Mapping Urban Water Demands Using Multi-Criteria Analysis and GIS

A multi-criteria spatial data analysis method is presented to seek and model major determinants of future growth of urban water demands based on the urban growth trend by a case study performed in the city of Mytilene (Lesvos island) in north-eastern Aegean archipelagos, Greece. Domestic water use/demand is a complex element of socio-economic and physical characteristics, urban planning strategies, infrastructures and public water policies. Under a GIS environment, these factors correspond to different thematic layers, such as road network distance, distance from the city centre, distance from the coastline, topographic slope, land use/land cover, General Urban Plan of Mytilene, areas in which buildings with less than two storeys are allowed, the respective areas of buildings with more than two storeys, present population density and existing water supply and sewerage system. The Analytical Hierarchy Process applied in the evaluation of these factors led to spatial potential water demand map, which was classified into five priority zones. Results showed that a large percentage of the study area was identified as very high and high priority areas for future domestic water demand. The applied method was verified against the prepared maps showing the varying rates of water consumption and active water connections. The comparative evaluation of these maps validated the accuracy of the proposed method which can be used by the local officials of Mytilene in adopting policies and strategies aiming towards sustainable water resource management and development.