Multi-criteria spatial decision analysis for forecasting urban water requirements: a case study of Dehradun city, India

A uniform spatial water distribution system will help in distributing domestic water equally to all places with proper pressure. It will avoid the probable risk of failure in the complete distribution system and can make the system cost effective. In the present study a scientific approach has been adopted to compute drinking water requirements at present and in the near future in a spatial environment using multi-criteria decision analysis techniques. Drinking water problems in the city of Dehradun, India, have been studied and causes of drinking water scarcity have been analysed. Different thematic layers required for the study such as, road network map, landuse/landcover, have been prepared in a Geographic Information System environment using very high-resolution digital data of IKONOS satellite coupled with the field data. Future drinking water demand areas have been identified considering numerous variables such as: distance from the main city, road distance, topographic slopes, landuse/landcover, present population density, soils, floodplains, and the existing water supply system. A questionnaire has been conducted to compute the weights for these variables. Additional supplies that have to be provided for the next two decades have been computed and analysed with the present supply system. A spatial future water demand map has been prepared to produce more thorough and accurate means of assessing city development, and allow the planning and construction of optimum and efficient water supply system.