Publications

This report is one in an annual series of reports that depicts water-level altitudes and water-level changes since 1977 and compaction since 1973 in the Chicot and Evangeline aquifers in the Houston-Galveston region, Texas. The report, prepared in cooperation with the City of Houston and the Harris-Galveston Coastal Subsidence District, presents maps for the Chicot and Evangeline...

Accurate estimates of watershed denudation absent anthropogenic effects are required to develop strategies for mitigating accelerated physical erosion resulting from human activities, to model global geochemical cycles, and to examine interactions among climate, weathering, and uplift. We present a simple approach to estimate predevelopment denudation rates using in-situ-produced...

Methanol extracts of dorsal skin layers, eyes, gills, and livers from ultraviolet-B (UVB) radiation-sensitive and UVB-tolerant species of freshwater fish were examined for a substance that appears to be photoprotective. Significantly larger amounts of this substance were found in extracts of outer dorsal skin layers from both UVB-sensitive and UVB-tolerant fish when compared with...

An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciatazoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH3) were conducted to determine zoospore sensitivity. Zoospore germination...

The CETAC ADX-500 autodiluter system was tested with ELAN?? v 2.1 software and the ELAN 6000 ICP-MS instrument to determine on-line automated dilution performance during analysis of standard solutions containing nine analytes representative of the mass spectral range (mass 9 to mass 238). Two or more dilution schemes were tested for each of 5 test tube designs. Dilution performance was...

This report presents the results of a study conducted by the U.S. Geological Survey in cooperation with the Missouri Department of Natural Resources from December 1995 through May 1997 to describe the water quality, hydrologic, and invertebrate characteristics of three remnant wetlands. These data may be used to help develop selected water-quality standards for wetlands in Missouri...

Nutrient, bacteria, organic carbon, and suspended- sediment samples were collected from 1993-95 at 43 surface-water-quality sampling sites within the Ozark Plateaus National Water- Quality Assessment Program study unit. Most surface-water-quality sites have small or medium drainage basins, near-homogenous land uses (primarily agricultural or forest), and are located predominantly in the

No abstract available.

The U.S. Geological Survey, in cooperation with the Texas Department of Transportation, conducted a study of extreme precipitation depths for various durations and storm areas for Texas, excluding the Trans-Pecos region. The extreme precipitation depth is an estimate, from documented storms, of the largest precipitation depth expected to occur over a given area. The extreme precipitation...

Quantitative information concerning recharge rates to aquifers and ground water in storage is needed to manage the development of ground- water resources. The amount of ground water available from the regolith-fractured crystalline rock aquifer system in Guilford County, North Carolina, is largely unknown. If historical patterns seen throughout the Piedmont continue into the future, the...

This Flood Tracking Chart for the Illinois River Basin in Illinois can be used to record and compare the predicted or current flood-crest stage to past flood-crest information. This information can then be used by residents and emergency-response personnel to make informed decisions concerning the threat of flooding to life and property. The chart shows a map of the Illinois River Basin...

The Edwards aquifer is the sole source of water for about 1.3 million people in and near San Antonio, Texas, as well as for ranchers and farmers throughout south-central Texas. Because of the demand for this resource, various studies have been conducted to better understand the Edwards aquifer and how the aquifer reacts to environmental changes and human influences. In July 1996, the U.S