AN ASSESSMENT OF CLIMATE CHANGE IMPACT ON WATER RESOURCES IN SPAIN

摘要

Some results are shown of work carried out in CEDEX to assess the climate change impact on water resources in natural regime. The work is developed under the coordination of the Spanish General Directorate of Waters. 12 climate regionalized projections were provided by the Spanish Office of Climate Change (OECC) and the Spanish Meteorological Agency (AEMET). They give estimates of precipitation and maximum and minimum daily temperatures during the control period (1961-1990) and three future periods (2011-2040, 2041-2070 and 2071-2100) in which the impact was evaluated. A preliminary comparison of climate projections and observed data was done for the control period. It was followed by an interpolation of the atmospheric forcing variables. Also potential evapotranspiration was estimated. Finally, atmospheric forcing variables were implemented in a semidistributed version of Temez model to obtain maps of actual evapotranspiration, soil moisture, groundwater recharge and runoff. The model is integrated into SIMPA (An Integrated System for Rainfall Runoff Modelling) system, a GRASS based GIS tool, being developed by CEDEX since the 90's.Atmospheric and hydrological variables are distributed with the exception of groundwater discharge, which is simulated using a tank model in defined hydrogeological units. More than 200,000 maps of 1 km2 resolution have been generated covering the whole of Spain in a monthly basis. The impact of climate change on water resources is presented as percentage deviations of runoff in each future period of the XXIth century with respect to the control period.