DESIGN AND IMPLEMENTATION OF A WEB-BASED GIS (IN RESPONSE PHASE) FOR EARTHQUAKE DISASTER MANAGEMENT IN TEHRAN CITY M. Saydi , M.J. Valadan Zoej , A. Mansourian Faculty of Geodesy and Geomatics Eng. K.N.Toosi University of Technology, No 1346, Mirdamad cross, Valiasr st., Tehran, IRAN -(Saydi_maryam, AliMansourian)@yahoo.com, valadanzouj@kntu.ac.ir Commission PS WG VII/5 KEY WORDS: Earthquakes, Disaster, Management, GIS, Web based ABSTRACT: Natural hazards (i.e. earthquakes, floods) become disaster when they strike the man-made environment. To effectively reduce the impact of every disaster, governments prepare a complete strategy, called disaster management. Availability of data such as: buildings, lifeline systems, roads, hospitals and etc, will help the managers to better decision-making. The majority of this data is spatial and can be mapped. So a Geographical Information System (GIS) can support disaster management as a powerful tool for collecting, storing, analysis, modeling and displaying large amount of data. Many organizations which involve in disaster management, require to access to the right data in the right time to make the right decisions. So designing a GIS to distribute geospatial information on a network such as Web, gives a chance to the managers of organizations to easy access to the information about disaster any time and any where they are. This paper outlines different steps of developing a Web-based GIS to manage and response to earthquake in a central district of Tehran as a case study. Lack of a model to estimate the size and extend of damages immediately after earthquakes is one of the major problems in developing such a system. In this research a Building Damage Estimation Model (BDEM) has been developed to optimize the response time and cost against earthquake disaster. 1. INTRODUCTION Earthquake, as the natural hazard, is the part of the world around human being. Its occurrence is inevitable. It destroys natural environment but the natural environment takes care of itself. So Earthquake becomes a disaster when it crosses paths with the man-made environment, such as buildings, roads, lifelines and crops. The man-made environment, in contrast to natural environment needs disaster management. Government of each country is responsible for disaster management at all levels (local, state, and regional). Disaster management can be divided into some phases: Planning, Mitigation and Preparedness are all pre-event phases, Response and Recovery are two during and post-event phases. These phases are related by time and function to all types of emergencies/disasters. Also, they are related to each other, and each involves different types of skills. As disasters (earthquakes, floods and hurricanes…) are usually spatial events therefore all phases of disaster management depend on data from a variety of sources. So, Geographical Information System (GIS) as a tool to collect, store, model, analyse and display large amount of spatially information layers, supports all aspects of disaster management. Tehran, as the capital city, the most populous and centre of political and economical activities of Iran, has a special situation against natural disasters. As the Greater Tehran Area is located at the foot slope area of the Alborz Mountains, which form part of the Alps-Himalayan Orogenic Zone and this zone is one of high seismic potential with many peculiar active faults, this city is threatened by earthquakes. Seismologists believe a strong earthquake will strike Tehran in the near future because the city has not experienced a disastrous earthquake since 1830.Although, Iranian government have been performing a lot of prevention plan in order to mitigate possible seismic damages in Tehran city, according to the expanse of Tehran and multiplicity of spatial features, still there are many features which are vulnerable against potential earthquakes. Therefore a sudden occurrence of such a potential earthquake may expose Tehran's population to the risk of death or injury and may damage or destroy private property and social infrastructure. So, it is urgently necessary to make a plan for response phase of earthquakes disaster management in order to reduce human losses and physical losses from damage. Gathering relevant data through all of governmental departments, organizations and input this data in a GIS as an appropriate tool to process and analyse it, can help managers to make a better decision during and just after of an earthquake. This paper describes design and development of a web-based GIS for disaster response. In order to test the system, a case study was conducted in one of the districts of Tehran, the capital of Iran. 2. EARTHQUAKE RESPONSE PHASE ACTIVITIES Earthquake response phase includes activities take place during or just after an earthquake, which are designed to provide emergency assistance for victims. Just after the earthquake, repairing lifelines networks to stabilize the situation and reduce the probability of secondary damages (for example, gas network to prevent secondary damages or shutting off contaminated water supply sources…),search and rescue activities, transport and communication, evacuation are the priorities to operate. Quick rescue of people by search and rescue teams from collapsed buildings, after the impact of a destructive earthquake, can save considerable number of lives. Then, emergency sheltering should be managed and distribution of water, food and public services should be provided also, medical heath centres should be identified in order to give medical care to the casualties. Other activities in this phase