Deriving spatially explicit water uses from land use change modelling results in four river basins across Europe

The objective of this study is to provide spatially distributed water use maps at a high spatial and thematic resolution as detailed input data for further modelling purposes. The maps were derived on the basis of official water statistics and land use maps to represent the current conditions in four European river basins affected by water scarcity (Adige, Ebro, Evrotas and Sava) and allow setting up reference scenarios. The present land use distribution was modelled based on CORINE data with the land use change model iCLUE. Modelling the land use allows to create dynamic land and water use maps adapted to the needs of eventual scenario analyses compared to using only observed land use maps. The availability of several CORINE datasets allowed calibrating and validating the results of the iCLUE model carrying out a three map comparison. Sectoral water uses were attributed to different land use classes and by this means located in space. Both the location and the magnitude of urban and agricultural water uses can be derived from the final maps. The created maps together with the corresponding land use data provide a coherent set of information crucial to most environmental modelling activities and often missing at this spatial and thematic resolution. This work also aims at visualizing and validating the water use statistics provided by official institutions such as the River Basin Management Plans. The results show that in some cases they are not consistent and underline the importance of harmonised data collection regarding water statistics, as otherwise comparisons within one study area and with others are hampered. This study is embedded in the EU-FP7 GLOBAQUA project which analyses the effects of stressors, such as changes of land and water use, on aquatic ecosystems in areas suffering water scarcity.