Publications

The hydrogeologic subdivisions within the Barton Springs segment of the Edwards aquifer outcrop in northeastern Hays and southwestern Travis Counties generally are porous and permeable. The most porous and permeable appear to be hydrogeologic subdivision VI, the Kirschberg evaporite member of the Kainer Formation; and hydrogeologic subdivision III, the leached and collapsed members...

The U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program has three objectives, one of which is "to define trends (or lack of trends) in water quality" (Leahy and others, 1990). Water-quality trends are of interest for at least three reasons: First, trends can improve our understanding of the influence of human activities on water-quality conditions; second, trends can...

Trends are computed for nutrient inflows from 37 streams discharging into the Gulf of Mexico. The drainage areas of these streams represent about 86 percent of the drainage area to the Gulf from the conterminous United States. The period analyzed varies for each stream, but generally includes water years 1972-93. Stations included in this analysis primarily are part of the National...

The two States, Oklahoma and Texas, that compose Segment 4 of this Atlas are located in the south-central part of the Nation. These States are drained by numerous rivers and streams, the largest being the Arkansas, the Canadian, the Red, the Sabine, the Trinity, the Brazos, the Colorado, and the Pecos Rivers and the Rio Grande. Many of these rivers and their tributaries supply large...

No abstract available.

This National Water Summary on Wetland Resources documents wetland resources in the United States. It presents an overview of the status of knowledge of wetlands at the present time-what they are, where they are found, why they are important, and the controversies surrounding them, with an emphasis on their hydrology. Wetland resources in each State, the District of Columbia (combined...

The Lower Colorado River Authority sells and distributes water for irrigation of rice farms in two irrigation districts, the Lakeside district and the Gulf Coast district, in the lower Colorado River Basin of Texas. In 1993, the Lower Colorado River Authority implemented a water-measurement program to account for the water delivered to rice farms and to promote water conservation. During...

Large quantities of ground water are available for use from three regional aquifer systems in the central Midwest of the United States. Parts of the lowermost aquifer contain nearly immobile brine and may be hydrologically suitable for material storage or waste disposal. Results of numerical modeling and geochemical analyses confirm general concepts of ground-water flow in the regional...

Completion logs are presented for 16 monitoring wells installed by the U.S. Geological Survey at Air Force Plant 4 and Naval Air Station, Joint Reserve Base, Carswell Field, in the Fort Worth area, Texas. Natural gamma-ray logs are presented for selected monitoring wells. Also included are survey data for eight wells installed by Geo-Marine, Inc.

No abstract available.

A model parameter set for use with the Hydrologic Simulation Program FORTRAN watershed model was developed to simulate storm peaks and storm volumes for the 28 subbasins of the West Fork Trinity River Basin upstream from Lake Worth, northwest of Fort Worth, Texas, from the calibration and testing of 5 gaged subbasins. These parameters can be transferred to the 23 ungaged subbasins. The...

Nonpoint sources of pesticides are a national issue and are a major interest in the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program because of their potential toxicity to humans and aquatic life. Using the water-quality data collected by the Trinity River Basin NAWQA study-unit team, an analysis of pesticides in urban and agricultural streams was made by...