陇东地区近5年植被变化与降水的关系

Relationship between Vegetation Variation and Precipitation in Northeast Gansu Region

利用NOAA卫星AVHRR遥感资料, 对甘肃省陇东地区1997-2001年地表植被指数的空间分布和年变化进行了分析, 并对相应时段内的降水量与植被指数之间的关系, 以及降水对该地区植被的影响进行了分析.结果表明, 该5年陇东地区平均植被有减小趋势, 但北部有所增加﹔降水量的多少对地表植被的月变化起重要作用, 特别是对农作物区植被的影响;对于林区植被, 降水的年际变化对地表植被的影响比较小, 森林区植被指数最高;2000年及2001年的1～6月, 尤其是2001年植被指数最低.

Using the NOAA satellite data of AVHRR, the spatial distribution and annual changes of surface vegetation index in Northeast Gansu region from 1997 to 2001 was studied and the relationship between precipitation and vegetation index and the impact of precipitation on vegetation index in this region were analyzed as well. The results showed that the averaged vegetation has decreasing trend in the recent 5 years, but it has some increasing one in the north of this region. The precipitation played an important role in the monthly changes of surface vegetation and especially in the agricultural area. The vegetation in forest area, in which has the highest vegetation index, the impact of annual change of precipitation on surface vegetation was slight. The lowest vegetation index occurred in January-June 2000 and 2001, especially in 2001.