Mathematical modelling for the phosphate and nitrate carrying capacity of dams in Uttarakhand

The Himalayan State of Uttarakhand has abundant natural water resources and 98 Hydro Electric Power Project (HEP’s) have been constructed, 25 are under construction and, 336 are planned for the future. The water bodies of these HEP’s can also be utilized for other purposes besides electric power generation. To conserve the endemic aquatic biodiversity, it is necessary to understand the phosphate and nitrate dynamics of these water bodies. As there are several HEP’s on a single river and the human population around them, water bodies have changed drastically during the last decade. In this study, we have calculated the phosphate and nitrate load-carrying capacity of six dams in the Uttarakhand state of India using the Vollen-Weider mathematical model modified by Dillon, Rigler and Beveridge. We have also measured the phosphate & nitrate content of these water bodies to confirm if our modelling methods confirmed with actual finding of sampling sites. The phosphate and nitrate carrying capacity of these six dams were found to be in the range of 0.155 mg/l to 0.557 mg/l and 0.6 mg/l to 1.3 mg/l. To the best of our knowledge, this is the first study in Uttarakhand that addresses the phosphate and nitrate carrying capacity using a mathematical model.