Prediction of water quality in selected stretches of river PAMBA using water quality model
Water Quality Models have been widely used in predicting the probable changes to water quality of rivers, consequent to discharge of wastes. Disposal of treated or partially treated wastewater, into a river course deteriorates its water quality and thereby affects the health of the river. Pamba River serves as a major source of water for drinking and irrigation needs of many grama panchayats located on its banks. It is also considered to be one of the most sacred river of Kerala, since the famous pilgrimage centre Sabarimala is located on its bank. The river gets subjected to high pollution loads especially during the pilgrimage season. This study involves the application of water quality model for a stretch of 12.63 kms of River Pamba and its validation with the real time values of water quality parameters. Samplings done during the monsoon and postmonsoon seasons gave an overview of how the quality parameters varied along the whole stretch of the river. From the seasonal data, a suitable stretch of river was identified where the model is applied. Sampling data of pilgrimage season was used for calculations as it represented the worst scenario. In pilgrimage season sampling was done for the same stretch of 12.63 kms covering four sampling stations namely Athikkayam, Mukkam, Madammon and Ranni, where the water quality parameters were assessed. The entire study stretch was subdivided into reaches of smaller lengths and prediction has been done for each reach, where the concentration of pollutant at the downstream of a reach is taken as the concentration of pollutant at the upstream of the next reach. Prediction has been done for conservative and non-conservative parameters namely BOD Biochemical Oxygen Demand, Total Nitrogen (TN), Total Phosphorous (TP), Alkalinity and Total Suspended Solids (TSS). The model was calibrated and standard deviations were computed for each parameter.