Secondary disasters caused by earthquakes and their countermeasures

table of contents

Introduction Three secondary disasters caused by earthquakes and their countermeasures
1-1 Impact of tsunami
(1) Flooding in coastal areas
(2) Impact on human life
(3) Environmental impact
1-2 How to mitigate the damage of tsunamis caused by earthquakes…
(1) Development of an early warning system
(2) Education and training
(3) Appropriate land use planning
(4) Development of high seawalls and embankments
(5) International cooperation and information sharing
2-1 Effects of fire
(1) Danger to life
(2) Property loss
(3) Environmental impact
(4) Economic impact
(5) Psychological impact
2-2 How to mitigate fire damage caused by earthquakes...
(1) Improving the seismic resistance of buildings
(2) Fire prevention measures
(3) Installation of high-performance fire extinguishing equipment
(4) Formulation of an appropriate evacuation plan and training
(5) Establishment of information transmission and cooperation system in the event of a disaster
(6) Improvement of disaster prevention awareness
3-1 Effects of liquefaction
(1) Damage to buildings and structures
(2) Ground subsidence
(3) Rise of groundwater
(4) Damage to pipelines and gas lines
(5) Difficulty of post-earthquake restoration work
3-2 How to reduce the damage caused by liquefaction caused by earthquakes...
(1) Ground improvement
( 2) Adoption of appropriate foundation construction methods
(3) Improving the seismic resistance of buildings
(4) Damage to pipelines and gas lines
(5) Securing green areas and well-drained ground
(6) Regulations and guidelines for liquefaction countermeasures
summary

Introduction

Earthquakes are one of the most destructive natural disasters and can cause not only direct damage but also various secondary disasters. In this article, we will explain in detail the representative secondary disasters caused by earthquakes and countermeasures against them.

Three secondary disasters caused by earthquakes and their countermeasures

1-1 Impact of tsunami

(1) Flooding in coastal areas

A tsunami hits the coast as a huge wave of water. For this reason, areas along the coast may experience large-scale flooding when a tsunami arrives. A tsunami with a height of several meters to more than 10 meters hits buildings and land, injuring many people and affecting buildings and infrastructure.

 (2) Impact on human life

Tsunamis are extremely dangerous and can threaten people's lives. People in tsunami-reaching areas are at risk from tsunami momentum and flooding. When a tsunami is expected, evacuation advisories and evacuation orders are issued by the mayors of each municipality, and people need to move to a safe place.

 (3) Environmental impact

Tsunamis also adversely affect coastlines and marine ecosystems. Coastal ecosystems can be greatly disrupted by tsunamis, destroying plant and animal habitats. Tsunamis can also push seawater inland, causing salt damage and contamination of freshwater areas.

1-2 How to mitigate the damage of tsunamis caused by earthquakes…

(1) Development of an early warning system

When an earthquake occurs, it is important to use the tsunami warning system to send warning information early. By installing sensors and monitoring devices to detect earthquakes, it is possible to encourage people to evacuate when a tsunami is predicted.

 (2) Education and training

It is important to disseminate correct knowledge about earthquakes and tsunamis and to provide appropriate training to local residents and related organizations. Damage can be minimized by regularly informing people living in potentially dangerous areas of evacuation routes, evacuation shelter locations, and what to do when evacuating. Also, for elderly people, people with disabilities, and households with infants, make a specific evacuation plan for how to evacuate.

 (3) Appropriate land use planning

In order to mitigate tsunami damage, it is important in land use planning to avoid constructing buildings on coastlines or areas with high tsunami threat. In addition, it is necessary to secure evacuation routes and access to high ground, and to develop evacuation shelters.

 (4) Development of high seawalls and embankments

In order to minimize flood damage caused by tsunamis, it is necessary to develop seawalls and levees with appropriate height and strength. This will reduce the force of the tsunami and protect coastal buildings and people.

 (5) International cooperation and information sharing

As earthquakes and tsunamis are transnational disasters, international cooperation and information sharing are essential. Through scientific research and data sharing on earthquakes and tsunamis, as well as the exchange of technology and experience, more effective disaster mitigation measures can be realized.

2-1 Effects of fire

(1) Danger to life

Fire caused by an earthquake is a very frightening disaster. When an earthquake occurs, there is a possibility that a fire may break out due to fire sources such as electricity or gas. Also, if an earthquake causes buildings to collapse or roads to be cut off, firefighting activities will be difficult. Especially in densely populated areas, fires spread easily and cause damage to many lives and property.

 (2) Property loss

Fires can cause extensive damage to buildings and property. Damage to structures, gas leaks, electrical system failures, etc., caused by earthquakes can cause fires, which can destroy buildings and their contents.

 (3) Environmental impact

Smoke and toxic emissions from fires can have serious effects on the surrounding environment. Smoke causes air pollution, and toxic emissions can contaminate soil and water sources. Fires can also destroy wildlife habitat.

 (4) Economic impact

Large fires can also have a significant impact on local and national economies. Damage to buildings and infrastructure can bring business and traffic to a halt, and recovery and rebuilding can be costly and time-consuming.

 (5) Psychological impact

Fire damage can also affect people's psychological health. Losing your home or property can cause deep grief and stress. Witnessing injuries or deaths caused by fires can also be traumatic.

2-2 How to mitigate fire damage caused by earthquakes...

(1) Improving the seismic resistance of buildings

By strengthening buildings in accordance with seismic design standards, collapse of structures due to earthquakes can be minimized. It is also important to take measures to prevent fires from spreading, such as adopting fire-resistant structures and installing firewalls.

(2) Fire prevention measures

In order to prevent fires, it is necessary to check and maintain electrical wiring, detect and repair gas leaks early, and call attention to the handling of fire. Also important is the installation of fire doors, appropriate fire extinguishers, and regular inspection and maintenance.

 (3) Installation of high-performance fire extinguishing equipment

When a fire breaks out, it is important to extinguish it quickly and quickly. Equipped with advanced fire extinguishing equipment such as automatic fire alarm systems and automatic sprinklers, fires can be detected early and extinguished quickly.

 (4) Formulation of an appropriate evacuation plan and training

In the event of a fire, prompt evacuation is important to save lives. It is necessary to display evacuation routes, install emergency exits, and secure evacuation routes in buildings. It is also important to conduct regular evacuation drills to ensure that employees and residents learn appropriate behavior.

 (5) Establishment of information transmission and cooperation system in the event of a disaster

Accurate and prompt transmission of information is important when an earthquake occurs. It is necessary to strengthen cooperation with local governments and related organizations so that appropriate information is shared and evacuation orders are issued. Cooperation with local disaster prevention organizations and volunteer groups is also important.

 (6) Improvement of disaster prevention awareness

It is also important to raise awareness about earthquakes and fires. It is effective to provide residents and employees with disaster prevention education and information, and encourage them to take appropriate actions and prepare for disasters.

3-1 Effects of liquefaction

(1) Damage to buildings and structures

When liquefaction occurs, the bearing capacity of the soil is reduced, and buildings and structures may tilt or sink. This can lead to structural damage and collapse of buildings.

(2) Ground subsidence

When liquefaction occurs, the ground behaves like a liquid and the ground surface can subside. This can damage infrastructure such as roads and railroads and render them unusable.

 (3) Rise of groundwater

When liquefaction occurs, groundwater can rise to the surface. This can flood basements and underground facilities. Rising groundwater can also reduce land stability, creating the risk of further landslides and collapses.

 (4) Damage to pipelines and gas lines

Liquefaction can damage buried pipelines and gas lines. This can lead to gas leaks, burst water pipes, etc., creating safety risks and interruptions to the supply.

 (5) Difficulty of post-earthquake restoration work

In areas damaged by liquefaction, restoration work such as ground stabilization, building repair, and infrastructure reconstruction can be difficult. This can be time-consuming and expensive, and can have a significant impact on local livelihoods and economies.

3-2 How to reduce the damage caused by liquefaction caused by earthquakes...

(1) Ground improvement

Soil improvement is important in areas prone to liquefaction. One of the ground improvement methods is to suppress liquefaction by consolidating the ground using the dynamic compaction method or vibration method. Ground improvement methods such as the ground improvement method and piles are also effective.

 (2) Adoption of appropriate foundation construction method

It is also important to properly select the foundation construction method of the building. In areas where liquefaction is expected, it is necessary to design a stronger foundation and firmly fix the building to the ground. For example, pile foundations and base expansion foundations may be considered.

(3) Improving the seismic resistance of buildings

Improving the seismic resistance of buildings that are subject to earthquake shaking also contributes to reducing liquefaction damage. It is important to strengthen buildings according to seismic design standards and minimize deformation and collapse of structures during earthquakes.

 (4) Appropriate ground investigation and evaluation

In areas with a high risk of liquefaction, it is important to conduct a geotechnical survey and assessment in advance. You can grasp the properties of the ground and the risk of liquefaction in detail, and take appropriate countermeasures. In order to select earthquake-resistant ground, it is also important to seek the advice of a geotechnical expert.

 (5) Securing green areas and well-drained ground

Securing green areas and well-drained ground can also help reduce liquefaction damage. In order to increase the water permeability of the ground, it is important to maintain a ground cover and drainage facilities.

 (6) Regulations and guidelines for liquefaction countermeasures

It is also important to implement liquefaction countermeasures in accordance with local and national laws, regulations and guidelines. The Building Standards Act and the City Planning Act may stipulate liquefaction countermeasures.

summary

Earthquakes can cause secondary disasters. Typical examples are tsunamis, fires, and liquefaction. In order to deal with these secondary disasters, various measures are being taken, such as preparing storm surge evacuation sites, introducing tsunami warning systems, introducing ground improvement technology, appropriately managing groundwater, creating disaster prevention maps, and installing high-performance fire extinguishing equipment . In order to prepare for earthquake risks, it is necessary to recognize the importance of these countermeasures and further strengthen preparations for earthquakes.