基于RS的北京山区植被覆盖变化空间特征

Analysis of Spatial and Topographical Characteristics of Vegetation Coverage Changes of Beijing Mountainous Areas Using Remote Sensing

利用1979年和2005年的Landsat TM/MSS影像,采用基于植被指数的像元二分法分别计算了北京山区的植被覆盖度,分析了植被覆盖变化及地貌对植被覆盖变化的影响。结果显示:北京山区高海拔地区植被覆盖较稳定,低海拔区变化剧烈;陡坡区生态较脆弱,缓坡区生态修复和植被退化的概率较大;同一时相阳坡植被覆盖度小于阴坡,西北坡生态较脆弱,东南坡植被生态修复机率较大。

The spatial distribution and temporal changes of vegetation coverage is closely related to terrain conditions, such as elevation, slope and aspect. There were two Landsat TM/MSS images of Beijing, which acquired on July 14, 1979 and July 25, 2005, selected. These two vegetation coverage images were calculated using the vegetation index based on two components sub-pixel model, then the temporal changes between the two years were monitored. And the variation images of vegetation coverage was linked to the topographical data. The result showed that the vegetation changes were closely related to topographical features. The vegetation coverage in higher altitude was more stable than it in the lower; the ecology status in large slope area was more vulnerable, and the probability of ecological restoration and vegetation degradation in the small slope area was higher; the coverage in shade slope was better than in sunny area, the vegetation ecology in northwest aspect was vulnerable than it in southeast aspect.