Significance of earthquake risk research

Facing the grim situation of China's earthquakes and the debate on whether earthquakes can be predicted or not, in order to promote the development of earthquake prevention and disaster reduction, on the basis of Li Siguang's earthquake theory and China's earthquake science and earthquake prevention and disaster reduction work, under the guidance of earth system science and system holistic view, this paper puts forward the theoretical method and practical significance of establishing earthquake risk management mode to guide earthquake prevention and disaster reduction and earthquake emergency, and writes the book "Earthquake Risk Theory" [148], which includes the identification of earthquake risks; Earthquake risk prediction; Earthquake risk assessment and management, etc. The book wrote in the preface:

"On May 12, 2008, an earthquake of magnitude 8 suddenly occurred in Wenchuan, Sichuan Province, killing 70,000 people and causing economic losses of hundreds of billions of yuan. This devastating earthquake shocked the whole world. April 4, 20 10, an earthquake of magnitude 7. 1 occurred in Yushu. Ruins, chaos, crying, a scene as sad as Wenchuan. Similar scenes, similar grief, similar rescue ... In less than two years, the same earthquake disaster once again fell heavily on this land.

From Wenchuan earthquake to Yushu earthquake, frequent earthquake disasters not only test the emergency ability of people and government in disaster areas, but also torture earthquake researchers. As a result, many seismologists and seismologists are arguing endlessly about whether earthquakes can be predicted, amid the doubts from all walks of life in the country about the competent departments of earthquakes and seismology.

In this case, we can't help but think of Li Siguang's scientific assertion that earthquakes can be predicted. The strategies for earthquake prevention and disaster reduction in Hejian, Tangshan, Bohai, Haicheng, Tonghai and Songpan are correctly deployed; I think of his grandiloquence that Beijing is a "safe island", and ask Chairman Mao to sleep in peace. I can't help but think of the achievements of seismologists in Li Siguang and the whole country for decades.

For decades, China Seismological Bureau and seismologists have done a lot of work in earthquake monitoring, prediction and prediction through unremitting exploration and innovation. The ten-year earthquake climax of 1966 ~ 1976 has comprehensively promoted the earthquake prediction in China. A multidisciplinary earthquake monitoring network has been established nationwide, and an earthquake monitoring and forecasting team with a certain scale has been built, and the practice of earthquake prediction has been widely carried out. After decades of unremitting exploration and innovation, the vast number of seismologists have initially formed the scientific idea of gradual earthquake prediction with China characteristics, and achieved more than 20 short-term and imminent earthquake predictions with effective disaster reduction, which has had an important impact on international earthquake prediction and prediction research, and has always been in the leading position in the world in long-,medium-and short-term earthquake prediction, especially in the medium-and long-term earthquake prediction.

It is puzzling why several years have passed and China's science and technology have developed rapidly, but now some people think that earthquakes are unpredictable.

It must be pointed out that Article 13 of People's Republic of China (PRC) Earthquake Prevention and Disaster Mitigation Law, which came into effect on May 1 2009, stipulates: "Earthquake prevention and disaster reduction planning should follow the principles of overall arrangement, highlighting key points, rational layout and comprehensive prevention, and fully consider people's life and property safety, economic and social development, resources and environmental protection, etc. based on the earthquake situation and earthquake damage prediction results." Article 26 stipulates: "The competent department of earthquake work in the State Council and the departments or institutions in charge of earthquake work of local people's governments at or above the county level shall make predictions on the location, time and magnitude of possible earthquakes based on the research results of earthquake monitoring information. According to the trend of seismic activity and the prediction results of earthquake damage, the competent department of earthquake work in the State Council put forward the opinions on determining the key areas for earthquake monitoring and defense, and submitted them to the State Council for approval. Article 48 stipulates: "After the opinions on earthquake prediction are released, the people's governments of the provinces, municipalities, autonomous regions and municipalities directly under the Central Government concerned may declare an impending earthquake emergency period according to the predicted earthquake situation ..."

In the earthquake prevention and disaster reduction law, earthquake prediction is obviously a guiding disaster reduction measure. Earthquake prevention, earthquake emergency, disaster relief and reconstruction, as well as the deployment of earthquake observation stations and the formulation of construction plans are all based on long-term, medium-term, short-term and imminent earthquake prediction and earthquake development trend prediction. If the problem of earthquake prediction cannot be solved, how to implement the earthquake prevention and disaster reduction law? A few days ago, the State Council issued "the State Council's Opinions on Further Strengthening Earthquake Prevention and Disaster Reduction", demanding that by 2020, efforts should be made to make short-term or imminent earthquake prediction. Thirdly, seismologists must be ambitious and attach importance to earthquake prediction as the primary work of earthquake prevention and disaster reduction.

However, it should also be objectively acknowledged that earthquake prediction is a worldwide problem, which is difficult to solve in a short time and needs difficult exploration. For those earthquake types with more precursor anomalies, only under the conditions of good monitoring foundation and in-depth research in the earthquake area can we make medium-term or even a certain degree of short-term and imminent prediction. Therefore, in earthquake prevention and disaster reduction, although people expect to put short-term and imminent earthquake prediction in the first place, based on the current level of earthquake prediction in China, it is not only unrealistic to base earthquake prevention and disaster reduction entirely on short-term and imminent earthquake prediction, but also may cause greater losses and even affect social stability, that is to say, it will cause greater earthquake risks. To this end, Li Siguang pointed out at that time: "Our earthquake work has not been accurately predicted ...' Only prevention, as far as possible to reduce disaster losses'. And pointed out:' prevention is the most important thing, and it is important to determine the danger zone'' We not only put forward the danger zone, but also pointed out the danger zone. It is necessary to draw a first-class danger zone, followed by an important danger zone and a general danger zone. If we want to distinguish between special danger areas and special danger points, we must implement this work one day. "Li Siguang once said:' We made a mistake and didn't carry out this work in strategic key areas 10 and 15 in advance.' It can be seen that Li Siguang was already considering the earthquake risk. Unfortunately, the study of earthquake risk has not attracted enough attention so far.

While the earthquake raged, the flood disaster also raged in Chinese mainland. At present, the accuracy of rainstorm forecast is only 30%, which is basically the same as that of short-term and imminent earthquakes, but the flood control and flood fighting work in the country is being carried out in an orderly manner; Although there are also house collapses, secondary geological disasters, casualties and property losses, it seems to be understood by the people. Why are there such different situations? This is closely related to the disaster reduction strategy. Since 2000, the whole world has taken "risk management" as the focus of flood control and disaster reduction. Based on system science and risk management theory, the risk of flood and drought disasters in different basins and regions is analyzed, which not only conforms to the evolution law of nature, but also follows the objective law of social and economic development and disaster tolerance, and has made remarkable achievements in exploring disaster reduction strategies according to local conditions. This year (20 10), due to abnormal weather, heavy rain caused disasters, and the economic loss reached 200 billion yuan by the end of August. In response to the increasingly serious flood disaster, the Ministry of Water Resources immediately decided to compile a more detailed national flood risk map to guide flood control and disaster reduction. From this point of view, it is necessary to learn from the disaster reduction experience of other natural disasters and consider the development direction of earthquake science and earthquake work strategy in China more deeply and widely.

With the activities of the International Decade for Disaster Reduction and the progress of scientific research on natural disasters, earthquake science has also made great progress, and gradually realized the dual attributes of earthquake disasters, forming a step-by-step research program of earthquakes, namely, earthquake risk research, earthquake risk research and earthquake risk research. It is recognized that only under the premise of understanding the earthquake risk and the ability of society to bear the earthquake risk can we formulate targeted and appropriate countermeasures for earthquake prevention and disaster reduction.

It should be pointed out that earthquake disaster, earthquake risk and earthquake risk are three concepts with different meanings, and earthquake disaster belongs to natural disaster; The harmfulness of earthquake is the social damage caused by earthquake; Earthquake risk generally refers to the possibility and loss of future earthquakes. Earthquake risk refers to the potential earthquake risk and harmfulness. If the risk lacks effective prevention and management, once the time is ripe, hidden risks will turn into explicit hazards. Therefore, the object of earthquake prevention, disaster reduction and earthquake emergency is not the earthquake disaster that has occurred in the historical period, but the possible earthquake risk in the future. Therefore, the formulation of earthquake prevention and disaster reduction plans and earthquake emergency plans should not be based only on the intensity of earthquakes that have occurred in the region, nor on the magnitude of earthquake disasters, but on the comprehensive evaluation and risk prediction of regional earthquake risk, harmfulness, risk, social tolerance, earthquake prevention and disaster reduction and earthquake emergency response capabilities. We should take Scientific Outlook on Development as the guide and social development as the general scale to measure the possible risks of earthquakes in China and various regions to social development, and resolve the positive impact of earthquake risks on social development. In other words, earthquake prevention and disaster reduction should enter a new stage of risk management.

The 55th United Nations General Assembly held in 2000 made a resolution on the action of "International Strategy for Disaster Reduction", the goal of which was to change simple disaster prevention (including earthquakes) into comprehensive disaster risk management. According to statistics, 265,438+0 countries such as the United States, Japan and China have formulated disaster prevention and mitigation plans, actively responded to the Hyogo Declaration and Hyogo Action Plan (2005) issued by the United Nations, strengthened international cooperation in disaster risk reduction, promoted the integration of disaster reduction activities with development planning and practice, and improved the ability of regions and countries to resist disaster risks, and formulated the 2005-2065,438.

Among all kinds of natural disasters, earthquake disaster is one of the focuses of research. Li Siguang and other predecessors, the Seismological Bureau of China, the former State Science and Technology Commission, the State Planning Commission and the State Economic and Trade Commission have done a lot of work, which makes us deeply realize that the ultimate goal of earthquake prevention and disaster reduction should be to reduce casualties, economic losses and environmental damage, that is, to reduce earthquake risks; The core of earthquake science should be to study earthquake risk.

Through practical work, we believe that the focus of earthquake risk research is:

First, understand the earthquake risk.

Although the mechanism and development law of earthquake formation are not clear at present, it is at least certain that plate activity is only one of the causes of earthquake formation, and it is difficult to explain why Wenchuan earthquake and Yushu earthquake occurred in their positions only by the collision theory of' Indian plate'. It is even more difficult to predict where the next plate collision will cause an earthquake, and it is difficult to achieve the purpose of understanding the earthquake risk. Therefore, we must also pay attention to seismic geological investigation and research, find out the nature of active structures that cause earthquakes, identify active structural systems, study the composite problems of structural systems, and determine the mode and direction of geostress and the characteristics of tectonic stress field. According to the development and evolution law of tectonic system and geostress field, the mechanism and development trend of seismic dynamics are studied. Structural system compounding; The degree of earthquake precursor activity and crustal stability, divide the safe areas (safe islands) and earthquake risk areas with different degrees of danger, and understand the law of earthquake activity in earthquake risk areas.

Second, carry out earthquake risk prediction and earthquake risk assessment.

We believe that in the study of long-term, medium-term, short-term and imminent earthquake prediction, the three elements of earthquake prediction-time, place and magnitude should be studied as different risk contents, and the risk prediction of different scales and grades should be carried out. According to the current level of earthquake science in China, since great progress has been made in medium and long-term earthquake prediction and earthquake development trend prediction in China, we should make full use of these achievements when formulating countermeasures for earthquake prevention and disaster reduction. On the one hand, according to the development trend of natural disasters and the prediction of risk areas, regional seismic risk assessment is carried out, and a series of seismic risk zoning is compiled to guide the formulation of regional economic construction planning and seismic fortification grade standards; On the other hand, according to the regional differences of earthquake risk degree and earthquake prevention and disaster reduction ability, according to the principle of risk management, the zoning countermeasures for earthquake prevention and disaster reduction are formulated. Then carry out detailed observation and research work in seismogeology, geophysics, geochemistry and other aspects in the dangerous areas where earthquakes may occur, comprehensively collect and comprehensively analyze various precursor data, and predict possible earthquake occurrence points, possible earthquake occurrence times and magnitudes. Then, according to the prediction results of long, medium, short and imminent earthquakes, a gradual earthquake emergency plan is formulated.

It is unrealistic to try to reach a unified opinion in a short time because of the serious differences in understanding of earth science and earthquake science at present. In this case, I think it is feasible to supplement Li Siguang's opinions on earthquake prevention and disaster reduction, which have been accepted by most people and tested by practice, and the work achievements of the earthquake department for many years, and then formulate an earthquake risk management plan according to the needs of earthquake prevention and disaster reduction and earthquake emergency.

Third, strengthen earthquake risk management.

Earthquake risk management is a systematic project, which includes not only the design and implementation of earthquake monitoring and prediction, disaster prevention, emergency rescue, recovery and reconstruction, and social response system, but also the determination of the research objectives and contents of earthquake disaster society, disaster economy, disaster environment and earthquake disaster science and technology, as well as the systematic consideration of linkage, hierarchy and integrity.

The State Council's Opinions on Further Strengthening Earthquake Prevention and Disaster Reduction pointed out that to strengthen earthquake prevention and disaster reduction, we should put people first, put people's life safety in the first place, adhere to prevention first, combine prevention with rescue, rely on science and technology, rely on the legal system, and rely on the masses to comprehensively improve earthquake monitoring and prediction and emergency rescue capabilities, and form a pattern of earthquake prevention and disaster reduction with government-led, military-local coordination, special group integration and maximum participation of the whole society. The National Plan for Earthquake Prevention and Disaster Reduction (2006-2020) sets the overall goal of earthquake prevention and disaster reduction in China in 2020. To achieve this goal, we must first raise the awareness of earthquake risk in the whole society. Understand and understand the earthquake risks faced by all localities; It is necessary to comprehensively improve the ability of governments at all levels to cope with earthquake risks, and earnestly strengthen the comprehensive defense ability before the earthquake, the emergency response ability in the epicenter, the emergency rescue and resettlement ability after the earthquake, and the recovery and reconstruction ability in the earthquake zone. Therefore, it is necessary to strengthen the study of earthquake risk, and predict and evaluate the earthquake risk and its development trend in China. Determine the regional earthquake risk, harmfulness, earthquake prevention and disaster reduction ability and risk grade, as well as the risk and risk grade of earthquake secondary disasters and disaster chains, and complete the comprehensive zoning of earthquake risk grade in China, so as to provide scientific and technological support for China to reasonably prevent and avoid earthquake risks and realize social security and sustainable development.

To this end, we collected research results based on data before 2000 and wrote this book.

Although this book makes a comprehensive analysis of earthquake risk and risk management in China and related issues, objectively speaking, many new ideas are only preliminary explorations, with incomplete data, and there is still a considerable gap between theory and methods and the expected goals, and the understanding and conclusions are not necessarily correct. Moreover, with the development of China's economy and the improvement of earthquake emergency response capability, most of the basic data will continue to change, which is obviously only for discussion and reference. However, we firmly believe that, firstly, the occurrence of earthquake risk is a natural-social process, and a new model of earthquake prevention, disaster reduction and emergency response should be established according to the dual attributes of earthquakes and the understanding, prediction and evaluation of earthquake risks; Second, emergency response to earthquake prevention and disaster reduction is a socialized action, which requires that the focus of earthquake science research should be shifted from regional earthquake situation and disaster situation research centered on' earthquake phenomena' to earthquake risk research centered on' social disasters and disaster reduction'; Thirdly, we should guide earthquake prevention, disaster reduction and emergency work according to the principle of risk management, and establish a new earthquake risk management model. These are all research directions worthy of further development. The data of earthquake risk assessment in this book, based on the statistical data in 2000, is not the latest, but on the other hand, it can be based on the actual situation of earthquakes in recent ten years, which has played a role in testing the original understanding. "