Fluxes of water and nutrients from river runoff to the Mediterranean Sea using GIS and a watershed model

The Mediterranean Sea is an important regional European Union (EU) sea, often used to assess the global change of the environment because of its practically enclosed character. As most of the northern part is bordered by the EU, it is also of interest in the evaluation of the environmental and economic impact of the implementation of the EU Water Framework Directive and related legislation. Within this framework, nutrient loads from the adjacent land surfaces need to be assessed. For this purpose, the geographic information system (GIS)–interfaced hydrologic/water quality model ArcView Generalized Watershed Loading Function Model (AVGWLF) was applied to all coastal‐adjacent catchments of the Mediterranean Sea. Results of this exercise have shown that the modeled average streamflow and nutrient loads fall within the ranges reported in the literature. Therefore, successful application of this model is feasible. However, for improved representation of the actual Mediterranean Sea streamflow and nutrient status, more accurate input data are required, particularly for the Asian and North African regions.