An Input-Output Hydroeconomic Model to Asses the Economic Pressure on Water Resources in Tuscany

In this work, an input-output hydro-economic model methodology is applied for the Tuscany region in Italy. The model integrates the input-output table (for the year 2017) of the regional economy developed by IRPET with a satellite account of flows of water resources between the hydrological system and the economy. Three innovations are incorporated with respect to previous literature: i) a methodology for calculating the extended water demand (ED) (blue, green and grey water) by economic sector; ii) the reclassification of the ED by extracting and demanding sectors; and iii) the construction of new indicator of economic pressure on water resources (EWEI: Extended Water Exploitation Index) based on the ED and a measure of water supply (Feasible Supply: FS) taking into account technological and institutional constraints to the exploitation of water resources. The empirical model is built based on economic and hydrological data generated by the different national and regional institutions. The model provides estimates of the net water demand and the extended water demand generated by 56 economic sectors, considering both the extracting and the demanding sector classification. The proposed indicator of pressure supports a better understanding of the linkages existing between economic activities and the regional hydrological system and a more accurate assessment of pressures on water resources.