The researchers analyzed the water quality of Fuyang River and found that the amount of pollutants being discharged into the river exceeds its capacity to handle them. By using a water quality model, they calculated the river's capacity for COD and NH3-N pollutants. They discovered that the river's capacity is higher during the dry season due to upstream reservoir control. To reduce the total amount of pollutants being discharged into the river, measures need to be taken to decrease the current level of pollution.