For the first time, a dedicated release of the hydrology and water use model WaterGAP3, tailored to the basins draining into the Mediterranean and Black Sea, has been set up and applied within the STREMP project. WaterGAP3 calculates all water fluxes (e.g. runoff, evapotranspiration) and water storage compartments (e.g. groundwater, snow storage) on a 5 arc minute grid (~6x9 km). Additionally, within the WaterGAP3 modelling framework five water use models for the sectors households, irrigation, livestock, electricity production, and manufacturing industries have been further developed and applied to account for extensive water abstractions in the region. Within the SPP1257 WaterGAP3 model output is being used to correct the estimation of water mass change for hydrology leakage on land (see Fig. 1) and to account for freshwater inflow into both oceans.
An evaluation of modeled river runoff with regard to observed discharge generally yields good results with coefficients of determination R² being higher than 0.5 (see Fig. 2). Furthermore, Figure 2 also includes a comparison of WaterGAP3 to its global low resolution counterpart WaterGAP2 (or WGHM), which shows the advantages of high spatial resolution modeling, updated water use models, and improved process descriptions.
Further information about the applied methodology and results can be found in Aus der Beek et al. (2011). For questions please contact Tim aus der Beek (firstname.lastname@example.org)