Abstract

The European Water Framework Directive encourages the management of rivers at the basin scale requiring an understanding of the interdependencies between the physical environment and the local hydrology, ecology and climate. The current and future climate of the Spanish Ebro river basin, including its tributary, the Gállego, has been studied extensively within the EU AquaTerra (AT) project along with the hydrology and behaviour of environmental pollutants with respect to climate change. This chapter provides an overview of current research carried out for the Ebro and the Gállego and provides a summary and review of the recent and new AT studies examining climate, water resources and environmental pollutants. AT climate studies suggest that the Ebro will become significantly hotter and drier in the future, especially in summer. For example, regional climate models (RCMs) project a decrease in daily mean precipitation of up to 50.5% in the summer by the 2080s (Bürger et al. Environ Pollut 148:842–854, 2007). Future climate scenarios from an ensemble of RCMs have been used to provide input data to hydrological models of the Ebro and Gállego catchments to simulate the impacts of climate change on the basins. These results suggest that changes in climate will reduce water availability in the area, especially during the summer months when irrigation demands are highest. In addition, AT pollutant studies have revealed that persistent organic pollutants such as DDT are found in high concentrations near industrial sites, and heavy metal, pesticide and nutrient pollution are widespread. Problems of poor water quality in the basin may be exacerbated in periods of low water flow as pollutants will be more concentrated due to a lack of dilution with respect to high flow periods. AT studies have shown that this leads to a bioaccumulation of bio-available brominated flame retardants in fish, with potentially serious health effects. Changing climate patterns may influence degradation, turnover, sorption and transport behaviour of pollutant contamination with unknown effects. The effect of climate change on pollutants has not yet been quantitatively assessed with the same rigour as applied to hydrological assessments, and there remains considerable potential for further integration of climate impact assessment within the pollutant monitoring and modelling communities to improve future projections. These studies have important implications for future integrated basin management strategies in the Ebro.