Multi-criteria analysis and modeling with GIS for the location of landfills: A case study in the southern region of Santiago Island, Cape Verde

Urban Solid Waste Management (USWM) is, in terms of Geographical Information Technologies one of the most interesting and also daring fields of research. Not also because it deals with one of the major problems of development but also because it's an environmental and social issue. It is also a very important theme when it comes to public policies and territorial planning and management. The optimal location of a landfill is obviously a very difficult decision and the consequences of a bad choice will be totally determinant to social and economic variables. Populations, their public health and environment are only the visible sides of a long list of problems with unpredictable consequences. This study uses multi-criteria analysis in Geographic Information Systems (GIS) for the location of a landfill in the southern region of Santiago Island, Cape Verde. The methodology is based (mainly) on a raster model GIS with multicriteria analysis and integration of the Analytical Hierarchy Process (AHP). Multi-criteria analysis assesses the suitability of the study area while the AHP ranks the problem and define the relative importance of the criteria. To identify areas with the ability to locate the landfill, fourteen criteria were used. The possible areas were divided into Zero, Low, Medium and High capability and they resulted from the overlap of criteria based on the relative weights. In areas with high suitability, locations with values equal or above 13.9 ha were selected as optimum locations for implementing the landfill.