Publications

Clear Creek is a small stream that drains the eastern Carson Range near Lake Tahoe, flows roughly parallel to the Highway 50 corridor, and discharges to the Carson River near Carson City, Nevada. Historical and ongoing development in the drainage basin is thought to be affecting Clear Creek and its sediment-transport characteristics. Previous studies from water years (WYs) 2004 to 2007...

Elevated levels of selenium (Se) in aqueous environments can harm aquatic life and endanger livestock and human health. Although Se occurs naturally in the rocks and soils of many alluvial aquifers, mining and agricultural activities can increase its rate of mobilization and transport to surface waters. Attention is given here to regions where nonpoint source return flows from irrigated...

Groundwater availability studies in the arid southwestern United States traditionally have assumed that groundwater discharge by evapotranspiration (ETg) from desert playas is a significant component of the groundwater budget. However, desert playa ETg rates are poorly constrained by Bowen Ratio energy budget (BREB) and eddy-covariance (EC) micrometeorological measurement approaches...

Rock samples have been collected, analyzed, and interpreted from drilling and mining operations at the Nevada National Security Site for over one-half of a century. Records containing geologic and hydrologic analyses and interpretations have been compiled into a series of databases. Rock samples have been photographed and thin sections scanned. Records and images are preserved and...

Global-scale studies suggest that dryland ecosystems dominate an increasing trend in the magnitude and interannual variability of the land CO2 sink. However, such model-based analyses are poorly constrained by measured CO2 exchange in open shrublands, which is the most common global land cover type, covering ∼14% of Earth’s surface. Here we evaluate how the amount and seasonal timing of...

The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service collected data on water and bottom-sediment chemistry to be used to evaluate a new water rights acquisition program designed to enhance wetland habitat in Stillwater National Wildlife Refuge and in Lahontan Valley, Churchill County, Nevada. The area supports habitat critical to the feeding and resting of...

The Carson River is a vital water resource for local municipalities and migratory birds travelling the Pacific Flyway. Historic mining practices that used mercury (Hg) to extract gold from Comstock Lode ore has left much of the river system heavily contaminated with Hg, a practice that continues in many parts of the world today. Between 1998 and 2013, the United States Geological Survey...

The impact of groundwater withdrawal on surface water is a concern of water users and water managers, particularly in the arid western United States. Capture maps are useful tools to spatially assess the impact of groundwater pumping on water sources (e.g., streamflow depletion) and are being used more frequently for conjunctive management of surface water and groundwater. Capture maps...

This report documents methodology and results of a study to evaluate groundwater discharge by evapotranspiration (GWET) in sparsely vegetated areas of Amargosa Desert and improve understanding of hydrologic-continuum processes controlling groundwater discharge. Evapotranspiration and GWET rates were computed and characterized at three sites over 2 years using a combination of...

This report documents a process used to estimate net infiltration from precipitation, evapotranspiration (ET), and soil data acquired at two sites on Rainier Mesa. Rainier Mesa is a groundwater recharge area within the Nevada National Security Site where recharged water flows through bedrock fractures to a deep (450 meters) water table. The U.S. Geological Survey operated two ET stations...

Groundwater-flow models are often calibrated using a limited number of observations relative to the unknown inputs required for the model. This is especially true for models that simulate groundwater surface-water interactions. In this case, subsurface temperature sensors can be an efficient means for collecting long-term data that capture the transient nature of physical processes such...

To explore steady state fractionation processes in the unsaturated zone (UZ), we measured argon, krypton, and xenon isotope ratios throughout a ∼110 m deep UZ at the United States Geological Survey (USGS) Amargosa Desert Research Site (ADRS) in Nevada, USA. Prior work has suggested that gravitational settling should create a nearly linear increase in heavy-to-light isotope ratios toward...