Abstract:
Accurate assessment of groundwater potential zones is crucial for effective resource
planning and use in complex hydrogeological systems. The main aim of this study is to use
geographic information systems (GIS) based AHP and electrical resistivity techniques to
identify the groundwater potential zones in the Batena - Guder Catchment (Hadiya Zone
District, Lemo & Analemo Woreda). Thus, the groundwater potential of the research
region has been identified by overlaying the weights of ten thematic elements, and then
assigning numerical weight and ranking based on the GIS data. Availability of the
groundwater in the watershed covers 690.4 km2, which is designed into five categories;
“Very low”, “Low ”, “Moderate”, “High” and “Very high” Groundwater Potential zones
viz., 76.27 km2 (11.05%), 166.43km2 (24.11 %), 170.98 km2(24.77 %) and 172.51 km2
(24.99 %) respectively. The “Very High” Groundwater potential covers 104.21 km2 (15.09
%). The study used Schlumberger configurations to acquire 10 Vertical Electrical
Sounding (VES) with 4 profiles to determine depth, resistivity, thickness, and geoelectric
sections. The data is analyzed using ZondRes2D software in three geoelectric layers. Based
on the result profiles 1,2 and 4 show moderate to high groundwater potential occurrences
with a low resistivity(<10 Ω.m) value. Groundwater zones are typically found in the
middle layer, which is thicker than the top and has a higher porosity than the top layer. The
validation of the drilling sites with groundwater potential zones was achieved through 36
shallow wells and 7 borehole logs data, resulting in a fairly satisfactory 74.5% agreement.
The sensitivity analysis suggests that rainfall has the greatest impact on high and extremely
high groundwater potential maps.
