气候变化对阿拉善荒漠植被的影响研究

 利用1982—2003年NASA GIMMS归一化植被指数(NDVI)数据集和阿拉善左旗、右旗和额济纳旗气温和降水资料,对阿拉善地区NDVI变化和气候变化特征及其相互关系进行了分析。结果表明：①1982—2003年东部地区(左旗植被指数略有增加,而中部(右旗)和西部地区(额济纳旗)则呈下降趋势。季节变化东、中、西部表现不同。左旗和额济纳旗多年平均NDVI的月变化和右旗相反。②东部地区升温率最大,其次是西部和中部地区。降水表现为东部和西部地区(额济纳旗)稍有增加,而中部地区(右旗)呈缓慢减少趋势。季节变化东、中、西部表现不同。多年平均气温和降水量的月变化趋势东、中、西部一致,呈单峰型曲线。③东部地区和中部地区,降水量与植被指数存在明显的年相关、隔季和当季相关,而西部地区额济纳旗没有明显的相关性。阿拉善地区NDVI同温度的相关性不好。

Impact of Climate Change on Desert Vegetation in Alxa Region

The variation characteristics of vegetation and their relationship with climate change in Alxa region from 1982 to 2003 were studied by using the GIMMS Normalized Difference Vegetation Index (NDVI) data and meteorological records from Alxa Left Banner, Alxa Right Banner and Ejin Banner in order to find out the regional response of the vegetation to the global change. The results showed that: ①From 1982 to 2003, the annual mean of NDVI weakly increased in the eastern Left Banner but descended in the middle Right Banner and in the western Ejin Banner of Alxa. The season variation of NDVI was different: the monthly variation of 22-year averaged NDVI in Left Banner and Ejin Banner was contrary to that in Right Banner. ②Rate of temperature increase was the biggest in the eastern Left Banner and the smallest in the middle Right Banner from 1982 to 2003. The annual mean precipitation slightly increased in the eastern Left Banner and in the western Ejin Banner but descended slowly in the middle Right Banner. The seasonal variation of temperature and precipitation was also different: the monthly variation of 22-year averaged temperature and precipitation appeared to vary in a single-peak curve in Left Banner, Right Banner and Ejin Banner.③The NDVI showed a positive annual correlation, interseasonal correlation and seasonal correlation with precipitation in the eastern Left Banner and the middle Right Banner, but there was no correlation between NDVI and precipitation in the western Ejin Banner. There was no correlation between NDVI and temperature in Alxa region.