APPLICATION OF SRM MODEL IN SNOWMELT RUNOFF SIMULATION USING NOAA AVHRR IMAGES IN UNGAGED BASINS

In mountain regions, snowmelt runoff is a key hydrologic component that controls flow regime. In such regions, it is usually impossible to sufficiently measure the climatic and hydrologic data in the spatial and temporal scale required for the simulation of uncertainty. Therefore, predicting snowmelt runoff is carried out with some unknown degree of uncertainty. When calibrated, Snowmelt Runoff Model (SRM) is a hydrologic model, capable of simulating daily discharge in case of minimum measured snow data. The SRM is applied in order to study the capability of this model in simulating the snowmelt runoff in a basin in Iran, which lacks sufficient data. Khersan a sub-basin of Karoon river is considered for this case study. An Advanced Very High Resolution Radiometer (AVHRR) data is also considered to determine the time series of snow-covered areas. The time-series of daily discharge in 1996 are used for model calibration. Accuracy of the parameters is evaluated based on the time series of daily discharge in 1997. Model accuracy in snowmelt and rainfall runoff simulation is 88% based on evaluation results. The determination coefficient R2 is 0.774. The difference between the simulated and measured total discharge is I% for the study period. Based on the results of this research, SRM can be considered as an effective tool to estimate the snowmelt runoff and the quantity of rain and snow contributions. The application of this model is recommended for basins with no measured data.