The Influence of Climate Change on the Water Budget in the Regional Park of the Po River Delta (Italy)

An end-of-the month water balance model called Watbal was used to calculate the components of the hydrologic water budget for several sites of the Regional Park of the Po River Delta (Italy). A sandy soil covered with Pine trees, served as an analogue for the Pinewoods of San Vitale (Ravenna) and the Pinewoods of Cervia, a clay rich soil covered with Swamp Reed served as an analogue for Punte Alberete (Ravenna), and a clay-rich soil with corn simulated agricultural land near Cervia. Both long term measured monthly average temperature and precipitation values served as input as well as three other climate scenarios with increased average temperatures and/or precipitation, to simulate climatic changes in the near future. The modeling results show that the effect of a change in temperature is much more dramatic than a change in precipitation: the increase in evapotranspiration due to average air temperature increase by two degrees, is not compensated by an increase of 2.5 % of the average accumulative monthly precipitation. This effect is more pronounced on clay rich soils than on sandy soils. Clay will release more moisture in warmer times while the soil moisture in sand is very low during the warmest months also now, and cannot decrease much further. The predicted loss of freshwater due to increased evapotranspiration would have a large effect on the water supply for irrigation and drinking water and would alter many of the habitats posing a danger for existing plant and animal communities.