090. Conventional symbols mining enterprises map
Conventional symbols mining enterprises map
Environmental impact of mining industry
Mining industry is one of the sectors strongly and comprehensively affecting the environment. The intensive use of land lots for mining mineral resources leads to the destruction of the surface ground layer, creation of mining openings, disturbance of the hydrological regime of rivers, soil and surface and underground water pollution, and destruction of the environmental integrity and natural landscapes.
The importance of mining industry for Siberia and Mongolia is explained by their mineral resources specialization. Within the context of transitioning to sustainable (balanced) development, the high cost-effectiveness of the mining industry along with environmental compliance and the increase of social and living standards of the population are especially important.
This map reflecting the impact of mining on the environment was created to reveal the ecological component of sustainable development in the Baikal basin.
In the process of creating this map, the following library and published data were used: “National atlas of the Mongolian People’s Republic” (1990), “The ecological and geographic map of the Russian Federation” (1996), “Atlas of social and economic development of Russia” (2009), and “National atlas of Mongolia” (2009), etc. High-resolution satellite images (made in 2010-2013) were deciphered and used to examine the landscape structure of the territory. The state of the industrial sector and environment in the areas of mineral resources management was determined.
The objects of ecological evaluation were mineral deposits and mining enterprises. The information about them is provided on the basic maps that are part of this Atlas: “Fuel-energy resources and their development”, “Resources of ferrous, non-ferrous, and rare metals and their extraction”, “Basic types of nonmetallic materials, resources, and development”.
The biggest part of the researched area is part of the central and buffer zones of the Baikal Natural Territory within the Russian Federation. The Baikal basin in Mongolia is a natural continuation of this buffer zone. According to the Russian law “On the Protection of Lake Baikal”, the ecological zoning of the Baikal Natural Territory is the main tool for its implementation. Specific conservation restrictions are applied in the central ecological zone surrounding the Lake Baikal depression. Among the types of activities prohibited in this zone are the extraction of crude oil, natural gas, and radioactive and metal ores and the exploration and mining of previously undeveloped new deposits. The extraction of mineral resources within the water area of Baikal, in its water-protection zone, and in spawning rivers and their water-protection zones is prohibited.
In the buffer zone, the prospected and prepared for the development deposits, as well as mining operations are located within the ecological districts of Type 6, which includes industrial districts with a regulated intensive development. This type of districts is characterized by highly valuable landscapes and their components with an average or low sensitivity to stress. They mostly include the valley, piedmont, steppe and sub-taiga landscapes. The reason for singling out these districts is the importance of mining for the economy of the region. However, mining operations should not negatively affect the ecological system of Lake Baikal.
The cartographic evaluation of the technogenic disturbances of landscapes within the studied territories is provided for 380 mineral deposits. At present, 75 deposits are being developed. At 12 deposits mining operations are suspended, and they are either moth-balled or turned into reserves. The impact of mining enterprises on the environment is primarily determined by mining methods, the toxicity of raw materials and reagents used in processing, and landscape features.
The maximum impact on the environment, which is manifested in the drastic transformation of the relief with the formation of the technogenic denudation and accumulated forms, is caused by open-pit mining operations that remain a preferred mining method in the majority of cases due to economic considerations. On the territory under observation, 73 deposits are being developed by the open-pit mining method, and only 2 deposits are developed by the underground mining methods (the Bom-Gorkhon tungsten deposit and Nalaikh brown coal deposit). The main indicator of technogenic impact on the lithosphere is the area of disturbed land in square km, which is assessed using the following grades: I – over 10 km2 – the strongest impact, II – 1-10 km2 – strong impact, III – 0.1-1 km2 – moderate impact, IV – less than 0.1 km2 – weak impact. The largest disturbed land areas have been formed as a result of mining operations at the deposits of Erdenetiyn ovoo (Fig. 1), Gusinoozersky (Fig. 2), and Olon-Shibirskoe.
Sizable areas of disturbed lands in river valleys form due to the placer gold mining, which results in the intensification of erosion, change of structure and productivity of floodplains, pollution and deformation of riverbeds, decrease of groundwater level, and destruction of biotic components of ecosystems. On the surveyed territory, there are about 30 sites, where placer gold is being mined. Nearly all of them are located in the mountain river valleys of the Krasny Chikoy and Zakamensk district and the Selenge and Tov aimags. The maximum size of the disturbed land (about 40 sq. km) was found in the Tuul river valley (Fig. 3).
At the undeveloped deposits, the main source of the impact on the lithosphere are exploration works, including the development of drill holes and trenches, drilling, construction and exploitation of temporary roads and settlements. The area of such disturbances is relatively small and conventionally accepted as 0.01 sq. km.
The background indicator of technogenic disturbances of lands is the density (prevalence) of disturbances. This indicator is determined as a ratio of the total area of the disturbed land in an administrative district to the total area of this district. The following grades of disturbance are used (sq. km / thou. sq. km): I – over 10 – very high, II – 1.0 to 10 – high, III – 0.1 to 1.0 –intermediate, IV – 0.01 to 0.1 – low, V – less than 0.01 – lowest. Using this scale, the following aimags and districts have been classified as territories with a very high and high levels of land disturbance: the Orkhon, Darkhan-Uul, and Tuv aimags, Ulaanbaatar, the Petrovsk-Zabaikalsky, Zakamensky, Slyudyansky and Selenginsky districts.
At several operating mines, such as Olon-Shibirsky (coal), Tumurtolgoy (iron), Erdenetiyn ovoo (copper, molybdenum), Bom-Gorkhon (tungsten), Boroo (gold), etc., the extracted mineral resources undergo primary processing. In order to store or bury tailings, tailings ponds and dumps are created (Fig. 4). If built without paying due attention to filtering and other factors, they pose environmental risks and become the source of contamination of surface and ground water, as well as the atmosphere (dust). The most serious environmental consequences are found at the tailings ponds of the Erdenet Mining Company, Dzhidinsky tungsten-molybdenum mill (now shut down) and Kyakhta mill (currently not operating).
Extracted raw materials and enrichment products are classified into five categories of toxicity according to the degree of their ecological risk: I – very high: rare metal and radioactive ores, II – high: ores of nonferrous and precious metals, fluorite, III – increased: coal and brown coal, iron ores, IV – moderate: placer gold and tungsten, V – low: nonmetallic raw materials.
For every mining enterprise, environmental components (nature, economy, and people’s health) are differentiated by the degree of technogenic impact.
A negative impact on the environment and health is exemplified by the dumps and tailings ponds of the non-operating Dzhidinsky tungsten-molybdenum mill, which is located within the administrative borders of Zakamensk (Fig. 5). The production waste accumulated during the 50 years of the mill’s operations is a strong source of pollution contaminating the surface and ground water with toxic components and the air (dusting).
The mining enterprises are shown as symbols of varying shapes, sizes, structures and colors. The shape designates a mining method, the size shows the degree of land disturbance. The external contour (rim) shows landscape stability, while the internal contour points at its significance. The color of the contour corresponds to the values of indicators. A circle in the center of the map and its color show the level of toxicity or ecological risk of extracted materials and their enrichment products. The circles on the map designate the deposits undergoing different stages of geological exploration. The density of disturbed lands in administrative districts is reflected on the map using the quantitative background technique.
The map shows that the majority of mining enterprises is concentrated in the central most developed part of the territory. On the southwestern flank within the Mongolian part of the basin, there are many deposits, the majority of which are currently not developed. The lands are least disturbed in the northeast. In the central ecological zone of the Baikal Natural Territory, there are three operating non-ore deposits (the Angasolka deposit of construction stone, Slyudyanka cement marble deposit, and Tarakanovsky cement limestone deposit) located over 4 km away from the coast of Lake Baikal. The extracted materials belong to the low class of ecological risk. The development of these deposits is not included into the types of activities prohibited in the central ecological zone of the Baikal Natural Territory and does not significantly affect the ecosystem of Lake Baikal.
References
National atlas of Mongolia. (2009).
Atlas of social and economic development of Russia. (2009). Мoscow: Cartography. p 155-215.
The ecological and geographic map of the Russian Federation. Scale 1:4,000,000 (1996). Мoscow: GUGC.
National atlas of the Mongolian People’s Republic. (1990). Moscow-Ulaanbaatar. p 144
Fig. 1. Production and social infrastructure facilities at the copper molybdenum deposit Erdenetiyn Ovoo. There is a tailings pond in the northern part of the photo. The open pit is shown in the southern part, while production and residential zones – in the southwest.
Fig. 2. The nature of soil degradation at the Gusinoozersk brown coal field: open pits filled with water and waste rock dumps.
Fig. 3. Technogenic damages to the Tuul valley landscapes at a placer gold mine.
Fig. 4. Boroo gold mine: open pit is in the southwestern part of the photo, tailings pond is in the northeastern part of the photo.