Study On Ecological Restoration In Coal Fires Area

Abandoned coal fire areas have brought a lot of damages to our human beings. First of all, valuable resource, coal has being wasted, resulting in considerable economic loss. Secondly, a lot of land was damaged increasing the contradiction between people and land. Thirdly, environment where human is living is worsening because of coal fire, affecting the normal life of resident. In addition, under high temperature, the survival of plants and animals are threatened, soil is scorched, rock turn burned rock and cracks and collapse pits appear. Finally, harmful gases including carbon dioxide, methane from coal fire cause greenhouse effect.Wuda mining area in Inner Mongolia as the study area in this paper is located in northwest China. Using ecology, restoration ecology, soil science and botany knowledge, ecological restoration of abandoned coal fire areas was researched after study in the field and reference from literature.By reviewing the literature and studying in the field, overview of the study area including geographical location, climatic characteristics, traffic condition and coal production is surveyed. Based on study in the field and collection of specimens, distribution feature of vegetation is estimated, the types of plants existing in the coal fire areas were recorded, the biological characteristics, ecological adaptability, economic value of existing plants were analyzed. During the study in the field, using GPS and Testo 925 thermometer, temperature of ground in fire areas was tested, and the result tested was analyzed. Ecological restoration methods were proposed based on the actual situation. The main conclusions are as follows:(1) Abandoned coal fire areas were simply caused by spontaneous combustion of coal seam. The internal reasons for spontaneous combustion of coal seam are mainly coal seam thickness, coal rank, sulfur content, calorific value, ash content and so on. The external cause is mainly coal mining of small coal mines in disorder. (2) In Wuda mining areas, vegetation is sparse, plant species are simple. There is no tree in community. Shrub layer is low. The spatial pattern is clumped.(3) The limit elements of ecological restoration in coal fires areas are fund shortage, techniques for fire fighting, soil factor, temperature factor and man-made factor. Soil factor is leading factor showing a lack of soil layer, high soil temperature or low soil moisture content. Unfavorable temperature factor is caused by coal fires showing too high temperature has exceeded the tolerance limits of most living creature.(4) Ecological restoration technologies of abandoned coal fire areas in Wuda include engineering technology and biotechnology. First, coal fires should be extinguished by extinguishing fire project, fissures and collapse should be managed, and the fire areas should be covered with soil. Then, vegetation should be restored; soil animals and micro-organisms should be brought in order to improve the ecological system in fire areas. After investigation in the field and analysis, the species have priority in vegetation restoration were selected.(5) Ecological restoration of abandoned coal fire areas in Wuda will bring significant social, economic and ecological benefits. Pollution source will be eliminated completely and people's living environment near the mining areas will be cleaner; The restoration will increase land reclamation rate, increase available land area, ease contradiction between people and land and contribute to land reclamation in our country; Coal fires management will save a lot of valuable coal. Plenty of grass, crop and plants to be used for medicine will grow in reclaimed land giving local people considerable economic income. The ecological restoration of the area will avoid releasing a large number of greenhouse gases and other toxic and harmful gases. Extinction of coal fires will prevent rock and soil above the fires from being destroyed.