Wetlands are the areas where water is the primary factor controlling the environment, associated plant and animal life. Present study had been conducted to investigate the physico-chemical characteristics of water. Five lakes, i.e. Tamor, Beeshazar, Kingfisher, Athaieshazar and Chepang of Chitwan National Park were studied during post-monsoon season. Four different sites were studied for each lake. Twelve replica of water samples were collected from each site of the lakes and physico-chemical parameters, i.e. pH, Temperature, DO, Total Alkalinity, Conductivity, Total Hardness, Nitrate, Inorganic phosphorus, Total Solid Matter and Free CO2 were analyzed by using standard method of APHA, 2012. Data obtained from water analysis were analyzed by SPSS statistics 20. Higher value of nitrate was found in Beeshazar Lake i.e. 4.41±0.52 mg/L and higher value of inorganic phosphorus was found in Tamor Lake i.e. 2.93±0.29 mg/L. All the studied lakes showed hyper-eutrophic category on the basis

Hyper-eutrophic, Invasive, Macrophytes, Physico-chemical Characteristics.

In conclusion, studied two lakes, i.e. Kingfisher and Athaieshazar had moderately hard water (i.e. hardness values ranges between 75-150 mg/L) whereas other three lakes, i.e. Tamor, Beeshazar and Chepang had soft water (i.e. hardness values ranges between 0-75 mg/L). Present study showed three lakes, i.e. Tamor Lake, Kingfisher Lake and Athaieshazar Lake had good water quality and two lakes, i.e. Beeshazar Lake and Chepang Lake had poor water quality in terms of DO. Variations on the physico-chemical characteristics of lakes implies the cumulative effect of excessive growth of the invasive macrophytes, high human and wild animal’s disturbances as well as natural disasters. Richness in total nitrogen and phosphorus ranked all the studied lakes hyper-eutrophic. Runoff of polluted water with agricultural fertilizers, pesticides and untreated industrial discharge as well as domestic wastes from Khageri canal and excessive growth of invasive macrophytes are major threats of studied lakes.

Bhusal, A. and Devkota, A. (2020). Physico-Chemical characteristics of Lakes of Chitwannational Park, Central Nepal. Biological Forum – An International Journal, 12(1): 33-39.