Research On Monitoring And Evaluation Of Mine Environment Based On Remote Sensing And GIS In Longnan Gold Mine Area

Mineral resources are the important material foundation for subsistence and development of the mankind. With the rapid development of society and economy, the increasing demand for mineral resources not only caused the over-exploitation and unreasonable development of mineral resources, but also could melt the resources away and damage the ecological environment. How to use earth resources rationally and efficiently, has become one of the most noticeable issues in the world. The remote sensing and GIS are the key technology to achieve sustainable development of resources and environment. Comparing with other technology, they play an irreplaceable role in resources investigation, monitoring and evaluation of environment.With the Longnan gold mine area in Gansu province as the reseach area, this paper applied the various image enhancement technology to extract the information of mining occupied land and water pollution, which used the SPOT5 high-resolution remote sensing data on the basis of the analysis of geology background, distribution of mineral deposits, current environmental status and image spectral features. And this article also carried on environmental quality comprehensive assessment through GIS technology in the study area. Major achievements were as follows:1,Regional geological characteristics of mineral, mineral planning, mine environment and the cause of environmental problem were deeply studied, which established a foundation of the follow-up research.2,The method of ortho-rectification and true-color transform of SPOT5 image was carried out on the basis of the full analysis of SPOT5 basic parameter and band performance, which solved the problems of geometrical distortion and shortage of blue band of the raw data, enriched the remote-sensing data, improved the accuracy of the data, and provide good precondition for extracting mineral environment information and comprehensive evaluation of mineral environment.3,The remote sensing information computer automatic extraction model was established on the basis of full analysis of image spectral characteristics of mining occupied land. The disturbance information was removed by using the ratio method. The information of mining occupied land was extracted by using filering enhancement method and density separation and other methods. And this article also analyzed and evaluated the precision of extracting information according to field verification, the results showed that the precision touched 88%. From the above analysis, the remote sensing information automatic extraction model was feasible, made up for the lack of visual interpretation, which had heavy labor intensity, long period, low productivity, and low accuracy for getting information.4,Based on the analysis of water spectrum characteristic and the SPOT5 band performance, the surface water and its range were extracted accurately by using slope as the auxiliary factor, as well as the decision tree category method. The 3D remote sensing image of topography was established through using texture mapping technology by placing the image data and vector data on the digital elevation modeling. This way not only provide the intuitionistic and visual obserbation of the spatial relationship between pollution source and water body, also distinguish the mountainous shadow and water body, and thus ensuring the extracting accuracy of water pollution information.5,Field checking of mining occupied land and water pollution information adopted a method combined with point,line and region. The statistical analysis of extracted information through MapGis software on the basis of amended, supplement and improvement, which provided accurate and reliable base data for comprehensive evaluation of mineral environment quality.6,The comprehensive evaluation technical process of mineral environment quality was established by adopting the base geography map, geological mineral map, remote-sensing image, DEM, the result of environmental monitoring for mine environment as the main information sources. The application program of analytic hierarchy process was developed so as to achieve the rapid calculation of index weight. The factors which affect mine environmental quality are quantitative analyzed inaccordance with weighted average method of index mathematical model based on MapGis software. And thus the comprehensive evaluation grade of mineral environment quality in Longnan gold mining area was obtained, which supplied government office with scientific basis to formulate mine environmental protection, recovery and treatment policy.