Abstract:

Based on GIMMS NDVI 3g datasets and temperature, precipitation data at 26 weather stations of Qinghai Province during 1982-2013, the spatial and temporal changes of vegetation coverage in the source region of the Yellow River and its response to climatic factors were studied by using trend analysis and correlation analysis. The results are as follows: (1) The vegetation coverage decreased from southeast to northwest in the source region of the Yellow River. The temperature increased significantly, while the precipitation increased weakly during 1982-2013, which indicated that climate was turning to warm and wet. At the same time, the vegetation coverage appeared a weak increasing trend as a whole, but it decreased in local regions of the source region of the Yellow River, and the decadal variation of vegetation coverage was obvious. (2) There was a significantly positive correlation between NDVI and temperature, precipitation in the source region of the Yellow River during the growing season (from May to September) from 1982 to 2013. Compared with the precipitation, the correlation of NDVI with temperature was higher, which indicated that temperature was main influencing factor to vegetation, and the influence increased with the increase of altitude.

Key words: vegetation coverage, climatic factors, the source region of the Yellow River, GIMMS NDVI 3g

摘要：

基于1982—2013年GIMMS NDVI 3g数据集及黄河源区26个国家气象观测站同期气温与降水观测资料，利用趋势分析和相关分析方法，对黄河源区植被覆盖的时空变化特征及其驱动因子进行分析。结果表明：（1）黄河源区植被覆盖呈现从东南向西北递减的空间特征。近32 a来，黄河源区气温呈显著升高、降水则呈微弱增加的趋势，气候由干冷逐渐向暖湿化转变；植被覆盖呈现整体缓慢升高、局部退化的趋势，且“先增后降”的年代际变化特征明显。（2）1982—2013年，黄河源区生长季（5—9月）植被受气温和降水共同影响，植被最大NDVI与气温和降水有显著正相关关系。与降水相比，NDVI与气温的相关性更强，气温是影响黄河源区植被变化的主要气候因子，且随着海拔高度的升高影响越大。

关键词: 植被变化, 气候因子, 黄河源区, GIMMS NDVI 3g