"INVESTMENTS IN THE MODERNIZATION OF IRRIGATION SYSTEMS HAVE BEEN A KEY FEATURE IN RIVER BASIN PLANS IN SPAIN, WHERE THE ESTATE HAS INVESTED 3,800 MILLION EUR FOR A SURFACE OF 1,5 MILLION HA (THIS EXCLUDES PRIVATE INVESTMENTS). THIS PROJECT IS AIMED AT INVESTIGATING THE GLOBAL IMPACT OF THE MAIN AGRICULTURAL POLICY HAVING BEEN IMPLEMENTED IN SPAIN IN THE LAST 20 YEARS. WE PROPOSE TO APPLY A SOCIO-ECONOMIC APPROACH ENCOMPASSING TECHNICAL, ECONOMIC AND ENVIRONMENTAL ASPECTS (USING AN ECOSYSTEM SERVICES-BASED APPROACH). FOR THIS PURPOSE, WE WILL DEVELOP A DECISION-MAKING MODEL OPERATING AT TWO LEVELS: THE �MICRO� LEVEL (FARMER) AND THE �MACRO� LEVEL (BASIN/COUNTRY). THE �MICRO� COMPONENT WILL BE BASED A MULTI-ATTRIBUTE ANALYSIS OF FARMERS DECISION-MAKING. WE WILL DESCRIBE AND PREDICT WHAT VARIABLES HAVE AN INFLUENCE IN DECISION-MAKING (E.G. CROP PLANNING, WATER ALLOCATION, FREQUENCY OF IRRIGATION, IRRIGATION TECHNIQUE, AMONG OTHER INPUTS) AND THE ATTRIBUTES LINKED TO PRODUCTIVE DECISIONS (I.E. RENT, EMPLOYMENT, WATER AND ENERGY CONSUMPTION, IMPACT ON GDP, MULTIPLIER EFFECT AND DROUGHT AND CLIMATE CHANGE VULNERABILITY). THE FARMER�S DECISION-MAKING MODEL WILL INCORPORATE TWO INNOVATIONS. ON THE ONE HAND, THE MULTI-OBJECTIVE FUNCTION WILL BE BASED ON THE COBB-DOUGALS FUNCTION. ON THE OTHER HAND, WE WILL INTEGRATE DEFICIT IRRIGATION AND IRRIGATION SYSTEM�S EFFICIENCY IN THE PROGRAMMING MODEL. AT THE �MACRO� LEVEL (BASIN), THE PROJECT AIMS AT DEEPENING THE UNDERSTANDING ON THE VALUE OF THE ECOSYSTEM SERVICES PROVIDED BY THE WATER AND AGRICULTURAL SYSTEMS. ONCE IDENTIFIED AND VALUED, THE INFORMATION ON ECOSYSTEM SERVICES WILL BE USED TO ASSESS DIFFERENT WATER POLICIES. THIS WILL BE DONE THROUGH IN-DEPTH INTERVIEWS AND DISCUSSION GROUPS WITH KEY STAKEHOLDERS, USING PARTICIPATORY DELIBERATIVE APPROACHES. WE WILL EVALUATE THESE POLICIES AT THREE TIME HORIZONS: BEFORE MODERNIZATION (YEAR 2004), PRESENT (2014) AND FUTURE (2024). THIS SCENARIO ANALYSIS WILL SIMULATE THE EFFECT OF INCREASED COSTS AND CLIMATE CHANGE. THE PROJECT WILL ANALYSE INCOME AND COSTS OF IRRIGATION MODERNIZATION, AS WELL AS ITS EXPECTED EVOLUTION. WE WILL INCLUDE INNOVATIVE ASPECTS SUCH AS CHANGES IN WATER DEMAND ELASTICITY AND CHANGES IN LABOUR AND ENERGY USE. ADDITIONALLY, WE WILL INVESTIGATE THE POTENTIAL REBOUND EFFECT OF MODERNIZATION (�JEVONS PARADOX�), WHICH PREDICTS AN INCREASE ON WATER CONSUMPTION FOLLOWING UP MODERNIZATION. WE WILL ANALYSE SUCH EFFECT (IF WE DETECT THAT IS PRESENT), STUDYING ITS CAUSES, EFFECTS AND THE REGULATORY AND TECHNICAL TOOLS THAT MAY HELP PREVENTING IT. THE MOST INNOVATIVE ASPECT OF THIS PROJECT IS THE RIGOROUS STUDY OF THE EFFECTS OF IRRIGATION MODERNIZATION, THE APPLICATION OF NEW DECISION-MAKING SIMULATION MODELS AND THE ANALYSIS OF ECOSYSTEM SERVICES OF IRRIGATION SYSTEMS IN SPAIN. THE CASE STUDY AREAS INCLUDE A RANGE OF SYSTEM TYPOLOGIES THAT GIVE THE POTENTIAL OF THE OUTPUTS OF THIS PROJECT TO BE RELEVANT AT THE NATIONAL AND EUROPEAN LEVEL, AS WELL AS FOR OTHER ARID REGIONS IN THE WORLD. THE OUTPUTS ARE ALSO EXPECTED TO BE RELEVANT FOR THE IMPLEMENTATION OF RIVER BASIN PLANS AND THE REVIEW OF THE WFD, PLANNED FOR 2019 "