中文摘要：

利用美国NOAA／NASA归一化植被指数（the Normalized Difference Vegetation Index，NDVI）数据和英国CRU（Climatic Research Unitl全球气温降水数据，分析了1982-2006年陕西泾惠渠灌区年均植被和年均气温、年总降水的变化趋势，研究了植被变化和气温、降水变化的相关关系。结果表明，1982-2006年泾惠渠灌区植被（NDVI）呈明显增加趋势（0．1％／年，P〈0．05），年均气温也明显增加（0．085℃／年．P〈0．05），但年总降水呈微弱减少趋势。年均NDVI与年均气温正相关（相关系数R=0．49，P〈0．05），但与年总降水的关系并不明显。气温增加导致生长期延长和泾惠渠合理提供植被用水是泾惠渠植被覆盖增加的主要原因。在月尺度上，月气温增加可为植被的生长提供更适宜的温度环境；月降水量增加可为植被生长提供更充足的水分，但当月降水量大于100mm时．该月NDVI并无明显增加趋势。

英文摘要：

Using the Normalized Difference Vegetation Index （NDVI） from NOAA/NASA and the global temperature and precipitation data from Climatic Research Unit （CRU） of United Kingdom, this present study analyzed the trends of annual mean vegetation cover （NDVI）, annual mean temperature and annual total precipitation of Jinghui Canal Irrigation Area in Shaanxi province of China from 1982 to 2006, and investigated the relationships among vegetation cover, temperature and precipitation. The results showed that the annual mean vegetation cover significantly increases by 0.1%/a （P〈0.05）, and the annual mean temperature also markedly increases by 0.085℃/a （P〈0.05）, but the precipitation decreases slightly. Furthermore, the annual mean NDVI was positively correlated with annual mean temperature （correlation coefficient R=0.49, P〈0.05）, but was poorly correlated with annual total precipitation. The prolonged growing period resulted from increasing temperature and the reasonable water usages of vegetation cover provided by Jinghui Canal are two main factors which facilitate the increase in vegetation cover in Jinghui Canal Irrigation Area. At the monthly scale, the increase in monthly temperature can provide more temperate environment for vegetation growth. Also the increase in monthly precipitation will supply more water for vegetation growth, but the monthly NDVI does not show a significant increasing trend while the monthly precipitation is more than 100 mm.