Do a physical examination for the mountains and rivers? How to do this physical examination?

On May 12, 2023, the Science Popularization China Starry Sky Forum, with the theme of "Scientific Disaster Prevention and Mitigation to Protect People's Safety", invited 5 experts from the field of disaster prevention, mitigation and relief to guide the public to improve their awareness of risk prevention and control through explaining scientific knowledge about disasters and popularizing common sense about emergency risk avoidance, push emergency management checkpoints forward, focus on preventing safety risks at the source, and fundamentally eliminate potential safety hazards.

Yuan Yi, Deputy Director of the Risk Monitoring and Comprehensive Disaster Reduction Department of the Ministry of Emergency Management, gave a speech entitled "Understanding Natural Disasters and Recognizing Disaster Risks."

The following is an excerpt from Yuan Yi’s speech:

01

What are natural disasters?

"Natural" means that the triggering factor of the disaster is a natural phenomenon. Traffic accidents and bumps in daily life are not natural disasters.

"Disaster" emphasizes the consequences, that is, the process must be harmful, either threatening human life or destroying the work and living environment we rely on. If the wind we see is a gentle breeze and drizzle, it has no effect on us and cannot be called a disaster. If a typhoon destroys houses, lightning strikes injure people, or heavy rain floods roads, causing trouble or damage to our study, work, and life, then it is a natural disaster.

Our country is one of the countries with the most serious natural disasters in the world . Not only are there many types of disasters, they are distributed over a wide area, and they occur frequently and cause heavy losses. Over the past 20 years, our country has suffered many major natural disasters, leaving a lot of pain.

For example, the severe floods in the Yangtze River Basin in 1998, the Wenchuan earthquake on May 12, 2008, the severe mountain torrents and mudslides in Zhouqu County, Gansu in August 2010, the severe rainstorms and floods in Zhengzhou, Henan in 2021, as well as frequent forest fires and strong typhoons... All kinds of natural disasters in the world have occurred in our country, and all provinces in our country have been affected to varying degrees.

Photo courtesy: Yuan Yi

Every natural disaster may mean casualties, resource destruction, and various direct or indirect economic losses. For example, the heavy rainstorm and flood disaster in Henan Province in July 2021 that we just mentioned affected nearly 15 million people and caused direct economic losses of 120 billion yuan.

According to statistics, since the beginning of this century, that is, from 2000 to 2022, various natural disasters in China have caused an average of 5,790 deaths and disappearances each year, and the direct economic losses caused by disasters have reached 340 billion yuan.

We cannot prevent natural disasters such as earthquakes and typhoons, but can we mitigate the impact of these disasters? This requires us to talk about how natural disasters are formed.

02

How are natural disasters formed?

From a professional perspective, the interaction between disaster-causing factors, disaster-prone environment, and disaster-bearing bodies leads to the occurrence of natural disasters.

Disaster Factors

Refers to natural phenomena and natural events that can have adverse effects on human life, property and various activities and are potentially destructive.

For example, there are rainstorms, typhoons, and hail in the sky, earthquakes, landslides, and mudslides on the ground, storm surges and tsunamis in the ocean, as well as the common high temperatures, droughts, and cold waves...

Generally speaking, the greater the intensity of the disaster-causing factor, the more serious the consequences may be.

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Disaster-prone environment

That is, the place or environment where the disaster occurred.

For example, large rivers are prone to floods, which are flood-prone areas. Mountain areas with unstable geological environments or serious vegetation damage are prone to landslides, mud-rock flows, and mountain torrents. Typhoons often land in coastal areas in the south, which are typhoon-prone environments.

Disaster-bearing body

It usually refers to human society itself that is directly affected or destroyed by disasters, including people themselves and all aspects of the economic society.

The infrastructure such as the houses we live in, the schools, hospitals, roads, bridges, dams, etc., the land we rely on for study, work and life, our agriculture, industry, service industry, etc., these are what we call disaster-prone bodies.

If the disaster-bearing body has a strong enough ability to resist disasters, the losses caused by the disaster may be relatively small. For example, if the house we live in is strong enough, the damage caused by the earthquake may be small.

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With the rapid development of social economy, the urbanization process has accelerated, the population has increased and become more concentrated, the consequences of disasters have become more and more complicated, and our rescue and disposal efforts have become more and more difficult.

In particular, many natural disasters often trigger a series of secondary disasters, which we call the "disaster chain phenomenon."

A disaster chain event that everyone may be more familiar with is the magnitude 9 earthquake that occurred in the waters east of Japan on March 11, 2011. The direct damage caused by this earthquake included collapsed houses, collapses, landslides, and damage to coastal embankments. The most serious thing was that it triggered a huge tsunami, resulting in the death and disappearance of 20,000 people.

A more far-reaching impact is that an earthquake of such high intensity caused a nuclear leak at the Daiichi Nuclear Power Plant in Fukushima Prefecture, Japan. The nuclear leak triggered a series of major problems such as social panic, power outages, and damage to marine and terrestrial ecosystems. In addition, the problem of nuclear waste water discharged into the sea, which we may see from time to time on TV, has been plaguing Japan and the world.

Therefore, the secondary and derivative disasters caused by natural disasters may exceed the direct impact of the disasters themselves . The consequences of the disaster chain are very complex, making disaster rescue and disposal more complicated and difficult.

After a disaster, we need to rescue people, urgently restore lifeline projects such as roads, electricity, communications, and water supply, and prevent secondary accidents such as fires, explosions, and even nuclear leaks. At the same time, the indirect impact of large-scale suspension of work and production in the disaster area may be greater, and the full recovery of the disaster area will take a longer time.

Photo courtesy: Yuan Yi

03

What can be done to mitigate the impact of natural disasters?

Here we need to discuss a very important concept, which is disaster risk . We often say that disasters are possible, so possible disasters and their consequences are called "disaster risk", which includes its possibility and consequences.

By exploring the possibility of disasters and intervening in the factors that influence their consequences, can we reduce the impact of disasters on human society?

The answer is yes.

We can use technical means to monitor, warn, and forecast the occurrence of disaster-causing factors , and make necessary disaster preparations, such as forecasting heavy rains through radar monitoring;

We can also make human society more resilient to natural disasters , such as building stronger houses, building reservoirs and dams to prevent floods and droughts, and reducing soil erosion by planting trees and grasses;

We can also master a lot of knowledge and skills about risk avoidance and self-rescue . When a disaster is about to come or has already occurred, we know how to reduce the impact of the disaster on us.

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In order to better reduce disaster risks, scientific understanding of disaster risks is the first priority.

My colleagues and I are currently focusing on the first national comprehensive natural disaster risk survey .

This work was organized and carried out under the unified deployment of the Party Central Committee and the State Council, led by the Ministry of Emergency Management and jointly organized by many departments and units. There are different tasks at the national, provincial, municipal and county levels. Many enterprises, institutions, social organizations and families directly participated in this census. We affectionately call this census the "mountain and river physical examination."

Physical examination, as the name implies, is to check the body. To check the mountains and rivers means to check the disaster-causing factors, disaster-bearing bodies, and disaster-pregnant environments that affect the occurrence of natural disasters in our country. Specifically, we checked six major types of disasters: earthquake disasters, geological disasters, meteorological disasters, floods and droughts, marine disasters, and forest and grassland fires. These disasters are all very serious disasters that affect our country.

We examined disaster-prone objects such as population, housing, infrastructure, public service systems, and tertiary industries. This information can be called "causes."

We also investigated historical disaster information, that is, we mastered our medical history, investigated and evaluated the region's comprehensive disaster reduction capabilities, found out "what kind of immunity the body has", carried out natural disaster risk assessments, and obtained the natural disaster risk levels and patterns of the country and various regions, that is, we grasped the "patterns of our body's illness", and proposed a national comprehensive natural disaster prevention and control zoning and prevention and control recommendations.

All these physical examination data are recorded in the database, which can help us better judge the "physical condition" and propose solutions to difficult and complicated problems.

You may think that physical examination is a routine activity every year, and “Shanhe Physical Examination” should not be a difficult thing, right?

In fact, before this, the physical examinations our country conducted for mountains and rivers were mostly single specialized examinations, such as geological disaster surveys, water conservancy surveys, mountain torrent disaster surveys, forest resource surveys, land surveys, etc.

Based on these single-subject specialized examinations, we conducted the first national comprehensive natural disaster risk survey across the country.

Photo courtesy: Yuan Yi

Why do we need to conduct a comprehensive survey? Because we realize that our economic and social development is very fast and that extreme disasters may have serious consequences. In the face of a nature that we do not fully understand and an increasingly complex economy and society, we need to conduct a comprehensive physical examination.

Through the census, we have obtained information on six major categories of natural disasters, six major categories of disaster-bearing bodies, and dozens of other risk factors that affect natural disasters, and achieved many "firsts".

For example, for the first time, we have figured out the inventory of housing buildings in China . Apart from people themselves, the houses we live in can be said to be the largest disaster-prone objects. This census has for the first time obtained massive construction data of nearly 600 million urban and rural houses across the country, and learned about the spatial location, structural properties and other information of various types of buildings. For the first time, urban and rural buildings have their own digital ID cards, laying the foundation for us to better improve the safety of houses.

The second example is that we have for the first time figured out the total amount of forest combustibles in the country . In recent years, forest fires have frequently appeared in our field of vision. Some forest fires have caused serious casualties and property losses. Forest combustibles are one of the culprits. All organic matter in the forest, such as leaves, trunks, roots, dead branches and leaves, grass, moss, lichens, etc., can be burned and are all combustibles.

In this census, we used investigations and experiments to find out where these combustible materials are distributed and how many there are in total, allowing us to better assess the forest and better prevent forest fires.

Photo courtesy: Yuan Yi

As an ordinary citizen, what can we gain from the census?

The goal of the census is to make the environment we live in safer and enable us to better resist natural disasters.

Government departments can use these census results to better prevent risks at the source and improve their ability to prevent and respond to natural disasters.

At the same time, through the census, we can know the natural disasters and potential risks around us, improve our family's disaster prevention capabilities, make our living environment safer, and we can also consciously learn more disaster prevention and risk avoidance knowledge and skills, know how to identify disaster risks and hidden dangers around us, how to avoid risks and hidden dangers, and once a disaster strikes, we can carry out self-rescue or even mutual rescue to protect ourselves and our families.

I hope everyone can actively participate in the use of the census results and contribute their own efforts to creating a safer environment.