gully erosion hazard zoning using of dempster-shafer model in the gharnaveh watershed, golestan province

the goal of this research is gully erosion hazard zoning by using dempster-shafer theory for the garnaveh watershed (golestan province). for this purpose, at first a gully erosion inventory map with the scale of 1:200000 (dependent variable) for the gharnaveh watershed has been prepared using multiple field surveys and satellite pictures. from total gullies 70% of them have randomly selected for building gully erosion hazard zoning model while the residuals (30%) have used for validating the model. in the next stage, seven data layers contain slope percent, slope aspect, plan curvature, lithology, land use, distance from rivers and distance from roads have been selected as gully erosion conditioning factors (independent variables) and digitized in arcgis software. the amount of gully density in each factor class have calculated from combination of independent and dependent variables, and rating of classes have done based on dempster-shafer equations. finally, the gully erosion hazard zoning map has drawn from summation of weighting maps. the results of model classification show that from total considered gully zones for model validating in the gharnaveh watershed %68.06 are in the class of high and very high hazard. also, the result of model validating with using the receiver operating characteristic (roc) curves and areas under the curve (auc) showed that dempster-shafer model is appropriate for gully erosion hazard zoning in the studied area with accuracy of %96.1 and standard deviation of 0.003