Chapter 8 - An area facing climate change: monthly water availability in the Emilia-Romagna region during 1961–2015

Abstract

Climate change affects areas worldwide by modifying their hydrological cycle. In the Mediterranean area, the water resources are experiencing an overall decrease in water quantity together with a worsening of their quality because of climate change. Emilia-Romagna region is one of the Italian regions with the highest water demand due to agricultural and industrial activities. There, quantification of water availability (WA: the proportion of precipitation available at the soil surface for subsequent infiltration and runoff processes) can no longer be postponed. Thus the monthly actual evapotranspiration (AET0m) was calculated using a simply downscaling Budyko approach. The method was applied to 100 controlled and homogeneous meteorological stations, located in the Emilia-Romagna region in the north of Italy. The datasets were divided into two subperiods, from 1961 to 1990 and 1991 to 2015, in which the monthly AET0 and WA were calculated. This information is needed by stakeholders in charge of groundwater management for further adaptation plans, such as managed recharge and the development of agricultural best practices able to induce an increase in groundwater levels and water quality. To assess the variation of water resources in the Emilia-Romagna region, we have downscaled the formula of annual AET0 established by Budyko to the monthly scale. Further, the monthly WA was computed at high spatial resolution. The climate data of monthly minimum and maximum temperatures and monthly precipitations over 1961–2015 from 100 weather stations were used. Results show a remarkable reduction of WA (about 10%) in the whole region, with the exception of the northeastern part of the Emilia-Romagna region. The decrease in the mean annual WA is more focused in the winter months (about 83mm) and mainly affects the mountainous areas. This study lays the foundations to rethink and improve the management of water resources in the area.