Evaluating groundwater hydrochemistry and quality for drinking and irrigation in the Hormat-Golina subbasin, Northern Ethiopia

ABSTRACT Graphical abstract summarizing the key findings of the groundwater hydrochemistry and quality assessment study in the Hormat-Golina subbasin, Northern Ethiopia, illustrating the study workflow from sample collection through hydrochemical analysis to drinking and irrigation water quality evaluation, highlighting dominant water types (Ca-Mg-HCO3, Ca-Mg-Na-HCO3, and Na-Ca-HCO3), Water quality index classification results (55.6% poor drinking quality), and irrigation suitability findings including medium to high salinity characteristics and rock weathering as the primary control on groundwater chemistry. The Hormat-Golina subbasin in Northern Ethiopia, noted for its agriculture and livestock, is facing serious groundwater quality issues due to both natural and human factors. This decline affects residents who depend on groundwater for drinking, household needs, and irrigation. The study aims to conduct a thorough assessment of groundwater quality, examining hydrochemical characteristics and its suitability for drinking and irrigation. Unlike previous studies that primarily focus on groundwater potential and recharge assessments, this research combines multiple analyses of hydrochemistry and water quality for drinking and irrigation to provide a comprehensive view. It employs various hydrochemical methods, including acid–base titration and ion chromatography, and evaluates water quality using different parameters. The multi-method evaluation enhances the dependability and accuracy of groundwater quality assessment, providing vital information for decision-makers. The findings revealed that most water quality parameters, including pH (7.66) and electrical conductivity (702.4 μS/cm), met drinking water standards. However, the water quality index indicated that 55.6% of the samples had poor drinking water quality, while 24.75% were rated as good and 15.25% as very poor. For irrigation, certain indicators showed that the water was generally suitable without treatment, though concerns such as magnesium hazard and potential salinity suggest the need for soil management to prevent issues like compaction. The water samples exhibited characteristics of medium to high salinity with low alkalinity. The analysis indicated that rock weathering and cation exchange primarily influence groundwater chemistry, with a composition mainly of groundwater types: Ca–Mg–HCO3, Ca–Mg–Na–HCO3, and Na–Ca–HCO3.