Throughout this international geological congress, the hot areas of earth science related to geological disasters include the following aspects.
First, new technologies and methods for geological disaster investigation and detection.
Interferometric radar measurement and differential interferometric radar measurement technology, as fast and accurate (millimeter-scale) techniques to obtain topographic data, have attracted more and more attention, and many studies have used these two technologies for landslide monitoring and mapping. With the continuous improvement of GIS mapping and data analysis and processing capabilities, it is very common to apply 2D or 3D finite element models to the stability calculation and evaluation of landslides and collapses. Andrea Merri and others used Flac3D software to establish a three-dimensional geological model of Italy's Si trumbo Li volcano, so as to analyze the changes of stress and strain state under different magmatic structural states and predict the flow state of magma. The British Geological Survey has incorporated 3D geological modeling into its strategic science plan (2005 ~ 20 10). Compared with the strategic science plan issued by 1999, the most important change is the transformation from 2D geological survey technology to 3D geological survey technology, such as "Three-dimensional geoscience framework of British mainland" and "Three-dimensional characterization of coast, continental shelf and continental margin". With the development of geographic information system, 4D theory even appeared.
The second is the monitoring and early warning of geological disasters.
Geological disaster early warning system is not only a set of technical equipment, but also includes human factors, social factors and information communication. Norway is a country (region) where sudden geological disasters such as collapse, landslide and debris flow occur frequently. In 2005, Geo Extreme Research Plan was established, and it is planned to evaluate the geological disasters in Norway in the next 50 years in four years. This project includes four research modules: module A's main goal is to study the coupling between meteorological parameters and landslides and collapses, and in order to carry out this research, a database containing landslides and collapses has been established; Module b mainly predicts the regional climate prospect, focusing on extreme climate events such as precipitation and hurricanes; Module c uses the research results of module a and module b to generate the distribution map of possible geological disasters in Norway in the future. This module mainly studies four key areas that can represent different climate regions. Module D studies the economic losses caused by geological disasters in the past and predicts the future. The main factors are the loss caused by natural disasters and the cost of disaster reduction measures, experience and ability training, changes in plans and the impact on decision makers.
Three. Geological hazard risk management
Risk assessment and management of geological disasters has always been one of the effective ways to reduce and prevent disasters advocated and popularized internationally. "Reducing risk and increasing defense" is the theme of geological disasters in this conference, and it is also one of the top ten research topics in 2008 International Year of Earth. This topic mainly focuses on four aspects: ① How do humans change the lithosphere, biosphere and natural landscape, thus causing harmful changes to human life and environment and inducing geological disasters, and at the same time increasing the vulnerability of society to adapt to the earth (geology, geomorphology and hydrometeorology)? (2) What methods and technologies should be adopted to evaluate the adaptability of human beings and sites to disasters, and how should these methods and technologies be adopted on a global scale? (3) Under the current monitoring, forecasting and disaster reduction conditions, what is the relative proportion of various geological disasters, and what measures should be taken to change this state in a short time? (4) What are the obstacles between the risk application and the risk, vulnerability reduction measures and plans (including disaster reduction) of each geological disaster mastered by the government (and other institutions)? In order to solve these problems, this theme is devoted to achieving the overall balance of various research projects with other international organizations, focusing mainly on how these problems are related to the five action themes of the Hyogo Framework for Action of the United Nations International Strategy for Disaster Reduction.
Four, major geological disasters emergency system
Although there are not many papers on the study of geological disaster emergency system in this meeting, many researchers have mentioned this problem in the special discussion. The construction of geological disaster emergency system is mainly to carry out geological disaster information system construction, disaster prevention and mitigation drills and formulate emergency rescue plans according to the development characteristics of geological disasters in various regions. At present, different countries have different emergency measures for geological disasters, but there is still a certain gap in popularization and application. Sylfest Glimsdal and others found a large unstable block after studying a slope in Akneset, western Norway. If these unstable blocks slide as a whole, landslides will trigger a tsunami and cause destructive losses to many buildings in this bay. Through the digital modeling of slope, wave and 2D and 3D digital modeling, the stability of slope and the generation and spread of tsunami are simulated and analyzed. Finally, in the Wenchuan earthquake in Sichuan in 2008, Sangzao Middle School organized more than 2,000 students to go downstairs in only 1 minute and 36 seconds after the earthquake, and there was no casualty in the whole school, which created a miracle in the earthquake. This miracle is attributed to the school's fire drills and the repair and reinforcement of buildings. For geological disasters with strong destructive power, such as earthquakes and tsunamis, it is also one of the most effective methods to send an alarm in advance through the advanced earthquake and tsunami early warning system, so that people and vehicles can move to safety before the tsunami comes.
Five, the geological disaster risk assessment into urban planning and management.
With the increase of world population and the acceleration of urbanization, various geological disasters have become a negative factor restricting urban development planning. Strengthening the risk assessment of geological disasters is of great significance in urban planning and management. At this conference, relevant scholars introduced some practices of their respective countries (regions). Britain is a country with a small land area and a narrow coastline, but its population is very large and growing, and the competition for land use has been fierce. Therefore, in some areas that may suffer from land subsidence, landslides and floods, the pressure of using and developing land is quite great. In addition, some land polluted by industry needs to be improved and developed. When developing land in these areas, it is necessary to have a deeper understanding of the development of geological disasters in this area. Victor Osipov mainly considered the types of geological disasters in Moscow, such as landslide, karst, karst erosion process and groundwater flooding. On the basis of evaluating the process of geological disasters, he drew a map of Moscow's geological environment with a scale of1∶ 50,000, and analyzed the regional distribution of different geological environments according to the municipal planning and functional zoning, and divided Moscow into very unsuitable areas, unsuitable areas, suitable areas and suitable areas.
International cooperation in geological disasters with intransitive verbs
Although geologists all over the world have done a lot of work, geological disasters are still on the increase. Climate change makes things worse. On June 5438+ 10, 2005, the United Nations initiated and put forward the Hyogo Framework for Action 2005-2025 in Kobe, Japan. This plan has been discussed and adopted by 165 member countries, and it is one of the most important documents to reduce catastrophic natural disasters worldwide so far. The plan stipulates what positive measures all countries and international organizations should take to achieve better disaster reduction results. In addition, it also clarifies the responsibilities and obligations that the World Committee on Disaster Reduction should undertake. In a word, the basic idea of this action plan is that the international community should promise to protect citizens from the threat of disasters. The action framework classifies geological disasters according to earthquakes, tsunamis, landslides and volcanic eruptions, and each type of geological disasters has examples of catastrophic events and statistics of mortality and economic losses. Within the framework of this action, the importance of appropriate identification methods, risk reduction measures (including early warning system) and strengthening institutional management (including capacity building) was discussed in more detail.
Since the Asia-Pacific regional office of the International Council for Science accounts for the majority of the world population and the number of people who died from geological disasters accounts for 80% of the global total, the office decided to create a scientific plan on geological disasters and disasters, which initially considers three major geological disasters, namely earthquakes, floods and landslides, with the goal of alleviating natural disasters. In 2002, the implementation plan was put forward, which later developed into one of the eight themes of the global observing strategy and was released by the European Space Agency. In 2007, the French Bureau of Geology and Minerals improved this plan. After the Hyogo Framework for Action was put forward, Italian, China, Japanese and other countries carried out related work. At the Asian Conference on Disaster Reduction held in Beijing in September 2005, the Hyogo Framework for Action was implemented, and the key areas of disaster reduction in Asia and the contents of regional cooperation in the next decade were discussed. In 2007, the 6th Asian Regional Conference on Engineering Geological Disasters was held in Seoul, South Korea. China and South Korea signed a cooperation agreement to discuss in depth the cooperative study of geological disasters in Asia. The international landslide conference will be held in Tokyo, Japan on June+10/October 065438, 2008 to further discuss related issues.
(Zhang Yongshuang, Guo, Cai Xie)