A Simplified Mathematical Formulation for Water Quality Index (WQI): A Case Study in the Kelani River Basin, Sri Lanka

Surface water quality is degraded due to industrialization; however, it one of the widely used sources for supply systems worldwide. Thus, polluted creates significant issues health end users. However, poor attention and concern can be identified on this important issue in most developing countries, including Sri Lanka. The Kelani River Lanka heart whole Colombo area has intake drinking purposes near an industrialized zone (Biyagama). Therefore, study intends analyze effect industrialization surface variation basin terms index (WQI). We proposed a regression model predict WQI using parameters. Nine parameters, pH, total phosphate, electric conductivity, biochemical oxygen demand, temperature, nitrates, dissolved oxygen, chemical chlorine evaluated quality. was examine samples obtained at twelve locations from January 2005 December 2012. highest values were found Raggahawatte Ela throughout 8 years, located Biyagama industrial zone. relationship industries stated. gradually decreased as result development activities. work showcases recommends importance introducing necessary actions considerations future management systems.