Abstract
Study region: The Matahara region is located in the East Showa zone of Oromiya regional state (Ethiopia). Matahra Sugar Estate and Lake Basaka (highly saline, alkaline and sodic lake) are situated within the flat plains of Matahara region. The area is vulnerable to the occurrences of various tectonic and volcanic activities due to its location in the upper most part of the Main Ethiopian Rift Valley region. Study focus: In this study, the hydrochemical properties of different surface water and groundwater bodies available at Matahara region have been characterized for quality compositions. Water samples were collected from different water sources and analyzed for important major quality parameters following standard test procedures. Other chemical indices were derived from the measured quality parameters. The potential sources of minerals were suggested for each of the considered water sources based on their quality characteristics. New hydrological insights for the region: Overall, the study result elucidates that the chemical composition of different water bodies are due to natural processes and/or anthropogenic activities within the region. The local anthropogenic processes could be discharges from factory, domestic sewage and farming activities. Some of the water types are found to have relatively higher concentration of dissolved constituents. Irrigation waters have almost equal chemical compositions, indicating their hydrochemical sources are almost the same. Most of the concentrations are relatively high in Lake Basaka, groundwater and hot springs. It is easy to imagine the potential damaging effects of such quality waters on crop production, soil properties and environment of the region. Keywords: Chemical composition, Chemical indices, Lake Basaka, Matahara, Natural processes