Hydrogeochemical processes and groundwater evolution in complex volcanic highlands and alluvio-lacustrine deposits (Upper Blue Nile), Ethiopia

Spatial and seasonal groundwater quality assessment for drinking suitability using index and machine learning approach

“…Other previous researchers [ 85 ] employed the Piper, Durov, and Gibbs diagram and found comparable results to this particular study. The recent work [ 18 ] also confirmed that the principal hydrogeochemical process controlling the groundwater of the Tana sub-basin is rock weathering and dissolution.…”

“…The Ca–HCO 3 took about 75 % of the samples in the two study seasons. A related study conducted in the whole Tana sub-basin also found the hydrogeochemical facies including Na–HCO 3, Ca–HCO 3 , and Ca–Na–HCO 3 including others [ 18 ]. Other studies [ 47 , 105 ] conducted in the nearby area of the present study region also found Ca–HCO 3 as the dominant water type.…”

“…A very similar main hydrogeochemical facies (Ca–HCO 3 , Na–HCO3, and Ca/Mg–HCO3) were also obtained from the research work carried out in the Birr River watershed [ 11 ], a nearby area of the present study. The Ca–HCO 3 revealed the recharging and freshwater quality [ 18 , 85 , 106 ]. As aforementioned above, one can understand that the water types could also vary from season to season.…”

“…Particularly, the flat terrain of the Tana sub-basin (the present study area) in which GW resource is extracted mainly from tertiary and quaternary volcanic aquifers including quaternary alluvial and lacustrine deposits [ 18 ] faced quality problems. It was confirmed that poor-quality groundwater was pumped from some deep boreholes in the study region [ 19 ].…”