摘要
对流域NDVI进行计算的前提下,分析了雅鲁藏布江流域NDVI时空变化特征。时间上,流域NDVI具有很强的季节性。空间上,流域NDVI高值区主要分布于下游与中游的部分地区,而流域中上游与源头NDVI值相对较小。在流域DEM的支持下,把流域站点主要气候因子降水量与平均气温等数据采用Kriging方法插值成与流域NDVI相一致的空间Grid数据。流域NDVI与降水量、平均气温的关系进行F检验与双样本方差分析结果P=0,表明其相关分析的可信度较高。在0.05的置信水平上对其进行了线性与对数相关分析。结果表明,流域NDVI与降水量的平均线性相关系数达0.8,对数相关系数为0.71;流域NDVI与流域平均气温线性相关系数为0.77,对数相关系数为0.7。
As an index denoting vegetation cover, NDVI is influenced by many climatic factors such as precipitation and average air temperature. In this paper, NDVI is calculated on the basis of waveband characteristic of NOAA/AVHRR data （National Oceanic Atmospheric Administration/Advanced Very High Resolution Radiometer） for the Yarlung Zangbo River Basin. Then,the spatio-temporal change of NDVI is analyzed. The basin＇s NDVI is in consistency with season from 2001 to 2003. High value zone of NDVI is mainly distributed in the lower reaches and part of the middle reaches. Meanwhile, point data of principal climatic factors （precipitation and average air temperature） are interpolated to spatial grid data with Kriging method consistent with NDVI based on DEM of the Yarlung Zangbo River Basin. Then, the relation of NDVI and precipitation or average air temperature is analyzed with F checking and two-sample variance test in the basin. The result is P =0, which shows that correlation analysis has higher confidence. The linear and logarithmic correlation of NDVI and precipitation or average air temperature is analyzed at confidence level of 0.05. The conclusion is that NDVI and precipitation and average air temperature in the basin vary with seasons and are closely correlated. The linear correlation coefficient of NDVI and precipitation is 0. 8, and that of NDVI and average air temperature is about 0.77. And the logarithmic correlation coefficient of NDVI and precipitation is 0. 71, and that of NDVI and average air temperature is 0. 7.
出处
《地理研究》
CSCD
北大核心
2007年第1期60-66,I0003,共8页
Geographical Research
基金
国家科技攻关计划项目(2005BA901A11)
国家自然科学基金项目(40561002)
关键词
NDVI
降水量
平均气温
植被覆盖
雅鲁藏布江流域
NDVI
precipitation
average air temperature
vegetation cover
Yarlung Zangbo River Basin
