Multicriteria siting and sizing of desalination facilities with geographic information system

Desalination of sea and brackish water is gaining interest as a viable water source in several regions of the world where limited freshwater resources are under stress from increasing demands and deteriorating water quality. Although a few large desalination plants exist and are planned for future implementation, most desalination facilities are constructed on a small scale to satisfy domestic requirements for individual cities and resort areas. As the cost of desalination continues to decline with improved technologies, integrated methodologies are needed for optimally locating and sizing desalination facilities over regional scales. The problem is complicated by multiple, noncommensurate objectives related to economic, social, and political criteria and complex spatial analysis in locating facilities. A methodology is presented that integrates geographic information systems with multicriteria decision analysis for regionally locating and sizing desalination facilities for domestic water supply. Application to the northwestern coast of Egypt, a region remote from freshwater sources in the Nile Valley and Delta, prioritizes cities to be served and optimally locates and sizes desalination facilities over the region.