Water shortage risk mapping: a GIS-MCDA approach for a medium-sized city in the Brazilian semi-arid region
Maria José de Sousa Cordão, Iana Alexandra Alves Rufino, Priscila Barros Ramalho Alves, Mauro Normando Macêdo Barros Filho
Abstract
Water Shortage Risk (WSR) map is a tool to establish priorities to take actions in the management of Urban Water Supply Systems (UWSS). This work presents a methodology combining elements of Multi-Criteria Decision Analysis (MCDA) and Geographic Information Systems (GIS) to assess urban water shortage levels. The study case is Campina Grande, a Brazilian city which represents other cities of semi-arid with similar conditions, such as dry climate, water rationing periods and a mixed-income population. The WSR approach uses seven criteria, including hydraulic, socio-economic, and infrastructure and a set of weighted functions. The method used for weight allocation is the Analytic Hierarchy Process (AHP). Results show the WSR map as a dynamic tool, once it can be complemented with utility and operational data. The WSR map, combined with control variables, can be a planning instrument for automation and operational control and also for highlighting the inequalities in water supply services.