Groundwater Quality and Potential Assessment in Mekane Selam and its Surrounding Area, South Wollo, Ethiopia

The development of a balanced plan for water resource utilization necessitates a comprehensive
assessment of water resources in terms of quality, quantity, spatial distribution, and the land use and
land cover conditions of the entire catchment. The Mekaneselam and its surrounding area, located in
the northern part of Ethiopia within the South Wollo Zone, are bordered by the Blue Nile Gorge to the
south and the Yeshum River Gorge to the east. This region exhibits two distinct topographic features:
the highlands, covering approximately 80% of the area and dominated by the Ashengie Formation,
and the lowlands, comprising Quaternary volcanics. The catchment’s annual rainfall, determined
through arithmetic averaging of point data from nearby stations, is approximately 1268 mm/year.
Using a conventional recharge estimation method, the annual recharge rate of the catchment is
calculated to be 230.4 mm/year. The primary aquifers in the area consist of scoria and vesicular
basalt. Groundwater recharge, discharge conditions, and flow systems are predominantly influenced
by rainfall, topographic features, and structural geology. The groundwater potential of the area is
categorized into High, moderate, low, and very low, with the general groundwater flow direction from
northeast to southwest, albeit with minor irregularities due to local topographic variations, deep
wells, and structural influences. Hydrogeochemical analysis using Aquachem software identified four
water types, including Ca-HCO3, Na-Ca-HCO3, Ca-Mg-HCO3, and Ca-Mg-HCO3-Cl. The dominant
water type in the region is Ca-Mg-HCO3. Groundwater in the area evolves from Ca-HCO3 and CaMg-HCO3 types in recharge zones to Na-Ca-HCO3 types in discharge zones. This evolutionary trend
is governed by processes such as dissolution, precipitation, cation exchange, and hydrolysis of silicate
minerals. This study provides insights into groundwater recharge-discharge dynamics, flow systems,
and hydrogeochemical evolution to support sustainable water resource planning and emphasizes the
importance of implementing land use practices, monitoring water quality variations, and constructing
storage facilities to enhance resource utilization in Mekaneselam and similar catchments.