Determination of River Self-Purification Capacity Using Qual2kw Mode Case Study: divandare River

Knowledge of the process of change and the prediction of water quality parameters of the rivers provide the quantitative information needed to calculate the tolerable pollution load in the natural environment of the river, as well as a fuller understanding of the biological processes an environment. The main objective of this paper is to use the QUAL2Kw qualitative simulator model to model water quality in the Dyvandareh River and reduce river pollution by more adapting the amount of inputs of pollutants in different areas of the river with its ability to self-pollute. In this study, the process of changing the important parameters of the water quality of the Diwandreh River, such as dissolved oxygen (D0), biological oxygenation (CBOD), chemical oxygen demand (COD), acidity (pH), electrical conductivity (EC) and temperature, and Calculating the percentage of self-pollination of the river from the beginning of the branch before the connection of the tallar river to the decaying parameters of BOD and COD, and to predict their changes, the QUAL2Kw qualitative simulation model has been used. In order to calibrate the model, data from December 2008 were used. Due to the ability of the model for automatic calibration in this study, calibration was done both manually and effortlessly. In order to evaluate and validate the model results, AME and root mean square error (RMSE) were used.