Investigation of Some Models Derived from Data Layers Integration in Geographic Information System with Slope Layer for Providing Water-Soil Erosion Types Maps

摘要

The aim of this study is to investigate some models of data layers integration and slope layer (GIS) for providing erosion types maps in Roodbar sub-basin, downstream Sefidrood dam. From topographic layer, DEM was provided and then from that, four slope layers with different categories of slope were prepared. Nine working units' maps were provided from the integration of the land use, rocks erodibility, land unit and different slope layers. In basin, 652 ground control points were investigated with the view of erosion features (surface, rill and gully erosions) and the point's position were recorded by GPS. Homogenous points percent with the view of the surface erosion, rill erosion, gully erosion and erosion features were computed to derive the accuracy of working units. Mean accuracy of these working units has been considered as the accuracy of working units maps. Results indicated in providing erosion features, using slope layer is led to the high numbers of small area working units that in addition to increase in field controls expenses and executive limitations, it is also accompanied with cartographic limitations. Overall accuracy and precision of the model derived from the integration of land use, land units and rocks erodibility layers was investigated as compared with truth maps of surface, rill and gully erosions and erosion features map. Results indicated that this model can be used in providing erosion types maps with accepting error, but without forest land use, it is not proposed.