Climate change impacts on water availability and human security in the intercontinental biosphere reserve of the mediterranean (Morocco-Spain)

Abstract

The Mediterranean basin has been identified as one of the world most vulnerable regions to global change effects. Global and regional climate change scenarios foresee an increase in the average annual temperature over the planet’s mean. These scenarios project an increasing frequency of drought episodes adding to the complexity of water scarcity management and questioning the future sustainability of water resource uses. This study assesses the potential water vulnerability in the Intercontinental Biosphere Reserve of the Mediterranean (IBRM), located in the western side of the Mediterranean Basin between Spain (Europe) and Morocco (Africa). The vulnerability assessment proposes an innovative and multidisciplinary approach based on the use of climate change scenarios, a hydro-ecological model and the participation of stakeholders and local experts in expert meetings. Future scenarios draw a more arid climate for the IBRM, with more frequent water scarcity phenomena. A reduction of around 28.1-30.3 % is expected in stream flows by 2070. Agricultural water demands are expected to increase between 7.5 and 16 % in the Moroccan side in order to maintain the current production standards, whereas Spanish pastures are expected to maintain current productions with no need of supplementary water supply. Within forests, tree covered areas showed a higher potential vulnerability to future climate change than shrublands proving higher adaptation to arid conditions. Finally, the tourism will be impacted by the increase in summer temperature and in water supply shortages. Moreover, a significant spatial segregation of impacts is observed. Higher altitudes will be less affected by climate change and changes may be relevant to biodiversity but not to human activities. On the contrary, lower altitudes and coastal areas will experience an increasing water demand to sustain different uses by the end of the century in a higher water scarcity context.