Limnological assessment of Udhwa Lake, Sahibganj with reference to seasonal changes in water quality

Lakes are dynamic freshwater ecosystems whose water quality and biological productivity are strongly influenced by seasonal variations. The present study aims to assess the limnological characteristics of Udhwa Lake, Sahibganj, Jharkhand, with special reference to seasonal changes in water quality. Systematic sampling was carried out during three distinct seasons—summer, monsoon, and winter—to evaluate the physico-chemical parameters of the lake water. Parameters such as temperature, pH, transparency, turbidity, dissolved oxygen, biochemical oxygen demand, total alkalinity, total hardness, electrical conductivity, nitrate, phosphate, and chloride were analyzed using standard methods. The results reveal marked seasonal fluctuations in most parameters, largely driven by variations in rainfall, temperature, and anthropogenic inputs from surrounding areas. Higher temperature, alkalinity, and nutrient concentration were observed during the summer season, while monsoon months showed increased turbidity and nutrient influx due to surface runoff. Dissolved oxygen levels were relatively higher in winter, indicating improved water quality conditions. The overall water quality of Udhwa Lake ranged from moderately productive to eutrophic, suggesting increasing nutrient enrichment. Seasonal variation significantly influences the limnological status of the lake and directly affects its ecological health and suitability for aquatic life. The study highlights the need for regular monitoring and effective management strategies to prevent further degradation of this important wetland ecosystem. The findings provide baseline data that may be useful for future limnological studies and conservation planning of Udhwa Lake.