NIKKEN SEKKEI URBANISM

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REDEVELOPMENT FOR ADVANCEDDISASTER PREVENTION FUNCTIONSEARTHQUAKE MOTION DETECTORHOSPITALHOTELSTOCK WAREHOUSEBANQUET ROOM AVAILABLE FOR EVACUEESENERGY NETWORKSAFE UNDERGROUND SPACEFOR EVACUATION ROUTESUFFCIENT OPEN SPACEView of Shizugawa in Miyagi Prefecture, showing the devastating effects of the March 11th, 2011 Tsunami.that are more vulnerable to re and earthquakes. Transit infrastructure has also grown to accommodate demand, expanding in the form of complicated additions to existing stations or new stations deep underground, giving rise to extremely complex transit terminals. Above and below ground, this web of buildings and urban infrastructure has grown as existing underground malls are expanded and connected with passageways and shopping corridors in increasingly complex congurations. If a large earthquake were to occur in such a setting, there is a risk of widespread and unforeseeable turmoil due to damage to the urban infrastructure and the reactions of the many people present in the area. When the Great East Japan Earthquake struck, tremors in central Tokyo were relatively small and direct damage was light. But because services by all forms of transit were interrupted, large crowds gathered around terminal stations, traffic jams clogged arterial roads, and there was overcrowding on sidewalks as stranded commuters walked toward home. If it had been a large earthquake directly beneath the city, the damage to buildings would have been more severe. The streets would have been full of people who had rushed outside only to be exposed to falling objects and collapsing buildings. As crowds fled toward safety, they would have had to avoid immobilized injury victims on the sidewalks. In other words, there would have been a risk of serious secondary disasters occurring after the earthquake itself. To avoid this, we believe that both hard and soft measures are needed. Soft measures are being considered by groups of local representatives, and some hard measures have been implemented, such as stockpiling of emergency supplies. But these are only first steps. Genuinely effective planning will require coordinated action by disaster planning councils for the areas in question. The membership of such councils should include building and real estate owners, tenants and other building occupiers, transit station representatives, providers of water, gas, electricity, communications and other lifeline services, and representatives of medical institutions and government. The first task addressed by the planners should be to clarify the current situation. Data should be collected on the following: the population of the area; boarding and arrival statistics for terminal stations; the sizes of buildings in the area, their purpose, and their vulnerability to re and earthquakes; the amount of open space available for evacuation areas; and the state of streets and sidewalks leading from buildings to evacuation areas. With this data, simulations can be conducted to determine whether enough open space exists for the population and locations can be identied where confusion might be expected to occur during evacuations. Then the necessary countermeasures can be taken. Soft measures include guidance and information for evacuees, including precise information about the type and scale of the disaster, damage, transit conditions, and evacuation destinations. Hard measures include seismic retrofits, construction of reliable and resilient communication networks, removal of obstacles from sidewalks, and securing open plazas for use as

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