كليدواژه :
پهنه بندي , آسيب پذيري , زلزله , مدل تاپسيس و سا , شهرداري منطقه 4 تبريز
چكيده لاتين :
Introduction During the development of human civilization, man has always been involved with a variety of natural disasters and in many cases irreparable damage caused by these disasters on human society entered. Urban expansion, urbanization and increasing the number of areas and densely populated areas, increasing the load on the environment make necessary Zoning of the earthquake to assess the potential of damage. Due to the nature of the earthquake and the need to take quick and correct decisions for unexpected phenomena, we need the knowledge as a risk assessment during in now, before, after an earthquake, to mitigate the effects of the accident and reduce its vulnerability. Applying the principles of urban planning, such as form, texture and structure of the area, urban networks and infrastructure, geological structure and etc can greatly reduce the effects and consequences of earthquakes. This study investigates the role of risk assessment of earthquake in Region Two of Municipality of Tabriz using TOPSIS and SAW model in GIS Environment. The necessity of this research are: Close proximity to the fault of Tabriz in the Region two of the Municipality of Tabriz, Indiscriminate construction with high densities, insufficient attention to issues of natural and tectonic situation, mistake Construction regarding the form and shape of the city in the northern region, Lack of attention to the correct location of land use and the natural limitations of the study area. Region Two of Municipality of Tabriz as one of the ten largest metropolitan areas in North West of Iran with an area of about 2104 hectares lies at the geographical location of 46 18 to 46 23 East and 38 2 to 38 4 North in the southern city of Tabriz.
Methodology For assessment and zoning of the earthquake in Region Two of Municipality of Tabriz, Distance from fault, material quality, construction quality, building density, building age, building blocks size, number of floors, population density, slope, distance from medical facilities, distance from dangerous and sensitive centers, distance from power line, accessibility to roads network, Movability in critical condition, and geological structure variables have been used. For preparation of database layers ArcGIS10 software with TOPSIS and SAW was used. Criterion of optimality is calculated according to method of Simple Additive Weighting (SAW). SAW method is best known and one of the simplest and widely used. Reference data are solution matrix and known significance quantity. Solution matrix cannot have non-numerical values. Besides, there must be defined criteria importance values (at least defined as equal sized). TOPSIS defines a “similarity index” (relative closeness) by combining the proximity to the positive-ideal solution and the remoteness of the negative-ideal solution. In this case “similarity index” would be KBIT. The chosen alternative should have the shortest distance from the positive-ideal solution and the longest distance from the negative-ideal solution. The criterion may be ordinal or cardinal. If criterion are ordinal (subjective), they must be quantified (equated to integer values). Results and Discussion Based on the TOPSIS and SAW, from the total area of 2104.83 hectares, about 729.61 hectares of vulnerability in areas with very low to low in the southern parts, 350.08 hectares in the vulnerabilities average in the center and 1025.14 hectares of vulnerability high to Very high in the northern and northwestern parts of the Region two. Overlaying of each variable to the earthquake hazard zoning map shows the relative position of danger zones in both the final map of the location is relatively equal. With regard to the nature of the two models appear TOPSIS model to get a quick view of the vulnerability of the area and the results of the SAW model to make decision about prioritization on retrofit actions, temporary housing and handling sensitive land uses. Overlap region two land use map with earthquake hazard zonation map was determined by SAW, 400 hectares of residential land use in high to very high risk zone that has been the lack of attention to earthquake risk reduction strategies for building and high population density.
Conclusion In recent years, rapid growth of urbanization and urban sprawl in different directions, usually without regard to principles of urban planning and risk considerations, caused material and moral damages and loss of investment in the government. Region Two of Municipality of Tabriz located in the one of the most sensitive and vulnerable area because proximity to the fault of Tabriz with high density of population and 143 thousand people and a wide range of industrial and service centers in place that recognize establishment of quality and quantity in different zones of risk is necessary. In this study, the ability of multi-criteria decision analysis method with TOPSIS and SAW model to identify the risk and distribution of the land use for solving complex problems Revealed. The development of appropriate strategies, monitor the issuance of building density, conductivity residence and activity center on marginal lands can be reduced from accumulation land uses in high risk areas and lead to environmental protection and optimal use of existing resources in the city.
