Eutrophication Check of Reservoirs with CE-QUAL-W2

In recent decades and by beginning of new century, one of earth planet's inhabitant population's worries and particularly countries located in dry lands such as our country is water problem in a way that availability to water with appropriate quality and quantity has been converted to a challenge. Temperature related features and stability of reservoirs could be predicted by use of mathematical modeling and in case of environmental problem, can be taken remedial way for decreasing problems by various ways. A vertical two-dimensional laterally averaged hydrodynamic and water quality model (CE-QUAL-W2) was used to simulate the hydrodynamics, temperature, and water quality in the Shirin Darre Reservoir over the years 2011 through 2012.Considering that the eutrophication of the Shirin Darre reservoir have been increased since in early August and reached to thehighest level in September until that the reservoir entered in eutrophication condition, the calibrated model was then applied to simulate water quality response to various nutrient reduction scenarios. Results of the model reveal that a 60% to 70% reduction of phosphorus loads will improve the water quality from eutrophic to mesotrophic. Also that, in the long term, with proper management strategies of reducing watershed nutrient loads can improve the water quality of this reservoir. The modeling effort has yielded valuable information that can be used for decision makers for the evaluation of different management strategies of reducing watershed nutrient loads.