Uncertainty about living near the death hole
It has been many weeks since the serious subsidence on National Highway 3B occurred, Ms. Loc Thi Mai (residing in Hiep Luc village, Kim Lu commune, Na Ri district, Bac Kan province) is not assured when returning home.
Although she had to be temporarily relocated to ensure safety, she still occasionally returned to check and continue raising livestock. The house is located next to the national highway, less than 10m from the house to the edge of the lake of death, after the first collapse, part of the fence in front of Mrs. Mai's family collapsed.
The entrance to the house began to show signs of cracking, and the soil sank. Meanwhile, the edge of the hole is tending to continue to widen, especially after recent heavy rains. Mrs. Mai was worried that if the soil continued to sink, the entire house and garden could be swept away.
"Now every time I pass by here, I am very scared because I don't know when the soil from my feet will drop. If this situation continues without measures or solutions, the only way into the house will no longer exist, and the whole house will be swallowed up" - Ms. Mai added.
Not only the fear of subsidence is waiting, Mr. Dam Van Viet, a household living about 20m from the cage, is also worried every day because the phenomenon of cracks and soil is spreading to neighboring areas. Many locations around the death hole on National Highway 3B have shown signs of subsidence, some places have land receded to the edge of the yard, and the walls have also begun to crack slightly.
In addition to the geological risk, local people are also concerned about domestic water sources. After the incident of people falling into the death hole on the evening of May 26, until now, they have not found it, causing many families to be hesitant and not dare to use well water like before.
"Since the incident, everyone has been confused, especially since the two missing people have not been found. Not only are people worried about the risk of further landslides, they are also worried about domestic water sources. No one dares to use well water, whether drilling or digging, because they are worried. We just hope that the forces will soon find the victim's body so that the people can feel somewhat secure" - Mr. Viet added.
Evacuating households, announcing emergency about subsidence
Faced with the increasing trend of subsidence, Mr. Nong Quang Nhat - Vice Chairman of the People's Committee of Bac Kan province - signed and issued a decision to declare a natural disaster emergency for the above phenomenon. The declaration of an emergency situation aims to deploy timely measures to ensure the safety of the people.
Speaking to Lao Dong Newspaper reporter, Mr. Truong Quang Trong - Chairman of Kim Lu Commune People's Committee (Na Ri) confirmed that as of the end of May, the commune had recorded at least 7 landslides and cracks along with a complex underground system underground.
"The sinkhole area on National Highway 3 through Hiep Luc village is showing an expansion trend. We have urgently relocated 5 households and arranged temporary accommodation with the necessary conditions. At the same time, closely monitor developments in the field" - the commune leader added.
The cause of the subsidence has not yet been determined.Based on the initial assessment, Bac Kan province is coordinating with the Institute of Geological Sciences and Mineral Resources to develop a project to investigate the cause and deploy long-term solutions.
Finding solutions to a series of sinkholes
Regarding the phenomenon of continuous sinkholes in Na Ri district (Bac Kan), Dr. Nguyen Xuan Nam - Deputy Executive Director of the Center for Karst and Geological Heritage (Institute of Geological Sciences and Minerals) said that it is necessary to conduct a field survey to accurately determine the cause.
The Institute's leader proposed 5 main scenarios for subsidence, including: existence in the underground cave system of limestone; impact of geological fractures; impact of prolonged heavy rain; excessive underground water exploitation and the load from national highways.
In particular, the phenomenon of water receding and rising simultaneously at neighboring pits shows the possibility of the existence of connecting underground cavities. If these structures become unstable, they can cause unexpected land subsidence. Notably, the expert also mentioned the suspicion of there being a possibility of illegal gold mining in the area in the past.
"It is necessary to verify whether there were underground mines that were not filled in before. Such void areas are often the underlying cause of sudden subsidence, said Mr. Nam.
Currently, the area around the sinkhole has been cordoned off, fenced off, and searched for missing victims. In addition, the work of ensuring safety for residential areas and vehicles is being urgently deployed by competent authorities.
As reported by Lao Dong Newspaper, at around 9:34 p.m. on May 26, at the subsidence point on National Highway 3B through Hiep Luc village, Kim Lu commune (Na Ri, Bac Kan), a motorbike driver fell down a barrier and fell into a deep hole. The identity of the missing person was identified as Mr. Nguyen Duy Ph. (born in 1989, residing in Kim Hy commune, Na Ri district).
