兰州南北两山植被覆盖变化动态监测

摘要

以2000年、2008年和2013年3期Landsat TM/TM+遥感影像计算获得的植被覆盖度分级图为基础,通过统计分析各时相、各级别的植被覆盖面积及计算得到的转移矩阵,定量分析兰州南北两山植被覆盖度的变化.结果表明:2000-2013年间,劣等植被覆盖面积从2000年的393.07 km2减少到2013年的0.12 km2;中等植被覆盖面积,在前8 a的变化相对较小,而后5 a变化较大;良、优等植被覆盖面积均有明显的扩大.劣等级的植被覆盖一直在向优等转移,而优等的植被覆盖转移到劣等的相对较少.兰州南北两山植被覆盖总体呈明显的增长趋势,至2013年,南北两山植被已经进入良好的生长期,生态建设成效显著.%Based on fractional vegetation coverage classification graphs obtained by means of analysis of remote sensing images in three issues (2000, 2008 and 2013) of Landsat TM/TM+, the variation of the fractional vegetation coverage (FVC) on southern and northern two mountains in Lanzhou was quantitatively analyzed by means of statistics and analysis of egetation coverage areas, in every periods for every classes and the transition matrixes calculated on the basis of the former.The result showed that from 2000 to 2013, the inferior vegetation coverage area decreased from 393.07 km2 in 2000 to 0.12 km2 in 2013.The moderate vegetation coverage area changed relatively less in the first eight years and then changed greater in the late five years.The both good and excellent vegetation coverage areas expanded obviously.During these years, the FVC of the inferior vegetation was continuously transferred to that of excellent one, but the FVC of the excellent one was less transferred to that of inferior one comparatively.Vegetation coverage on southern and northern two mountains in Lanzhou exhibited all in an obvious growth trend.By 2013, the vegetation has entered into a good growth period, and the effect of ecological construction was remarkable.