University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 55 6 2024 08 22 Evaluation of the efficiency of satellite precipitation data in simulating river flow using the IHACRES Model (Case study: Toroq Dam Watershed) Evaluation of the efficiency of satellite precipitation data in simulating river flow using the IHACRES Model (Case study: Toroq Dam Watershed) 979 1000 98475 10.22059/ijswr.2024.373933.669680 FA Abolfazl Mosaedi Department of Water Sciences and Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.   0000-0002-9698-5005 Sina Mohammadian Department of Water Sciences and Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran 0009-0003-7559-0498 Fereshteh Modaresi Department of Water Sciences and Engineering, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran 0000-0001-7033-5402 Journal Article 2024 03 13  <br />Modeling and predicting the flow rate of rivers is one of the fundamental needs in water resource management. Unfortunately, many watersheds lack precipitation measurement stations. The use of processed satellite data is one of the suitable alternatives to observational data; but the accuracy of estimated precipitation values extracted from satellite data should be compared and validated with ground data in different regions. In the current study, the IHACRES rainfall-runoff model has been used to simulate river flow in the Toroq dam watershed. For this purpose, daily and monthly data from ground stations and MERRA-2 satellite data have been used on a daily and monthly basis in two periods of 9 years and 29 years. The results show that over the study period, the accuracy of estimated precipitation values based on the MERRA-2 satellite has gradually increased compared to the measured values. In the 29-year period, the model validation results are weaker than the 9-year period, which could be due to conditions resulting from land use changes in the watershed and gradual temperature increase in the watershed. With a NSE coefficient of 0.846 obtained in the validation stage of the 9-year period with daily time steps using satellite data, as well as a Pearson correlation coefficient of 0.925, there is a good correlation between the daily-simulated flow using satellite data, and the daily measured flow. Therefore, the use of satellite data produced in the past decade can be a suitable substitute for incomplete precipitation data at ground measurement stations.  <br />Modeling and predicting the flow rate of rivers is one of the fundamental needs in water resource management. Unfortunately, many watersheds lack precipitation measurement stations. The use of processed satellite data is one of the suitable alternatives to observational data; but the accuracy of estimated precipitation values extracted from satellite data should be compared and validated with ground data in different regions. In the current study, the IHACRES rainfall-runoff model has been used to simulate river flow in the Toroq dam watershed. For this purpose, daily and monthly data from ground stations and MERRA-2 satellite data have been used on a daily and monthly basis in two periods of 9 years and 29 years. The results show that over the study period, the accuracy of estimated precipitation values based on the MERRA-2 satellite has gradually increased compared to the measured values. In the 29-year period, the model validation results are weaker than the 9-year period, which could be due to conditions resulting from land use changes in the watershed and gradual temperature increase in the watershed. With a NSE coefficient of 0.846 obtained in the validation stage of the 9-year period with daily time steps using satellite data, as well as a Pearson correlation coefficient of 0.925, there is a good correlation between the daily-simulated flow using satellite data, and the daily measured flow. Therefore, the use of satellite data produced in the past decade can be a suitable substitute for incomplete precipitation data at ground measurement stations. https://ijswr.ut.ac.ir/article_98475_3e2f03f5287a2fd4e513eb7e53b909e3.pdf