Water Accounting in the Po River Basin Applied to Climate Change Scenarios

Abstract The influence of humans on the earth's temperature and climate is a fact recognised by scientific community and it is mainly caused by deforestation and burning fossil fuels. Mediterranean area is turning drier, becoming more vulnerable to wildfires and drought. In the coming years, it is expected that the increasing water demand in combination with water scarcity due to climate change would intensify the current water stress. The Po is the longest river in Italy, with a length of 652 km and it is also the largest river with an average discharge of 1540 m 3 /s. The Po Valley covers the economically most important area of Italy, and a population of more than 16 million which produces 40% of the national Gross Domestic Product. As other Mediterranean areas, this river basin is subject to high flow variation, frequent floods and periods of low flows that may be amplified in the coming years. The main objective of this study is to apply a modelling chain for the development of water accounting analysis in the Po River Basin, including the impact of climate change on the region. To do this, the climate change impacts have been obtained under the Intergovernmental Panel on Climate Change scenario RCP 4.5. The hydrological/hydraulic components are simulated through a physically based distributed model (TOPKAPI) and a water balance model at basin scale (RIBASIM). The accounting approach has been the SEEA-W. The results show that, in future scenarios, the application of measures will be required to mitigate climate change maintaining water allocations.