Assessment of seasonal variation in physico-chemical characteristics of a lentic waterbody of Bhopal, India

Abstract

The present study was conducted with an aim to assess the seasonal variation and nutrient status of a lentic water body (Lower lake) of Bhopal, India. Different variables involving water temperature (W.T), Secchi transparency (TRN), pH, total dissolved solids (TDS), conductivity (CON), total alkalinity (T.A), dissolved oxygen (DO), chlorides (CL), total hardness (TH), orthophosphate (PO4-3) and nitrate (NO3-N) were examined using the standard methodology of APHA (2005). Significant seasonal variation was observed in Secchi transparency which ranged from 27 cm to 83 cm, chlorides (29 mg/l to 58 mg/l, dissolved oxygen (1.6 mg/l to 9.2 mg/l), phosphate (1.76 mg/l to 2.9 mg/l) and nitrate (0.98 mg/l to 3.57 mg/l). Our results confer that the water body is undergoing nutrient enrichment especially littoral sites due to direct influx of untreated sewage from surrounding urban settlements which has resulted in the deterioration of water quality of the lake. Pearson correlation analysis was employed to determine the relationship among water parameters which revealed both significant positive and negative trends.