中文摘要：

以1998—04～2008—07的372景逐旬SPOT4VEGETATION数据（S10）为主要数据源，利用MVC法、一元线性回归趋势分析法和差值法，分析1998～2007年陕西省年最大化NDVI的变化趋势，并对年最大化NDVI和月最大化NDVI的年际变化规律和陕西省植被覆盖度动态变化及其空间分布规律进行分析。结果表明，1998～2008年间，年最大化NDVI整体呈变好的趋势，但是月最大化NDVI的年际变化趋势在不同月份存在很大的差异；年最大化NDVI和月最大化NDVI在每相邻2a间的变化均存在很大差异，植被退化与改善波动出现；1998～2008年陕西各地区植被覆盖度变化是很明显的，一般8、9月份植被覆盖度最高。从空间分布上看，陕北北部地区（榆林市的东南部和延安市北部地区）植被覆盖度显著增加，宝鸡市中南部、西安市、商洛和安康部分地区植被改善也较明显。

英文摘要：

The vegetation coverage is an important indication of the situation of ground vege- tation, and it is the foundation data for describing ecological system, and is also the main factors affecting soil erosion. Based on 372 images of SPOT4 VEGETA from April 1998 to July 2008, the change trend of the yearly maximum annual changes of yearly maximum NDVI and monthly maximum NDVI TION （$10） data NDVI, the inter- , and the dynamicchange and spatial distribution of vegetation coverage in Shaanxi Province are analyzed by means of maximum value composites （MVC）, one-dimensional linear regression and differ- ential approach. The results show that the yearly maximum NDVI of Shaanxi Province is on the whole improved from 1998 to 2008, but the inter-annual change trend of the monthly maximum NDVI has a great difference among different months, the changes during the adja- cent two years of both the yearly maximum NDVI and the monthly maximum NDVI have a great difference, and the vegetation degradation and improvement appear fluctuantly. The change of vegetation coverage is obviously during 1998 to 2008, and the vegetation is best in August and September. Vegetation coverage of most regions is increased, the obviously in- creased regions mainly appear in northern parts of Shaanxi Province （southeast parts of Yulin and north part of Yan＇an）, in south central of Baoji, parts of Xi＇an, Shangluo, Ankang are also improved.