The mean MSAVI image is based on two Landsat 5 Thematic Mapper (TM) scenes representing midsummer conditions in 2007 and 2008. MSAVI was calculated for each image which were then combined by calculating the mean for each pixel in the scenes. The resultant MSAVI image was used to estimate vegetation assemblages (ET units) within a mapped groundwater discharge area.

This data set represents evapotranspiration (ET) units based on a 2017-2018 summer mean modified soil adjusted vegetation index (MSAVI). The MSAVI information was used to partition Tule Valley and part of Sevier Valley, UT into six discharging ET units (playa; open water; very sparse desert shrub; sparse-to-dense desert shrub; grassland; and dense meadow and marshland), and scale estimates of groundwater evapotranspiration (ETg) to the basin level. ET units represent generalized groupings of vegetation and soil conditions. The units are constrained by a groundwater discharge area (GDA) which represents the area where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation.

This data set represents evapotranspiration (ET) units based on a 2017-2018 summer mean modified soil adjusted vegetation index (MSAVI). The MSAVI information was used to partition Tule Valley and part of Sevier Valley, UT into six discharging ET units (playa; open water; very sparse desert shrub; sparse-to-dense desert shrub; grassland; and dense meadow and marshland), and scale estimates of groundwater evapotranspiration (ETg) to the basin level. ET units represent generalized groupings of vegetation and soil conditions. The units are constrained by a groundwater discharge area (GDA) which represents the area where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation.

This USGS data release consists of three data sets used as the basis for estimates of groundwater discharge from evapotranspiration in Tule Valley and part of Sevier Valley, UT. The data sets are a mapped groundwater discharge area (GDA), a mean modified soil adjusted vegetation index (MSAVI), and evapotranspiration (ET) units derived from the MSAVI within the GDA. The GDA represents the area within each valley where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation. The GDA was delineated during field reconnaissance of the study area using techniques similar to those used in previous studies throughout Nevada and eastern Utah. The mean MSAVI image is based on two Landsat 5 Thematic Mapper (TM) scenes representing midsummer conditions in 2007 and 2008. MSAVI was calculated for each TM image which were then combined by averaging the pixels within each scene. The resultant mean MSAVI image was used to estimate vegetation assemblages (ET units) within a mapped groundwater discharge area.

This USGS data release consists of three data sets used as the basis for estimates of groundwater discharge from evapotranspiration in Tule Valley and part of Sevier Valley, UT. The data sets are a mapped groundwater discharge area (GDA), a mean modified soil adjusted vegetation index (MSAVI), and evapotranspiration (ET) units derived from the MSAVI within the GDA. The GDA represents the area within each valley where discharge from evaporation by open water or bare soil and transpiration from phreatophytic plants exceeds the volume of water contributed by precipitation. The GDA was delineated during field reconnaissance of the study area using techniques similar to those used in previous studies throughout Nevada and eastern Utah. The mean MSAVI image is based on two Landsat 5 Thematic Mapper (TM) scenes representing midsummer conditions in 2007 and 2008. MSAVI was calculated for each TM image which were then combined by averaging the pixels within each scene. The resultant mean MSAVI image was used to estimate vegetation assemblages (ET units) within a mapped groundwater discharge area.

The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1992 for the Death Valley regional flow system. The index has been shown to increase the dynamic range of the vegetation signal while further minimizing the soil background influences, resulting in greater vegetation sensitivity as defined by a "vegetation signal" to "soil noise" ratio. The data set was used in determining phreatophyte boundaries for a ground-water evapotranspiration study and relative differences in vegetation density between discharge areas.

The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1992 for the Death Valley regional flow system. The index has been shown to increase the dynamic range of the vegetation signal while further minimizing the soil background influences, resulting in greater vegetation sensitivity as defined by a "vegetation signal" to "soil noise" ratio. The data set was used in determining phreatophyte boundaries for a ground-water evapotranspiration study and relative differences in vegetation density between discharge areas.

The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1989 for Sarcobatus Flat. The index has been shown to increase the dynamic range of the vegetation signal while further minimizing the soil background influences, resulting in greater vegetation sensitivity as defined by a "vegetation signal" to "soil noise" ratio. The data set was used in determining phreatophyte boundaries for a ground-water evapotranspiration study and relative differences in vegetation density between discharge areas.

The raster-based Modified Soil Adjusted Vegetation Index was derived from Landsat Thematic Mapper imagery data acquired during June 1989 for Sarcobatus Flat. The index has been shown to increase the dynamic range of the vegetation signal while further minimizing the soil background influences, resulting in greater vegetation sensitivity as defined by a "vegetation signal" to "soil noise" ratio. The data set was used in determining phreatophyte boundaries for a ground-water evapotranspiration study and relative differences in vegetation density between discharge areas.

These data represent the extent and spatial distribution of irrigated acreage delineated from maximum Normalized Difference Vegetation Index (NDVI) derived from Landsat scenes in the Walker River Basin, California and Nevada, at five-year intervals from 1975-2010. The field boundaries in this data set are digitized from one-year composite maximum NDVI data derived from atmospherically corrected Landsat 2 Multispectral Scanner (MSS), Landsat 5 MSS, and Landsat 5 Thematic Mapper (TM) scenes. NDVI was calculated from the corrected reflectance data for each selected scene during the growing season (May through early October) and a single, composite image of maximum NDVI values was derived for each five-year interval. Selecting the maximum NDVI value removed low values associated with plant phenology, harvest cycles, and irrigation operations. Initial field boundaries were digitized from the 2010 National Agriculture Imagery Program (NAIP) data and boundary geometries were divided and shaped based on temporal changes in irrigation practices, crop rotations, and other changes identified in the Landsat-derived maximum NDVI data. Each polygon is attributed with an estimated irrigation status of irrigated or non-irrigated. Mapped fields were classified as irrigated during a growing season if more than 45-percent of a field had a maximum NDVI value greater than or equal to 0.4.