3.3 - Japan and Nepal earthquakes: rebuilding resilience

Risk assessment and hazard mapping

Risk assessment combines what may happen with what is exposed and how vulnerable it is. A hazard map represents processes such as expected shaking, tsunami inundation, liquefaction or landslides under stated assumptions. A risk map adds people, buildings and services. Neither is a guarantee of the exact next event.

For Japan's coastal rebuilding, elevation, inundation scenarios, evacuation access and the location of essential services help compare sites. For Nepal, slope stability, fault/shaking evidence, construction and road access help identify places where rebuilding could repeat or compound danger. A site safer from one hazard may still face another.

Consider this simulated planning comparison, not observed Japanese or Nepali fieldwork:

The map does not automatically select B. It shows why B's slope, services and travel costs need investigation, while A needs a defensible inundation/evacuation strategy. C's access dependence can turn a local slope failure into isolation. Combine layers and consult the people who will use the rebuilt place.

Japan: relocation, infrastructure and continuing recovery

Japan's June 2011 Reconstruction Design Council recommendations proposed moving homes and core functions to safer higher ground where appropriate, while recognising land constraints and coastal industries' needs. The Reconstruction Agency, established in February 2012, coordinated the longer process.

Rebuilding in Tohoku has included housing, transport, raised or relocated communities and coastal protection. The Reconstruction Agency's 2021 progress account describes around 48,000 new housing units and relocation of communities to higher ground. These changes aim to reduce exposure while restoring essential services.

Engineering protection has limits. A wall can reduce more frequent inundation yet be exceeded by an extreme tsunami. Relocation may reduce exposure but separate people from harbours, jobs or former neighbours. A sustainable plan therefore combines land use, warnings, evacuation, suitable buildings and livelihoods rather than relying on one line of defence.

Fukushima's nuclear accident also created a recovery problem beyond ordinary debris clearance. Evacuation restrictions, environmental management, public confidence and long-term decommissioning affected whether residents could return. Japan's May 2023 evacuation figures show that substantial progress and continuing displacement can exist together.

Nepal: owner-driven safer housing

Nepal's reconstruction addressed a very large housing need alongside damaged schools, services, roads and livelihoods. The Earthquake Housing Reconstruction Project supported an owner-driven approach: households made reconstruction decisions, with financial and technical support to meet safer standards.