3.5 4.b, 5.b - Earthquake risk and responses in Japan and Nepal

Living in earthquake-prone places

People inhabit active regions because employment, land, infrastructure and social networks are geographically concentrated, while moving away from one hazard can create other costs. Decisions are also made over different timescales: an infrequent severe earthquake competes with daily needs for food, income and housing.

Japan, with its advanced economy, occupies an active plate-margin region with large urban and industrial networks. Ports, fisheries, manufacturing, transport and established housing draw people to coastal places, including Tōhoku. Attachment to community and livelihoods can persist despite well-known seismic risk. Moving an entire national economy beyond all earthquake influence is not a realistic option; reducing exposure and vulnerability within it is central.

Nepal lies within Indian–Eurasian convergence and Himalayan mountain building. Its developing economy concentrates employment, markets, government and education in Kathmandu, supporting urban growth. Rural households may depend on inherited farmland, livestock, tourism or local trade. Steep terrain limits accessible land and transport alternatives. The Government of Nepal's 2015 needs assessment places housing, livelihoods and settlement planning within the recovery challenge.

A national income label cannot describe every household. An isolated older resident in Japan may need substantial evacuation support, while Nepalese communities possess local knowledge, mutual-help networks and skilled organisations. Tenure, savings, disability, infrastructure and political access shape feasible choices. Explain why settlement persists through opportunities and constraints, rather than assuming residents are unaware or that all choices are freely made.

Japan earthquake and tsunami impacts

On 11 March 2011, a very large megathrust earthquake occurred offshore north-eastern Japan, where the Pacific Plate descends beneath the overriding plate region. USGS's preferred catalogue gives $M_w9.1$, while Japanese official summaries commonly report magnitude 9.0. These are agency estimates for the same event, not separate earthquakes. The USGS event record and Japan Reconstruction Agency overview provide the geographical and historical context.

Direct shaking damaged infrastructure and affected buildings, while permanent sea-bed displacement generated a tsunami. Inundation washed away homes, vehicles and equipment, struck ports and fisheries, and deposited debris and saltwater across coastal land. Damage varied with elevation, coastal form, settlement and construction; not every Japanese city experienced the same waves or losses. A building surviving seismic loading could still be destroyed by water and debris.

The Reconstruction Agency's overview records more than 470,000 people evacuated at the disaster's peak and approximately 30,000 evacuees remaining in May 2023. The latter is a dated recovery observation, not a current count. Loss of homes, bereavement, interrupted schooling and prolonged displacement affected well-being beyond the initial physical destruction. Temporary accommodation and disrupted community networks could create continuing difficulties even after roads were repaired.

The Fukushima Daiichi accident was a cascading technological impact. Shaking damaged external power supplies, and tsunami inundation disabled important electrical and safety infrastructure. Loss of cooling contributed to overheating, core damage and radioactive releases, leading to evacuation and restrictions. The IAEA's 2015 investigation explains that sequence. It is inaccurate to attribute the disaster's entire death toll to radiation or to describe the tsunami as a nuclear explosion.

Economic impacts included destroyed coastal assets, interrupted power and supply chains, lost production, fisheries disruption and large reconstruction costs. Environmental effects included inundation, debris, salt contamination and radionuclide releases in affected areas. Political effects included scrutiny of planning and nuclear safety, new institutions and revised risk-management priorities. Japan created a Reconstruction Agency and pursued long-term rebuilding; the World Bank's 2021 lessons account examines changes in infrastructure, preparedness and regulation. National resources reduced some vulnerabilities but did not prevent an extreme multi-hazard disaster.

Nepal earthquake impacts

The $M_w7.8$ Gorkha earthquake struck central Nepal on 25 April 2015, with thrust movement on the Himalayan convergence system. A $M_w7.3$ event on 12 May formed part of the subsequent sequence. The USGS scientific overview explains the rupture and aftershocks. Damage and continuing fear therefore developed through a sequence, rather than a single shock followed immediately by uninterrupted rebuilding.

Poorly reinforced masonry and other vulnerable construction contributed to collapse. Injuries, deaths and loss of homes disrupted households, while damage to schools and health facilities affected essential services. A USGS one-year account published in 2016 reports about 9,000 fatalities, 23,000 injuries and more than 700,000 damaged or destroyed houses. These rounded account-specific figures should not be converted into exact final totals or assumed all to result from one instant of shaking.

Mountain slopes created additional exposure. Landslides and avalanches buried settlements and blocked roads and trails, delaying access to remote communities. Langtang suffered a destructive avalanche involving snow, ice and entrained debris; elsewhere slope failures damaged villages and dammed rivers. USGS field observations show why relief logistics and later flood risk depended on terrain as well as building damage. Distance alone cannot describe access if the only route is blocked.

Economic losses included housing, productive assets, tourism and damaged services. Cultural heritage damage in the Kathmandu Valley affected identity and visitor income as well as repair budgets. Environmental effects included disturbed slopes, debris and changed river conditions. The 2015 government needs assessment documents sectoral losses and recovery priorities. Household farming could remain constrained by inaccessible land or labour loss even after a road reopened.

Political impacts included the need to coordinate domestic agencies, international assistance, land decisions and reconstruction finance. The National Reconstruction Authority's 2016–2020 recovery framework set priorities and institutional arrangements. The existence of a framework did not guarantee equal delivery: remote terrain, eligibility, technical capacity and households' resources influenced implementation. Nepal's lower income helps explain financial constraints, but earthquake geometry, steep relief and existing settlement patterns also distinguish this case from Japan.