SWAT Literature Database for Peer-Reviewed Journal Articles

Title:A SWAT- based evapotranspirative water conservation analysis performed on irrigated croplands to determine potential regional water savings 
Authors:Gayley, A. 
Journal:Journal of Irrigation and Drainage Engineering 
Volume (Issue):139(6) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic only 
Primary Application Category:irrigation impacts or irrigation BMP scenarios 
Secondary Application Category:evapotranspiration assessment 
Watershed Description:2,040 km^2 San Miguel Creek in south central Texas, U.S. 
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Abstract:In our global natural resource climate, where all potential strategies for water savings warrant consideration, agricultural irrigation should not be overlooked as a significant target for identifying efficiencies. The U.S. Geological Survey indicates that water production for agricultural irrigation is the second overall water use category behind thermoelectric power plant cooling, only; typified by 37% of all freshwater withdrawals (178 of 484 million cubic meters per day, MCM/day) used to irrigate crops. Agriculture use climbs to 67% when focusing on fresh ground water withdrawals (74 of 110 MCM/day) utilized for irrigation in the U.S., and up to 94% percent in some areas of Texas. Significant water savings might be realized, regionally and nationally, if an additional fraction of cultivated land was converted to a more effective form of irrigation (e.g. from furrow-flooding to center pivot or drip, where feasible). To quantify potential savings, we used the ArcMap-based United States Department of Agricultural (USDA) Agricultural Research Service (ARS) Soil and Water Assessment Tool to model hydrologic budgets in the San Miguel Creek watershed, Texas; and applied findings to regionally similar agricultural land in the Edward’s Aquifer Groundwater Conservation District and Texas State Regional Water Planning Area L (RWPA-L). Up to 26.1 MCM and 99.8 MCM of potential agricultural water savings were identified in these two areas, respectively. The straightforward approach can be used to predict water demand and potential water savings in other areas where agricultural irrigation is prevalent, where water scarcity may be a concern, in closed river basins, where competing rural/urban interests persist among various user groups, or across borders. 
Keywords:irrigation, evapotranspiration, sustainable agriculture, water conservation, Priestly-Taylor