Automatic Thermal Calibration of Two Dimensional CE-QUAL-W2 Model in Karkheh Reservoir Applying Particle Swarm Optimization Algorithm

In this study، Particle Swarm Optimization (PSO) algorithm has been used to calibrate CE-QUAL-W2 model as a water quality simulation model. PSO algorithm as an optimization technique is applied to optimize the objective function of automatic thermal calibration process. Sum of the absolute difference between simulated results and field data in monitoring stations in Karkheh Reservoir has been considered as an objective function. With sensitivity analyzing، the most significant parameters have the most influence on the temperature profile in Karkheh Reservoir have been identified. These parameters were wind sheltering coefficient (WSC)، extinction coefficient for pure water (EXH2O)، solar radiation absorbed in surface layer (BETA)، and empirical coefficients of wind speed function (AFW، BFW، and BFW). The efficiency of the automatic calibration model (PSO-CE_QUAL_W2) has been evaluated with the hypothetical data in Karkheh reservoir. Then the evaluated model has been applied in vertical temperature calibration in Karkheh Reservoir during 90 days. The vertical temperature profiles of the model results agree closely with the set of field data.