News 1+1丨After the Luding earthquake, what should we do about the hidden dangers of geological disasters?
On September 9, the 6.8-magnitude earthquake in Luding, Sichuan has entered its fifth day.
The first round of geological disaster investigation has been completed in the earthquake-stricken areas, and 195 new hidden danger points of geological disasters have been found.
How to increase the prevention of secondary geological disasters in earthquake-stricken areas?
What are the characteristics of the 6.8-magnitude earthquake in Luding County this time, what enlightenment does it bring to disaster prevention and mitigation in the future?
"News 1+1" connected Xu Liang, deputy director of the Geological Disaster Prevention and Control Division of the Sichuan Provincial Department of Natural Resources; Ren Junjie, director of the National Institute of Natural Disaster Prevention and Control of the Ministry of Emergency Management, and the director of the Earthquake Disaster Research Center. How to deal with hidden dangers?
How to prevent and reduce disasters in areas prone to geological disasters?
Wenchuan earthquake in 2008, Lushan earthquake in 2014, Sichuan has been doing house reinforcement work after several earthquakes, and the Luding earthquake with a magnitude of 6.8, the houses in many towns and towns in the epicenter are still damaged to varying degrees.
In addition to house reinforcement, what other measures are needed for disaster prevention and mitigation in the future for areas such as Luding County, which are prone to geological disasters?
Long-term secondary geological disasters must be strictly prevented in the Luding M6.8 earthquake
Ren Junjie, director of the Earthquake Disaster Research Center of the National Academy of Natural Disaster Prevention and Control of the Ministry of Emergency Management:
We have done a lot of research on the location of the earthquake with a magnitude of 6.8 in Luding, Sichuan.
The earthquake occurred in the southeastern section of the Xianshuihe fault zone, which has experienced frequent strong earthquakes in history.
In addition, through research, we also found that there are a wide range of secondary disasters such as collapses, landslides, and dammed lakes in this area.
The secondary geological disasters caused by large earthquakes last for a long time, sometimes as long as ten years or even decades.
For example, two years after the Wenchuan earthquake in 2008, a large-scale debris flow occurred in Yingxiu, which caused a diversion of the Minjiang River with a width of about 120 meters.
In addition, in 2017, another major landslide occurred in Xinmo, Diexi Town, Maoxian County, which destroyed the entire Xinmo Village at that time, resulting in the death of 83 people.
Is relocation considered in the high-risk area of geological disasters in the Sichuan earthquake area?
Xu Liang, deputy director of the Geological Disaster Prevention and Control Division of the Sichuan Provincial Department of Natural Resources:
The Sichuan Luding M6.8 earthquake mainly occurred in Ganzi and Ya'an, which itself is located in the transition from the Qinghai-Tibet Plateau to the plain, and is a high-incidence area of geological disasters. Construction land and arable land are very scarce.
Although the population here is relatively small, in some places the population of towns and villages is relatively concentrated.
During the investigation, we found a lot of hidden dangers, and the threat to these towns and villages is still quite big.
Sichuan Province has been doing relocation work before, and has moved a lot. In these two places in the earthquake-stricken area, nearly 1,000 households have been moved.
What factors should be considered in post-disaster reconstruction site selection?
Ren Junjie, director of the Earthquake Disaster Research Center of the National Institute of Natural Disaster Prevention and Control of the Ministry of Emergency Management: The
reconstruction site should follow the relevant regulations on post-earthquake recovery and reconstruction, including earthquake fortification and disaster prevention and mitigation.
From the perspective of this earthquake, far from the fault, the loss of this earthquake disaster will be much smaller. Therefore, post-disaster reconstruction should avoid seismically active faults as much as possible, and it is forbidden to build buildings across active faults.
For some unavoidable areas, such as a road, it must pass through this active fault, and we must avoid crossing the active fault like bridges or tunnels.
In addition, judging from the damage of the houses in this earthquake, if the seismic fortification is constructed in strict accordance with the standards, the degree of damage will be much smaller. Therefore, during the post-disaster reconstruction, the construction should be carried out in strict accordance with the national seismic fortification requirements.