چکیده:
The estimation of instantaneous peak discharge is important for watershed management because there is a insufficient climatic and hydrologic data in countries such as Iran. Researchers have been forced to link constant parameters (geomorphology) and variable parameters (hydrology) to models with minimum dependence on climatic and hydrologic data for hydrologic estimation. The present study used a synthetic unit hydrograph at three drainage basins in the central Alborz watershed (Kan, Amameh and Mehran) and compared the results with peak discharge in the study areas to derive the best model. The results of the instantaneous peak discharge estimation were similar for
each drainage basin. A comparison of the models using relative mean error (RME) and root of mean square error (RMSE) for the three drainage basins showed that the mean RME for GIUH was 21.31, for Snyder was 82.25, for SCS was 227.34, and for triangular was 231.27. The mean RMSE for GIUH was 12.76, for Snyder was 17.05, for SCS was 42.84, and for triangular was 43.62. This confirms that the best estimation was produced by GIUH,followed by the Snyder, SCS and triangular models.
خلاصه ماشینی:
ir DESERT 18 (2013) 105-111 Estimation of Instantaneous Peak Discharge Using GIUH, Snyder, SCS and Triangular Models: a Case Study of Central Alborz Watershed H.
The present study used a synthetic unit hydrograph at three drainage basins in the central Alborz watershed (Kan, Amameh and Mehran) and compared the results with peak discharge in the study areas to derive the best model.
The results of the instantaneous peak discharge estimation were similar for each drainage basin.
The study of drainage basins must consider geomorphological characteristics that affect discharge characteristics of major rivers and tributary streams, along with the sediment they generate (Ahmadi, 2006).
Snyder (1938) proposed a method in accordance with the attributes of unit hydrographs for a drainage basin in the Appalachian Mountains (Alizadeh, 2000).
The result is GIUH, an instantaneous unit hydrograph derived using Horton law for the construction and structure of drainage basins describing the engineering of stream networks and the resulting of geomorphology response (Karonen, 1998).
2. Material and methods Study area Central Alborz watershed contains three drainage basin; Kan, Amameh and Mehran (Fig 1).
5. Peak discharge estimation The Snyder, SCS and triangular models used the relation presented in Mahdavi (1999) and Alizadeh (2000).
A study in Paskohak drainage basin by Rahimian and Zare (1995) was used for comparison of the results of the 4 methods results.
If one drainage basin does not have hydrometric and gauge rain stations, the Snyder model is recommended.
It is recommended that the GIUH model be further tested as a suitable method for other drainage basins in Iran.