Study On Ecological Security About Coal Mining Area

Ecological security is an important part of establishing harmonious society.It is a kind of state of not or seldom being threathen by ecological environment. At present, ecological security has become a hot research topic of geography science, resource environmental science as well as ecology.The research will have important theory and practical significance for regional environmental management and sustainable development.The paper is divided into eight chapters.The first chapter mainly introduces research background and significance,domestic and foreign research status of interrelated fields,research objects and contents,research methods and technical rount as well as the innovation points.The second chapter mainly elaborates the nature, social and economic profile of Natun coal mine area.The third chapter carries on analysis and evaluation of land subsidence cumulative effects.The fourth chapter analyzes dynamic change of land use.The fifth chapter evaluates ecological security of Nantun coal mining area.The sixth chapter carries on the research of economic analysis of ecological security.The seventh chapter puts forward countermeasures and suggestions.of ecological security.The eighth chapter includes conclusions and discussions.Through the research, the main conclusions include:(1)The analysis and evaluation of land subsidence cumulative effects include analyzing influences of land subsidence to soil properties and land productivity.The results show:①The land subsidence accelerates soil erosion, which significantly affects the soil physical and chemical properties of arable land, being most affected by the 0-20cm soil layer, followed by 20-40cm layers, 40-60cm layers again.②The soil moisture of different levels increases with increasing depth. The change trend of soil moisture of three levels has consistency. The soil moisture of upper layer are smaller than lower layer at different levels. The soil moisture of subsidence arable land in 0.5 m are lower than normal arable land. However the soil moisture of subsidence arable land are higher than normal arable land when the depth exceed 1m.③The soil bulk density of different levels increase with increasing depth. The soil bulk density is biggest in 2m. The soil bulk density decrease when the depth exceed 2m. In addition, soil bulk density of upper layer are bigger than lower layer. The change regulation of soil porosity contrasts with soil bulk density.④The soil organic matter and nutrient of different levels increase with the increasing depth. The soil organic matter and nutrient are least in 1m. The soil organic matter and nutrient decrease when the depth exceed 1m.⑤The influence of land subsidence on soil moisture is bigger than soil bulk density and soil porosity.The influence of land subsidence on soil organic matter is biggest,followed by TN, available P and K.⑥The land productivity of subsidence arable land is lower than normal arable land, lower 21.81 percent in 1m, 16.26 percent in 2m, 10.71 percent in 3m.(2)The main conclusions drawn from analysis of land use change are:①The area of arable land decreases from 1978 to 2007. However the area of other land types increase.The area change of arable land and subsidence land are bigger than other land types.②The arable land has been decreasing in 29 years, changes rates and annual changes rate for -39.32% and -1.36% respectively.The subsidence land increases at first and then decreases, change rate and annual rate for 10281.82% and 354.55% respectively.③The information entropy of land use in Nantun coal mining area from 1978 to 2007 has been increasing, from 1.14 in 1978 to 1.81 in 2007.However the balance index and dominance index has been decreasing,which indicates land use system evolutes toward a disordered state④The land use degree index in 29 years in Nantun coal mining area increases at first,then decreases.The land use degree index increases from 1978 to 1987,which indicates land use is in development stage. The land use degree index decreases from 1987 to 2007,which indicates land use is in adjustment stage.⑤The notable trend of land type change is that arable land changes into subsidence land and residential and warehouse land. (3)According to conceptual model and evaluation principles of ecological security,a index system is established,which includes 22 indicators.Then fuzzy comprehensive evaluation and AHP methods are used to evaluate ecological security of Nantun coal mining area.The results show:①The situation of ecological security in Natun coal mining area in 2005 is:"Ⅴ"rank of 8.1 percent,"Ⅳ"rank of 22.3 percent,"Ⅲ"rank of 44.3 percent,"Ⅱ"rank of 18.1 percent,"Ⅰ"rank of 6.7 percent.The evaluation score is 60.37 point.According to ecological security rank, ecological security in Natun coal mine area in 2005 is in the"Ⅲ"rank.②The situation of ecological security in Natun coal mining area in 2008 is:"Ⅴ"rank of 16.3 percent,"Ⅳ"rank of 19.6 percent,"Ⅲ"rank of 35.3 percent,"Ⅱ"rank of 23.0 percent,"Ⅰ"rank of 5.9 percent.The evaluation score is 61.91 point.According to ecological security rank, ecological security in Natun coal mine area in 2008 is in the"Ⅲ"rank.③The ecological security of Nantun coal mining area in 2005 and 2008 are in the"Ⅲ"rank and"general"state.The ecological safety in 2008 was better than that in 2005, but the situation is not optimistic.(4)Ecological security is studied based on ecosystem service value. The results show:①Ecological service values of Nantun coal mining area are 55,248,801.15 yuan, 51,247,706.87 yuan, 48,236,130.56 yuan, 45,267,219.43 yuan and 48,252,531.64 yuan in 1978, 1987, 1997, 2004 and 2007 respectively.②The ecosystem service value increase at first,then decrease.It decreases from 55,248,801.15 yuan in 1978 to 45,267,219.43 yuan in 2004. In 29 years,the ecosystem service value decreases 6,996,269.51 yuan,annual decreasing 241,250.67 yuan.③From 1978 to 2007, ecosystem service value of arable land has been decreasing, from 29,638,601.20 yuan in 1978 to 17,984,009.61 yuan in 2007.In 29 years, it decreases 11,654,591.59 yuan. Ecological service values of other land use types increase in 29 years.The decreasing of ecological service value of arable land is the main reason of the decreasing of ecosystem service value in Nantun coal mining area.