Mining subsidence causes more environmental damage than earthquakes

The consequences of mining subsidence damage are similar to earthquake, but its occurrence and development process is slow, and the damage degree is gradually developed from slight to severe. Compared with underground mining, there is a time lag process, that is, the underground goaf is often formed weeks, months or even years before the subsidence develops to the surface, and the scope of surface damage is many times larger than the scope of underground goaf. For example, in some mines, the diameter of the drop funnel is 1 km, and the hydrogeological situation has been damaged in an area of 7,500 hectares, which indicates that the surface far from the mine is also affected. Thus, the strange phenomena described at the beginning of this section are not easily detected in time at first, and once detected, the damage is irreversible, especially the damage to the environment cannot be overestimated. The damage does not become apparent even after production has ended. A large number of shocking facts are enough to explain the harm of mine subsidence disasters, but so far, has not caused enough attention to the relevant departments. The state invests a lot of manpower, material and financial resources in the research of earthquake, flood and fire every year, but the investment in the research of mine subsidence disaster is very little, which can not be said to be a misunderstanding.

Mining subsidence damage will continue to occur in our country

During the Ninth Five-Year Plan period, we conducted a field survey on the subsidence damage of large-scale coal mines in Northeast China and eastern Inner Mongolia, and found that all coal mines had the problem of damaging the environment due to mining, and it was very serious.

The Huotai mine and the Longfeng mine in Fushun Mining area mine coal under the urban area, affecting buildings within 160 square kilometers of the surface, and losing 7,200 mu of farmland due to subsidence. In March of this year, hundreds of houses in the Xinqiu mining area of Fuxin city sank and damaged, leading to a collective petition by residents. The subsidence of Hunchun mining area in Jilin Province even affected the opening to the outside world.

According to incomplete statistics, the 12 mining administrations in Northeast China mined 134 million tons of coal and destroyed 22,400 mu of land, an average of 1.7 mu of land per 10,000 tons. These mining authorities in the farmland under the coal reserves of 1.344 billion tons, will also destroy 228,500 mu of land, the situation is extremely serious.

It is necessary to strengthen the study of mining subsidence

It is decided by our energy policy to strengthen the research of mining subsidence science. Theoretically, the reduction and prevention of mine subsidence disasters should be carried out from both the root and the symptom. The most fundamental way is to change our energy structure, like Japan and some developed countries, to oil as the main energy, but this is not in line with our national conditions. It is estimated that in the 21st century, China's energy structure is still dominated by coal (accounting for 50%-60% of primary energy). Coal mine production is the most important factor that causes mine subsidence disaster. Therefore, on the one hand, measures should be taken to avoid or reduce subsidence disasters as much as possible (such as strip mining, filling mining, underground gasification, etc.); On the other hand, for the land that has been damaged and the land that will inevitably be destroyed in the future coal mine production, land reclamation or land restoration measures need to be taken. The purpose of reclamation is to restore the land destroyed by human activities such as mining to the desired state according to local conditions. In terms of land reclamation, many mine and mining residents in our country have created some feasible methods. But these methods must be adapted to local conditions, can not blindly imitate.

According to preliminary statistics, the reclamation area of mine land in China only accounts for 1% of the destroyed area. On the one hand, people do not know enough about the harm and severity of environmental damage in relatively remote mining areas. On the other hand, some enterprises and farmers lack the awareness of land protection and reclamation knowledge, and are unwilling to deal with or do not know how to deal with the destroyed land. There is a long way to restore the ecology in mining area, so it is urgent to research a land reclamation mode which accords with our country's conditions. Mining enterprises should be fully aware of their own responsibility in land and environmental protection, and take the initiative to reduce the extent of mining subsidence damage. It is necessary to raise the awareness of land danger and protection of the whole nation, and jointly pay attention to this easily forgotten corner - mining area.