Evaluation and analysis of urban instability in earthquake instability (Case Study of Mashhad Metropolis)

Due to the growth of urbanization and the expansion of informal settlements and worn out tissues, environmental hazards such as earthquakes in the metropolitan area can cause serious damage and cause urban development disruption. The city of Mashhad, as the second largest city in the country, is considered as one of the most vulnerable areas due to being located on several faults and being in the earthquake belt of the world. So, with regard to the situation in Mashhad, the question is, which urban areas are physically and natural in nature with unstable and vulnerable levels? This research is descriptive-analytic. In this study, three main indicators (demographic, physical and natural hazards) and eight criteria (household size, population density, absolute population, number of households in residential units, type of materials, age of building, quality of buildings) as indicators Demographic and physical distances from the fault as the most important indicator of natural hazards in 17260 urban blocks using AHP and GIS have been investigated. The results show that the range of middle and middle-aged corroded tissues (8%) and informal settlements formed in northern and northeastern cities of the city (11%) due to wear and tear of texture and the use of low-durability materials in construction As well as the lifetime of buildings, as well as the southern region of the city (21%), is vulnerable due to the presence on the fault line.