Local municipalities in developed countries
The need to reduce damage in regions that face greater risks from more intense storm surges due to climate change, and from tropical cyclones, etc., and the resulting damage from inundation.
By reducing settlements and economic activities and reinforcing built structures in hazard zones, exposure and vulnerability to climate change will be reduced and impacts on humans, property, and economic activities will be reduced.
・ Conduct land use in ways that respond to type, nature, and risk levels of disasters likely to occur, in order to avoid or mitigate damage from storm surges and inundation, etc. Avoid settlements and other types of buildings in zones with particularly high risk levels.
・ Risk levels are studied and analyzed, and zones with high risk levels are identified, then (1) new construction of housing and so on is prohibited or controlled in the hazard zones, (2) resettlement is conducted or support offered for resettlement outside the hazard zones, and (3) efforts are made to reduce land use in the high-hazard zones. In addition, buffer zones are protected or enhanced through the use of windbreak forests and sand berms, etc., in an effort to reduce impacts on other zones.
(1) Prohibition or control of new construction of housing and so on in the hazard zones
New construction of housing and other buildings in hazard zones are prohibited by legislation and regulations, or construction designs are controlled (e.g., floor height, etc.).
(2) Resettle and support offered for resettlement outside of the hazard zones
Housing and other buildings already standing in the hazard zones are moved outside those zones. Financial subsidies are offered to support resettlement.
(3) Efforts are made to reduce land use in the high-hazard zones.
Zones are classified based on hazard level, that information is made public, and disaster insurance rates are adjusted to reflect those classifications (insurance rates are set higher in high-hazard zones, and in particular, new construction in hazard zones is discouraged by higher insurance rates in those zones).
Costs differ depending on methods and circumstances behind changes and regulation of land use (e.g., whether or not compensated; land prices; the availability of new sites, etc.).
・ It is important that land use regulations and so on can be accepted socially, because they will place restrictions on land use by individuals, and on construction, etc. It is important to provide scientifically-convincing explanations of the zone classifications, although this is not an easy task, as the accuracy and methodology will depend on the type of disaster and land characteristics.
・ Where urbanization is already well advanced, a ban on construction of any buildings becomes extremely difficult. Also, high land prices and a lack of available land can hinder resettlement efforts.
・ Capacity building is important to facilitate research and analysis for the establishment of hazard zones.
・ Where it is difficult to ban new construction due to preexisting urbanization, and instead the use of sites is permitted within the hazard zone on condition of building reinforcement and the construction of evacuation areas, it is important to conduct evacuation drills and disaster preparedness/response trainings, and to implement other "soft" measures, including systems to issue advisories and warnings.
・ Where measures include the resettlement of residents, it is important to also take steps to reduce their economic burdens.
・ Rather than being done after the fact, it is more effective and efficient to conduct proper planning and impose land use restrictions at the initial phase of development.
・ This approach will help promote systematic planning of land use.
Case 1: Nagoya City, Aichi Prefecture (Japan)
・In Japan, based on the Building Standards Act, municipal governments use ordinances to designate disaster hazard zones where risks are especially high due to tsunamis, storm surges, flooding, and so on, and they are able to prohibit housing construction and regulate the construction designs in those areas.
・In Nagoya City, Aichi Prefecture, learning from the experience of a major typhoon that struck Ise Bay in 1959, in order to prevent a repeat of that disaster, enacted the Nagoya Coastline Disaster Management Zone Construction Ordinance in 1961 as part of a disaster management program.
・Four zones were designated, and in each zone restrictions were placed on the height of the first floor and on building design.
|Zone||1st Floor Height above Nagoya Water Level||Design Restrictions||Diagram|
|1||> 4m||Wood structures prohibited|
|2||> 1m||Occupied rooms must be on 2nd floor or above, but restrictions reduced if one of the following applies:
|4||> 1m||Occupied rooms must be on 2nd floor or above, but restrictions reduced if one of the following applies:
・ Natural Disaster Information Office of National Research Institute for Earth Science and Disaster Prevention (NIED): Introductory classes on disaster management (in Japanese)
・ Japan International Cooperation Agency (Global Environment Department) 2011: "Handbook on Climate Change Adaptation in the Water Sector: A Resilient Approach that Integrates Water Management and Community Development"
・ Nagoya City website (regarding the Nagoya Coastal Disaster Management Zone Construction Ordinance)
http://www.city.nagoya.jp/jigyou/category/39-6-3-2-6-0-0-0-0-0.html (in Japanese)
・ Community Resettlement Promotion Program for Disaster Management
http://www.mlit.go.jp/crd/city/sigaiti/tobou/g7_1.html (in Japanese)