Water Quality Assessment of Sisauli Wetland of Morang District, Nepal

Abstract

Wetlands provide essential ecosystem services, including biodiversity conservation, water purification, nutrient cycling, and hydrological regulation. Assessing their water quality is therefore important for understanding environmental conditions and informing conservation priorities. This study evaluated the post-monsoon water quality of Sisauli Wetland in Morang District, Nepal, using selected physicochemical parameters to characterize aquatic conditions and identify monitoring needs. Water samples were collected from five representative sites following standard sampling procedures. Temperature, pH, total dissolved solids (TDS), and dissolved oxygen (DO) were measured in situ, whereas the remaining physicochemical parameters were analyzed in the laboratory using standard methods. Recorded values included a temperature of 30.2 °C, pH of 8.5, TDS of 92.2 ppm, and DO of 9.64 mg/L. Total alkalinity was 92 mg/L, while nitrate, nitrite, ammonium, and iron concentrations were 6.8, 0.48, 0.02, and 0.26 mg/L, respectively. The results characterized the sampled water as well oxygenated, with low dissolved solids, alkaline conditions, and alkalinity indicating buffering capacity. Nevertheless, the reported nitrite concentration and localized alkaline conditions warrant periodic monitoring to determine their persistence and ecological significance. The measurements provide a baseline for understanding post-monsoon physicochemical conditions, while conclusions about overall ecological health remain limited by the parameters assessed and the seasonal scope of sampling. Continued assessment across seasons, supported by biological indicators, would strengthen the evaluation of wetland condition and potential environmental pressures. The study recommends regular monitoring of nutrients, pH, and DO, together with effective conservation measures, to detect changes in water quality and support the long-term ecological integrity of Sisauli Wetland.