把 AVHRR-NDVI 基于 NOAA 从 1981 ～ 2001 的数据， digitalized 中国植被地图(1:1,000,000 ) ， DEM，温度和降水数据，和领域调查，空间模式......

Trends of annual and monthly temperature, precipitation, potential evapotranspi- ration and aridity index were analyzed ......