Numerous coal fires burn underneath the Datong coalfield because of indiscriminate mining.Landsat TM/ETM,unmanned aerial vehicle（UAV）,and infrared thermal imager were employed to monitor underground coal fires in the Majiliang mining area.The thermal field distributions of this area in 2000,2002,2006,2007,and 2009 were obtained using Landsat TM/ETM.The changes in the distribution were then analyzed to approximate the locations of the coal fires.Through UAV imagery employed at a very high resolution（0.2 m）,the texture information,linear features,and brightness of the ground fissures in the coal fire area were determined.All these data were combined to build a knowledge model of determining fissures and were used to support underground coal fire detection.An infrared thermal imager was used to map the thermal field distribution of areas where coal fire is serious.Results were analyzed to identify the hot spot trend and the depth of the burning point.
植被是综合体现矿区生态环境状况的关键因子。以NDVI值为参数,基于像元二分的遥感估算方法测度了1999—2010年大同矿区的植被覆盖情况。利用Global Moran's I、Getis-Ord General G、Getis-Ord Gi*、Anselin Local Moran I等空间关联指数分别从全局演变和局部效应的视角揭示了矿区植被受煤炭开发等活动扰动的时空演化和内在作用机制。研究结果表明:(1)大同矿区植被盖度变化在空间上呈集聚分布状态,表现出很强的空间自相关性,这一现象在植被盖度最低时期最明显;(2)在植被盖度上升期,其变化的热点区不断减少或向次热点地区分散,矿区植被变化集聚效应越发不显著,总体上呈离散的态势。(3)煤炭开发对矿区植被的扰动呈现整体性特征,与煤炭产量成正比。(4)不同植被类型受煤炭开发扰动呈现不同的变化特征。(5)采用循环工艺的高效高产矿井大规模煤炭开发对植被的扰动作用尚不明显,但长期效应有待进一步研究。
