Knowledge of geological disasters?
Geological disasters refer to the interaction and influence of the atmosphere, hydrosphere and biosphere on the surface of the earth's crust, caused by natural geological processes and induced by human activities, causing losses to human life and material property, or causing ecological damage. Disaster events that damage the environment. I will introduce it to you below, I hope it will be helpful to you.
1. What are geological disasters? What geological disasters mainly occur during the flood season?
Both natural variations and human actions may cause geological environment or geological disasters. When this change reaches a certain level, the consequences will cause harm to humans and society, which are called geological disasters, such as collapses, landslides, debris flows, ground fissures, ground subsidence, ground subsidence, rock bursts, and tunnel outbursts. Water, sudden mud, sudden gas, coal seam spontaneous combustion, loess collapse, rock and soil expansion, sand and soil liquefaction, land freezing and thawing, soil erosion, land desertification and swampification, soil salinization, as well as earthquakes, volcanoes, geothermal damage, etc.
Geological disasters that occur during the flood season are mainly sudden geological disasters such as collapses, landslides, debris flows, and ground subsidence related to rainfall.
2. How to identify some common geological disasters in the flood season?
1. How to identify possible collapse bodies?
For possible collapse bodies, the main basis is the slope. Identify the characteristics of the body's topography and geological structure. Generally, slopes that may collapse have the following characteristics in a macro view:
***1*** The slope is greater than 45 degrees, and the height difference is large, or the slope forms an arc and stands at the mouth of a mountain. Or a concave steep slope.
***2*** Internal cracks develop in the slope, especially steep cracks perpendicular to and parallel to the slope extension direction, and the fissures and fissures cutting the slope may soon be connected, making it ** with the parent body The *mountain* has formed a tendency of separation.
***3*** There is an open space in the front of the slope, or there is collapse material, which shows that a collapse has occurred before and may happen again in the future.
Slopes with the above characteristics are potential collapse bodies. Especially when the upper tensile cracks continue to expand and widen, the speed increases suddenly, and small falls continue to occur, it indicates that collapse will occur soon and is in a state of imminence.
2. How to identify whether the landslide is stable?
In the wild, by observing the landslide from a macro perspective, you can roughly judge its stability based on some external signs and characteristics. how.
The stabilized old landslide with accumulation layer has the following characteristics:
***1*** The back wall is higher and covered with trees. No scratches can be found, and Very stable;
***2*** The landslide platform is wide and leveled, and the soil is dense and there is no subsidence;
***3*** The front edge of the landslide The slope is gentle, the soil is dense, covered with trees, and there is no looseness or collapse. The part of the front edge facing the river shows signs of being washed by the river;
***4*** The current river water is far away from the tongue of the landslide, and there are even floodplains and terraces outside the tongue; < /p>
***5*** The natural scour grooves on both sides of the landslide are very deep, even reaching the bedrock;
***6*** The tongue of the landslide is There is clear spring water flowing out at the foot of the slope and so on.
Unstable landslides generally have the following signs:
***1*** The overall slope of the landslide surface is steep, extends for a long time, and the slope surface is uneven;
***2*** There is a landslide platform, the area is not large, and it does not slope downward gently and is not flattened;
***3*** The landslide surface There are springs, wetlands, and new gullies;
***4*** The surface of the landslide body has regional platforms with uneven subsidence;
* **5*** The soil and rocks at the front edge of the landslide are loose, small collapses occur from time to time, and there is a risk of river erosion;
***6*** There are no huge upright trees on the landslide.
3. What are the general conditions for the formation of a debris flow?
Generally, the following three conditions should be met for the formation of a debris flow: steep topography that is convenient for water and material collection. ; Abundant loose material; Large amounts of water available in a short period of time.
3. How to prevent geological disasters such as collapses, landslides, and debris flows during the flood season?
***1*** Local governments and relevant departments at all levels must take serious measures to prevent The occurrence of geological disasters during flood season can effectively reduce disaster losses.
***2*** The general public should carefully read and understand the "Understanding Card" for geological disaster prevention issued by local governments and relevant departments.
In the vast areas prone to geological disasters and dangerous areas, local governments and land and resources authorities have produced "Geological Disaster Prevention Clear Cards" for hidden danger points and dangerous points in the area and issued them. It has been distributed to the units responsible for monitoring and the people threatened by disasters, and they must carefully read and understand the contents on the "Understanding Card".
***3*** Pay attention to the weather forecast and geological disaster weather forecast.
***4*** Pay attention to the changes in mud and sand entrained by water flow in the slopes and valleys in front of and behind the house, report these abnormal situations to the relevant departments in a timely manner, and cooperate with *** and relevant departments to take measures Monitor measures or proactively take avoidance measures. Before the occurrence of geological disasters such as collapses, landslides, and debris flows, there are some precursors of varying degrees, such as mountain cracks, falling rocks, muddy spring water, an increase in mud and sand carried by water flow in valleys, and abnormal reactions of livestock and poultry. When these conditions are discovered, , should promptly report to the relevant departments, and actively cooperate with the *** and relevant departments to take relocation and avoidance measures.
***5*** In geological disaster risk areas and areas prone to geological disasters, do not carry out production and living activities that can easily induce geological disasters.
4. How to escape when geological disaster emergencies such as collapses, landslides, and debris flows occur?
In the face of sudden collapses, landslides, and debris flows, you must stay calm and first determine the collapse. , the area threatened by landslides and mudslides, and then escape from the danger area in time. Specifically, when collapses, landslides, or debris flows occur, rolling rocks, slopes, or debris flows move from high to low places. Therefore, you should choose to escape from the danger area in the left and right directions instead of following the rolling rocks or debris flows. Escape from the direction of slope or debris flow movement. If you are on a moving landslide and there is really no time to escape from the slide, you can cling to nearby thick trees for self-protection.
Types of geological disasters
1. Classification according to the dynamic causes of disaster-causing geological processes
Disaster-causing geological processes are all caused by certain dynamic forces. Temptation There are natural and man-made motivations. Accordingly, geological disasters can be divided into two categories: natural geological disasters and man-made geological disasters based on dynamic causes. Some divide natural geological disasters into two categories based on dynamic causes: internal dynamics of the earth and external dynamics. The former such as tectonic movement, magma activity, earthquakes, etc.; the latter such as weathering, erosion, transportation, sedimentation, etc.
The location, scale and frequency of natural geological disasters are restricted by natural geological conditions and are not affected by human development history and human will. Man-made geological disasters are restricted by human engineering and development activities, and often become increasingly serious with social and economic development. Human activities have become a powerful geological force, participating in the evolution of the earth's crust surface system, and having a great impact on changes in the earth's environment. Human activities alone or superimposed on natural geological processes have intensified and induced many geological disasters. Therefore, it is necessary to prevent human activities from The occurrence of geological disasters has become a focus of geological disaster prevention and control.
2. Classification according to the occurrence and development process of geological disasters
Some of the occurrence and development processes of geological disasters are completed gradually, while others are very sudden. Based on this, geological disasters are generally divided into two categories: gradual geological disasters and sudden geological disasters. The former include land subsidence, soil erosion, water and soil pollution, land desertification, siltation, etc.; the latter include earthquakes, collapses, landslides, debris flows, underground engineering disasters, etc. Gradual geological disasters have obvious precursors and slow development. As long as people pay attention to them and their prevention and control can be carried out predictably and calmly, the consequences of the disaster usually only cause economic losses and few casualties. However, due to its slow development, the consequences of disasters are not obvious in the short term. Therefore, they are often ignored by people. Over time, the consequences of disasters are also catastrophic, and it is very difficult to manage. Sudden geological disasters occur suddenly, develop rapidly, and have poor predictability. Prevention and control work is often carried out passively or on an emergency basis. In addition to economic losses, the disaster consequences often cause casualties. Sudden geological disasters are also the main type of geological disaster prevention and control.
Methods for responding to geological disasters
1. Pedestrians and vehicles should not enter or pass through landslide and collapse danger areas with warning signs.
2. When signs of landslides or collapses are found, the local police or relevant departments should be reported immediately, and other threatened groups should be notified at the same time. Be alert, observe closely, and be prepared to evacuate.
3. When you are on a landslide and feel a change on the ground, leave immediately and escape to stable areas on both sides as quickly as possible. It is dangerous to run above or below the landslide!
4. When you are in the middle of the landslide and cannot escape, find an open space with a gentle slope to stay, but be sure not to get close to houses, walls, or telephone poles Wait until you get too close.
5. When you are at the front of a landslide or beneath a collapse, you have no choice but to escape quickly to both sides.