evaluation of the efficiency of awbm, sacramento and tank rainfall runoff model in runoff simulation in arazkoose - goorganrood basin, golestan porovince

according to variety of accessible hydrological models, evaluateing the efficiency of models for different management objectives are essential. therefore, models with simple structure and using minimal input that can provide an acceptable result can serve as an effective tool to watershed managers. hence, the objective of this research is to evaluate the relative performances of the lumped conceptual-based hydrological awbm, sacramento and tank rainfall runoff models for daily simulation in arazkoose tributary of goorganrood river, golestan porovince. automatic calibration of the models were done for a 5-year period (1984-1988), followed by a 4-year validation period (1992-1995). the results were evaluated by several criteria, i.e. root mean square error (rmse) and nash coefficient efficiency coefficient (ens) and the coefficient of determination (r2). according to the evaluation criteria the results were satisfactiory. statistic and graphic results show that sacramento model is performing most accurately among the models with r2= 0.823, ens= 0.677 and rmse= 4.565 in calibration periods and r2= 0.719, ens= 0.669 and rmse= 7.905 in validation periods. simulation of the models was more accurate for calibration period rather than validation period. also the models’ minimum and average values of runoff are accurate and despite good simulated peak flow values, the results show that the models cannot accurately simulate all of the peak values. since these models do not require much input data and their use is not time-consuming and costly, they can be preferred for surface water resources management.