赣南稀土矿开发区生态环境遥感动态监测与评估

Eco-environmental dynamic monitoring and assessment of rare earth mining area in Southern Ganzhou Using Remote Sensing

稀土矿业的发展在促进区域经济发展的同时,也对生态环境带来影响。为研究江西赣南稀土矿产开发及其对生态环境的影响,采用SPOT1/2/5、Landsat7和ALOS等多源遥感数据,对该区域2000—2010年稀土矿开发进行遥感动态监测。采用面向对象的方法对研究区进行生态系统分类,同时结合回溯法可较好地减少伪变化,并可快速地提取稀土矿开采区的变化信息。通过分析发现赣南稀土矿开采集中分布在几个主要的乡镇,从2000年至2010年这10年间整体上呈增加的趋势,但前5年主要体现为扩张,后5年复垦的力度在加强。新增的稀土矿矿区在开发过程中破坏的生态系统类型主要为林地,而废弃稀土矿区通过治理后主要恢复成耕地。稀土矿开采对植被覆盖、生物量、土地退化以及景观的破碎化都有一定的影响。同时稀土矿开采可能引发水体流失、山体滑坡等环境问题和风险。

Although development of the rare earth mining industry has resulted in significant contributions to regional economies,such benefits have also caused severe environmental problems. In order to create land cover maps and thereby monitoring the changes in eco-environmental impacts caused by rare earth mine exploitation in southern Ganzhou,China,during 2000—2010,object-oriented classification was conducted using SPOT1 /2 /5,Landsat7,and ALOS satellite images.A retrospective approach was also used to reduce the amount of false change information and thus efficiently extract the change information in this region. The total rare earth mining area increased from approximately 36. 02 km2 in 2000 to 49.58 km2 in 2010. The results indicate that the rare earth mining area was mainly distributed in the towns of Ling Bei,Zu Dong,and Guimei Shan. During 2000—2005,the rare earth mining area expanded rapidly before slowing in 2005—2010due to implementation of a reclamation program. The results also showed that most newly expanded rare earth mine areas were converted from forests,whereas the major reclaimed areas were farmland. Rapid development of rare earth mining is shown to cause severe environmental problems including vegetation destruction,biomass change,land degradation,and landscape fragmentation in addition to potential risks such as soil erosion and landslides.