Sediment Yield Estimation Due to Forest Road Network Using SEDMDEL and GIS

Forest roads are important components of forest management units and involving special roles in wood transporting and the other forest uses such as hunting, tourism, etc. One of the most important problems due to forest roads developing is increasing erosion of different forms of soils around roads, sediment yield resulting of vegetation destroy, ruining of soil structure, increasing run off velocity and instability of slope.
In this research, sediment due to existence forest roads was estimated in a part of Experimental Forest Station of Tarbiat Modares University using of SEDMODEL and GIS. In this model effective factors consist of geology, road, slope, precipitation, vegetation cover and drainage network.
Findings: Created erosion resulting of this road network was estimated about 1576.4 ton/year without considering SEDMODEL. This amount was estimated about 140.7 ton/year with considering SEDMODEL on basis distance of waterway.
Discussion and Results showed that the share of roads sediment yield is about 1.33 percent of watershed exit, but roads includes 0.017 percent of watershed areas. Paying attention to the covered areas by roads in watershed, the amounts of sediment yield is 78 equal of sediment yield average in watershed area.