K Shirani; A Seif; A Nasr
Abstract
Regarding their nature and their variety, and hazards that landslides have for humans life and properties, landslides have always been the center of attention and study by scientist from different fields of study such as: geology, engineering geology, geomorphologies, these phenomena are a complex activity ...
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Regarding their nature and their variety, and hazards that landslides have for humans life and properties, landslides have always been the center of attention and study by scientist from different fields of study such as: geology, engineering geology, geomorphologies, these phenomena are a complex activity and different factors and variables could be effective in this occurrence, numerous studies have been done to recognize the effective factors, classification, zooming and modeling. Accordingly, we have tried to study the landslides in Kahredan basin in northern part of Semirom, DenaMountain in Zagros zone suburban area in Esfahan province and provide a landslide hazard zonation map by using the statistical method and the hazard map which has the most accuracy and precision will be selected. So finally we specify the order of effective parameters in landslides. According, by selecting following six parameters: slope aspect, lithology, land use, rainfall and distance from drainage, we provided the distribution of landslides map by using following four methods.
Information value, linear regression, discriminate analysis and area density. The best landslide hazard zonation map has been statistical method of information value which is capable of using in planning and urban developments. Effective parameters in landslides according to their importance are, lithology, distance from drainage, land use, slope and rainfall.
K. Shirani; A. Seif
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 ...
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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.
