三江源地区基于植被生长季的NDVI对气候因子响应的差异性研究

采用1999—2008年NDVI和三江源地区及周边31个气象站点的温度和降水旬数据,在确定每年5月中旬至9月底作为三江源地区植被生长季（14旬）的基础上,分析NDVI对气候因子变化响应的区域差异。结果显示：以巴颜喀拉山为界,三江源西部生长季内NDVI指数对温度、降水的线性相关性明显比中东部普遍,同时,不同海拔地段响应程度存在着明显的差异,且海拔5300m左右为线性响应的最高限,NDVI对气候因子的线性响应主要表现为对温度正相关和降水负相关。因此,对三江源生长季内植被生长而言,水条件明显好于温度条件,并且温度对植被覆盖的影响通过直接正相关和降水负相关表现出来,温度是三江源地区植被生长的主导因子。

Spatial disparity of NDVI response in vegetation growing season to climate change in the Three-River Headwaters Region

The purpose of this paper is to analyze spatial differentiation of NDVI response to the climate change in vegetation growing season, which is from mid-May to September, using NDVI, temperature and precipitation of 31 climate stations from 1999 to 2008. The results showed that the linear correlation of NDVI to temperature and precipitation in the west of BaYanKaLa mountain was more widespread than that in the eastern part; Spatial differentiation was obvious in different altitude area, and 5 300 meters was the highest one with linear correlation. It was also found that the response of NDVI to climate factors were mainly showed as posi-tive relation to the temperature and negative correlation to the precipitation. It could be concluded that the water condition was better than temperature and temperature was regarded as a leading factor for vegetation change during vegetation growing season in the Three-River Headwaters Region. Moreover, the impact of temperature on NDVI worked through directly positive correlation be-tween temperature and NDVI and indirectly negative correlation between precipitation and NDVI.