GIS based spatial-temporal distribution of water quality parameters and heavy metals in drinking water: Ecological and health modelling

Drinking water samples from different sites of Offa Woreda, Ethiopia's Southern Nations were obtained and based on physicochemical characteristics and trace metals water quality indexing (WQI) and ecological risk indexing (ERI) were carried out. Physicochemical parameters such as pH, temperature, total alkalinity (TA), total hardness (TH), total dissolved solids (TDS), total suspended solids (TSS), etc. Along with carcinogenic heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), and other metals such as zinc (Zn), iron (Fe), etc. were analyzed. Findings obtained revealed that metals such as Cd, and Fe were above the prescribed maximum permissible limits of the World Health Organization (WHO) while the concentration of metal ions such as Cr, Cu, Pb and Zn were within permissible limits. Different statistical approaches such as Contamination factor (CF), Contamination degree (CD), pollution load index (PLI), and quantification of contamination index (QoC) along ERI were applied to check the suitability of water for the drinking purpose and their possible health implications in near future. Moreover, the spatial and temporal distribution of water quality parameters and heavy metals along with their health implications in this region was elucidated using Geographic Information System (GIS) a modern tool to analyze multiple layers of data through maps and images.