Global ecological restoration of abandoned mines

In 1973, Japan developed a fiber soil greening method by mixing fiber, sandy soil and mud, and spraying in a step pattern. Since 1960, some developed countries began to develop slope greening technology, combining engineering and vegetation, such as horizontal grid, planting bag greening and guest soil planting technology, and finally developed into spray mixed planting technology.

02. Main technologies of mine restoration in China

The research on ecological restoration of abandoned mines in China started relatively late, starting in the 1980s and forming a certain scale after the 1990s. The research field mainly focuses on the vegetation coverage of abandoned coal mines and non-ferrous metal tailings ponds.

At present, the domestic research on mining abandoned land is mainly combined with land development and land consolidation, and according to the actual situation, the abandoned mine development is transformed into industrial land, cultivated land, tourism landscape and tourism land, storage land, breeding land, military land or green land.

Because of the difference of mineral resources, the treatment key of abandoned mines is also different. The environmental problems of coal mine wasteland are goaf area, subsidence area, coal gangue pile, etc. The key of its treatment is the treatment of goaf area and coal gangue pile. Non-ferrous metal mines such as copper, lead and zinc mines, in addition to the treatment of the pit, but also chemical treatment of waste slag heap, waste slag heap and other pollution of the nearby soil and groundwater through the rain action; The abandoned quarry is mainly used for the prevention and control of geological disasters such as landslide and debris flow and the restoration of vegetation.

As a kind of abandoned mining land, the restoration and treatment process of abandoned quarry should be as follows: investigation of the status quo of abandoned quarry → overall planning of restoration and treatment → geological disaster prevention → treatment of unstable slope, waste gas pit, mine pit, etc. → vegetation restoration.

03. Classic cases of mine restoration at home and abroad

At present, there are many successful cases for mine transformation at home and abroad, which are mainly divided into the following 7 types: ecological restoration, natural resources utilization, tourism development, reclamation, water diversion and lake making, waste treatment plant and storage.

Because of the early start of urban infrastructure construction in foreign countries, the ecological environment problems of quarry occurred earlier and more serious, so the research and practice of ecological restoration of quarry are more in-depth. In recent years, the practice of research and exploration on the restoration and management of abandoned quarry has been emerging.

01, Japan's state-run Akashi Strait Park

Japan's state-run Akashi Kaikai Park was originally a massive quarry that, from the 1950s to the mid-1990s, provided 1.06 trillion cubic meters of sand for the construction of Kansai Airport and artificial islands off the coast of the cities of Osaka and Kobe, digging more than 100 meters deep to create exposed mountains covering about 140 square kilometers.

Beginning in the 1980s, Hyogo Prefecture, where the island is located, commissioned renowned designer Tadao Ando to carry out planning and design, and set up a committee of greening experts to restore vegetation. The plan emphasizes the restoration of the natural state, the formation of a good landscape and the creation of a recreational space for people, and its theme is "to bring the park back to life".

The overall goal is first and foremost to heal the scars left by decades of mining. The Greening Committee believes that planting must start from the seedlings, and the trees are difficult to survive in such a harsh natural environment, but the seedlings can let nature take its course, so a total of 240,000 seedlings planting project began in 1994. The scientific method of planting makes this plan possible, including fixing a honeycomb of three-dimensional metal plates on the bedrock, filling it with new soil and covering it with grass curtains to conserve water. The irrigation system uses embedded polyethylene pipes with a density of 1 meter.

At the same time, because the local precipitation is relatively low, so in order to meet the needs of plant growth, the use of surface water collection, water recycling and other technologies. Rainwater collection pipes are buried under the road, while the park also serves as a service infrastructure for the area, including an international conference center, a star-rated hotel, a large greenhouse, an open-air theater and other facilities to create a future-oriented leisure place.

02, France Biville quarry ecological restoration

Biville Quarry in France has the characteristics of large scale, large height difference and serious ecological degradation. During the renovation, the industrial traces of the site are retained and transformed into a distinctive and iconic place in the new landscape structure, which reflects the respect for the historical context of the site.