Document Type : Research Paper
Authors
1 Department of Watershed Management, Faculty of Natural Resources, Tarbioat Modares University
2 Department of Watershed Management, Faculty of Natural Resources, Tarbiat Modares University
3 Department of Watershed Management, Faculty of Natural Resources, Sari Agricultural Sciences and Natural Resources University
Abstract
Due to the lack of data about soil erosion and sediment yield in many watersheds of Iran, the use of appropriate empirical methods is inevitable to erosion estimation, sediment yield and especially sediment delivery ratio. For this purpose, in the present study, empirical models for estimation of the sediment delivery ratio based on easy-to-measure variables and three models of SATEEC, InVEST and WaTEM/SEDEM were used in the Khamsan representative-paired watershed, western Iran. To evaluate the used models, the results of calculating the sediment delivery ratio using the 137Cs method obtained from previous researches were used, which are 25.61% and 58.94% for the entire watershed and the average of 15 sub-watersheds, respectively, and its accuracy is based on the observed sediment data at the outlet of the watershed has been confirmed. Among the studied sediment delivery ratio models, Renfro and Waldo (1983), Williams and Brendt (1972), Roehl (1962) considering one hour excess precipitation, Walling (1983), Ferro (1995), Vanoni (1975) and USDA (1972) provided the closest estimates (±10%) to the 137Cs method for the whole watershed scale and the Renfro (1975), USDA (1972), USDA-SCS (1979), SATEEC and Roehl (1962) considering one hour excess precipitation for the sub-watershed scale provided the closest estimates (±10%) to the 137Cs method for the sub-watershed scale and were selected as suitable sediment delivery ratio models for Khamsan representative-paired watershed. Also, these models can be used to estimate the sediment delivery ratio in watersheds similar to Khamsan representative-paired watershed.
Keywords
)