Identification and Mapping Groundwater Potential Areas Using GIS and Remote Sensing in Wolaita Zone, Southern Region, Ethiopia

Abstract

Recently water is becoming a vital natural resource that can be used for many things in human life i.e. hydropower generation, sanitation, drinking, irrigation, and transportation. But surface water is not enough to satisfy all demands of humans. So besides surface water, groundwater resource is by far huge in amount and not much exploited yet. Now a day exploitation of groundwater through hydrogeological surveying, identification, and delineation of better groundwater potential areas is implemented in many places of the world to satisfy the need for water. This research was done on the place where it is called the Wolaita zone located in the southern region of Ethiopia. The main objective of this research was to delineate and map the groundwater potential areas in terms of relative groundwater availability. Groundwater potential zone mapping was done using GIS and remote sensing integrated with the analytical hierarchical process to meet the objective. Seven thematic map layers (land use/cover, soil, slope, drainage density, lineament density, rainfall, and geology) were used as an input to the weighted overlay of layers for delineation of groundwater potential zones. As a result, the study area was classified into “poor”, “good” and “very good” groundwater potential zones. Accordingly, “poor” and “good” groundwater potential areas were occupying almost the same percentage from the total area which is 44.19% (198,0445ha) and 44.51% (199,460ha) respectively. But “very good” groundwater potential zones are covering 11.30% (50,652.2ha) of the study area. In this regard better groundwater potential areas were identified in the east and northern east direction of the study area. Wolaita zone was also clustered in 12 woredas and one town. From all twelve woredas, a High percentage of “very good” groundwater potential is found in Boloso sore, Duguna Fango, Boloso bombe and Damot sore woredas and relatively “poor” groundwater potential is situated in Kindo Koyisha, Kindo Didaye, Ofa, Humbo, and Sodo zuriya woredas and the remaining part of Wolaita zone is dominantly covered by “good” groundwater potential in Wolaita zone. Furtherly each woredas were also classified as “poor”, “good” and “very good” groundwater potential zones with their percentage of area coverage. Therefore the identified groundwater potential areas can be used for digging of wells and bore holes, conducting further research, a benchmark for water resource management practice, or as an input for policymakers to make research-based decisions.