The possibility of using map of land units as map of working units in providing maps of surface, rill and gully erosions by Geographic Information System (GIS)

The possibility of using map of land units as map of working units in providing maps of different water erosion types was investigated in the downstream of Latian dam. The real maps of land units in each surface, rill, gully erosions and erosion features were provided and the digitized layers of each along with crossed land units were given, the rate of accuracy, error, and precision of this layer as a model in estimating each of erosion types were computed. Results showed that the accuracy of land units in providing surface, rill, gully maps of erosions, and erosion features is 66.1, 66.6, 82.0 and 53.0 percent respectively. This map has a low accuracy in providing map of erosion features; therefore, it cannot be used in preparing map of erosion types as the map of working units.