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A. M. O’Reilly

Publications and source records attributed to A. M. O’Reilly.

5 recordsLinked to original sources
USGS2008

Sensitivity of wetland saturated hydraulic heads and water budgets to evapotranspiration

The sensitivity of wetland saturated hydraulic heads and water budgets to evapotranspiration (ET) was examined using a simplified hydrologic model and eight representations of ET. Estimates of ET that created the most reliable wetland saturated hydraulic heads and water budgets employed vegetation coefficients to correct potential ET, calculated by the Priestley-Taylor equation, to actual ET. The accuracy of simulated hydraulic heads generally improved by < 1 cm, however, when using the most reliable ET estimates based on vegetation coefficients. An ET estimate that used a regression-defined extinction depth created substantial errors in simulated water budgets. Specifically, the extinction-depth ET overestimated the annual actual ET by about 40 (400 mm). An ET approximation that overestimates actual ET by 400 mm annually applied in a regional hydrologic model over the 5400 km 2 area of Everglades National Park would underestimate the annual volume of water available for ground-water recharge and surface-water runoff to coastal estuaries by 2.3 billion m 3 . For comparison, this underestimation is about two thirds of the mean volume of water in Lake Okeechobee (3.8 billion m 3 ), the largest lake in Florida, and clearly demonstrates unbiased estimates of ET are necessary for reliably simulating wetland water budgets. ?? 2008 The Society of Wetland Scientists.

Wetlands↗
USGS1995

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)

Florida↗
USGS1994

Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, Florida, May 1994

This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 1994. The map is based on water-level measurements made at approximately 1,000 wells and several springs. 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 125 feet above sea level in Polk County to 32 feet below sea level in Nassau County. Water levels in May 1994 generally were 0 to 3 feet lower than those measured in May 1993. Water levels in May 1994 in northeast Florida generally were 0 to 3 feet higher than in September 1993, except in the lower St. Johns River basin, where water levels were 0 to 4 feet lower than in September 1993. In the rest of the mapped area, water levels in May 1994 generally were 0 to 4 feet lower than those measured in September 1993.

Open-File Report↗