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Study On Remote Sensing Monitoring The Rare Earth Mining And Its Environmental Impacts And Evaluation In South China

Posted on:2017-04-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:H K LiFull Text:PDF
GTID:1221330482481395Subject:Cartography and Geographic Information Engineering
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As an important strategic resource and high-tech material, rare earth has been widely used in various fields of national economy in present society. Especially, the type of southern ionic rare earth resource in China is unique to world. However, for its most mines were in remote hinterland with the high mountains and thick forests, it is difficult to monitor and manage the large amount of illegal minings which were scattered around the obscure village. The disorder and extensive way of resource development not only wastes the resources, also brings a series of ecological environment problems such as the large areas of land damaged, the vegetation destruction and the soil and water losing. Combined with Lingbei mining area’s features in Dingnan County, which undertook environmental problems caused by the different mining technologies, the paper established the RS monitoring and estimated methods which can settle multi-temporal the land usage, the vegetation cover, the soil erosion and the surface disturbance problems. Which it analyzed the mining area’s environmental evolution in different mining models,this can provide a theory of mining environmental restoration,and analysize the change law of time and space of the mining area environment, the influence of different rare earth mining mode for the mining area environment, and provide scientific basis for mining area environmental governance.All works are expected to promote the rare earth mining area ecological environment in the direction of green sustainable development.In section one of the thesis, the background, significance and content structure were introduced. Firstly, based on the reality state of south ionic rare-earth mining, we pointed out that the series of ecological environment problems in region of rare earth mining which were mainly caused by long-term disordered mining. We illustrated the research background and significance of the article. In light of the existing problems, the paper summarized the domestic and foreign relevant results, and points out that the southern rare earth mine locates in hilly fragile ecological area, and it is lack of effective the perfect mining area’s environment RS monitoring according its features and estimated methods due to its special ore-forming environment and mining methods. So the research content, research method and technical route can be suggested.In section two of the thesis, the paper focused on and analyzed the influence of Long-term land use changes under different rare earth mining technology on land use in Lingbei rare earth mining area of Dingnan County with using 24 years long Landsat TM and HJ satellite CCD remote sensing data. First, the method of post-classification comparison was improved by using the fractal texture auxiliary classification. The two kinds of model of the band selection and the fractal window named the separable index and the J-M distance were established, and compared its adaptability. All of these provide a quantitative method for selecting fractal texture to assist classification of TM and CCD images in rare earth mining area. Second, mining area land using change was monitored analyzed according to the method, the results showed that the mining area desertification has become more serious with the continuous expansion of mining, and even showed a merging tendency which made it hard for governance. By promoting the in-situ leaching mining technology and mining reclamation, it partly slows down the deterioration tendency. The degradation phenomenon appeared in vegetation around rare earth mines, mainly caused by the water and soil pollution of rare earth.In section three of the thesis, vegetation coverage extraction method was studied in Lingbei rare earth mining area of Dingnan County by using series of Landsat data and Pleiades high resolution image. Based on them, the paper focused on the space-time distribution characteristics and evolution law of landscape pattern for vegetation covering. The results showed that LSMM is more suitable for the extraction of vegetation coverage due to considering the spectral characteristics of the peculiar tail sand in rare earth mining area. The percentage of low vegetation coverage less than 30% although is not high, but concentrated trend is evidently. The main reason is the bare surface for the pool leaching/heap leaching mining procession; the ecological problem is serious. The main type of vegetation degradation is local degeneration caused by mining, despite a certain extent, in-situ leaching mining process can reduce the damage to the vegetation, but due to the inevitable leakage of ore leaching liquid, it could lead to a wider range of vegetation degradation. The low vegetation coverage areas concentrated in the mines and the mines surrounding, become a landscape distribution patterns with rare earth mining area features under ecological environment continuously improve.In section four of the thesis, the paper established the quantitative evaluation of soil erosion and the space-time evolution analysis of the different mining mode in Lingbei rare earth mining area by using RS, GIS and RULSE model. The results showed that the soil erosion area accounted for the entire mining area in 1990, 1999, 2008, 2013 four years is 22.04%, 11.60%, 7.74%, 12.62%, total erosion situation is not too serious. The severe erosion area is larger. it is the main source of soil erosion in mining area. Since 1999, the soil erosion status in mining area is to the direction of two levels of development, mountain of lush vegetation becomes bare surface because of pool leaching/heap leaching process, it directly changed the way of land use and vegetation status in mining area, is the most likely cause of the rapid changes in surface erosion. The most serious soil erosion is mines area in mining area, as the scale continues to expand, the soil erosion in mines area have intensified trend in the whole mining area erosion tending to get better.In section five of the thesis, the Lingbei rare earth mining area was taken as example, its land surface temperature was deduced and comparatively analyzed in time series nearby area with the high resolution remote sensing image by using the temperature variation under different surface disturbance rules which was explored by building temperature differential coefficient. According to the method, the disturbance of Lingbei mining area from 2000 to 2014 was analyzed. It delivered a method to monitor and manage the environment of mining disturbance. The results showed that the temperature differentiation coefficient in rare earth mining area can be well corresponded to the surface disturbance levels, as indicating factor of mining area ecological disturbance, it has better performance than NDVI. The data analysis results from 2000 to 2014 verified the effectiveness of the rare earth mining led to the obvious temperature differential effects of mining area surface disturbance from another aspect. Severe and heavier temperature distribution area has high correlation with mines position in the spatial distribution. The distribution of heavier and moderate temperature differential regional is taken severely temperature differential area as the center, with dot diffusion, the mining area ecological deterioration in space is a gradual process.In section six of the thesis, we reviewed the main research focus and the main conclusions, clarified the innovation point of the article, and prospected the work in the future.
Keywords/Search Tags:ionic rare earth, remote sensing in rare earth mining area, the environment of rare earth mining area, land use, vegetation coverage, soil erosion
PDF Full Text Request
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