Spatial Distribution of Non-Point Source Pollution of Vembanad Lake, Kerala, South India

The Vembanad lake is bordered by Alleppey, Kottayam and Ernakulam districts of Kerala covering an area of about 200 sq.km. and extending 80 kms in a NW-SE direction, from Munambam in the North to Alleppey in the South. The purpose of this study is to analyse the pollution levels and plot a spatial distribution of pollution parameters on the Vembanad lake. Spatial and Temporal variation across 35 representative sites and in postmonsoon and pre-monsoon seasons was plotted. The various parameters analysed were acidity, hardness, chloride, sulphate, COD and iron. The spatial distribution of the parameters was plotted with the aid of Geographic Information System (GIS). The analysis results were used for identifying relatively more polluted areas and hence would be helpful in adopting measures to ameliorate water quality and control outflow of wastes into the lake.