Water-Energy-Food-Ecosystems pathways towards reducing water scarcity in Europe

The LISFLOOD-EPIC coupled hydrological/crop model European setup has successfully simulated for Europe using a meteorological reference scenario, and individual and combined water saving measure scenarios for the period 1990-2018. In this study, five policy relevant water saving measures are considered, i.e., improvement of efficiency scenarios for irrigation, reduction of leakage in the urban water supply, re-using treated wastewater, reducing energy water withdrawals and desalination. The largest challenge in comparing the what-if and reference scenario is the choice of a single, fit-for-purpose indicator that can give a qualitative indication on the performance of the scenario, and still capture the complexity of the issue. In this work, the Water Exploitation Index Plus (WEI+) indicator is used to estimate the impact of water saving measures on water scarcity in current climate. It is calculated for the consumption of water and is defined as the ratio of the total water net consumption divided by the available freshwater resources in a region including upstream inflowing water. The differences in WEI+ between a reference scenario and the proposed measure or measures, is a clear indication of the improvement this measure is capable of achieving as a percentage of the total water availability. Therefore, in this report, the results focus on the differences in WEI+ values, rather than on absolute values. The results showed that the scenarios with combined measures are the most effective, and future work will focus to estimate if this improvement will be sufficient to tackle water scarcity issues if climate change is also taken into account.