This data set contains polygons representing evapotranspiration (ET) units for the upper Humboldt River Basin, northeastern Nevada.

This USGS data release represents the evapotranspiration units and potential areas of groundwater discharge geospatial data from the following publication: Plume, R.W., and Smith, J.L., 2013, Properties of basin-fill deposits, a 1971–2000 water budget, and surface-water-groundwater interactions in the upper Humboldt River basin, northeastern Nevada: U.S. Geological Survey Scientific Investigations Report 2013-5077, 38 p., http://pubs.usgs.gov/sir/2013/5077/. The data set consists of 2 separate items: 1. evapotranspiration units 2. potential areas of groundwater discharge

This USGS data release represents the evapotranspiration units and potential areas of groundwater discharge geospatial data from the following publication: Plume, R.W., and Smith, J.L., 2013, Properties of basin-fill deposits, a 1971–2000 water budget, and surface-water-groundwater interactions in the upper Humboldt River basin, northeastern Nevada: U.S. Geological Survey Scientific Investigations Report 2013-5077, 38 p., http://pubs.usgs.gov/sir/2013/5077/. The data set consists of 2 separate items: 1. evapotranspiration units 2. potential areas of groundwater discharge

Accurate estimates of ground-water discharge are crucial in the development of a water budget for the Basin and Range Carbonate-rock Aquifer System (BARCAS) study area. One common method used throughout the southwest United States is to estimate ground-water discharge from evapotranspiration (ET). ET is a process by which water from the Earth's surface is transferred to the atmosphere. The volume of water lost to the atmosphere by ET can be computed as the product of the ET rate and the acreage of vegetation, open water, and moist soil through which ET occurs. The procedure used in the study, groups areas of similar vegetation, water, and soil conditions into different ET units and assigns an average annual ET rate to each unit. The data sets and the procedures used to delineate the ET-unit map are described in this metadata.

The U.S. Geological Survey and Desert Research Institute, in cooperation with the Natural Resources Conservation Service, Texas State Soil and Water Conservation Board, Victoria County Groundwater Conservation District, Victoria Soil and Water Conservation District, and the San Antonio River Authority, evaluated the hydrologic effects of Vachellia farnesiana var. farnesiana (huisache) removal on rangeland evapotranspiration in Victoria County, Texas. Measurements of evapotranspiration (ET), rainfall, and related properties were made at two sites during March 2015 through August 2018. One site was predominately grassland. The other site was dominated by dense huisache vegetation that was removed about halfway through the study period. To obtain the meteorological and surface energy flux data needed for the calculation of ET, the two sites were instrumented with LI-COR Biosciences eddy-covariance systems (LI-COR Biosciences, 2019). The resulting ET data were examined for differences between the locations and differences between the pre-removal (2015–16) and post-removal (2017–18) periods to assess the effects of huisache removal on ET. ET measurements were made using the eddy-covariance method and were supplemented by remote-sensing estimates of ET derived from thermal and optical satellite images. The data presented in this data release include various types of meteorological data (for example air temperature, relative humidity, wind speed and direction, and precipitation) and various energy flux data pertaining to ET (for example latent and sensible heat flux). Turbulent fluxes were compared to measured radiative fluxes to assess the energy budget. The sensible-heat flux was computed by taking variations in temperature into consideration. The relation between a given ET rate and the associated latent-heat flux was calculated. Details of the various energy flux calculation are described in the LI-COR Biosciences, 2016. The methods are further described along with the results of the study in the companion report (U.S. Geological Survey Scientific Investigations report 2020-XXX).

The U.S. Geological Survey and Desert Research Institute, in cooperation with the Natural Resources Conservation Service, Texas State Soil and Water Conservation Board, Victoria County Groundwater Conservation District, Victoria Soil and Water Conservation District, and the San Antonio River Authority, evaluated the hydrologic effects of Vachellia farnesiana var. farnesiana (huisache) removal on rangeland evapotranspiration in Victoria County, Texas. Measurements of evapotranspiration (ET), rainfall, and related properties were made at two sites during March 2015 through August 2018. One site was predominately grassland. The other site was dominated by dense huisache vegetation that was removed about halfway through the study period. To obtain the meteorological and surface energy flux data needed for the calculation of ET, the two sites were instrumented with LI-COR Biosciences eddy-covariance systems (LI-COR Biosciences, 2019). The resulting ET data were examined for differences between the locations and differences between the pre-removal (2015–16) and post-removal (2017–18) periods to assess the effects of huisache removal on ET. ET measurements were made using the eddy-covariance method and were supplemented by remote-sensing estimates of ET derived from thermal and optical satellite images. The data presented in this data release include various types of meteorological data (for example air temperature, relative humidity, wind speed and direction, and precipitation) and various energy flux data pertaining to ET (for example latent and sensible heat flux). Turbulent fluxes were compared to measured radiative fluxes to assess the energy budget. The sensible-heat flux was computed by taking variations in temperature into consideration. The relation between a given ET rate and the associated latent-heat flux was calculated. Details of the various energy flux calculation are described in the LI-COR Biosciences, 2016. The methods are further described along with the results of the study in the companion report (U.S. Geological Survey Scientific Investigations report 2020-XXX).

This data release contains geospatial data for the lower Walker River basin from the 2009 publication: Allander, K.A., Smith, J.L., and Johnson, M.J., 2009, Evapotranspiration from the lower Walker River basin, west-central Nevada, water years 2005-07: U.S. Geological Survey Scientific Investigations Report 2009-5079, https://doi.org/10.3133/sir20095079.

This data release contains geospatial data for the lower Walker River basin from the 2009 publication: Allander, K.A., Smith, J.L., and Johnson, M.J., 2009, Evapotranspiration from the lower Walker River basin, west-central Nevada, water years 2005-07: U.S. Geological Survey Scientific Investigations Report 2009-5079, https://doi.org/10.3133/sir20095079.

This data release contains geospatial data for the lower Walker River basin from the 2009 publication: Allander, K.A., Smith, J.L., and Johnson, M.J., 2009, Evapotranspiration from the lower Walker River basin, west-central Nevada, water years 2005–07: U.S. Geological Survey Scientific Investigations Report 2009-5079, https://doi.org/10.3133/sir20095079.

These data were created as part of a hydrologic study to characterize groundwater budgets and water quality in the Diamond Valley Flow System (DVFS), central Nevada. This dataset represents evapotranspiration (ET) units derived from the mean Enhanced Vegetation Index (EVI) calculated from two Landsat 5 Thematic Mapper scenes from the summer of 2010. ET units were defined within the DVFS groundwater discharge area (GDA) to group areas characterized by similar phreatophytic vegetation type and cover and to extrapolate site-scale groundwater ET estimates across the study area. This dataset represents three ET units: shrubland, grassland, and playa. The shrubland unit is composed of low to high density phreatophytic shrubs and bare soil while the grassland ET unit is composed of grassland, meadow, and marshland vegetation assemblages. The ET units were developed using a combination of EVI and site scale discharge measurements. The data were used to evaluate and estimate groundwater discharge by evapotranspiration in the study area. ET unit delineations reflect general spatial changes on the landscape and are not intended to be exact delineations of plant communities or soil conditions.