Spatial dependencies during multi-criteria analysis for groundwater resource management at a local scale

Abstract

The growth of emerging and intermediate cities in Latin America and the Caribbean has been one of the main causes of the gaps found in the access to water quality and sanitation services; therefore, there is a pressing need to significantly improve water resources management to ensure a sustainable development is achieved. In fact, Geographic Information Systems and Multi-Criteria Decision Analysis have proven to be very powerful and effective tools, but when the analysis is carried out on the basis of biophysical variables mixed with socioeconomic criteria, problems in the spatial discretization of the data appear, thus making spatialization and rating of variables difficult. The aim of this paper is to compare two types of spatial alternatives in a multi-criteria analysis for groundwater resource management in an intermediate city in Argentina: one made from an hydrological approach (14 watersheds) and the other made from a socioeconomic approach (7 ad-hoc defined zones). Three stages of the multicriteria analysis process were analysed in this paper; firstly the definition of the alternatives to be prioritized, secondly, the sub-criteria rating process using the direct and inferred rating methods, and finally the model results. The map of priorities by watershed and by zones was then generated and the results were classified into first, second and third priority based on groundwater management needs. Furthermore, a sensibility analysis and comparative synthesis between the use of alternatives considering watersheds and ad-hoc zones, were carried out. While the hydrological watershed has demonstrated its usefulness as a land unit for decision-making on water resources issues, it can be noted that this should not be a reason to rule out other alternatives for discretizing a territory that may have socioeconomic rather than physical boundaries, and that may provide a more appropriate outcome for a decision-making process.