潞安矿区净初级生产力和土地覆被变化及成因

Change and Causes of Land Cover and Net Primary Productivity in Lu′an Coal Mine Area

净初级生产力和土地覆被变化是指示区域生态环境变化的重要指标。基于EOS/MODIS卫星遥感数据,运用地理信息系统软件ArcGIS 9.3的统计与分析模块对2001—2006年潞安矿区净初级生产力、土地覆被变化及其成因进行了研究和分析。结果表明:(1)2001—2003年的矿区绝大部分区域净初级生产力大于0.2kg/(m2.a),而2004—2006年的净初级生产力低于0.2kg/(m2.a)即研究时段内矿区净初级生产力呈明显减少趋势;(2)灌丛向稀树草地,稀树草地向农用地,地表水域向裸地转换是土地覆被变化的主要特征;(3)煤炭开采,农用地开垦等人类活动和降水量减少,气温升高为特征的气候变化是研究区植被覆盖度和净初级生产力降低的两个主要原因。总之,煤炭开采和土地垦殖为主的人类活动所引起的土地覆被变化直接导致了潞安矿区净初级生产力的降低。

Land cover change and net primary productivity change are the important indicators of regional eco- environment. Based on EOS/MODIS satellite remote sensing data and using spatial analysis module of soft- ware named ArcGIS9.3, this paper analyzes the spatiotemporal pattern of land cover change and net primary productivity and their relationship in Luran coal mine area from 2001 to 2006. Net primary productivity from 2001 to 2003 in most area is higher than 0.2 kg/（m^2·a） and from 2004 to 2006, lower than 0.2 kg/（m^2·a）, which means a significantly decreased trend of net primary productivity in the investigated period. In the same period, there are three main types of land cover conversion, i. e. , shrub to savanna, savanna to crop, and water area to non-vegetated. The spatiotemporal changes of both land cover change and net primary pro- ductivity are mainly resulted from human activities and climate change. The former includes coal mining and farming and the latter, decreasing precipitation and increasing temperature. In short, as a result from both coal mining and farming, human activities have caused land cover changes which have directly led to the de- crease of net primary productivity in Lutan coal mine area.