Landsat Thematic Mapper (TM) data were used to estimate that about 51,000 acres of crops were irrigated with water pumped from the Edwards aquifer in Uvalde and Medina Counties, Texas in 1991. Areas calculated for irrigated crops were 31,000 acres for Uvalde County and 20,000 acres for Medina County. Quantities of water pumped from the Edwards aquifer to irrigate crops in 1991 were estimated as 65,000 acre-feet for Uvalde County and 18,000 acre-feet for Medina County. Differences in estimates of ground water used for irrigation in the two counties were attributed primarily to greater pre- cipitation in Medina County than in Uvalde County. The total number of acres of irrigated crops estimated using Landsat TM data was about 9 percent lower in Uvalde County and about 13 percent lower in Medina County than the number of acres calculated from data reported by the U.S. Department of Agriculture, Agricultural Stabilization and Conservation Service (ASCS). The total quantity of water pumped from the Edwards aquifer in 1991 for irrigation in the two counties, about 83,000 acre- feet, was about 5 percent greater developed than the quantity calculated from data reported by the ASCS.
Additional publication details
USGS Numbered Series
Use of landsat thematic mapper data to identify crop types and estimate irrigated acreage, Uvalde and Medina counties, Texas, 1991
Water-Resources Investigations Report
U.S. Geological Survey ;
U.S. Geological Survey ESIC, Open-File Reports Section [distributor],