Publications

The use of one-dimensional hydraulic models currently is the standard method for estimating velocity fields through a bridge opening for scour computations and habitat assessment. Flood-flow contraction through bridge openings, however, is hydrodynamically two dimensional and often three dimensional. Although there is awareness of the utility of two-dimensional models to predict the...

This report documents the development and application of a box model to simulate water level, salinity, and temperature of the Alviso Salt Pond Complex in South San Francisco Bay. These ponds were purchased for restoration in 2003 and currently are managed by the U.S. Fish and Wildlife Service to maintain existing wildlife habitat and prevent a build up of salt during the development of...

The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin are currently (2007) obtained solely from ground-water resources. An...

The Maryland Coastal Plain region is, at present, largely dependent upon ground water for its water supply. Decades of increasing pumpage have caused ground-water levels in parts of the Maryland Coastal Plain to decline by as much as 2 feet per year in some areas of southern Maryland. Continued declines at this rate could affect the long-term sustainability of ground-water resources in...

Although fecal contamination of streams is a problem of national scope, few investigations have been directed at relatively pristine streams in forested basins in national parks. With approximately 1.8 million visitors annually, Shenandoah National Park in Virginia is subject to extensive recreational use. The effects of these visitors and their recreational activities on fecal indicator...

During September 2006, samples from public water-delivery systems, ground water, surface water, bed-sediment, and fish-tissue sources were collected at 32 locations within the Standing Rock Sioux Reservation and analyzed to aid in the evaluation of any immediate water-quality concerns. Samples were collected from Solen, Selfridge, and Fort Yates, North Dakota, water-delivery systems and...

Agricultural chemicals applied at the land surface in northeast Nebraska can move downward, past the crop root zone, to ground water. Because agricultural chemicals applied at the land surface are more likely to be observed in the shallowest part of an aquifer, an assessment of shallow ground-water and unsaturated zone quality in the northeast Nebraska glacial till was completed between...

On-site wastewater disposal has the potential to introduce contaminants into ground water and subsequently, by ground-water discharge, to streams. A pilot study was conducted during 2005 by the U.S. Geological Survey in cooperation with the Chester County Health Department and the Chester County Water Resources Authority to determine if wastewater components, including inorganic...

Water-quality samples were collected from surface- (stream-) and ground-water sites on and near the Prairie Band Potawatomi Reservation in northeastern Kansas (fig. 1) from June 1996 through August 2006 as part of a cooperative study between the U.S. Geological Survey (USGS) and the Prairie Band Potawatomi Nation (Schmidt and others, 2007). Surface- and ground-water quality were...

This report describes surface- and ground-water-quality data collected on the Prairie Band Potawatomi Reservation in northeastern Kansas from November 2003 through August 2006 (hereinafter referred to as the "current study period"). Data from this study period are compared to results from June 1996 through August 2003, which are published in previous reports as part of a multiyear...

We synthesize and update the science supporting the Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force 2001) with a focus on the spatial and temporal discharge and patterns of nutrient and organic carbon delivery to the northern Gulf of Mexico, including data through 2006. The...

The objective of this study was to evaluate the potential sources of pesticides to the Yolo Bypass, including those that could potentially impact critical life stages of resident fish. To assess direct inputs during inundation, pesticide concentrations were analyzed in water and suspended and bed sediment samples collected from source watersheds during high-flow events. To understand...