京津冀城市群地区植被覆盖动态变化时空分析

基于MODIS NDVI遥感数据,采用线性回归分析、稳定性分析、重新标度极差分析等数理方法,反演了2005—2015年京津冀地区植被覆盖时空演变趋势和稳定性,并在此基础上对植被未来变化趋势进行评估和预测。结果表明:(1)2005—2015年京津冀地区植被覆盖度呈上升趋势(增长速率0.065/10年),增长过程经历两次飞跃期后,进入平稳波动阶段;(2)京津冀地区植被恢复以显著改善为主(47.45%),不显著变化区域占全区面积的三分之一(33.9%),主要以华北平原为中心展布,退化区域比重为6.8%,零星散布于各大城市周边;(3)京津冀地区植被持续恢复为主,植被覆盖持续改善区域比重超过一半以上(58.8%),反持续性改善比重为34.4%,主要集中在张家口、沧州以及保定东南地区;持续退化比重为4.8%,主要分布在天津、廊坊、沧州一带。研究结果将有助于辨识京津冀城市群地区的植被动态演化和生态网络连通性现状和趋势。

Temporal-spatial analysis of vegetation coverage dynamics in Beijing-Tianjin-Hebei metropolitan regions

Identifying the dynamics of vegetation coverage is important for the research of ecological security and ecosystem services. This study analyzed MODIS NDVI remote sensing data and identified the temporal-spatial dynamics of vegetation coverage during 2005-2015 in Beijing-Tianjin-Hebei metropolitan regions. The analysis methods included linear regression, coefficient of variation, R/S analysis, and other mathematical methods. The results showed that (1) the vegetation coverage increased by 0.065 from 2005 to 2015. The vegetation restoration experienced a stable fluctuation phase after two fast-improving periods. (2) The significantly improved area occupied 47.45% of the region and the insignificant area accounted for 33.9% of the region, which was mainly in the North China Plain. The degraded area accounted for 6.8% of the region and was scattered in the surroundings of big cities. (3) The sustainability of vegetation restoration was dominant (58.8%) in the Beijing-Tianjin-Hebei region. The vegetation area of anti-sustainability accounted for 34.4%, mainly distributed in Zhangjiakou, Cangzhou, and the south-east of Baoding. The continuous degradation area was only 4.8% of the region and distributed in the cities of Tianjin, Langfang, and Cangzhou. These results could be useful for identifying the dynamics of vegetation coverage and predicting the potential trends of ecological network connectivity.