Future Scenarios for Aridity under Conditions of Global Climate Change in Extremadura, Southwestern Spain

Aridity conditions in semi-arid lands with warm climates are key variables that must be assessed to properly manage water and plan minimise the threat of desertification. This study analyses spatial distribution aridity Extremadura, southwestern Spain, using De Martonne index (IDM), considering a historical reference period (1971–2005) three-time intervals: 2006–2035 (near future), 2036–2065 (mid-century) 2066–2095 (end century). Projections were computed set ten global climate model (GCM) regional (RCM) combinations under two representative concentration pathways (RCPs), RCP4.5, an intermediate anthropogenic radiative forcing scenario, RCP8.5, fossil-intensive emission scenario. Progressive strengthening over Extremadura was evident until end century, mainly RCP8.5 From predominance Mediterranean class south region during period, will soon spread across this zone, occupying most it mid-century later. In north less arid reduced highest elevations, increasing categories, particularly Consequently, projected increase make more vulnerable change. Policies devoted adapting expected controlling areas necessary mitigate negative impacts, significant environmental socio-economic implications region.