1982—2006年京津冀地区植被时空变化及其与降水和地面气温的联系

利用NOAA/AVHRR归一化植被指数（Normalized difference vegetation index,NDVI）,分析过去25年（1982—2006年）京津冀地区生长季（4—10月）植被覆盖时空变化、趋势及其与降水和地面气温的联系。经验正交函数展开（EOF）、奇异值分解（SVD）及相关分析,结果表明：过去25年京津冀地区植被总体呈增加趋势,其中,河北中部地区增长速率超过3%/10 a。植被覆盖年际变化与气温变化呈正相关,但与降水变化的正相关更加显著。1989年和1999—2002年的干旱导致当年NDVI显著减少,而1990、1998年和2003—2005年降水增加使得研究区NDVI明显增加。

Spatial-temporal changes in vegetation cover and their relationships with precipitation and surface air temperature over the Beijing-Tianjin-Hebei region from 1982 to 2006

The spatial-temporal characteristics and trends of the growing season（April～October） vegetation change and their relationships with precipitation and surface air temperature over the Beijing-Tianjin-Hebei region from 1982 to 2006 are investigated,by using the NOAA/AVHRR Normalized Difference Vegetation Index（NDVI） data and multivariate statistical methods including the Empirical Orthogonal Function（EOF）,Singular Value Decomposition（SVD） and correlation analyses.It is found that the vegetation cover of study region generally increased during the past 25 years,with a maximum increasing rate of 3%/10 a occurring in central Hebei province.The inter-annual variation of growing season vegetation cover is positively related to the temperature change and especially to the precipitation fluctuation.The growing season vegetation was reduced significantly when the precipitation decreased in 1989 and from 1999 to 2002,while enhanced evidently as the precipitation increased in 1990,1998 and from 2003 to 2005.