1982—2017年黑河流域植被指数动态及其对气候变化与生态建设工程的响应

Vegetation dynamics and their response to climate change and ecological protection projects in the Heihe River Basin from 1982 to 2017

为改善黑河流域生态系统整体功能,缓解植被退化趋势,中国自2000年起先后在黑河流域实施了一系列生态建设工程。在气候变化背景下,客观衡量生态建设工程的效益具有重要意义。本研究基于1982—2017年归一化差异植被指数(NDVI)数据集和气候数据,采用趋势分析研究黑河流域植被的动态变化,结合偏相关分析和残差分析来剥离气候变化和生态建设工程对植被的影响。结果表明:(1)1982—2017年黑河流域植被NDVI总体波动上升,2000年后NDVI增加速率呈上升趋势;(2)气温和降水的增加趋势对NDVI起正向作用,且降水增加对NDVI的影响更显著;(3)自2000年生态建设工程实施后,人类活动对植被NDVI变化的影响占据主导地位,30.18%的研究区受到生态建设工程的正向影响,其中在耕地和林地的表现尤为突出。这表明生态建设工程对黑河流域植被增加产生重要影响。

In order to improve ecosystem functions and prevent vegetation degradation in the Heihe River Basin,China has implemented a series of ecological protection projects in the Heihe River Basin since 2000.It is of great significance to quantitatively isolate the contribution of ecological projects from the effect of climate change to better assess the effectiveness of these projects.Based on NDVI and climatic datasets in the Heihe River Basin,this study adopted trend analysis to derive the spatial and temporal patterns of vegetation dynamics,and used the combined partial correlation analysis and residual analysis to distinguish the impact of climate change from that of ecological protection projects on vegetation from 1982 to 2017.The results showed that:(1)NDVI exhibited an upward trend in the Heihe River Basin from 1982 to 2017,especially after 2000.(2)Temperature and precipitation had a positive effect on the NDVI,and the increase in precipitation made more contribution to the greening trend.(3)After the implementation of the ecological protection project in 2000,the impact of human activities dominated the change of NDVI.The implementation of ecological construction projects explained up to 30.18%of the total variance of NDVI,and the contribution was even more in cultivated lands and forests.We concluded that the ecological protection projects played an important role in the greening of vegetation in the Heihe River Basin.Our research could improve the understanding of vegetation dynamics in the Heihe River Basin and provide scientific evidence for promoting ecological construction and sustainable development in arid areas.