|
This paper summarizes the existing environmental impact assessment concepts, methods and procedures of research results on the basis, in accordance with the environmental impact assessment index system to establish the general principles and processes, combined with the analysis of the ecological impact of opencast coal mine opencast coal mine environment After assessment of the establishment of the index system made exploration and research, and as an example of open pit coal mine, through data collection, field investigation, laboratory analysis and processing means, the use of a single index evaluation method, analytic hierarchy process, fuzzy comprehensive evaluation method and ecological principles and methods, the application of the index system on the coal Heidaigou ecological impact assessment analysis, in order for that type of project environmental impact assessment study provides reference and guidance, the conclusions are as follows: 1, the establishment of opencast coal mine ecological impact assessment index system contains 3 level indicators, namely vegetation characteristics, soil properties and landscape index, specific and detailed 10 secondary indicators, the biomass of the herbaceous layer; species richness; species diversity; uniform species degrees; soil organic matter; soil total N, total P, a wholly K; soil hydrolysis of N, the effective P, rapid-acting K; soil heavy metals; landscape diversity and landscape evenness. The results of the assessment in the individual indicators instances of open pit coal: 1) compared to the original landscape and the surrounding plant community species richness is low, but slightly higher than the biomass of mine dump revegetation The original topography, species diversity index and evenness index were higher, the mine plant communities in general toward the good development trend. 2) mine rehabilitation alkaline soil nutrient levels in the middle and lower, compared with the original landscape soil, waste dump organic matter, total N, hydrolytic N content is low, total P, K, effective P, available K content is higher; dump soil heavy metals Cd, Hg, As, Cu and Cr content in the range of background value, Pb and Zn exceed the maximum background value, the soil Cd, As, Cu, Zn content is higher than the original landscape, Hg Pb, Cr content is lower than the original landscape, but the heavy metals did not exceed the their pollution starting value and soil environmental quality level standards. 3) compared with the pre-mining, Mining Landscape types and their area of ??significant changes, the main landscape remains grassland and farmland, grassland area increased significantly, difficult to be used to significantly reduce the area of ??new industrial land, farmland, residents points and road landscape area is reduced, forest, water and wetland vegetation landscape has increased in varying degrees; landscape diversity index and landscape evenness index decreased. Comprehensive assessment of the ecological status of open pit coal AHP to determine the importance of the three indicators Sort vegetation gt; soil gt; landscape, fuzzy comprehensive assessment model results show that the ecological status of the open pit coal mine \
|