Study On Quality Assessment Of Ecological Restoration In Mine Derelict Land In Beijing

Through the general evaluation of the landscape characteristics and aesthetic qualities of the mined area, the plant community characteristics of the mined wasteland after ecological restoration was assessed, and an evaluation method from macroscopic to microcosmic perspective of ecological restoration of mined wasteland in Beijing was established, which was of scientific instructiveness towards the standards of successful ecological restoration and the selection of the methods applied to achieve this standard. This thesis involved consultation with experts and a great deal of reference as well as principal component analysis, analytic hierarchy process, fuzzy comprehensive assessment, psychophysics and kansei engineering were used to determine the indexes and the evaluation model. Finally Beijing Shouyun iron mine was researched for the evaluation of ecological restoration on mined wasteland.(1) Based on the SPOT4 images in October,2009 and the relief map (1:2000) of the research area which were collated and interpreted by ENVI, the landscape indexes were extracted by using FRAGSTATS.The principal components and the weight of each index were determined by PCA. The results showed that the landscape index of Beijing Shouyun iron mine was 0.28 and overall landscape stayed in a fairly low level. This result corresponded with the current status of ecological damages caused by the expanding manufacture in mine area, which testified the result.(2) An evaluation indexes system of plant community was established based on the analytic hierarchy process, and the community characteristics of mined wasteland in Beijing Shouyun iron mine were evaluated by means of fuzzy comprehensive assessment. Sample survey had been done for the vegetation types in the dam faces of tailings storage and the natural community around. Fuzzy comprehensive assessment was made according to different restoration stages and the natural community on the dam faces. The result showed that the general vegetational restoration in the dam faces of tailings storage was good with the fifth year owning the highest comprehensive assessment grade of 0.3368, and all dam faces (artificially restored) comprehensive assessment grades surpassed that of natural community, which was 0.3173.Another sample survey was done among 5 forest types in mine dump which were artificially restored, and fuzzy comprehensive assessment was made according to different forest types. The result showed that Type 5 (mixed forest of Cotinus coggygria var. cinerea, Koelreuteria paniculata Laxm, Pinus tabulaeformis and Robinia pseudoacacia) owned the highest grade of 0.3554 while Type 4 (pure forest of Rhus typhina) owned the lowest grade as 0.2190. The other grades were:Type 1 (mixed forest of Robinia pseudoacacia and Platycladus orientalis):0.3208, Type 2 (mixed forest of Robinia pseudoacacia, Platycladus orientalis and Populus alba):0.3314, Type 3 (pure forest of Eucommia ulmoides):0.3000.(3) Different landscapes of Beijing Shouyun mine were estimated by scenic beauty estimation method which demonstrated that farmland landscape (18.8)> vegetation restoration landscape in mine dump (13.9)> vegetation restoration landscape in dam faces of tailings storage (8.085)> natural brushes (7.9)> waterscape (5.4)> road revegetation landscape (-3.15)> exploitation side landscape (-12.2)> palisades (-26.4)> other landscape (-79.8). The landscape elements of the mine dump were estimated by building the relationship model between landscape elements and SBE. The result showed that among all 13 influence elements to SBE, constructive arrangement, shape of plants, constitution of tree species and litter fall were central elements.(4) For further understanding the influences of the ecological structure towards landscape, site conditions and recovery measures for tailings storage and mine dump were analyzed. The botanical diversity, biomass, physicochemical property of soil, relationship between vegetation and soil factor, bioconcentration factors were studied thoroughly. The result showed that the biomass on dam faces of tailings storage peaked in the fifth or sixth year and declined in the followed years. The study on BCF with different years showed that BCF of lead in aerial part of plants after 13 years'restoration enhanced as much as 36.63% compared with that of the plants after 1 year's restoration, which demonstrated that the plants used in the artificial restoration of tailings storage had the ability of heavy metal accumulation. The biomass of the 5 forest types in mine dump were:Type 5> Type 1＞Type 3> Type 2> Type 4 and the richness index were:Type 2> Type 1＞Type 5> Type 3 > Type 4.The results of ecological structure analysis corresponded with the community characteristics evaluation, which testified the evaluation system of community characteristics.