DECISION-SUPPORT SYSTEMS FOR EFFICIENT IRRIGATION IN THE MIDDLE RIO GRANDE

摘要

Water is the lifeblood of the American West and the foundation of its economy, but it remains itsrnscarcest resource. The explosive population growth in Western United States, the emergingrnadditional need for water for environmental uses, and the national importance of the domesticrnfood production are driving major conflicts between these competing water uses. Irrigatedrnagriculture in particular is by far the largest water user of diverted water – 80% country wide andrn90% in the Western U.S – and since it is perceived to be comparatively inefficient user, it isrnfrequently asked to decrease its water consumption (Oad and Kullman, 2006). The case of thernMiddle Rio Grande illustrates the problem very well. The river is the ecological backbone of thernChihuahuan Desert region in the western United States, and supports its dynamic and diversernecology, including the fish and wildlife habitat. The Rio Grande Silvery Minnow is federallyrnlisted as endangered species, and the irrigated agriculture in the Middle Rio Grande has comernunder increasing pressure to reduce its water consumption while maintaining the desired level ofrnservice to its water users. This paper will present our on-going research on options to makernirrigation system operations more efficient in the Middle Rio Grande Conservancy District.rnSpecifically, it will describe formulation and implementation of a Decision-Support Systemrn(DSS) that can assist the MRGCD managers to more efficiently plan and implement their waterrndelivery operations, thereby reducing river diversions. Since year 2000, MRGCD has beenrnmodernizing their physical water delivery network, and the DSS will be used in tandem withrnSCADA software in making water delivery decisions based on real-time knowledge of availablernwater supplies and crop water requirements. In irrigation systems, the conceptual problemrnaddressed by the DSS is how best to route water supply in a main canal to its laterals so that thernrequired water diversion is minimized. The MRGCD DSS uses linear programming to find anrnoptimum water delivery schedule for canal service areas in the MRGCD irrigation system. Forrnthe past three years, the model has been validated in the field and the evaluation indicates that thernmodel recommendations are realistic and represent ditch-rider practices.