Publications

The intensive herbicide use associated with the 'Corn Belt' marks the Midwestern United States as a region where herbicide contamination of ground water could be a problem. To better understand the regional occurrence of herbicides in shallow aquifers of the Midwest, a sampling network of 303 wells across 12 States was developed. The results documented relatively widespread, low-level

The U.S. Geological Survey collected fish, benthic macroinvertebrate, and stream habitat data at sampling sites in the Houston-Galveston Area Council service area, a 15-county area with a population of about 4.3 million people. The data were collected for a 1997?98 study in cooperation with the Houston-Galveston Area Council to provide data for the Texas Clean Rivers Program for...

No abstract available.

A preliminary assessment of the distribution and variability of total mercury concentrations in five sediment environments—open water, ship channel, dredged spoil, oyster reef, and salt marsh—of the Lavaca-Matagorda Bays estuarine system along the central Texas Gulf Coast shows that the largest total mercury concentrations in the bays are in the 10- to 20-centimeter sample-depth zone in...

The Bauman Park Lake occupies a former sand and gravel quarry in the Village of Cherry Valley, Illinois. The lake is eutrophic, and nuisance growths of algae and aquatic macrophytes are supported by nutrients (nitrogen and phosphorus) that are derived primarily from ground-water inflow, the main source of water for the lake. The lake has an average depth of about 18 feet, a maximum depth...

The U.S. Geological Survey collected hydrologic (rainfall, streamflow, and reservoir content) and water-quality data in the Seco Creek watershed, south-central Texas. Most of the data from 15 sites were collected as part of a study in cooperation with the U.S. Department of Agriculture and the Texas State Soil and Water Conservation Board to evaluate the effects of agricultural best...

This is a collection of five papers intended to summarize the results of an assessment of the ground-water quality of the Central Oklahoma Aquifer. The papers include a summary of investigations, the diagenetic history of Permian rocks in the aquifer, a geochemical characterization of solid-phase materials, a summary of geochemical and geohydrologic investigations of the Central Oklahoma...

Statistical summaries of streamflow data collected at 156 streamflow-gaging stations in Iowa are presented in this report. All gaging stations included for analysis have at least 10 years of continuous record collected before or through September 1996. The statistical summaries include (1) statistics of monthly and annual mean discharges; (2) monthly and annual flow durations; (3)...

No abstract available.

This volume contains a summary of the flooding in the upper Mississippi River Basin during the spring and summer of 1993 and 36 articles describing severe, widespread, or unusual flooding in the United States from January 1, 1992, to the end of the 1993 water year, September 30, 1993. Each flood is described to an extent commensurate with its significance and the availability of data on...

Artificially increasing primary productivity decreases plant species richness in many habitats; herbivory may affect this outcome, but it has rarely been directly addressed in fertilization studies. This experiment was conducted in two Louisiana coastal marshes to examine the effects of nutrient enrichment and sediment addition on herbaceous plant communities with and without vertebrate...

We describe a stochastic simulation model that simulates avian foraging in an agricultural landscape to evaluate factors affecting dietary insecticide exposure and to predict post-exposure cholinesterase (ChE) inhibition. To evaluate the model, we simulated published field studies and found that model predictions of insecticide decay and ChE inhibition reasonably approximated most...