Abstract

Introduction Twentieth century began with a billion peoples and 10 percent of urban dwellers and has been ended with 6 billion people and 50 percent of urban dwellers Therefore, urban planning is more important and represents land use optimal distribution and utilities centers, which often have to work with planners.Accordingly, one of the most basic needs of disaster victims in the initial hours after the man-made disasters is health utilities. Supplying and equipping of health care systems and their proper distribution among urban regions is one of biggest challenges for crisis managers. According to maps extracted by network analyst model shows that hospital centers distribution in Tehran 3 district do not comply with the principle of equitable distribution and adequate access for all citizens.  Based on the lack of proper distribution and lack of appropriate services in times of man-made crises in this region is main reasons for this research. In this paper allocation of hospital centers in Tehran 3 district should be done by colonial competitive algorithm. Research Method The research method in this paper based on combination of descriptive and analytical procedures. The case study area included Tehran 3 District in northern Tehran, with six regional and 11 neighborhoods and population of 290,726 in 2006, with an area of 29.38 hectares. Necessary information for this research has been collected from housing and population census data, 1:2000 maps and comprehensive and master plans of Tehran and also magazines and books related to the research topic. The results of this research has been obtained from Arc/GIS, Super Decisions and Matlab software's and use of network analysis, ANP model and ICA algorithm that used for hospital centers allocation.  Research finding One of cases that is very important in today's urban system,the flexibility of these systems have the potential utilization of internal rules and regulations and to meet the expectations of external passive defense system which planners and urban designers about creating a healthy and safe urban demand.According to analysis that appeared the pattern of hospitals centers distribution in the study area is Inappropriate and has many deficiencies. Therefore, in this study, in order to optimal allocation of these centers has been allocated according to the principles of passive defense. The allocation of hospital in this research based on three principals: safety, consistency and efficiency. Consequently, the principles, pollution, population density, surrounded by streets, access roads, suitability, and neighborhood service area criteria for these measures are defined in this case study. After converting the layers to measurable criteria the final Weights was calculatedby NetworkAnalysis Model(ANP).After calculating theweightof eachlayerin order to layers overlay and finding suitable area weighted sumfunction were used in geographical information systemsoftware, and finally suitable area for hospital centers.Finally,after optimization algorithmbasedon colonialcompetitive hospitals center has been allocated in case study area. Conclusion In this study,medical centers have been allocation with an emphasis on the principles of passive defense.This new approach to site selection for urban applications using aheuristic algorithm colonial competition.Also network analysis model with time consideringwere usedto examinethe distribution ofand access tohospital facilities. The results of network analysis shows that these centerscannot provide appropriate services in man-made crises in the region and do not follow the same distribution in the region.In order to optimize site selection and basic principles of passive defense network analysis models, ANP model and algorithm of ICA were used for site selection of the best medical centers. The results of this study showed that colonial competitive algorithm can be used as a suitable model for urban land use site selection and helped to urbanplannersforunderstand andprioritizeandfindingbest solutionsfor urban issues.