【摘要】 植被覆盖状况是决定大城市地区生态环境质量的重要因素之一,但在快速城市化进程下城市内部及周边地区植被覆盖的动态变化状况尚不清晰,需结合遥感数据进行分析。以北京市为研究区,基于Landsat影像获取植被覆盖度的空间分布,计算移动窗口内植被覆盖度的均值和标准差,将其分别作为表征局部植被覆盖水平和植被覆盖度异质性的指标,采用Mann-Kendall检验识别均值和标准差具有显著变化趋势的窗口,并使用Sen’s Slope估算变化梯度,进而分析北京植被覆盖度变化趋势。结果表明在1984～2014年间:(1)植被覆盖水平呈显著上升趋势的区域主要分布在市中心与西部和北部山区,而在市中心外"东北、东、东南、南、西南"方向的近郊分布有大量植被覆盖水平显著下降的区域;(2)植被覆盖度异质性呈显著上升趋势的区域主要分布在平原区,呈显著下降趋势的区域主要集中在北部山区。更多还原

【Abstract】 Vegetation cover is a crucial determinant of ecological environment in big cities. But the spatial-temporal dynamics of vegetation cover in the inner city and peri-urban areas in the process of rapid urbanization are still unclear and need to be researched in combination with remote sensing data. This study estimated the distribution of Fraction Vegetation Cover(FVC)of Beijing by using Landsat images,and calculated moving window mean value and standard deviation of FVC,which were respectively used as proxies for local vegetation coverage and FVC heterogeneity. Then the moving windows with significant change trend were identified by Mann-Kendall test and the slope of change was estimated by Sen’s Slope. And on this basis,we analyzed the change trend of FVC of Beijing. The results showed that during 1984～2014 the areas with significant increasing trends of vegetation coverage were mainly distributed in the urban center and the north and the west mountainous areas,and the areas with significant decreasing trends of vegetation coverage were mainly distributed in the northeast,east,southeast,south and southwest suburbs. Besides,the areas with significant increasing trends of FVC heterogeneity were mainly in flatlands while the areas with significant decreasing trends of FVC heterogeneity were mainly in the north mountainous areas.更多还原