Prominence of seasonal water quality assessment in a tropical river using multivariate analysis: Kerala, India

Abstract

Abstract An account of seasonal water quality variability has been taken as a proxy for the changes of environmental setting occurring in the catchment areas and helps to illustrate the ecological system processes associated with it. The present study in Meenachil River (L = 78 km, A = 1272 km2) comprising of stations from upstream to downstream for pre monsoon (PRM), monsoon (MON) and post monsoon (POM). Ca2+ and SO4 2− show an erratic trend while extreme deviations were observed at S6 and S7 stations. Na+, K+, Cl−, DIC and DOC showed a similar trend in most stations, i.e. (PRM > POM > MON). Significant rise of DIC and DOC at S7 during POM and PRM could explicate changes ensued in adjacent Vembanad lake system. Strong correlations of DIC and DOC for Na+, K+ and Cl− ions were noted in the study. HCA dendrogram reveals that ion chemistry in S6 and S7 was strictly controlled by neighbouring lake water dynamics. The results demonstrate high F1 variance of 73, 68 and 72% followed by F2 comprising of 17, 19 and 21% for PRM, MON and POM, respectively. General understanding into the autochthonous process associated within the river lake interface region was evident from the nutrient variability scenario.

Keywords

• Seasonal water quality
• Tropical river
• Multivariate analysis