Assessing the Impacts of Climate and Land Use Changes on the Water Quality of a Transboundary Balkan River

Abstract

The Mediterranean area is highly vulnerable to climate changes that combined with potential land use changes could influence its aquatic systems significantly. The Evros River is one of the most important surface water bodies in the Balkans with an ecologically significant delta that is protected by international legislation. The aim of this study is to analyze the impacts of climate and land use changes on Evros River water quality, for different climatic and socioeconomic scenarios. For this purpose, a hydrodynamic and advection-dispersion model was set up and calibrated, three IPCC climatic scenarios were applied, and the pollution loads of the catchment area were estimated. These scenarios involved river discharge decrease due to regional climate changes and socioeconomic and technological development that would lead to population growth and to the decrease of agricultural activities. The results indicated that in the case of discharge reduction only, the total nitrate and phosphate concentrations will be increased, while in case of combined land use and discharge changes, the concentration of nutrients will be decreased. Thus, a transboundary long-term management plan of the entire River is needed that would eliminate the pollution pressures and restore its good ecological status.