Une approximation de la prévision saisonnière des étiages et sécheresses en Catalogne

Abstract

Low flows and droughts are a hydro-climatic feature in Spain. The last drought that has affected Spain has last four years in Catalonia from 2004 to the spring of 2008. The aim of this contribution is to show its evolution and the potential use of seasonal forecasting to improve the water management in Catalonia. Due to the fact that the principal rivers in the Internal Basins of Catalonia born in Pyrenees and Pre-Pyrenees region the analysis of the precipitation is focused on this region. Monthly precipitation series representatives of the three basins of study have been obtained from 127 raingauges for the period 1940-2008. These series have been used to calibrate the hydrological model and to validate the seasonal forecasting. All seasonal predictions from internet sites have been analysed and one have been selected ECM4 and later validated for the region of study with 127 raingauges for the period 1998-2008. Then a seasonal prediction index has been created as a linear combination of climatic data and the ECM4 prediction that has been validated too. This information has implemented into a hydrological model and it has been applied to the last drought considering the real water demands of population. It has been found a considerable advance in the forecasting of water volume into reservoirs that can be applied in the future. The advantage of this methodology is that it only requires seasonal forecasting free through internet. This work has been developed into SOSTAQUA project. © Société Hydrotechnique de France, 2010.