State of Water Quality of Two Tropical Urban Lakes Located at Mumbai Megacity

The study focused on identifying the significant physico-chemical parameters to understand the prevailing water quality conditions of two urban lakes located at Mumbai megacity. Out of the different water quality parameters analyzed, biochemical oxygen demand, total organic carbon, ammonia, alkalinity and minerals showed higher mean values in Powai Lake compared to Vihar Lake. Physico-chemical parameters were subjected to factor analysis to decipher the significant factors loaded with parsimonious variables which can explain the total variation. Two factors extracted explained the cumulative variation of 62.75% and showed significant loadings of water quality parameters. Separation of Powai and Vihar lakes with respect to water quality parameters is quite evident based on score plot. Powai showed higher score coefficients for the two factors in comparison with Vihar. Phytoplankton evaluation was carried out to determine the trophic status of both the lakes and identified mesotrophic condition in Vihar and eutrophic condition in Powai. The study also identified substantial reduction in Powai Lake area in recent years which will exacerbate the lake pollution. The findings will serve as baseline information for detailed studies in near future and also helps in devising remedial measures to prevent the deterioration of health of the lake ecosystem.