中文摘要：

基于延安市1998年4月到2008年7月SPOT VEGETATION的旬合成NDVI数据,以及同时期延安市的气象资料,用回归树法分析了影响该地区NDVI年内及年际变异的主要气象因子.结果显示：各气象因子对NDVI变异性的影响随季节及滞后时间的不同而不同;气温和降水是影响NDVI年内变异的主要气象因子;导致NDVI年际变异的气象因子为平均最高气温.回归树在判断影响NDVI的主要气象因子方面具有较强的优势,但它无法建立气象因子与NDVI之间的定量表达关系,从而限制了对其更加广泛的应用.

英文摘要：

Based on the 10-day SPOT VEGETATION NDVI data and the daily meteorological data from 1998 to 2007 in Yan＇an City,the main meteorological variables affecting the annual and inter-annual variations of NDVI were determined by using regression tree. It was found that the effects of test meteorological variables on the variability of NDVI differed with seasons and time lags. Temperature and precipitation were the most important meteorological variables affecting the annual variation of NDVI,and the average highest temperature was the most important meteorological variable affecting the inter-annual variation of NDVI. Regression tree was very powerful in determining the key meteorological variables affecting NDVI variation,but could not build quantitative relations between NDVI and meteorological variables,which limited its further and wider application.