CALIFORNIA'S FOOD, ENERGY AND WATER SYSTEMS (FEWS) ARE HIGHLY INTERDEPENDENT AND INCREASINGLY STRESSED BY LONG-TERM GROWTH IN RESOURCE DEMANDS, EVER MORE STRINGENT ENVIRONMENTAL POLICIES, AND A SEVERE AND PERSISTENT DROUGHT. THE PREMISE OF THIS PROPOSAL IS THAT CALIFORNIA THEREFORE REPRESENTS A CRITICAL OPPORTUNITY TO LEARN HOW TO MONITOR AND JOINTLY MANAGE FOOD, ENERGY, WATER SYSTEMS THAT ARE UNDER STRESS. FURTHER, THE MOST IMPORTANT INSIGHTS INTO THESE SYSTEMS REQUIRE THAT MODELS RESOLVE DETAILS SUCH AS AGENT BEHAVIORS, BIOPHYSICAL CROP RESPONSES, AND INFRASTRUCTURE OPERATION WHILE AT THE SAME TIME COMPREHENSIVELY CAPTURE KEY LINKAGES AMONG THE SYSTEMS AND LONG-TERM TRENDS (E.G., INTERANNUAL OR DECADAL) IN THE SUPPLY AND DEMAND OF RESOURCES.MOST MODELING EFFORTS ARE EITHER NARROWLY FOCUSED ON SPECIFIC COMPONENTS OR MECHANISMS OF INTERACTION AMONG THE THREE SYSTEMS OR ELSE ASSESS REGIONAL OR GLOBAL INTERACTIONS SO BROADLY THAT VITAL DETAILS AND SENSITIVITIES ARE NOT REVEALED AND RESULTS NOT ACTIONABLE. THE PROPOSED WORK THUS TARGETS THE MODELING "SWEET SPOT" WHERE IMPORTANT INTERACTIONS AMONG THE FOOD, ENERGY AND WATER SYSTEMS ARE COMPREHENSIVELY ASSESSED AT A LEVEL OF SPATIAL, TEMPORAL AND MECHANISTIC DETAIL THAT CAN MOST ADVANCE OUR UNDERSTANDING AND THEREBY INFORM FUTURE DECISIONS REGARDING RESOURCE MANAGEMENT IN CALIFORNIA AND ELSEWHERE.OUR PROPOSED MODELING EFFORTS INTEGRATE METHODS FROM GEOSCIENCES, ENGINEERING AND ECONOMICS, STRUCTURED IN THREE PHASES:1. ESTIMATION OF ECONOMIC AND BEHAVIORAL RESPONSES TO CHANGING WATER SUPPLY. WE WILL CONDUCT A RIGOROUS EMPIRICAL AND ECONOMETRIC ANALYSIS OF CHANGES IN WATER USE SINCE THE ONSET OF THE CALIFORNIA DROUGHT IN 2011. THIS ANALYSIS WILL COMBINE USDA AND CALIFORNIA STATE DATASETS AND INDEPENDENT, REMOTELY-SENSED DATA ON CROPPING PATTERNS AND SOIL MOISTURETO ESTABLISH NECESSARY CONTEXT FOR PROJECTING FUTURE CROPPING PATTERNS AND HYDROPOWER GENERATION GIVEN THE HISTORICAL ELASTICITY OF WATER DEMAND AMONG DIFFERENT WATER RIGHTS HOLDERS, FARMER RESPONSES IN THE ABSENCE OF STRICT GROUNDWATER REGULATION, AND PRIORITIES OF RESERVOIR OPERATION.2.QUANTITATIVELY MODEL AND ASSESS THE STRENGTH OF IMPACTS AND DEPENDENCIES AMONG THE EXISTING FOOD, ENERGY, AND WATER SYSTEMS IN CALIFORNIA. INFORMED BY THE OBSERVED RESPONSES OF FOOD, ENERGY AND WATERSYSTEMS DURING THE RECENT DROUGHT, WE WILL BUILD AN INTEGRATED MODELING FRAMEWORK REPRESENTING ALL THREE SYSTEMS AS THEY NOW EXIST IN ORDER TO MEASURE THEIR INTERDEPENDENCE AS THEY HAVE BEEN RECENTLY MANAGED.3.ROBUST SCENARIO-BASED MODEL ASSESSMENT OF IMPACTS AND DEPENDENCIES AMONG THE FUTURE FOOD, ENERGY, AND WATER SYSTEMS IN CALIFORNIA. WE WILL CREATE AND PROBABILISTICALLY INTERROGATE LARGE NUMBERS OF MODEL SCENARIOS FOR EACH OF SEVERAL FUTURE STORYLINES TO TEST SENSITIVITIES AND IDENTIFY CRITICAL LEVERAGE POINTS WHERE POLICY AND TECHNOLOGY COULD MOST EFFICIENTLY AND EFFECTIVELY PROMOTE RESILIENCE AND SUSTAINABILITY ACROSS THE SUPER-SYSTEM OF FOOD, ENERGY AND WATER.THE PROPOSED WORK WILL DRAMATICALLY ADVANCE UNDERSTANDING OF FOOD, ENERGY AND WATER SYSTEMS BY GENERALIZABLE MODELING THAT IS EXPANSIVE, DETAILED, AND INFORMED BY CAREFUL OBSERVATIONS OF THE INTERRELATED SYSTEMS DURING A RECENT PERIOD OF ACUTE STRESS. NEW FEWS INDICATORS WILL ALSO BE ESTABLISHED AND QUANTIFIED AS PART OF THE WORK.