Ground-water-flow modeling and optimization techniques applied to high-ground-water problems in San Bernardino, California
No abstract available.
California↗
Geology topics
J. R. Freckleton
Publications and source records attributed to J. R. Freckleton.
Geohydrology of the Foothill ground-water basin near Santa Barbara, California
Geohydrologic data presented in this report indicate that the East Subbasin of the Goleta groundwater basin and Storage Unit II of the Santa Barbara groundwater basin should be considered as a separate groundwater basin, which is referred to as the Foothill groundwater basin in this report. The 4.5 sq-mi Foothill groundwater basin is bordered on the north and northeast by the Santa Ynez Mountains and on three sides by faults that impede groundwater flow. Sedimentary rocks of Tertiary age underlie the groundwater basin and form its lower boundary. Unconsolidated deposits of the Santa Barbara Formation (Pliocene and Pleistocene age) form the principal aquifer of the basin. Where a zone of low permeability separates it from overlying Quaternary alluvium, the aquifer is confined. In the early 1950's, groundwater levels declined more than 60 ft during periods of heavy pumping. From the mid-1950 's to the late 1970 's, groundwater levels generally rose. Water levels during 1984-87 generally declined. Nitrate concentrations in samples from two wells exceeded the primary maximum contaminant level established by the U.S. Environmental Protection Agency. Secondary maximum contaminant levels for dissolved solids, chloride, and sulfate also were exceeded in some samples. A three-dimensional finite-difference model was developed for part of Foothill groundwater basin. Steady-state verification and transient-state model calibrations were used to estimate or confirm estimates of basin recharge and natural discharge. (USGS)
Water-Resources Investigations Report↗
Aquifer response to recharge and pumping San Bernardino ground-water basin, California
No abstract available.
California↗
A two-dimensional dam-break flood plain model
A simple two-dimensional dam-break model is developed for flood plain study purposes. Both a finite difference grid and an irregular triangle element integrated finite difference formulation are presented. The governing flow equations are approximately solved as a diffusion model coupled to the equation of continuity. Application of the model to a hypothetical dam-break study indicates that the approach can be used to predict a two-dimensional dam-break flood plain over a broad, flat plain more accurately than a one-dimensional model, especially when the flow can break-out of the main channel and then return to the channel at other downstream reaches. ?? 1985.
Advances in Water Resources↗
Ground water in the Twenty-Nine Palms Indian Reservation and vicinity, San Bernardino County, California
The Twenty-Nine Palms Indian Reservation is in San Bernardino County, California. Movement of ground water in the area is impeded locally by faults which act as ground-water barriers. There are indications that a fault probably crosses the reservation in an east-west direction; such a fault may interfere with ground-water pumping. The water-table altitude near the northern boundary of the reservation is estimated to be 120 to 130 feet below land surface datum; the aquifer thickness in the area is unknown. Pumping-test results for wells near the reservation show specific capacities ranging from 9.2 to 70.0 gallons per minute per foot of drawdown. Wells drilled on the reservation would probably fall within this range. Sodium concentrations, which may pose a hazard to those who must restrict its intake, and excessive fluoride are present in water samples from wells near the reservation. High sodium and fluoride concentrations are probably present in water in the saturated material underlying the reservation. (USGS)
Water-Resources Investigations Report↗
Two-dimensional and three-dimensional digital flow models of the Salinas Valley ground-water basin, California
The Salinas Valley ground-water basin is in central coastal California. The ground-water basin extends from Monterey Bay southeastward along the Salinas River to San Ardo, a distance of about 70 miles, and has a maximum thickness of about 2,000 feet. Annual recharge to the ground-water basin, which is derived mostly from the Salinas River, is about 290,000 acre-feet. Annual discharge, which is mostly from pumpage but also includes the consumptive use of ground water by riparian vegetation along the Salinas River, is about 507,000 acre-feet. About 45 percent of the pumpage, or about 217,000 acre-feet of water annually, returns to the ground-water system. A system of interacting hydrologic models was developed for the Salinas Valley. These models include the small-stream model, river model, two-dimensional ground-water model, and three-dimensional ground-water model. The small-stream model simulates ground-water recharge from small streams that are tributary to the Salinas River. The river model simulates ground-water recharge from the surface-water discharge in the Salinas River. The two-dimensional and three-dimensional ground-water models simulate hydraulic head in the ground-water basin. (Woodard-USGS)
Water-Resources Investigations Report↗