IRRIGATED AGRICULTURE IS AT THE CORE OF THE NEXUS OF FOOD, ENERGY, AND WATER (FEW) SYSTEMS; IT IS BOTH THE LARGEST GLOBAL CONSUMER OF WATER AND A MAJOR CONSUMER OF ENERGY. GLOBAL CHANGE IS EXPECTED TO PLACE ADDITIONAL PRESSURE ON THESE SYSTEMS, AS CLIMATE ACROSS THE US WARMS AND BECOMES MORE VARIABLE, AND DEMAND FOR FOOD INCREASES DUE TO GLOBAL POPULATION GROWTH AND DIET SHIFTS. SIMULTANEOUSLY INCREASING FOOD PRODUCTION WHILE ADAPTING TO CHANGE AND SHRINKING AGRICULTURE'S ENVIRONMENTAL FOOTPRINT WILL REQUIRE IMPROVED MANAGEMENT, INNOVATIVE POLICIES, AND MORE EFFICIENT WATER AND ENERGY TECHNOLOGIES. THIS TRANSDISCIPLINARY PROJECT TEAM PROPOSES TO DEVELOP PATHWAYS FOR SUSTAINABLE IRRIGATED AGRICULTURE USING COUPLED SOCIOECONOMIC AND BIOPHYSICAL MODELS, FOCUSING ON TWO MAJOR IRRIGATED REGIONS OF THE US, PLUS A REGION THAT HAS SEEN A RAPID INCREASE OF IRRIGATION. THE PROJECT WILL: QUANTIFY THE EFFECTS OF PROJECTED INCREASES IN FOOD PRODUCTION ON ENERGY CONSUMPTION AND WATER RESOURCES UNDER A CHANGING CLIMATE; SIMULATE THE EFFECTS OF POTENTIAL WATER POLICIES AND THEIR ASSOCIATED INFLUENCE ON THE ENERGY AND WATER FOOTPRINTS OF US AGRICULTURE; AND QUANTIFY THE LIKELY EFFECTS OF LARGE SCALE SHIFTS IN IRRIGATED AGRICULTURE OVER THE NEXT CENTURY ON REGIONAL CLIMATE. THIS RESEARCH WILL ALSO EXAMINE TRADEOFFS AMONG MULTIPLE DIMENSIONS OF SUSTAINABILITY, AND HOW THOSE MAY BE INFLUENCED BY CHANGES IN POLICY, TECHNOLOGIES, AND CLIMATE. THE PROJECT WILL MAINLY RELY ON PUBLICLY AVAILABLE DATA PLUS AN EXTENSIVE DATASET THAT HAS ALREADY BEEN COLLECTED BY THE TEAM IN PREVIOUS NSF AND NIFA PROJECTS.THIS PROJECT PROPOSES A TRANSFORMATIVE SYNTHESIS OF HYDROLOGY, CROP GROWTH, REGIONAL CLIMATE, AND SOCIOECONOMIC SYSTEMS MODELS THAT WILL BE APPLIED TO TWO KEY IRRIGATED AGRICULTURAL REGIONS OF THE UNITED STATES AND AN AREA UNDERGOING RAPID IRRIGATION EXPANSION. THE MODELS WILL BE USED TO UNDERSTAND HISTORICAL INTERACTIONS AMONG THESE FEW SYSTEMS, AND TO QUANTIFY THE IMPACTS OF CHANGES INMANAGEMENT, CLIMATE, POLICIES, AND TECHNOLOGIES ON WATER SUPPLIES, FOOD PRODUCTION, AND ENERGY USE ACROSS PORTIONS OF 13 STATES. THE PROPOSED RESEARCH WILL DEFINE MORE SUSTAINABLE PATHWAYS FOR IRRIGATED AGRICULTURE TO MEET CURRENT AND FUTURE DEMAND FOR FOOD, USING A SYSTEMS FRAMEWORK THAT EXPLICITLY ADDRESSES TRADEOFFS BETWEEN WATER AND ENERGY USE WITH ECONOMIC LIVELIHOODS. EFFICIENT IRRIGATION AND RENEWABLE ENERGY HOLD CONSIDERABLE PROMISE TO REDUCE THE ENVIRONMENTAL FOOTPRINT OF IRRIGATED AGRICULTURE; THIS PROJECT TEAM WILL SIMULATE THE POTENTIAL BENEFITS OF THOSE TECHNOLOGIES, ALONG WITH THEIR ADOPTION TO BETTER UNDERSTAND WHAT FACTORS IMPACT DECISION MAKING. RECENT WORK BY THE TEAM SUGGESTS THAT IRRIGATION IS COOLING LARGE REGIONS OF THE EASTERN UNITED STATES; THE PROPOSED PROJECT WILL EXAMINE THIS CAUSATIVE RELATIONSHIP IN DETAIL, INCLUDING AN ANALYSIS OF POTENTIAL CHANGES TO CLIMATIC EXTREMES AND RENEWABLE ENERGY POTENTIAL DUE TO THIS FEEDBACK.THIS PROJECT TEAM WILL QUANTIFY HOWDIFFERENT POTENTIAL WATER AND ENERGY POLICIES COULD ENHANCE THE SUSTAINABILITY OF FUTURE WATER SUPPLIES WHILE MAINTAINING CROP YIELDS FOR CRITICAL IRRIGATED REGIONS OF THE US. THE PROJECT TEAM INCLUDES A STRONG NETWORK OF SCIENTISTS, FARMERS, DECISION MAKERS, AND POLICY MAKERS FROM THE HIGH PLAINS, MICHIGAN, AND CALIFORNIA'S CENTRAL VALLEY, ENABLING THE RESEARCH TO HAVE A SIGNIFICANT IMPACT ON DECISIONS THAT CAN INCREASE EFFICIENCY OF WATER, ENERGY, AND NUTRIENT USE, WHILE MAINTAINING CROP YIELDS AND FARMER PROFITABILITY. OUTREACH EFFORTS WILL INCLUDE DEVELOPMENT OF A MOBILE APP TO DIRECTLY SHARE EFFICIENT MANAGEMENT PRACTICES WITH FARMERS, AND TO IMPROVE UNDERSTANDING OF THEIR DECISION MAKING. THIS RESEARCH WILL ALSO PROVIDE A SOUND BASIS FOR IMPROVED POLICIES AND INCENTIVES, WHICH CAN PROMOTE SUSTAINABLE AGRICULTURAL PRACTICES ACROSS THE US AND AROUND THE WORLD. STUDENTS AND EARLY CAREER SCIENTISTS WILL RECEIVE TRAINING AND EDUCATION ON INTERDISCIPLINARY SCIENCE FROM AN EXPERIENCED TEAM WORKING AT THE FEW NEXUS. THE PROPOSED RESEARCH WILL PROVIDE CRITICAL INSIGHTS INTO PATHWAYS TOWARD SUSTAINABILITY OF IRRIGATED AGRICULTURE, REACH OUT DIRECTLY TO FARMERS MAKING DECISIONS ABOUT SUSTAINABILITY, AND TRAIN THE NEXT GENERATION OF SCIENTISTS TO PROVIDE THE KNOWLEDGE NEEDED TO MANAGE THIS CRITICAL FEW SYSTEM.