四川省植被覆盖时空演变及未来变化趋势分析

四川省地处长江上游,是长江流域重要的生态屏障;解析该区域植被覆盖的时空演变特征,对长江上游的生态环境修护与治理具有重要意义。基于长时间序列的MODIS NDVI数据,解析2000~2016年间四川省植被的空间分布格局与时间变化特征;采用趋势分析法和Hurst指数,预测未来植被的变化趋势及持续性。结果表明:(1)四川省NDVI多年平均值为0.50,植被覆盖整体上呈现川东高于川西的空间分布特征;(2)2000~2016年间,四川省的NDVI值在0.48至0.53之间波动,整体呈上升趋势,增长率为0.002 5/a;(3)植被覆盖度在未来变化将呈现改善大于退化的趋势;植被持续性改善的面积大于持续性退化的面积。

Spatial-temporal evolution of vegetation coverage and analysis of future trends in Sichuan Province

Sichuan Province, an important ecological barrier in the Yangtze River Basin, is located in the upstream of the Yangtze River. The analysis of spatial-temporal evolution of vegetation coverage in the area is of great significance to the ecological environment restoration and management. Therefore, based on the long-term MODIS NDVI data, the spatial-temporal evolution of vegetation coverage in Sichuan Province was analyzed from 2000 to 2016, and Trend Analysis and Hurst index were used to predict the trend and sustainability of the coverage. The results showed that: (1) The annual average NDVI in Sichuan Province was 0.50, and generally the vegetation in the eastern area was higher than that in the west. (2) NDVI fluctuated between 0.48 and 0.53 during 2000-2016, and it showed generally an upward trend with a yearly growth rate of 0.0025. (3) The improved area of vegetation will be larger than the degraded area in the future and the continuously improved vegetation area is larger than the continuously degraded ones. The study is expected to be a reference for the restoration of the ecological environment in the upstream of the Yangtze River.