Daily Discharge Prediction Using IHACRES Model in Some Watersheds of Golestan Province

Accurate prediction of daily discharge in ungauged watersheds is an important issue in hydrology. Several models have been developed for predicting discharge. The IHACRES is a friendly use model with limited input data which is being used for simulation of watershed outputs. The present study was conducted to assess the applicability of the IHACRES model to simulate daily mean discharge in seven sub-watersheds of Gorganrood in Golestan Province، Iran. Daily time series data of rainfall، stream flow and temperature were applied for the duration of 1986 to 2007. The model was calibrated and consequently validated for each study watershed. The results of the evaluation showed that the model performance in prediction of high flows was fairly good while its performance for flows with frequency of more than 60% was weak. The results also indicated that the simulated peak flows were lower than observed values in almost all stations and in both the calibration and validation periods. The efficiency of IHACRES model in predicting daily discharge was found to be fairly good with maximum and respective coefficients of determination and efficiency of 0. 67 and 0. 70 (P<0. 05).