Spatial and temporal variations of river water quality: A case study of River Kabini at Nanjangud in Karnataka

Abstract

Water pollution is alarming all over the globe and necessitates better understanding of spatial and temporal variations of pollutants in the rivers. In this study, the data sets of 8 water quality monitoring stations in River Kabini at Nanjangud which comprised of 10 water quality parameters monitored monthly over 12 years (2000-2011) are used. Temporal variation of the physico-chemical parameters in each station is represented by Box plots. High positive skewness is observed for total dissolved solids (TDS), conductivity, chemical oxygen demand (COD), and chlorides for all stations, showing rampant pollution in the river due to anthropogenic sources. The microbiological parameters in each station shows the river is polluted with total coliform and faecal coliform across baseline, trend and impact stations. The results suggest that the Kabini River is polluted from anthropogenic sources because bathing ghat exists along the river and domestic wastewater is let into the river without treatment. This study provides critical information for river conservation and its protection by suggesting possible treatment of domestic wastewater before letting in the river. Key words: Box plots, temporal variation, anthropogenic sources, total coliform, faecal coliform.