基于时序NDVI的露天煤矿区土地损毁与复垦过程特征分析  

Character analysis of mining disturbance and reclamation trajectory in surface coal-mine area by time-series NDVI

作　　者：李晶[1] Zipper Carl E. 李松[2] Donovan Patricia F. Wynne Randolph H. Oliphant Adam J. 夏清[1] 

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]弗吉尼亚理工大学农业与生命科学学院,美国24061 [3]弗吉尼亚理工大学自然资源与环境学院,美国24061

出　　处：《农业工程学报》2015年第16期251-257,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家科技支撑计划(2012BAC04B03);国家留学基金资助项目(201306435013)

摘　　要：露天煤矿区是人类活动强扰动地区之一。该文以阿巴拉契亚煤田区韦恩县为研究区域,应用遥感时序分析法分析了像元尺度的土地损毁和复垦过程特征。得出结论:1984-2010年间,韦兹县露天开采扰动区域占采矿权范围的45.80%,其中植被恢复区域占开采范围的66.45%,开采时间越早,植被恢复像元比例越高;开采造成的地表无植被覆盖期时长中位数为6 a,均值为7 a;已充分复垦的区域,NDVI值恢复至采前水平的加权平均时长为12 a。基于像元变化轨迹的研究,除揭示土地损毁-复垦过程特征外,能较好地反映空间异质性,可以为土地复垦管理和相关政策决策提供科学依据。Open-pit coal mines are among the most drastic anthropogenic land disturbances. Using Wise County in the USA＇s Appalachian coal field as the study area, this paper evaluates the mine land disturbance and reclamation process over a 27-year period by conducting time-series analysis of.multispectral remote-sensing data at the pixel scale. Twenty TM/ETM images obtained by the Landsat satellites, with 30 m spatial resolution, are treated as a multiple-year chronosequence. Polygonal vector files defining mining permitted areas and 6 high-resolution aerial images are used as auxiliary data; and the normalized difference vegetation index （NDVI） is used as a vegetative cover indicator. The methodology and study process include 3 steps. First, training data are prepared and multispectral image data are preprocessed. Data preprocessing includes band stacking, extracting the study area as image subsets, masking of cloud, cloud shadow and water, and computing NDVI based on each study-area pixel in each image. After the training data are generated, they are used to identify the NDVI thresholds for separating bare-ground from vegetated pixels, and ever-mined pixels from those un-mined. These separations are performed by visually inspecting each individual TM/ETM image displayed through a combination of the band of 2, 3 and 4 while referencing all available high-resolution aerial images and polygon vector files defining mining permitted area. Second, each pixel＇s time-series NDVI trajectory is constructed and analyzed. Based on individual inspection of training points＇ NDVI trajectory and qualitative trajectory classification, the characteristic parameters, including the NDVI maximum, the NDVI minimum, the difference of NDVI maxima before and after mining, the bare-ground threshold and ever-mined threshold, are designed, computed and used to identify whether the pixel is ever mined, revegetated or revegetated to the land cover level before mining. The relationship between NDVI minimal values and ever-mined thresholds f

关 键 词：土地复垦 煤矿 遥感 露天煤矿 归一化植被指数 时序分析 

分 类 号：F205[经济管理—国民经济] X171.4[环境科学与工程—环境科学]