Evapotranspiration Units, Groundwater Discharge Area, and 2007-2008 Summer Mean Vegetation Index for Tule Valley and part of Sevier Valley, Utah

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.