Abstract:
This study reports the development of a new spatial multi-criteria decision analysis (SMCDA) software tool for selecting suitable sites for Managed Aquifer Recharge (MAR) systems. The new SMCDA software tool functions based on the combination of existing multi-criteria evaluation methods with modern decision analysis techniques. More specifically, non-compensatory screening, criteria standardization
and weighting, and Analytical Hierarchy Process (AHP) have been combined with Weighted Linear Combination (WLC) and Ordered Weighted Averaging (OWA). This SMCDA tool may be implemented with a wide range of decision maker’s preferences. The tool’s user-friendly interface helps guide the
decision maker through the sequential steps for site selection, those steps namely being constraint
mapping, criteria hierarchy, criteria standardization and weighting, and criteria overlay. The tool offers
some predetermined default criteria and standard methods to increase the trade-off between ease-ofuse
and efficiency. Integrated into ArcGIS, the tool has the advantage of using GIS tools for spatial
analysis, and herein data may be processed and displayed. The tool is non-site specific, adaptive, and
comprehensive, and may be applied to any type of site-selection problem. For demonstrating the
robustness of the new tool, a case study was planned and executed at Algarve Region, Portugal. The
efficiency of the SMCDA tool in the decision making process for selecting suitable sites for MAR was also
demonstrated. Specific aspects of the tool such as built-in default criteria, explicit decision steps, and
flexibility in choosing different options were key features, which benefited the study. The new SMCDA
tool can be augmented by groundwater flow and transport modeling so as to achieve a more comprehensive
approach to the selection process for the best locations of the MAR infiltration basins, as well as
the locations of recovery wells and areas of groundwater protection. The new spatial multicriteria
analysis tool has already been implemented within the GIS based Gabardine decision support system as
an innovative MAR planning tool.
