Assimilation Capacity Changes of Gharehsou River, East of Ardabil Province, Iran 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. the best model simulation for ph parameter was obtained and in the next ranks, the parameters were, respectively do, bod, no3, and temperature. the results show low assimilative of parameters in gharehsou river and the severe impact of non-point sources in it. results showed that measured and modeled values have a good agreement with each other and the simulation in these parameters has been done well.