Evaluation of Water Quality Index to Assess the Impact of River Pollution on Vembanad Lake—A Ramsar Site

Abstract

AbstractEvaluation of the degree of pollution in the water bodies is becoming a matter of prime concern globally, as the number of countries becoming water stressed is on the rise. A single number that adequately subsumes the pertinence of various physicochemical parameters on the quality of water like pH, dissolved oxygen, alkalinity, dissolved solids, hardness, coliform content, etc., is the water quality index. In the study, a generic Python code was developed to promptly compute the water quality index, using a method proposed by the Council of Ministers of the Environment of Canada, for any water body, by inputting 24 physicochemical parameters for four consecutive years. Vembanad Lake is one among the Wetlands of International Importance in Kerala and is listed as a Ramsar site. The lake receives drainage from ten rivers and is rich in biodiversity. The wetland is a major source of livelihood for the people in various districts of the state over which the lake is spread. The levels of pollution in the rivers draining into the Ramsar site have been analyzed by determining its water quality index, using the Python code. It has been observed that some of the river stations of River Periyar that drain into the lake are having marginal and poor water quality, due to high levels of fecal and total coliform. As a result of the pollution from the river and few other reasons like tourism and agricultural practices, the water quality index of Vembanad Lake is 60 and falls in the marginal category.KeywordsVembanad LakeWater quality indexWater pollutionRamsar siteKerala rivers