湖北大冶矿区生态环境动态遥感监测

RS Based Ecological Environmental Dynamic Monitoring in Mining Area

运用遥感技术动态监测矿区生态环境,对于保护矿区生态环境,合理开发矿产资源具有重要的现实意义。该文以湖北大冶为研究区,采用多时相陆地卫星遥感影像,通过不同波段组合,以及铁矿指数(ironoxide)和归一化差异植被指数(NDVI)等的应用,在分析地表地物光谱特征和空间特征的基础上,采用基于知识的决策树方法进行分类,大幅度提高了分类精度,得到了具有高精度的分类结果图。并基于不同时相分类结果的变化检测,通过对研究区水体污染、矿区复垦、耕地变化等的分析,定量分析了矿区生态环境的动态变化。发现从1986年到2002年,研究区水体污染还比较严重,矿区植被严重退化,耕地大量减少,停产的矿区仅20%已复垦,为合理保护矿区生态环境和科学管理采矿企业提供了有用资料。

Land resources and the ecological environment are deteriorating due to heavy and disorder mining activities, and the sustainable development of resources and environment is seriously hampered. This paper reports an investigation into the use and application of remote sensing data for monitoring the eco-environment of mining area in Daye, Hubei province. Based on the spectral characteristic and the spatial knowledge of the ground objects in Daye as a training area, image composite, iron oxide index, normalized difference vegetation index (NDVI) and digital elevation model are used, and the decision tree classification method is used in the study area with multi-temporal Landsat TM (ETM) images. The classification algorithm is applied to all the Landsat TM (ETM) data in order to detect temporal and spatial changes in the mining areas, and the mining areas were separated into ten classes. The characteristics of the high accurate classification results enable high accurate change detection to quantitatively analysis of different mining area features, such as waste, water bodies, change of land use, reclamation process and estimation of vegetation cover in the affected areas. From the change detection results, it is observed that: The water quality of the whole waters is still serious. Though some serious contaminated water has changed to light contaminated water, the areas of light contaminated water increase 11.4 km^2 from 1986 to 2002; Vegetation shows decrease degradation trend,especially those areas close to the mining areas. Large areas of woodland and plantations are reduced, and instead the areas of bare land are increased. The decreased woodland areas are mainly changed to shrub,and the reduced plantations areas are mainly changed to bare land and residence. The scatter distribution pattern of the mining areas in 1980s is greatly improved. The reclamation percentage of the abandoned mining is about 74% from 1986 to 1994,which is relatively high. However,the percentage is only 19% from 1994 to 2002. The ecological environment in the study area is degenerated and may become worse unless the efficient management of mining business and effective eco-environment protection in mining area are carried out instantly.