How was the Zhouqu mudslide formed, and what year was the Zhouqu mudslide

At about 2 o'clock in the morning of the 9th, the Zhouqu County Headquarters reported in a meeting that after on-site inspection and comprehensive analysis by experts from the Ministry of Land and Resources, Gansu Land and Resources Department, it was initially believed that four factors led to the occurrence of Zhouqu catastrophic mountain flood geological disaster.

First, the local topography and special geological structure of Zhouqu are important reasons for the occurrence of disasters. According to the analysis of experts, the lithology of the geological structure near Zhouqu County is soft and relatively broken, and the degree of weathering is also very severe, and it is relatively prone to landslides, collapses and debris flows.

Second, the influence of Wenchuan is one of the important factors. Zhouqu County is one of the hardest-hit areas in Wenchuan, which has led to loosening of the mountains and broken rock formations around Zhouqu County. It takes 3 to 5 years to eliminate the loosening of the mountain caused by **, but it is only more than 2 years since the occurrence of Wenchuan**.

Third, the continuous drought in Zhouqu from the fourth quarter of last year to the first half of this year caused the disintegration of rocks around the urban area, and some mountains and rock cracks were exposed, making it easy for rainwater to enter and leading to landslides.

Fourth, it encountered heavy rainfall. On the evening of the 7th, a heavy rainstorm suddenly fell in the northeastern mountainous area of Zhouqu County, which lasted for more than 40 minutes, and the rainfall reached more than 90 mm, forming a debris flow, which directly caused a huge flash flood geological disaster.

The river water in the Bailong River is pouring in, and there is heavy rain.

Hydrodynamic conditions are one of the three major conditions for the formation of debris flows, and the fact that such a large debris flow can be produced indicates that the hydrological conditions there are very good, and there is continuous precipitation in the Zhouqu area, so there should be a lot of flowing water.

It's flowing from somewhere else.

In 2010.

At about 22 o'clock on August 7, 2010, the northeast mountainous area of Zhouqu County, Gannan Tibetan Autonomous Prefecture suddenly fell extremely heavy rain, the rainfall reached 97 mm, lasted for more than 40 minutes, triggered Sanyanyu, Luojiayu and other four ditch system of extremely large flash flood geological disasters, the debris flow is about 5 kilometers long, the average width is 300 meters, the average thickness is 5 meters, the total volume is 7.5 million cubic meters, the flow through the area was razed to the ground.

As of September 7, 2010, 1,557 people were killed and 284 people were missing in the Zhouqu 8.7 debris flow disaster, and a total of 2,315 people were outpatient.

Geological and geomorphological reasons. Zhouqu is one of the three major geological disasters prone to landslides, debris flows and geological disasters in China. The Zhouqu area is a folded belt in the western part of the Qinling Mountains, where the mountains are seriously differentiated and broken, and most of them belong to the soil mixed with carbon ash, which is very easy to form geological disasters.

5 12 "** shook the mountain. Zhouqu is one of the hardest hit areas of "5 12"**, which causes the mountain in Zhouqu to loosen and collapse, and it will take at least 3 to 5 years for the mountain to recover to the pre-earthquake level.

Meteorological reasons. Most parts of the country have suffered severe drought, which has caused the rock mass and soil to shrink, the cracks to be exposed, and the heavy rainfall has been encountered, and the rainwater is easy to enter the mountain crevices, forming geological disasters.

Instantaneous heavy rainfall and heavy rainfall. Due to the cracks in the rock mass, instantaneous heavy rain and heavy rainfall penetrate deep into the rock mass, resulting in rock collapse, landslides, and debris flows.

Characteristics of the freedom of geological hazards. Geological disasters are hidden, sudden, and destructive, and difficult to find out.

The Zhouqu debris flow was in 2010. At about 22 o'clock on August 7, 2010, a heavy rainstorm suddenly fell in the northeastern mountainous area of Zhouqu County, Gannan Tibetan Autonomous Prefecture, with a rainfall of 97 mm and lasted for more than 40 minutes, causing a huge flash flood geological disaster in four gullies such as Sanyanyu and Luojiayu, with a debris flow of about 5 kilometers long, an average width of 300 meters, and an average thickness of 5 meters.

Other factorsUpstream of the Sanyanyu drainage ditch, which was severely affected by the Zhouqu debris flow, a flood dam is being built, but the project, including four slag dams, had not yet been completed before the disaster.

After the debris flow disaster, the project was terminated; Dam No. 1, one of the four flood dams that has just been built, is filled with rocks and gravel inside the wreckage, and with a little force, the stones can be pulled out with bare hands. In the event of a disaster, these projects not only did not have their effect, but also had a negative impact.

First the forests, then the water conservancy, and finally the minerals, the plundering of local natural resources is like chewing sugar cane, chewing the boat koji section by section.

Due to the lack of follow-up funds, the Zhouqu debris flow prevention and control project could not be completed. The drainage and diversion project in Sanyan Village, a key early warning site, has not been implemented. It was from here that the mudslides that flooded the county poured down.

In fact, the occurrence of debris flow in Gansu is not the so-called natural disaster, Zhouqu is originally a location surrounded by mountains, and there is a river, coupled with people cutting down indiscriminately, causing the land to relax, so as long as it rains, the rainfall is too large, it may be caused by a mudslide!!

Because people overexploit and don't protect the plants, it causes such damage.

Indiscriminate deforestation and indiscriminate mining.

Overexploitation.