According to the latest news of the landslide in Maoxian County, Sichuan Province, at about 6:00 today, a sudden high-level collapse occurred in Xinmo village, Diexi Town, Maoxian County, resulting in the burial of 46 farmers, the loss of 141 people, the blockage of the river channel for 2 kilometers, and the burial of more than 1600 meters of roads. Because the students have holidays at home, there are more people in the village, and the village is a tourist attraction, not excluding tourists.
Three people have been rescued from the collapse of the mountain in Xinmo village, Diexi town. Maoxian people's Hospital said three people were not seriously injured and there was no life risk. (this article is exclusively compiled by WYH, editor of sihai.com. If you need to reprint it, please indicate the source and source. Related article link: http://www.4hw.com.cn/life/anquan.html)
So what is the cause of the landslide?
Three basic conditions are needed for the occurrence of landslide: energy condition (topography condition), material condition and triggering condition.
The formation of landslides must meet the following three conditions: steep terrain and landform which are convenient for collecting water and materials; abundant loose materials; and a large number of water sources in a short time. (this article is exclusively compiled by WYH, editor of sihai.com. If you need to reprint it, please indicate the source and source. Related article link: http://www.4hw.com.cn/life/anquan.html)
The current excitation is the most common trigger factor of debris flow disaster in China. From continuous rain, moderate to heavy rain, rainstorm, ice snow rain, melt water, river lake reservoir collapse and other water flows continue to act, so that one of the basic conditions exceeds the strength under stable conditions, triggering debris flow. That is to say, the number and energy of water body increase abruptly, strong scour promotes the movement of accumulation; external forces trigger, for example, other dynamic actions beyond the basic conditions such as strong blasting, collapse, landslide, volcano, earthquake of over ⅶ degree, etc., promote the start of debris fluid, or cause the liquefaction flow of water saturated soil mass; environment induces, for example, the destruction of forest, the increase of factory and mine waste slag, construction waste dump and slope It is caused by the indirect factors such as the steepening of the degree and the inrush of groundwater.
Induced factors of landslides
Due to the development of industrial and agricultural production, the degree and scale of human development of natural resources are also developing. When human economic activities violate the laws of nature, they will inevitably lead to the retaliation of nature. Some landslides lead to debris flow, which is caused by the unreasonable development of human beings. In recent years, landslides and debris flow disasters induced by human factors are increasing. There are three aspects of human engineering economic activities that may induce landslides. (this article is exclusively compiled by WYH, editor of sihai.com. If you need to reprint it, please indicate the source and source. Related article link: http://www.4hw.com.cn/life/anquan.html)
The weathering of rock is existing in the natural state. In this weathering process, there are not only the decomposition of rock by oxygen, carbon dioxide and other substances, but also the decomposition of rock caused by the absorption of acid substances in the air in the precipitation, the decomposition of rock layer under the soil by the substances secreted by the surface vegetation, and the soil caused by the freezing and dissolution of the soil by frost Loosening of soil. All of these factors can cause the thickening of soil layer and the loosening of soil layer.
Unreasonable excavation for the construction of railways, highways, canals and other engineering buildings. Some mudslides are formed by building roads, canals, railways and other construction activities, which damage the hillside surface. For example, due to the construction of roads and canals in laogangou of Dongchuan Kunming Highway in Yunnan Province, the mountain was damaged. In addition, the 1966 rhino Mountain earthquake resulted in collapse and landslide, resulting in more serious debris flow. For example, many large-scale projects and ground buildings have been built in Hong Kong over the years. Almost every project needs to be cut into mountains and filled with sea or fill to obtain a suitable construction site. A rainstorm in 1972 killed 120 people at the site of the excavation works under construction due to landslides. (this article is exclusively compiled by WYH, editor of sihai.com. If you need to reprint it, please indicate the source and source. Related article link: http://www.4hw.com.cn/life/anquan.html)
There are many cases of debris flow formed by unreasonable spoil, slag and quarrying. For example, in Hanluo valley of Lugu Iron Mine, Mianning County, Sichuan Province, due to unreasonable stacking of waste soil and slag, a heavy rain broke out in 1972, which washed out about 100000 cubic meters of loose solid materials, silted up 300 meters of Chengdu Kunming railway and 250 meters of Xi (DE) - Xi (Chang) highway, interrupted traffic, and brought serious losses to transportation. Another example is near the West Water of Gansu Sichuan highway. In the winter of 1973, stone was mined in the ditch along the highway. On July 18, 1974, a debris flow occurred, blocking 15 bridges and culverts.
Deforestation and reclamation will make vegetation disappear, hillside lose protection, soil loose, gully development, which will greatly aggravate soil erosion, and then the stability of hillside is damaged, collapse, landslide and other adverse geological phenomena are developed, resulting in debris flow easily. For example, the middle reaches of Bailong River in Gansu Province is now a famous debris flow prone area in China. But more than a thousand years ago, there were dense bamboo trees and beautiful mountains. Later, because of logging and burning charcoal, burning mountains and opening up wasteland, the forest was broken and the debris flow overflowed. Another example is the daertou on shiaozigou mountain of Ganchuan highway, which was originally a forest area. Because of deforestation, the downstream villages and roads were destroyed by debris flow in 1976, causing serious loss of people's lives and property. The local people said: 'open acres of wasteland on the mountain, and flush a light under the mountain'.