Rasterised Water Demands: Methodology for Their Assessment and Possible Applications

In this paper a methodology for the calculation of grid cell spatially distributed water demands—for the stakeholders domestic, municipal, industrial and agricultural (without rainfed or irrigated crop production) water use—is presented. As case study the Kitzbühel region in the Austrian Alps, encompassing 20 municipalities, was chosen. Austria is one of few countries within the European Union that provides data of the population and housing census of 2001 in a raster format, with resolutions 125, 250, 500, 1,000 and 2,500 m. From these available data, population and employment raster data were used for the analysis. Based upon the latter and a calibrated related rate of water use (litre per unit per time interval), rasterised yearly and winter water demands were calculated. These rasters represent the alpine character of the study area and are independent of political borders. They can be used in hydraulics related studies, a wide range of water resources management studies and for landscape and urban planning studies. The limiting factor and scale for all applicable studies is the resolution and availability of accurate population and water use data. This fine-resolution water demand dataset can only be generated with the high resolution census data and (reasonably) accurate water use data via survey and expert input. Therefore the scale of studies where the proposed methodology is applicable is limited to a local and regional scale, up to national borders where the detailed population and housing census of 2001 is available as raster data.