AHP based analysis of groundwater potential in the western escarpment of the Ethiopian rift valley

Abstract

This study investigated groundwater potential in the Western escarpment of the Ethiopian Rift valley, taking Dijo catchment as a case study, an area that is known for its critical shortage of water. Different thematic layers were used to determine the groundwater potential of the catchment. PCI Geomatica and Rockwork were used to automatically extract lineament and lineament orientation, respectively. Weights of parameters were computed using the analytical hierarchy process (AHP). Rank was assigned to each feature class for each thematic map according to their characteristics and interrelationship with groundwater. Once the mapping was done, validation of the estimated result was done. Accordingly, the result indicates that there is a matching between the analysis results and samples taken from boreholes with an accuracy result of 79.2%. The results revealed that nearly half of the catchment was found to have high-to-very-high groundwater potential while the remaining exhibiting limited potential for groundwater. Despite the high potential, there is a critical shortage of water. This is partly attributed to poor planning and limited capacity in identifying water resource potential. Thus, we suggest that efforts should be made to exploit the available water resources thereby to solve the societal problem.

Keywords

• groundwater potential
• pci geomatica
• dijo catchment
• main rift valley