Study Notes on the construction of geological disaster prevention and disaster reduction capacity and emergency management advanced workshop

 

I attended a senior training class in Mianyang over the past few days. Here are my study notes:

 

At the opening ceremony, the principal of Southwest University of Science and Technology introduced the situation of the school. Although the school was established for a short time, its concept of running a school is distinctive and pragmatic.

 

The first day of the morning course is the "Wenchuan earthquake Secondary Mountain disaster formation mechanism and Risk Control" project acceptance report.

 

Recognize the laws of disasters, identify potential risks, develop disaster reduction technologies, and propose countermeasures and suggestions.

 

The landslide distribution is mainly controlled by faults, river water system and topography, rock mass and slope structure.

 

Rainfall Landslides often occur between 25 degrees and 35 degrees, while earthquake Landslides often occur between 20 degrees and 50 degrees. If the slope is higher, there will be more collapse.

 

It is estimated that the loose solid Source generated in the hardest hit area of the Wenchuan earthquake is about 5.77 billion tons (more than 2 billion square meters), which is equivalent to the annual soil erosion volume in China.

 

Debris flows are more active after the earthquake and more active than before the earthquake. Many non-flat troughs become flat troughs after the earthquake. Within five years after the earthquake in the small watershed, the event occurred in the troughs within five years after the earthquake in the large watershed, and the main troughs were extremely active 5-10 years after the earthquake.

 

The main method of debris flow hazard assessment is to consider the volume and distribution density of loose debris.

 

Fine Particle migration and convergence play an important role in the debris flow starting process.

 

The timing of debris flow prevention and control is: it is not suitable for implementation in a short period of time after the earthquake. It should be considered three to five years after the earthquake, and it can be implemented in the most serious and general disaster areas after the earthquake. Prevention and control standards: the fortification standards for extremely serious and serious disaster areas should be appropriately increased. In addition to the fortification standards for extremely serious disaster areas, the congestion coefficient should increase by 50-100% when calculating peak traffic.

 

The seismic wave has the elevation amplification effect. The slope elevation has obvious amplification effect on the seismic wave, and the amplification factor is 1-3 times.

 

The course on the morning of the next day is "earthquake and geological disasters, damage to the ecological environment, and countermeasures for prevention and repair ".

 

There are about 1 million geological disasters in mainland China, and about 1000 people die each year due to geological disasters.

 

Main characteristics of China's engineering geological environment: four high (high steep terrain, high seismic intensity, high altitude and high altitude) and three disadvantages (unfavorable structural background, unfavorable geotechnical conditions, and unfavorable climate characteristics ).

 

Nearly 1/3 of the total victims and missing persons in the Wenchuan earthquake are associated with geological disasters.

 

Control Factors for seismic and geological disasters: fault control, topographic and landform effects, and lithology effects.

 

Most of the large-scale landslides triggered by strong earthquakes occur on the Upper Plates of the fault.

 

Landslide distance effect: A large Landslide of 75% is distributed within the range of 0-5km from the fault, and a landslide of 95% is within the range of 10km.

 

87% of landslides are distributed in the slope range of 20-50 degrees.

 

Earthquake Collapse and instability mainly occur in areas with a horizontal slope of more than 40 °, and the unstable area is mainly near the slope change point.

 

Post-earthquake debris flows are the most harmful geological disasters in the earthquake-stricken areas and the most difficult geological disasters to manage.

 

The course in the afternoon of the next day is the rocky desertification phenomenon in the karst area. It mentions two serious ecological problems in China: nanshi beisha.

 

The course on the morning of the third day is "the big split of the Earth-A New Thought on the evolutionary dynamics of the Earth ". Although this speech is not very closely related to the course itself, it is the most interesting and shocking one. It makes people feel ashamed to hear this speech.

 

This is a real research on big science. The speech basically overturned the existing concept of plate structure, and overturned my previous knowledge system on continental drift. A relatively complete theory is used to uniformly explain the main geological facts or events of the earth's evolution process, regardless of the controversy caused by this study, it is admirable only because of its courage and academic spirit to challenge traditional ideas. I think this research will surely attract great attention from the scientific community and society in the future. The following describes the content of this speech:

 

On the basis of questioning the new mechanisms of convection, submarine expansion and dive, a theory of pot covering is proposed ". The history of the evolution of the Earth is a history of the gradual decay of the earth's thermal energy in the cold-heat cycle. The transition between the Earth's crust and the Earth's crust under heat balance has induced a series of earth surface changes characterized by temperature rise and cooling, expansion and contraction, melting and solidification.

 

The cool of the universe is destined for the final decline of a vibrant Earth, but the earth's internal heat production, dominated by radioactive decay, heat production, phase change, etc., is the original driving force to maintain the pulse of the life cycle of the earth, it has driven the endless evolution of the Earth since its birth, including the formation, cracking, continental drift, collision, volcanic eruption, rock melting overflow, A series of major geological events related to each other, such as Glacier growth and ablation.

 

Global warming and cooling are inevitable in the evolution cycle of the Earth.

 

The evolution of the Earth enters the high temperature period, and soft fluids in the molten or semi-molten state appear on the surface of the earth's crust, which is a necessary condition for the existence of continental drift.

 

The plate boundary is actually the result of the great split of the Earth.

 

The filling of the Great Valley is not from the lava, but from the collapse and deposition of both sides.

 

The structural stress changes with the temperature period of the earth's evolution. The temperature at the boundary of the crust rises to produce expansion force in the crust, forming a structural stress dominated by horizontal stress. Structural Stress increases due to rising temperatures inside the Earth, which is the main force source of earthquakes.

 

It is not the reason that volcanic ash enters the lower layer to block the sun from the incident.

 

The bottom of the ice sheet and the flow of glaciers are the result of a warming inside the earth. The end of the ice period and global warming are not caused by carbon dioxide emissions, but by the increase in heat inside the Earth, which leads to a warm-up period, which is the inevitable result of the Earth's heat cycle.

 

The consistency between temperature and carbon dioxide does not indicate that the current global warming is caused by human activity.

 

The era of fossil energy will soon pass, and it is difficult for water and electricity resources to replace vacancies in fossil energy. Nuclear energy is not an ideal safe energy. Solar, wind, and other energy sources for humans may be extremely limited. Geothermal energy is an inexhaustible source of security and environmental protection energy for the future of mankind. Humans have just begun to tap the door to geothermal energy. After all, one day, we can safely use these infinite heat sources on the earth for the benefit of mankind.

 

The driving force of the earth's evolution: geothermal heat (radioactive decay heat, phase change heat, etc ).

 

The course on the afternoon of the third day is "Landslide and debris flow monitoring warning and prediction ".

 

As mentioned in this article, 30% of the collapse and landslide disasters are the geological disasters at the original hidden points, and 70% are new. Different debris flows occur in the original troughs. This data is also my recent concern.

 

The geological hazard zoning in Europe is good, and the buildings are distributed in the security zone. In the world, Hong Kong is the better place for disaster recovery monitoring in China.

 

In recent years, GIS has been widely used in geological disaster prediction and management.

 

China has made some progress in geological disaster monitoring and forecasting, but it still needs to strengthen research on the monitoring techniques and methods of geological disasters and their changing processes, it is urgent to carry out research on geological disaster monitoring and early warning demonstration zones to improve the overall level of scientific research in China and shorten the international gap.

 

Landslide monitoring and warning: Landslide Deformation Monitoring (surface and internal), groundwater dynamic monitoring, landslide thrust measurement, precipitation monitoring.

 

Debris Flow monitoring and warning: precipitation monitoring, soil water content monitoring, soil gap water pressure monitoring, mud position monitoring, and acoustic emission monitoring.

 

The difficulty of debris flow prediction is to forecast it six hours in advance.

 

3-layer Debris Flow Forecast System: Large Area Forecast Based on Numerical Weather Forecast (12-72 hours), medium and small area forecast based on static meteorological satellite cloud map and radar echo (1-3 hours) and troughs Based on telemetry rainfall (30 minutes-1 hour ).

 

Debris Flow Prediction Method: Based on the Formation Mechanism of debris flow, based on the Critical Precipitation statistics of disaster events, statistical forecast, between the mechanism forecast and Statistical Forecast-cause forecast.

 

Debris flow forecasts in large regions require the support of precipitation observation and refined numerical weather forecasts in the early stage.

 

Debris flow forecasts in Small and Medium areas must be supported by precipitation observation and Doppler weather radar.

 

The course on the afternoon of the fourth day is "micro-seismic monitoring ".

 

Mine security is not only technical security, but also social security.

 

Micro-earthquakes are earthquakes of magnitude 2 or lower.

 

Application of Micro-seismic in mine security.