Toby Welborn
Biography
Toby Welborn is a geographer at the Nevada Water Science Center of the U.S. Geological Survey. He graduated in 2003 with a Master’s in Applied Geography from Texas State University San Marcos where he studied slope stability mapping in the Rouge River Valley, Oregon. Mr. Welborn has had extensive training in geographic information sciences and remote sensing in mountainous terrain. For the past 10 years, he has worked on a wide range of groundwater, surface water, and water quality projects with both the Texas and Nevada Water Science Centers of the U.S. Geological Survey including GIS and database development for the National Water Quality Assessment program; assessing subsidence due to groundwater withdrawals utilizing LiDAR and historical elevation surveys from the 19th century in Harris County, Texas; mapping agricultural land use changes in the Walker, Carson, and Humboldt river basins, Nevada; utilizing Differential GPS to help quantify groundwater and surface water interaction along the Carson River, NV; and coordinating the collection of LiDAR data for the Lake Tahoe Basin, NV and CA.
Science and Products
Characterization of peak streamflows and flood inundation of selected areas in southeastern Texas and southwestern Louisiana from the August and September 2017 flood resulting from Hurricane Harvey
Hurricane Harvey made landfall near Rockport, Texas, on August 25, 2017, as a Category 4 hurricane with wind gusts exceeding 150 miles per hour. As Harvey moved inland, the forward motion of the storm slowed down and produced tremendous rainfall amounts over southeastern Texas, with 8-day rainfall amounts exceeding 60 inches in some locations,...
Watson, Kara M.; Harwell, Glenn R.; Wallace, David S.; Welborn, Toby L.; Stengel, Victoria G.; McDowell, Jeremy S.
Groundwater-level change and evaluation of simulated water levels for irrigated areas in Lahontan Valley, Churchill County, west-central Nevada, 1992 to 2012
The acquisition and transfer of water rights to wetland areas of Lahontan Valley, Nevada, has caused concern over the potential effects on shallow aquifer water levels. In 1992, water levels in Lahontan Valley were measured to construct a water-table map of the shallow aquifer prior to the effects of water-right transfers mandated by the Fallon...
Smith, David W.; Buto, Susan G.; Welborn, Toby L.
Soil, plant, and terrain effects on natural perchlorate distribution in a desert landscape
Perchlorate (ClO4−) is a contaminant that occurs naturally throughout the world, but little is known about its distribution and interactions in terrestrial ecosystems. The objectives of this Amargosa Desert, Nevada study were to determine (i) the local-scale distribution of shallow-soil (0–30 cm) ClO4− with respect to shrub proximity (far and near...
Andraski, Brian J.; Jackson, W.A.; Welborn, Toby L.; Böhlke, John Karl; Sevanthi, Ritesh; Stonestrom, David A. ARkStorm@Tahoe: Stakeholder perspectives on vulnerabilities and preparedness for an extreme storm event in the greater Lake Tahoe, Reno, and Carson City region
Atmospheric rivers (ARs) are strongly linked to extreme winter precipitation events in the Western U.S., accounting for 80 percent of extreme floods in the Sierra Nevada and surrounding lowlands. In 2010, the U.S. Geological Survey developed the ARkStorm extreme storm scenario for California to quantify risks from extreme winter storms and to...
Albano, Christine M.; Cox, Dale A.; Dettinger, Michael D.; Shaller, Kevin; Welborn, Toby L.; McCarthy, Maureen
The distribution and modeling of nitrate transport in the Carson Valley alluvial aquifer, Douglas County, Nevada
Residents of Carson Valley in Douglas County, Nevada, rely on groundwater from an alluvial aquifer for domestic use and agricultural irrigation. Since the 1970s, there has been a rapid increase in population in several parts of the valley that rely on domestic wells for drinking water and septic systems for treatment of household waste. As a...
Naranjo, Ramon C.; Welborn, Toby L.; Rosen, Michael R.
Phreatophytic land-cover map of the northern and central Great Basin Ecoregion: California, Idaho, Nevada, Utah, Oregon, and Wyoming
Increasing water use and changing climate in the Great Basin of the western United States are likely affecting the distribution of phreatophytic vegetation in the region. Phreatophytic plant communities that depend on groundwater are susceptible to natural and anthropogenic changes to hydrologic flow systems. The purpose of this report is to...
Mathie, Amy M.; Welborn, Toby L.; Susong, David D.; Tumbusch, Mary L.
Hydrogeology of the Lake Tahoe Basin, California and Nevada
Ground water in the Lake Tahoe basin is the primary source of domestic and municipal water supply and an important source of inflow to Lake Tahoe. Over the past 30-40 years, Federal, State, and local agencies, and research institutions have collected hydrologic data to quantify the ground-water resources in the Lake Tahoe basin. These data are...
Plume, Russell W.; Tumbusch, Mary L.; Welborn, Toby L. Hydrologic and Water-Quality Responses in Shallow Ground Water Receiving Stormwater Runoff and Potential Transport of Contaminants to Lake Tahoe, California and Nevada, 2005-07
Clarity of Lake Tahoe, California and Nevada has been decreasing due to inflows of sediment and nutrients associated with stormwater runoff. Detention basins are considered effective best management practices for mitigation of suspended sediment and nutrients associated with runoff, but effects of infiltrated stormwater on shallow ground water are...
Green, Jena M.; Thodal, Carl E.; Welborn, Toby L. Irrigated Acreage Within the Basin and Range Carbonate-Rock Aquifer System, White Pine County, Nevada, and Adjacent Areas in Nevada and Utah
Accurate delineations of irrigated acreage are needed for the development of water-use estimates and in determining water-budget calculations for the Basin and Range carbonate-rock aquifer system (BARCAS) study. Irrigated acreage is estimated routinely for only a few basins in the study area. Satellite imagery from the Landsat Thematic Mapper and...
Welborn, Toby L.; Moreo, Michael T. Mapping Evapotranspiration Units in the Basin and Range Carbonate-Rock Aquifer System, White Pine County, Nevada, and Adjacent Areas in Nevada and Utah
Accurate estimates of ground-water discharge are crucial in the development of a water budget for the Basin and Range carbonate-rock aquifer system study area. One common method used throughout the southwestern United States is to estimate ground-water discharge from evapotranspiration (ET). ET is a process by which water from the Earth's surface...
Smith, J. LaRue; Laczniak, Randell J.; Moreo, Michael T.; Welborn, Toby L. Water-Table Levels and Gradients, Nevada, 1947-2004
In 1999, the U.S. Environmental Protection Agency began a program to protect the quality of ground water in areas other than ground-water protection areas. These other sensitive ground water areas (OSGWA) are areas that are not currently, but could eventually be, used as a source of drinking water. The OSGWA program specifically addresses existing...
Lopes, Thomas J.; Buto, Susan G.; Smith, J. LaRue; Welborn, Toby L.
Estimating the susceptibility of surface water in Texas to nonpoint-source contamination by use of logistic regression modeling
In the State of Texas, surface water (streams, canals, and reservoirs) and ground water are used as sources of public water supply. Surface-water sources of public water supply are susceptible to contamination from point and nonpoint sources. To help protect sources of drinking water and to aid water managers in designing protective yet cost-...
Battaglin, William A.; Ulery, Randy L.; Winterstein, Thomas; Welborn, Toby