Document Type : Original Research Paper
Authors
1 Assistant Professor, Isfahan Research Center for Agriculture and Natural Resources, Isfahan, Iran
2 Assistant Professor, Dept. of Natural Geography, Faculty of Geographic Sciences and Planning, University of Isfahan, Isfahan, Iran
Abstract
The landslide hazard zonation was executed by different methods and many of these methods were based on special condition of the study area. This research, at first, Pishkuh region (fereyidonshahr administration) was selected with 77646 hectars area in west of Esfahan province. Then, landslide inventory map was obtained by using airial photos, satellite images (ETM+2002), geology maps and surveying of the field. Also, the 8 important factors are effective in occurrence of landslide including slope gradient, aspect, lithology, landuse, rainfall, and distance to fault, road and drainage were determined by using inspect of feild, literature review in similar regions of northern Karoon and Dez basins in scale of 1:50000. In order to increasing of precision, speed and facility of analysis, all of the attribute and spatial data were entered into ArcGIS software. After producing of information layers and weighting to effective factors by using inventory map, landslide hazard zonation was created by two bivariarte statistical methods including to Information value and Density area methods and the results were assessed. When the density ratios (Dr) Index (for the purpose of camparing between hazard classes) increase in each two method, then hazard rate will increase and the separation between hazard zone classes is acceptable and increasable. The quality sum (Qs) and precision (P) indices (in order to comparing of methods together) for Information value method are 0.65, 0.034 and for Density area method are 0.56, 0.028, respectively. It is clear that the information value is better than Density area in landslide hazard zonation.
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