关键词: 归一化植被指数, 时空变化, 不同气候区, 气候因子, 人类活动, 黄河流域

Abstract: Studying the temporal and spatial changes of vegetation coverage in different climatic regions and the relation between climatic factors and vegetation growth is of great significance to the construction and governance of ecological environment. Based on the GIMMS NDVI 3g dataset from 1982 to 2015, we examined the temporal and spatial changes of vegetation coverage in growth season in different climatic regions of the Yellow River Basin using the mean method, Sen+Mann Kendall trend analysis, partial correlation coefficient, multiple linear regression model plus residual method. We also analyzed the impacts of climatic factors and human activities on vegetation changes. Results demonstrated that: 1) The interannual change of NDVI in the Yellow River Basin and different climatic regions showed a slow upward trend from 1982 to 2015. The changes in arid region were steady, while the changes in semi-humid areas were more obvious. 2) In the past 34 years, vegetation increased remarkably in most of the climatic regions, of which the semi-arid region accounted for the largest proportion, whereas the southwest and south part of the semi-humid region mainly subjected to slight reduce. 3) Precipitation, temperature, and sunshine time in various climatic regions had positive impacts on NDVI, among which sunshine time had the greatest impact; in semi-arid region precipitation had the greatest impact on NDVI, whereas in semi-humid region the least impact; in semi-humid region temperature had the greatest impact on NDVI, while in arid region the least impact. 4) In the past 34 years, human activities exerted far more positive impact on vegetation than negative impact.

Key words: Normal Difference Vegetation Index(NDVI), spatiotemporal changes, different climate zones, climate factors, human activities, Yellow River Basin