Geospatial analysis and analytical hierarchy process for delineating groundwater potential zones

A case study in Debarwa catchment, Eritrea

Absztrakt

Groundwater is a crucial water resource worldwide, particularly in arid and semi-arid regions such as Eritrea. This study employs an approach that integrates geospatial techniques with the Analytical Hierarchy Process (AHP) to identify groundwater potential zones within the Debarwa catchment area in southern Eritrea. Seven key parameters significantly influencing groundwater recharge were selected for analysis: geology, soil, lineament density, rainfall, land use/land cover, drainage density, and slope. Using Geographic Information System (GIS) tools, thematic layers for each parameter were created and subsequently weighted through pairwise comparisons based on the 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 these categories revealed that 0.01% of the area fell into the ‘poor’ potential zone, 80.9% into the ‘good’ potential zone, 19.1% into the ‘very good’ potential zone, and 0.002% into the ‘excellent’ potential zone. These results indicate that most of the Debarwa catchment area has good to very good potential for groundwater resources. This delineation provides a valuable tool for decision-makers to prioritize regions for detailed groundwater exploration and management. The study’s innovative combination of GIS and AHP methodologies offers a systematic and objective framework for groundwater potential assessment. However, further validation studies are recommended to evaluate the accuracy and robustness of the proposed groundwater potential zones. Such validation would enhance the reliability of the findings and support sustainable groundwater resource management in the region. This integrative approach can be adapted and applied globally to similar arid and semi-arid areas to optimize groundwater exploration and utilization strategies.