Location Analysis Regarding Disaster Management Bases via GIS Case study: Tehran Municipality (No.6)

1- Intro duction Nowhere in the world is free from the risk. However, with increasing population and their relevant needs, the destruction and damaging power and magnitude of both natural disasters have been intensified. In other words, the Earth is more vulnerable than it used to be. In this context, disaster management headquarters in Tehran raised and adopted the original plan for disaster management in Tehran. The main goals of Construction of this site is to provide tactical and operational platform for achieving the appropriate preventive measures, preparedness and coping with various crises, particularly the great natural crises such as earthquakes, accelerate network development and system evaluation reticulum incident, and conduct operations control center of city of Tehran. In normal conditions, user education and sport (CS women) also for these categories is considered. Considering that the support bases, particularly in crisis situations play a very important role in the organization and crisis management, so it is necessary that through a comprehensive study the exact place for this type of construction is selected in order to improve efficiency and exploiting it to be effective. So, in this research, analysis and identification of the factors influencing location choice switching sites and appropriate manner based on the findings and scientific instruments is taken in to account so that, the most suitable places to establish these bases in found. For this purpose geographic information system is used as a powerful tool in managing and analyzing spatial data, and six Regional Municipality of Tehran are selected as the study area. 2- Theoretical Bases In order to weight to the effective criteria in setting the site location AHP is used and for integrating layers of index were used overlay and fuzzy models. Explanation about each concept is presented in the following part. - AHP (Analytical Hierarchy Process) AHP was introduced by Thomas L. clock in 1980. This system is one of the most comprehensive of systems designed for decision making with multiple criteria. This technique allows formulating the problem in a hierarchical pattern and makes it possible to consider various quantitative and qualitative criteria. This process involves various options in decision making and has the possibility of doing sensitivity analysis on the criteria and sub criteria. Furthermore, it is based on paired comparison and thus facilitate and calculations. It also shoes the compatibility and incompatibility of the decision which is a superior advantage of this technique in mult criteria decision making. - Index Overlay Model The index overlay model is a cmmon model to combine layers, which gives weight to the factors influencing site selection, based on their importance and role and according to expert opinions. This weight is numerical and determined in specific period. The numerical weight in the specified period shall be determined. In this connection is the weighed score for the issue or complication (polygon, pixel); is weight of ith input map and S ij is weight of jth class from ith map. - Fuzzy logic model (Fuzzy logic) Fuzzy logic is a multi- valued logic, i.e. its parameters and variables, in addition to assigning the numbers 0 or 1, can assign all values can be between these two numbers. Belonging of Each member of the reference set to a specific subset, is not definitive, i.e. it cannot be said decisively that the desired member belongs to this is set or not. This is done by attributing a namber between 0 and 1 to this member.