Estimation of daily runoff using of the semi- conceptual rainfall-runoff IHACRES model in the Navrood watershed (a watershed in the Gilan province

Due to lack of data, using of rainfall-runoff models with high accuracy that do not need to large amounts of data is an important issue. The IHACRES model is a semi- conceptual rainfall- runoff model. This model does not need to large amounts of data and calculates effective rainfall. Then this model simulates the value of runoff. The case study of this research is the Navrood watershed in the Gilan province. For simulation of rainfall and runoff in this research, IHACRES model utilizes daily flow discharge data in the Kharjgil hydrometric station and daily precipitation and temperature data in the Khalian synoptic station. The Kharjgil hydrometric station locates at outlet of watershed and the Khalian synoptic station locates at center of watershed. The model uses from data of time period 1391 to 1394 for calibration and time period 1387 to 1389 for cross validation. Nash- Sutcliffe model efficiency coefficient (E), mean of total error (BIAS) and average relative parameter error (ARPE) criteria are utilized evaluation of results of model. The value of E is 0.55 and 0.46 for calibration and cross validation respectively. These values show that results of this research are acceptable in comparison with previous researches.