Zoning of physical - infrastructural Vulnerabilities to landslides using GIS, case study: settlements in Tehran and Alborz provinces

Background and objectives: Tehran and Alborz provinces are important zones from an economic, social and political activities point of views in the country; most of the habitations in these provinces were built in areas which are in the risk of landslide. This research, studied the damages and physical-infrastructural vulnerabilities in these areas, considering the landslide hazardous zones based on the earthquake and rainfall incidents. Method: The present study were scored and compared 11 indices which affect landslide incident by using hierarchical group analysis method; after compiling landslide susceptibility maps, infrastructure, and buildings, equipment and facilities vulnerability in cities to the incident was assessed. Findings: According to the findings, there is a very high, high and medium probability of landslide risk in the northern strip, some parts of east and south of Tehran province and north and west of Alborz province. The development of physical and infrastructural elements in Tehran and Alborz provinces in these zones has caused high and medium vulnerability in this field. Subsequently, the probability of secondary disasters such as explosions and fires in some parts of the studied zones is assessed as high and medium. Conclusion: Considering the probability of landslides in cities and suburbs in Tehran and Alborz provinces, first, it is necessary to reduce the vulnerability of existing physical-infrastructural elements to landslides as a priority for urban planners and regional authorities. As well as, every future planning and development of urban and regional physical-infrastructural elements in these zones should consider the possibility of landslide.