Water criteria evaluation for drinking and irrigation purposes: a case study in one of the largest rivers of Sundarbans World Heritage region

Abstract Pasur river is one of the largest rivers in World Heritage Sundarbans mangrove forest region southwestern part Bangladesh. Due to lack alternative sources, more than 1 million inhabitants living basin area rely heavily on water for domestic, irrigation, and industrial purposes without proper reliable information qualities contamination types. The study aimed at evaluating suitability sustainability irrigation consumption practices, suitable hydrogeochemical techniques quality Sundarbon Bangladesh were investigated. Water samples collected from six locations during pre-monsoon post-monsoon seasons assessed drinking application. index (WQI) was calculated evaluate drinking. WQI indicates that both are safe good category. Sodium percentage (Na%), sodium adsorption ratio (SAR), magnesium hazard (MH), residual carbonate (RSC) investigated assess feasibility agricultural applications. Most indices, such as SAR, Na%, RSC results recommend irrigation. A suggestion made MH should be controlled use United States Salinity Laboratory (USSL) diagram Wilcox analysis also identified a usable category feasible seasons.