Publications

In accordance with the mission of the U.S. Geological Survey (USGS) Toxic Substances Hydrology Program, a pesticide study was conducted during 2003–04 to determine the occurrence of the fungicide chlorothalonil and its degradation products at 22 surface-water sites in five Southern States. Water-quality samples were collected during the peanut-growing season (June–September) in 2003...

Estimates of sediment and sediment-associated constituent loads and yields from drainage basins are necessary for the management of reservoir-basin systems to address important issues such as reservoir sedimentation and eutrophication. One method for the estimation of loads and yields requires a determination of the total mass of sediment deposited in a reservoir. This method involves a...

The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources...

In the North Platte River Basin, a ground-water model is being developed to evaluate the effectiveness of using water leakage from selected irrigation canal systems to enhance ground-water recharge. The U.S. Geological Survey, in cooperation with the North Platte Natural Resources District, used land-based capacitively coupled and water-borne direct-current continuous resistivity...

Cheney Reservoir, the primary water supply for the city of Wichita in south-central Kansas, and its main source of inflow, the North Fork Ninnescah River, were sampled between 1997 and 2003 for sediment, nutrients, and the taste-and-odor-causing compounds geosmin and 2-methylisoborneol (MIB). It is believed that objectionable tastes and odors in Cheney Reservoir result from cyanobacteria...

Riparian areas along a reach of Platte River passing through Nebraska Public Power District's Cottonwood Ranch Property were modified during 2002 to 2004 to enhance in-channel habitats for endangered and threatened avian species. A component of this alteration involved the removal of riparian vegetation from riverbanks and islands to provide roosting habitat for the endangered whooping...

A new process for simulating three-dimensional (3-D) variably saturated flow (VSF) using Richards' equation has been added to the 3-D modular finite-difference ground-water model MODFLOW. Five new packages are presented here as part of the VSF Process--the Richards' Equation Flow (REF1) Package, the Seepage Face (SPF1) Package, the Surface Ponding (PND1) Package, the Surface Evaporation...

Data compiled for the High Plains region of Kansas that includes five Groundwater Management Districts (GMDs) were analyzed for trends in irrigation water use, acres irrigated, precipitation, irrigation system types, and irrigated crop types to determine the effects of irrigation practices on water use over time. For the study period 1991 through 2003, precipitation decreased...

No abstract available.

No abstract available.

The locations of approximately 23,000 current and historical U.S. Geological Survey (USGS) streamgages in the United States and Puerto Rico (with the exception of Alaska) have been snapped to the medium resolution National Hydrography Dataset (NHD). The NHD contains geospatial information about mapped surface-water features, such as streams, lakes, and reservoirs, etc., creating a...

The historical and ongoing lead (Pb) contamination caused by the 20th-century use of leaded gasoline was investigated by an analysis of bottom sediment in eight small rural reservoirs in eastern Kansas, USA. For the reservoirs that were completed before or during the period of maximum Pb emissions from vehicles (i.e., the 1940s through the early 1980s) and that had a major highway in the...