Landslide risk evaluation for land use and developmental planning, case study: Hashtchin Region

In this research, a spatial prediction model (a quantitative method) and the fuzzy sets theory (a semi-quantitative method) have been used for landslide hazard and risk assessment, respectively. A procedure, compring two analytical stages, has been proposed to show the location of future slope instability. In the first step, 75% of the pixels with landslide have been entered to the model as the estimation set, in which new landslides have occurred with a moderate to high intensity or at least have displaced once or more in the last 50 years. At the second stage, the accuracy of prediction map has been examined by ROC curve (Receiver Operating Characteristic curve) based on 25% of the landslide pixels that have not been entered in the model. Landslide risk evaluation was considered by combination of the hazard potential and resource damage potential and using the fuzzy algebraic product operator in the region. The hazard potential and resource damage potential obtained typically from the hazard zonation map and the land cover/land use map. The area under the ROC curve is 0.795 for hazard zonation map, equivalent to an accuracy of 79.5%. In the base of multi-method approach results, 13.8% of the region is located in a high and very high risk level zone, and 78.1% of the area is placed in low and very low risk categories. Proposed method was used for landslide risk assessment in Hashtchin region and the results could be used to established land use planes, developmental activities, displacement and extension of settlement area, and patterns of building regulations.