An Assessment of the Water Resources Availability and of the Flood Hazard in a Climate Change Scenario in Tuscany

Abstract

The effects of the global climate change on the hydrological balance at regional scale received a growing attention in the last decade. While this issue affects all the components of the hydrological cycle, the most studied aspects refer the extreme events like floods and droughts, increasing the concerns about the water resource availability in such scenarios. Given a particular set of climate evolution forecasts, one of the available tools for the study of these topics is given by the distributed hydrological models. In this work a long-term simulation was performed on the Tuscany territory (Central Italy) with the hydrological distributed model MOdello di BIlancio Distribuito e Continuo (MOBIDIC) developed by the Department of Civil and Environmental Engineering of the University of Florence. The daily meteorological forcing (rainfall height, air temperature) used in the simulations were obtained by a meteorological simulation at 4-km horizontal resolution performed by a Limited Area Meteorological Model (LAM) based on the IPCC A2 scenario of climatological forecast for the 2070–2099 period. The MOBIDIC model was previously calibrated on the 1997–2007 period basing on the observations of the ground network of sensors of Tuscany Region. Analyses and comparisons of the results of the hydrological simulations between the two periods (current and climatic change scenario) are provided in terms of a statistics characterization of the extreme events and modifications in the rainfall regimes. A discussion of the results is provided.