How to scientifically evaluate the landslide events in Guizhou?

July is the main flood season in China, so it is often a disaster-prone month. 193 1 the Yangtze river flood is a natural disaster with the largest number of deaths in history, mainly in July. 20 12 The "7.2 1" torrential rain in Beijing occurred in July. In addition to disasters related to storms and floods, other disasters seem to occur easily in July. For example, the Tangshan earthquake of 1976 was on July 28th.

The latest disaster in July was the Chagou Formation landslide in Pingdi Village, Jichang Town, Shuicheng County, Guizhou Province. At 2 1 20 on July 23rd, a landslide occurred in Chagou Formation, Pingdi Village, Jichang Town, Shuicheng County, Liupanshui City, Guizhou Province. The picture below shows the location of Pingdi Village, about 40 kilometers west of Liupanshui City. It can be seen that the local vegetation is good, but the terrain is rugged, the height difference is large and the slope is steep. The top of the mountain is 2083 meters above sea level, and the bottom of the slope is 12 10 meters above sea level. In the horizontal distance of 2690 meters, the height difference reaches 873 meters. The initial position of this landslide is about 1540 meters above sea level on the mountainside, and the drop from the bottom of the slope is about 330 meters. 23 houses were buried, 22 people were killed, and the number of people who lost contact was unknown.

Heavy rainfall is an important cause of landslides. After the rainwater is absorbed by the soil, it goes down the mountain under the soil. Just as the same river is hidden under the soil and has tributaries, it can also converge into a large flow area. This is an invisible "river", and its shape determines the location and flow direction of the landslide. The middle area, because of its high terrain, is like an island in a river, and groundwater bypasses it from both sides. Because this area was slightly eroded by underground water flow, the soil moisture content was also small, and the adhesion between the surface soil and deep soil and rocks was not obviously weakened, so it survived. Judging from the traces after the landslide, this slope is not a rocky slope, but a loose soil slope. Before the landslide occurred, it rained continuously on July 2 1, July 22 and July 23, and there was a heavy rain on July 23, which should be caused by rainfall, liquefaction, unstable soil water and mudslides.

The rescue work is still in progress in an orderly manner. The relevant person in charge of the on-site emergency rescue headquarters introduced that at present, firefighters, armed police and all sectors of society are still fully organizing scientific search and rescue investigations on the lost persons, and disease control personnel timely disinfect and epidemic prevention in the affected areas. The lives of the affected people have been properly resettled.