Hydrology of the Floridan aquifer system in east-central Florida

Abstract

REGIONAL AQUIFER-SYSTEM ANALYSIS-FLORIDAN AQUIFER SYSTEM Floridan pumpage tends to induce leakage from the overlying surficial aquifer system and to reduce upward discharge to it, thereby lowering the water table. Hydrologic analysis of Floridan aquifer system discharge led to the discovery and measurement of two hitherto undocumented springs. PREVIOUS INVESTIGATIONS Many investigators have studied the Floridan aquifer system groundwater resource in east-central Florida. Among the more notable pioneer studies are those by

Selected Soil Physical Properties and Implications on Water Management System in Northeast Florida

“…This suggested that although there may be some localized temporary perching of water, the lack of continuity in these properties allows the infiltrated water to quickly reach the groundwater table, which is near the surface most times of the year. These results also support previous studies on the hydrogeology of northeast Florida region, which reported that the thickness of the surficial aquifer in the area may range from 9 m to 26 m from the surface (Healy, 1982), which at the bottom was separated from the deeper Floridan Aquifer system by a confining unit (Tibbals, 1990;Durden 1997;Brown et al, 1986;Krause and Randolph, 1989). According to Healy (1982), the water table elevations in the surficial aquifer are the reflections of the landscape configuration, and in low flat areas, the water table stands commonly at or within a few feet of the land surface.…”

Estimation and Prediction of Hydrogeochemical Parameters Using Extended Kalman Filtering

“…Figure 9-7 shows a map of the spatial distribution of the estimated recharge field. The recharge estimates range from -10.2 cm/yr to 11.3 cm/yr, and are within the range of published recharge-discharge values (Tibbals 1990). The area of known spring discharge is clearly identified by the large negative recharge values predicted in the northern portion of the study area.…”

“…Figure 9-3 shows that although the general trend for groundwater movement is approximately from southwest to northeast, there is significant spatial variability around this mean behavior. The pronounced dip in the 5 m to 10 m head contours in the northern portion of the study region is evidence of significant local discharge from seven major springs mapped in the area (Tibbals 1990). Figure 9-4 shows histograms of the estimation errors obtained using head and transmissivity measurements for estimating the head distribution (bivariate conditioning) compared with estimation errors obtained when only head measurements were used (univariate conditioning).…”

“…Parameters characterizing the statistical structure of the log transmissivity and head fields were estimated from 152 measurements of transmissivity in the SJR-WMD and 146 measurements of hydraulic head in the study region (see Figure 9-1 for study boundary and transmissivity measurement locations and Figure 9-2 for head measurement locations and long-term average head contours). There was insufficient information available to statistically estimate the mean, variance, and spatial correlation scale of the recharge field; therefore, physically reasonable values for these parameter were roughly estimated based on the very limited information available on recharge to and discharge from the Floridan aquifer in this region (Tibbals 1990). Details on the estimation procedures used to determine the required input parameters are given in Graham and Neff (1994).…”

“…metric head in a subregion of the Upper Floridan aquifer in the St. Johns River Water Management District (SJRWMD) in Florida. Details regarding the hydrogeology of this region can be found in Bush and Johnston (1988) and Tibbals (1990). In this application, the state equation was based on the two-dimensional infinite domain steady groundwater flow equation, and the model error term was assumed to be zero.…”