Study the assimilation capacity of Gharehsou River using Qual2kw model

In this study, the assimilative capacity changes of the Gharehsou River has been studied. Gharehsou River, in the East of Ardabil province of Iran in its flow path, is the entrance and discharge domestic sewage, industrial wastewater and agricultural drainage and for determining of assimilative capacity of this river, first, the calibrated model of Qual2kw simulated parameters change of NO3, BOD, DO, pH and temperature for two months of January and July, and then it was compared with observational data in Aladizgeh, Samian, Anzob and ArbabKandi stations. Given the mean correlation coefficient R2 and the mean average absolute error (MAE) for two months, the best simulation for pH (R2=0.43 and MAE=0.95) and then respectively, for temperature (R2=0.56 and MAE=5.75), DO (R2=0.69 and MAE=1.75), BOD (R2=0.75 and MAE=5.78), NO3 (R2=0.39 and MAE=2.17), have been done and with the exception of nitrate, for other parameters, the Simulation in July was better than January. Results showed that measured and modeled values have a good agreement with each other and the simulation in these parameters has been done well