Evaluating water Ecosystem Services Footprint of agricultural production under climate change scenarios

Based on the integration of hydrological modelling and Water Footprint (WF) analysis, this study aims at developing a methodology to analyze both the supply and demand of Water related Ecosystem Services (WES) connected to the agricultural sector under climate changes scenarios. The WES demand by the agricultural sector is determined using the WF Assessment methodology estimating the green, blue, and gray WF component and their variability due to climate change. The WES supply is analyzed by applying the Soil Water Assessment Tool (SWAT). The model simulates the main hydrological processes thus allowing the spatial explicit quantification of the variables estimating the water availability in its three components. After calibration and validation, possible scenarios of changes in water availability are evaluated under 20 climate change scenarios by means of  12 indicators of Hydrologic alteration (IHA) being the most representative of the flow regimes in Europe. Finally green, blue, and gray WES Footprint (WESF) through dedicated indicators in order to identify the main hotspots in agriculture water management and their future projections. The methodology is applied to a specific case study in the upstream part of the Arno River basin (Central Italy). The analysis allows the spatial explicit identification of the main hotspots associated to agricultural production in future scenarios. All scenarios outlined hydrological parameters that alter flow regime and affect surrounding ecosystem, despite a discrepancy between the northern part and the southern part on the basin. Magnitude of variability in monthly water availability and the changes in WF are explored suggest possible challenges to address. The use of footprint indicators, and in particular of WESF, can lead to a more sustainable water management revealing hidden costs and impacts of production of goods and services and sustaining the formulation of a conscious and integrative basin management plan.