Kilsby, C.G., Tellier, S., Fowler, H.J. and Howels, T. 2007. Hydrological impacts of climate change on the Tejo and Guadiana rivers. Hydrology and Earth System Sciences, 11(3), 1175-1189.

 

Abstract

 

A distributed daily rainfall-runoff model is applied to the Tejo and Guadiana river basins in Spain and Portugal to simulate the impacts of climate change on runoff production, river flows and water resource availability with results aggregated to the monthly level. The model is calibrated and validated, and then used for a series of climate change impact assessments for the period 2070-2100. Future scenarios are derived from the HadRM3H regional climate model (RCM) using two techniques: firstly using bias-corrected RCM output, with monthly mean correction factors calculated from observed rainfall records and, secondly, using a circulation-pattern based stochastic rainfall model. Major reductions in rainfall and streamflow are projected throughout the year; different from previous studies where winter increases are projected. Despite uncertainties in the representation of heavily managed river systems, it is found that the projected impacts are serious, and pose major threats to the maintenance of bi-partite water treaties between Spain and Portugal, and the supply of water to urban and rural regions of Portugal.