Tidal and seasonal variations in water quality of Thane creek, Mumbai, India: a statistical analysis

Abstract

Water quality of Thane creek was assessed spatially and temporally based on receiving waterbody standards and nutrient parameters. Due to large data set and variation in water quality, statistical analysis was carried out to summarize a data set quantitatively using Box and Whiskers plots. These plots helped to display data spread at a glance, reveal data symmetry and skewness as well as the presence of outliers. Further, Spearman’s correlation matrices were generated to establish the relationship between physico-chemical and bacteriological parameters and found to have significant correlation between them. The study reveals that the Thane creek is polluted based on receiving waterbody standards in all the seasons even during low and high tides. The creek water is more polluted in the upper stretch as compared to middle and lower stretches. Immediate attention is required for the improvement in water quality of the creek by enhancement in wastewater collection system, appropriate level of treatment, proper disposal and recycle/reuse of treated effluent rather than discharging into the creek.