Comparative analysis of multi-criteria decision-making techniques for groundwater potential mapping in highland of Eritrea

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Abstract

This study employs an approach that integrates geospatial techniques with the Analytical Hierarchy Process (AHP) and Fuzzy-AHP to identify groundwater potential zones in Debarwa. Seven environmental parameters significantly influencing groundwater potential were selected for analysis: geology, soil, lineament density, rainfall, land use/land cover, drainage density, and slope. A comparative study between the two methods was employed using Geographic Information System (GIS) and Remote Sensing (RS) tools. The thematic layers for each parameter were created and subsequently weighed through pairwise comparisons based on the AHP and Fuzzy-AHP methodology. Consistency tests were conducted to ensure the reliability of the assigned weights. The final weighted overlay map classified the groundwater potential into four categories: poor, good, very good, and excellent. The spatial distribution of the area coverage for the potential zone of AHP and Fuzzy-AHP fall under the good and very good zones. The results for good and very good use of AHP are 74.68% and 24.88%, respectively, with 80.12% and 19.87% for Fuzzy-AHP. While both methods produce comparable results, Fuzzy-AHP exhibits a slight advantage in refining classification accuracy by incorporating degrees of membership rather than rigid classifications. This makes Fuzzy-AHP potentially more effective when uncertainty and gradual transitions between groundwater potential zones are expected. The resulting outcome provides a valuable tool for decision-makers to prioritize regions for detailed groundwater exploration and management. The research recommends further validation using different approaches to evaluate the accuracy and robustness of the proposed groundwater potential zones.