Global ecological restoration of abandoned mines

Not long ago, we investigated in Heze, Shandong Province, and found that two large lakes were formed in the coal mine subsidence area, and their locations were exactly in the ancient Daye area.

If Shandong Dongying is a veritably Yellow River delta, then historically Heze is located in the area of Lu, Henan, Anhui and Jiangsu, precisely because of the barrier of the Taiyi Mountains on the Shandong Peninsula, and the formation of the Yellow River from Henan Kaifeng as the boundary, the new Yellow River to the northeast, and the Yellow River to the southeast inclined to Huai-Su, the big "delta" region held by. And this area is precisely the birthplace and gathering place of Chinese civilization.

There are many relics of prehistoric civilization here: there are Huaxu Lei Ze track, Fuxi origin ancestral land, Shennong from Lishan Mountain, Zhuanxu ruins, Yao burial valley forest, Shun farming Lishan Mountain, Yu river, Zhuolu wild, and so on. Archaeological discovery of Dawenkou site, Longshan cultural sites and so on. Historical legend has dragon born Lei Ze, west hunting Lin and so on.

In the southeast of the subsidence area, there used to be Fenghuang, Xuanwu, Qinglong and White Tiger four elephant mountains. However, due to the quartering in recent years, four deep ponds of tens of meters have been formed, and the four mountains have become four ponds. The chiselled mountain landscape is jagged and strange, and it has quite primitive features. The formation of an ancient cultural tourism experience scenic spot (see "Southwest Shandong Dashize Culture Exploration").

In the process of urbanization construction, abandoned mines (quarries) bring more serious landscape ecological problems to the city, such as soil erosion, threat to urban flood control, reduction of biological diversity, damage to the surface, etc., and have a certain impact on the sustainable development of urban ecology, society and economy.

According to the research and practical analysis of the transformation of abandoned quarry at home and abroad, the transformation of abandoned quarry is mainly to add humanistic landscape elements on the basis of its own land resources and unique natural landscape, and transform it into wetland park, ecological park, urban park and other tourist attractions with educational significance while restoring ecology.

01. Main technologies of mine restoration abroad

The western developed countries began the related work of ecological restoration of quarry at the beginning of last century.

Britain, the United States, Australia and other developed countries have a long history of mining, and the initial research on restoration ecology mainly focused on the restoration of abandoned land vegetation left after mining. In 1971, the reclamation rate of mine land in the United States was 79.5%.

The concept of land reclamation in the United States mainly emphasizes the ability to restore to the state before destruction, requiring the restoration of farmland and forests, and the control of water erosion and toxic sediment. Ensure that the land surface remains unchanged and the water table remains at its original level; Keep the topsoil in its original position; Pay attention to the prevention and control of harmful and acidic substances; Prevent landslides and other disasters caused by deposits.

Since 1940, Germany has paid great attention to reducing the damage to the ecological environment to the greatest extent in the mining process. The reclamation after mining is not only planting trees or land preparation, but also considering the ecological changes and residents' environmental requirements from a macro perspective.

Because of its dense population and developed industry, France first prevents pollution and restores ecological balance without changing the area of agriculture and forestry. France attaches great importance to planting grass in open waste dumps and promoting the activation of soil, which becomes new farmland after certain reclamation.

The Australian government attaches great importance to the restoration of abandoned mining areas, strictly regulates the ecological environment of production mining areas, and adheres to the road of sustainable ecological mining. It combines multi-expertise and introduces many new computer technologies, and now uses reclamation as part of the mining process.

In countries such as the United States and Australia, the modern 3S technology and other new technologies and new concepts currently quoted have been widely used in ecological restoration. The goal of ecological restoration is not only to plant trees and grass, but to establish a complete ecological service system that can maintain itself and run well.

The United Kingdom and the United States produced the earliest engineering greening technology, in the early 1940s, some European and American countries to prevent slope rain erosion invented plant POTS, hydraulic spray seeding technology; The United Kingdom invented plant seed spray and spray emulsion asphalt technology, and Japan developed a more practical spray greening technology after several tests in 1958.

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.

The Biville quarry at the top of Clairefontaine Canyon was closed in 1989 after 10 years of mining. The quarry pit is a 450m long, uniform width linear crack, a 45 degree slope barren and uneven, 20-40m drop.

The designers built it into a recreation area with a 3.5 square kilometer lake. The idea was not to hide the traces left by the stone mining process, but to preserve them as site features, simply to ensure continuity in the best locations for the natural restoration of the ecosystem, and then to introduce some vegetation to restore the abandoned quarry to a natural state.

The renovation includes the design of a series of facilities and equipment to direct the flow of water to the valley floor to form a lake. The lakeshore has been designed to accommodate the most popular leisure activity in the area - fishing.

To make it easier for visitors to enter the valley floor, the walls of the pit are built in the shape of steps, and each platform is lined with metal mesh and fixed stone as a barrier. At the same time, the form of the ladder allows runoff from the grass above to flow into the gutter, protecting the surface from water shock and erosion. The huge stone walls viewed from the valley floor become the most symbolic attraction in the area.

Adult trees are planted in strips on the site to resist wind erosion, and each section is planted according to its natural characteristics and topography.

03. Ecological restoration of Guri Mining field in Venezuela

For the first time, Venezuela has used water grass planting technology to ensure the rapid and effective formation of vegetation without the use of black soil and plant layers, and the ecological restoration of the earth dam quarry on the right bank of the Guri Hydropower Station is implemented at a very low cost, and is at the forefront of the application of water grass planting technology.

The Guri Project, located on the Caroni River in southeastern Venezuela, was constructed between 1967 and 1986 with a hydroelectric power plant, earth dam and rockfill dam, which required 40 million cubic meters of anti-seepage material to be extracted from a collection of about 700 hectares of forest not far from the dam.

Excavation of the mining site involves the removal of weathered gneiss, leaving exposed irregular concave surfaces and recesses that are susceptible to severe erosion by rain, resulting in poor sensory areas with topographic variations of up to 100m. In this regard, the Karoni Power Company has implemented a multi-faceted "ecological environment restoration plan" for the mining site, with the aim of restoring the ecological environment of the affected area during the construction of the Guri Hydropower Station.

The ecological restoration plan is divided into six stages: initiation stage, recovery stage, diagnostic examination stage, experimental stage, contract planting stage, and continuous treatment stage. The concept is to save nature by means of natural restoration.

The rescue measures mainly include: Select major local plant species and some introduced plant species as vegetation, plant a large number of local thriving trees under greenhouse conditions, plant resistant gramme seeds mixed with seeds proved to be suitable for the ecological and climatic conditions of the harvesting site, prohibit planting in the rainy season every year, and implement a protection plan suitable for the planting period after 3 years. Use biofertilizers and low chemical fertilizers to set up small oxidation ponds in flat low-lying areas with rainwater and dam leakage.

04, Shanghai Shimao Shenkeng Hotel

As the first hotel in the world to be built in a waste rock pit, the Shimao Deep Pit Hotel in Shanghai's Sheshan district is undoubtedly a strange project. Its construction method, building structure and traditional building requirements are very different, after completion or become the world's lowest elevation hotel, known as the world architectural miracle.

The "Deep Pit Hotel" is located at the foot of Sheshan Mountain in Shanghai Songjiang National Scenic Area. It is an abandoned pit with a depth of 80 meters. The deep pit was originally a quarry, and after decades of quarries, a deep pit with a circumference of kilometers and a depth of 100 meters was formed. Shimao Group has taken full advantage of the natural environment of the pit and has imaginatively built a five-star hotel that blends into the pit and complements it. This is a miracle in the history of human architecture, as well as a synthesis of nature, humanity and history.

Invested by Shanghai Shimao Group, the "Deep Pit Hotel" is the world's first five-star hotel built in the pit. The hotel is equipped with underwater scene suites, sky garden, spectacular waterfall, steel structure resistant to 9 earthquake buildings. In March 2013, the Deep Pit Hotel was officially started. On October 21, 2013, the wall and bottom rock of the pit were blasted for the first time, and the construction team expects that the hotel will be completed by the end of 2017, which may become the lowest altitude hotel in the world.

The "Deep Pit Hotel" has three floors above the ground, 17 floors underground and one floor underwater, and has entertainment items such as bungee jumping. The whole investment is about 600 million yuan, including natural indoor garden, large landscape waterfall, landscape presidential room, water scene room and so on. At minus 65 meters above sea level, the hotel is expected to become the lowest hotel in the world in an artificial pit.

The hotel rooms are built along the cliff face and face the Hengshan mountain, fully demonstrating the design concept of "blending into nature". The main building is made of glass and sheet metal, and the curved facade forms a "waterfall". All hotel rooms are equipped with terraces and balconies as "sky gardens", you can enjoy a close view of the 100-meter waterfall and Hengshan.

Combined with the characteristics of the quarry pit in the hotel base, the hotel also introduced a bungee jumping center, underwater restaurant, landscape restaurant, water SPA, indoor swimming pool and other recreational services suitable for cliff and water activities. In addition to the bungee jumping center and the landscaped restaurant located on the ground floor, the rest of the projects are set near the water

05, Shanghai Chenshan Botanical Garden mine garden

The mine garden of Shanghai Chenshan Botanical Garden is built using the natural terrain of the quarry mine. Based on the strategy of ecological restoration and cultural reconstruction, the potential of the site is fully expressed through the most possible links. A dangerous and inaccessible wasteland has been transformed into an attractive tourist destination for people to get close to the natural landscape and experience the culture of the quarrying industry, with a natural beauty and a natural charm.

Shanghai's new Botanical garden, Chenshan Botanical Garden, is located in Shanghai Songjiang Sheshan Scenic Area. Chenshan, one of the twelve peaks of the Songjiang River, was once used as a site for mining building stones, and the mountain was seriously damaged by excavation.

Chenshan Mountain is located in Sheshan Town, about 9.5km north of the county seat, about 2km southwest of West Sheshan, is the afterpulse of Tianmu Mountain. Chenshan Mountain is 700m long from east to west, about 300m wide from north to south, the highest point is 71.4m above sea level, with a total area of 12 hectares. The rocks in Chenshan are mainly acidic rhyolite with tuff and pyroclastic rocks. The Shandong side is Chenshan Pond, and the southern foot is Chenshan Town. Quarry excavation is carried out on the southwest and southeast parts of the mountain, forming two quarry pit relic areas in the east and west. Among them, the total area of the western mining pit is about 46200 square meters, and the bottom of the eastern side of the pit is formed by quarrying a deep pool with an area of 10,700 square meters. The mine garden is a characteristic garden with the west mine as the main body.

The designer divides the mine garden into three areas: deep pool area, flat lake area and platform area. In the Deep Tan area, the designer creatively designed a viewing path composed of inclined steel barrels, curved steel plate trestle, artificial transformation of the "one-line sky" landscape and winding wooden pontoon bridge.

At the end of the path, the designers also blasted a 150m long tunnel with a height difference of 25m, thus establishing a link between the eastern and western pits. In the Pinghu district, the designers re-shaped the terrain by digging ponds and filling them with soil, and formed new "Mirror Lake" and "Wanghua Terrace" attractions. In the terrace area, the designer re-constructs the rhythmic sequence of the facade with rusty steel plates and rough stone walls, and then sets up different hiking paths to lead people to the top floor of the terrace and visit the "secret" space with various plants.

06, Zhejiang Shaoxing East Lake Scenic Area

The history of the East Lake in Shaoxing can be traced back to the Qin Dynasty. During the Qin and Han Dynasties, the area around the East Lake became a quarry, which reached its peak in the Sui Dynasty. After thousands of years of craftsmen's hard work, the East Lake is like a ghost axe God chisel, and countless cliffs have been achieved. In the Qing Dynasty, Tao Junxuan built a garden here, imitating the artistic conception of peach land, built a dike on the lake as the boundary, the lake is inside the dike, built a bridge to build a pavilion, in this East Lake became a concentrated landscape essence of the state of Yue.

East Lake is located in the east of Shaoxing Ancient City, about six kilometers away from the ancient city, with the ingenious combination of cliffs, stone Bridges, lakes and caves, it has become a famous garden in China, and is one of the three famous lakes in Zhejiang Province. Although Shaoxing East Lake is small, but because of its strange caves, strange stones formed by the wonder of the East Lake become a rare "lake of wonder".

East Lake was originally a bluestone mountain, after the Han Dynasty, this mountain has become a local quarry, after a long time of mining, almost half of the bluestone mountain excavated, thus forming about 50 meters high cliff. Mining workers dug more than 20 meters into the ground, and over time formed a clear pond about 200 meters long and 80 meters wide.

East Lake made use of its original natural environment and human resources, and with the help of classical garden landscape techniques, a wall was built in the quarry to widen the water surface, thus forming a beautiful East Lake. Through long-term artificial modification, the East Lake has become a beautiful bonsai. Designers according to local conditions, because of the shape of the situation, the use of the original natural environment - quarry, on the basis of artificial restoration, to achieve the natural and artificial natural integration effect.

07, Tangshan Nanhu Ecological Park

The Central Ecological Park of Nanhu City in Tangshan was a coal mining subsidence area formed by Kailuan mining for more than 130 years before the reconstruction, which is the one with the greatest influence on the city. Since 1996, Tangshan began to implement the ecological environment management in the southern mining area, forming the South Lake Park. At present, Nanhu Park is a national AAAA scenic spot, which is a large urban central ecological park integrating natural ecology, historical culture and modern culture.

Tangshan Nanhu Scenic spot, located in the south of the city center, is one of the most influential coal mining subsidence areas in Tangshan city. After decades of settlement, the average height of the subsidence area is about 20m lower than the urban area, and the surrounding residents have been relocated, and it has become a rare wasteland.

At the end of the last century, the Tangshan municipal government began to carry out landscape ecological governance, and the transformation steps of the mining and subsidence area were as follows:

(1) Ecological restoration, water environment management, atmospheric environment management, mining area treatment, vegetation restoration, etc.;

(2) Park construction, the construction of urban parks, museums, recreation centers, etc.;

(3) Comprehensive development, the implementation of comprehensive utilization and comprehensive development of the surrounding land after the completion of the urban park.

Landscape ecological design in Nanhu area includes:

(1) Determine the subsidence affected area and influence area during the planning period according to the geological survey, estimate the water accumulation area, and carry out construction suitability analysis.

(2) Transformation of terrain and improvement of soil. Combined with geological survey and ecological characteristics of the material left in the site, the "water excavation and mountain building" project was carried out.

(3) Water system regulation. In the first stage, the polluted Qinglong River in the lot was diverted and separated from the newly formed water surface landscape.

In the second stage, with the migration of the river, the current lake is cleaned, the lake is drained, the garbage is removed, and a large water surface is formed. The soil and plant layer on the surface of large subsidence areas will be removed, and the excavated fertile soil will be transferred to fly ash fields and garbage mountains, making it possible to grow plants on the original barren land.

(4) Landscape ecosystem -- an ecological network composed of small pastoral grids, marginal parks, green pastures, reed fields, etc. From the perspective of ecology and aesthetics, the city and green Spaces penetrate each other, and define the boundary from the open water surface to the land, giving play to its ecological effects, so that the coal mining subsidence area forms a characteristic landscape.

08, Hubei Huangshi National Mining Geopark

Huangshi National Mining Park is located in the Tieshan District of Huangshi City, Hubei Province. The "Mining and Smelting Grand Canyon" is the core landscape of Huangshi National Mining Park. It is shaped like a huge gourd-shaped shape, 2200 meters long from east to west, 550 meters wide from north to south, with a maximum drop of 444 meters and an area of 1.08 million square meters. It is known as the "first sinkhole in Asia".

Huangshi National Mining Park is located in the Tieshan District, the famous Hanyeping coal and iron Company "ye" refers to the Daye Iron mine, after hundreds of years of mining, the east open-pit pit of Daye Iron Mine formed the world's highest steep slope with a drop of 444 meters; In order to control the ecological environment, the mine has invested tens of millions of yuan to form the largest hard rock reclamation base in Asia.

In the design of Huangshi National Mining Park, the natural ecology and human ecology of the mine are restored through the landscape design method of ecological restoration. The "ten highlights" of the mining area and the construction of the park are "seamless docking", and the focus of the development and construction of the park is to carry forward the mining culture, reproduce the mining civilization, display humanistic characteristics, improve the mine grade, open a new road to tourism, and position it in the "science popularization education base, scientific research and teaching base, cultural display base, environmental protection demonstration base".

It fully demonstrates the Chinese mining culture with a long history of thousands of years, provides people with a set of tourism, scientific activities and research in one place, and realizes the harmonious coexistence and common development of man and nature.

The park is divided into "geological relics exhibition area, mining industry exposition area, environmental restoration and transformation area three major sections, with sunrise East, mining expo, underground exploration, Shihai oasis, Zhan Mountain smoke rain, Lingshan ancient temple, millennium Ginkgo, Kowloon Dongtian and other eight core scenic spots.

09. The Garden of Eden in England

The Garden of Eden is located in Cornwall, England, on the tip of a peninsula jutting into the sea in southeast England, with a total area of 15 hectares. The site was originally a huge pit left by local people excavating clay, the project invested 130 million pounds, lasted two years, completed in 2000, and opened to the public in March 2001. It attracted more than two million visitors in its first year and has attracted more than ten million visitors since its opening.

The Garden of Eden in England is the world's largest single greenhouse, which brings together almost all the plants in the world, more than 4,500 species, 135,000 flowers and trees in this home. In the greenhouse with the structure of the giant space grid, a natural biological community is formed. Its goal statement is "to promote an understanding of the important relationship between plants, people and resources, and to manage this relationship responsibly, leading to a sustainable future for all."

The Garden of Eden is built around the plant culture, the integration of high-tech means of construction, with the theme of "coexistence and integration of people and plants", with "plants are indispensable friends of human beings" as the construction concept, with high scientific research, industry and tourism value of plant landscape theme park.

It consists of eight huge honeycomb domes full of futuristic colors, of which four dome-shaped buildings are connected into a group, respectively forming the "wet Tropical Pavilion" and "warm climate Pavilion", and forming an open-air garden in the middle of the two pavilions "Cool Climate Pavilion". The dome-like building mimics various ecological environments on the earth, displaying different biological groups, accommodating thousands of rare flowers and grasses from all over the world.

Eden's dome is made of a lightweight material that is not only lightweight, but also self-cleaning and recyclable. In addition, other buildings in the Garden of Eden are also made of environmentally friendly materials and clean renewable energy, which can be said that the garden itself is a model of energy conservation and environmental protection.