in Polk County to 86 feet below sea level in southern Georgia near the St. Marys River. With the additon of new wells in southern Georgia, water level data now indicate two distinct depressions at industrial well fields near the St. Marys River in southern Georgia and eastern Nassau County where previously there was only one depression indicated. Water levels measured in September 1994 generally were about 0 to 4 feet higher than those measured in September 1993, except in Seminole County, where increases of 1 to 7 feet above September 1993 levels were recorded at most wells. Generally, September 1994 water levels were 1 to to 5 feet higher than levels in May 1994 except in Union, Gradford, Alachua, Levy, and western Marion Counties where levels remained nearly unchanged, and in Seminole and northwestern Orange Counties where water levels generally were 3 to 12 feet higher than levels in May 1994.
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Geologic map of the Sarasota and Arcadia, Florida 30 by 60-minute quadrangles
No abstract available.
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Simulation of the water-table altitude in the Biscayne Aquifer, southern Dade County, Florida, water years 1945-89
A digital model of the flow system in the highly permeable surficial Biscayne aquifer of southern Dade County, Florida, was constructed for the purposes of better understanding processes that influence the flow system and of supporting the construction of a subregional model of the transport of brackish water from a flowing artesian well. Problems that needed resolution in this endeavor included the development of methods to represent the influence of flowing surface water in seasonally inundated wetlands and the influence of a network of controlled canals developed in stages during the simulation time period (water years 1945-89). An additional problem was the general lack of natural aquifer boundaries near the boundaries of the study area. The model construction was based on a conceptual description of the Biscayne aquifer developed from the results of previous U.S. Geological Survey investigations. Modifications were made to an existing three-dimensional finite-difference simulator of ground-water flow to enable an upper layer of the grid to represent seasonally occurring overland sheetflow in a series of transient simulations of water levels from 1945 to 1989. A rewetting procedure was developed for the simulator that permitted resaturation of cells in this layer when the wet season recurred. An "equivalent hydraulic conductivity" coefficient was assigned to the overland flow layer that was analogous, subject to various approximations, to the use of the Manning equation. The surficial semiconfining peat and marl layers, levees, canals, and control structures were also represented as part of the model grid with the appropriate choices of hydraulic coefficient values. For most of the Biscayne aquifer grid cells, the value assigned to hydraulic conductivity for model calibration was 30,000 feet per day and the value assigned to porosity was 20 percent. Boundary conditions were specified near data sites having long-term records of surface-water stages or water-table altitudes, and modifications to the simulator permitted the specification of time-varying pressures at boundary grid cells. Rainfall data from a station in Homestead generally were used as an areally uniform rainfall specification throughout the modeled region. Maximum evapotranspiration rates ranged seasonally from a minimum of 0.08 inch per day in January to a maximum of 0.21 inch per day between June and October. Shallow-root and deep-root zone depths for the evapotranspiration calculation were 3 and 20 feet in the coastal ridge and were 0.10 and 5 feet in the glades regions where peat and marl covers occurred. Results of sensitivity analyses indicated that the simulations of stages and water levels were relatively unresponsive to 50 percent changes in aquifer hydraulic conductivity, porosity, and the equivalent hydraulic conductivity of overland flow. However, 20 percent changes in rainfall and maximum evapotranspiration rates produced significantly different water levels, as did interchange of coastal ridge and glades deep-root zone (extinction) depths. Water levels were simulated very well at most measurement sites. Sensitivity analyses illustrated the significant influence of the uncontrolled agricultural drainage canals on pre-1968 regional water levels and the further influence of Black Creek Canal in draining a region of high water after 1961. Other analyses indicated that the flood-control system of 1968-82 lowered peak water levels in the affected region by as much as 1.5 feet in the wet summers of 1968, 1969, and 1981, and that Levee 67 Extended channeled flows from the S-12 spillway structures and raised overland flow stages in Shark River Slough. Hypothetical scenarios of well-field pumping in the vicinity of Levee 31N indicated that the pumping induced a significant amount of recharge from the adjacent borrow canal, the degree of which depended on the distance between the canal and the well field. The computed ratio of evapotranspiration to rainfall recharge ranged from 88 to 94 percent during water years 1945-82. The ratio increased to about 97.9 percent during water years 1983-89, possibly because of changing water-management practices and deficient rainfall.
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Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, May 1995
This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 1995. The map is based on water-level measurements made at more than 900 wells and springs. Approximately 30 new wells were added to better define the potentiometric surface mainly in the northwest area of the map. Data on the map were contoured using 5-foot contour intervals in most areas. Two new wells located north of Rainbow Springs indicate a slight northward extension of the depressed area surrounding the springs. Several new wells in Bradford County indicate a slight reduction in the size of the potentiometric-surface high along the northwest edge of the county. The potentiometric surface of this karstic aquifer generally reflects land surface topography. Potentiometric-surface highs often correspond to topographic highs, which are areas of recharge to the Upper Floridan aquifer. Springs within topographic lows along with areas of more diffuse upward leakage are natural zones of discharge. Municipal, agricultural, and industrial withdrawals have lowered the potentiometric surface in some areas. The potentiometric surface ranged from 127 feet above sea level in Polk County to 84 feet below sea level in southeast Georgia near the St. Marys River. Water levels measured in May 1995 generally were about 0 to 4 feet higher than those measured in May 1994 except in St. Lucie County and near Rainbow Springs, where levels were 1 to 3 feet lower. Generally, May 1995 water levels were 0 to 5 feet lower than levels in September 1994, except near Orlando, where levels were 6 to 12 feet lower, and across the northwest corner of the map area which includes Marion, Alachua, Bradford, Baker, and Nassau Counties, north and west Duval County, and south Georgia. (USGS)
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Preliminary analysis of down-core biotic assemblages Bob Allen Keys, Everglades National Park, Florida Bay
Introduction A series of short piston cores (< 2m) were taken from eleven stations in Florida Bay in May, 1994 by researchers from the U.S. Geological Survey (St. Petersburg, FL., Woods Hole, MA., and Denver CO.) in cooperation with South Florida Water Management District, and the Everglades National Park, and the National Oceanic and Atmospheric Administration (NOAA). Core 6A from Bob Allen Keys (25° 1.391” N, 80°39.41” W) penetrated 172 cm of Holocene sediments in 0.6 m of water on a grass covered mud bank, approximately 1.75 miles (2.82 km) east of the water monitoring station on the southern end of the Bob Allen Keys. Core 6A was sampled for particle size, insoluble residue, water content, loss on ignition, Pb 210 , Rasup>222, and paleontologic analyses. Here we present the results of the preliminary paleontologic analyses of the biotic components from core #6A. The Everglades/Florida Bay ecosystem has formed over the last 5000 years at the southern tip of peninsular Florida. Here it has been influenced by Atlantic, Caribbean and Gulf of Mexico waters, and by tropical and subtropical climatic regimes. This location ensures that over time the ecosystem has undergone climatic changes on both a seasonal and long term basis, and that it has been subjected to many major storms. Additionally, in the last century, the hydrologic regime of the region has been altered profoundly through construction of a canal system to control flooding in southern Florida. This system regulates the timing and amount of freshwater flow into Florida Bay. Recently, algal blooms, seagrass, and sponge die-offs, and declining numbers of shellfish, have been reported in Florida Bay; although it has been assumed that these changes have resulted from human alteration of freshwater flow into the bay, this assumption has not been rigorously tested. The research described here is part of a project designed to examine the history of the Everglades/Florida Bay ecosystem over the last 150 years and to test assumptions of cause and effect. The purpose of the project is two-fold; first, to determine the characteristics of the ecosystem prior to significant human-induced alteration, including the natural range of variation in the ecosystem. This information will establish a baseline for restoration of the system. Second, the project aims to establish the extent, range, and timing of changes to the ecosystem over the last 150 years, and to determine whether these changes correlate with human alteration of the environment, or meteorological patterns, such as precipitation and major storms, or a combination of factors.
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Potentiometric surface of the upper Floridan Aquifer, west-central Florida, May 1995
The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by a middle confining unit. The middle confining unit and the Lower Floridan aquifer generally contain highly mineralized water. In most reports on the hydrology of southwest Florida, the term "Floridan aquifer" has been applied to the water-bearing rocks, herin referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is a productive aquifer and supplies more than 10 times the amount of water pumped from either the surfical aquifer system of the intermediate aquifer system in most of the study area (Duerr and other, 1988). This map report depicts the potentiometric surface of the Upper Floridan aquifer in May 1995. The potentipmetric surface represents to the level to which water will rise in tightly cased wells that tap a confined aquifer system. The surface is mapped by determining the altitude of water levels in a network of wells and is represented on maps by contours that connect point of equal altitude. This map represents water-level conditions near the end of the dry season when ground-water withdrawals for agricultural use are usually high. The cumulative rainfall for the study area was 2.98 inches above average for the period from June 1994 through May 1995 (Southwest Florida Water Management District, 1995)
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Potentiometric surfaces of the intermediate aquifer system, west-central Florida, May 1995
No abstract available.
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Preliminary analysis of integrated stratigraphic data from the Phred #1 corehole, Indian River County, Florida
No abstract available.
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Water resources data, Florida, water year 1994: Volume 1A. Northeast Florida surface water
The Water Resources Division of the U.S. Geological Survey, in cooperation with State, local, and Federal agencies, obtains a large amount of data pertaining to the water resources of Florida each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the State.
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