Anàlisi de l'impacte del canvi climàtic en els recursos hídrics de la Conca de l'Ebre

Abstract

The objective of this study is to calculate a seasonal water balance that provides a detailed view of the available resource. The study has been considered for the Segre and Cinca basins. The methodology used has been the calculation of the water balance to know the quantity of the resource, from where the ETR value (plant evapotranspiration) has been calculated using the Zhang equation (Zhang et al. 2001) according to the percentage of land uses. Current results are compared with those of a future horizon for 2050 using the climate projections of Calbó et al. 2016. Seasonal variability decreases, making the conditions of high temperatures, high potential evapotranspiration and low rainfall period not the descriptive pattern of the climate that corresponds only to summer, also describe spring and autumn. For land use purposes, the lower part of the basins is altered by canalization and dams, causing the availability of water, water resources, and flows to be negatively altered with a considerable reduction in their volume, leaving the hottest months with a deficit of water. The lack of availability during the spring months causes the period of recharge required by the water cycle to disappear. This deficit of water will increase, more that now, by 2050. Recharge periods will be affected by making them be minimized, especially with a strong impact on the lower sub-basins of the interior. In synthesis, in a future horizon a situation of water stress is presented that threatens the availability of water necessary to cover both the demand for human consumption and agricultural activity. The defined seasonality of the Mediterranean climate is lost and the management of water regulation in reservoirs where recharge will depend on episodes of heavy rainfall should be improved