The variations of NDVI and the relation with climate in hilly and gully region of Northern Yan''an
延安北部丘陵沟壑区植被指数变化及其与气候的关系

The GIMMS and SPOT,which are the Normalized Difference Vegetation Index(NDVI),are utilized to analyze the historical evolution of the vegetation cover in Hilly and Gully Region of Northern Yan'an from 1982 to 2007 and relationship with climate factors.The results show that(1)The vegetation cover status is getting better continuously,although there were undulations in vegetation cover over past 26a in this region,and the averaged annual NDVI increased by 14.2%.The NDVI in summer is of maximum value and remar...