Assesment About Efficiency of SWAT Semi-Distribution Model for Simulation of Streamflow (Case Study in Talar Watershed,Mazandaran Province)

In this study, to evaluate the efficiency and effectiveness parameters about rainfall-runoff relations , SWAT models have been used inTalar watershed of Mazandaran province .By using of this model ,has done ,calibration based on 8 rainfall station with daily precipitation, 5 evaporation station with daily temperature along output discharge in shirgah-Talar hydrometric station.Performing the calibration and validation of this model , was simulated initially based on 21 parameters with high sensitivity . In validation phase of 21 selected parameters, study about p-value and t-state indices shows sensitivity and behavior of parameters .At this stage, CN2-MGT parameter with the least amount of p-Value index and the highest index value t-State is recognized as the most sensitive parameters .The first phase of model calibration results showed that weaknesses in the simulation model that is well coefficients p-factor, r-factor, R2 and NS respectively 0.04, 3/91 , 0/01, -44/15.Due to these issues by analyzing the results of the first phase of this study, we calibrated 8 sensitive parameters through the first 21 parameters until created better correlation between simulated and observed discharges. In validation stage of 8 sensitive parameters in 95% confidence interval, created high correlation between simulated and observed discharges and shows in the result of scatter plots of this phase . Comparison of p-factor,r-factor,R2,N.S with 0.93, 0.93 ,0.79 ,0.98 respectively shows the better model simulation that cause efficiency of model for simulation in this stage.