1982—2006年中国半干旱、干旱区气候与植被覆盖的时空变化

利用1982-2006年英国CRU(Climatic Research Unit)全球气温降水数据和NOAA/NASA归一化植被指数(theNormalized Difference Vegetation Index,NDVI)数据,分析了中国内陆半干旱和干旱区的气候、植被覆盖的时空变化。结果表明,虽然中国内陆半干旱和干旱区的部分区域降水减少,但整体上向暖湿化发展。在暖湿化背景下,中国内陆半干旱和干旱区的植被总体以改善为主(>1%.(10a)-1),特别是新疆西北部和青海东南部;但局部有微弱的减少趋势(0~-1)%.(10a)-1],如新疆南部和东部、甘肃西北部。最后,以乌鲁木齐为例,分析发现气温增加导致植被生长季延长和降水的增加,使得过去25年乌鲁木齐的植被覆盖有明显的改善。

Spatial-temporal changes of climate and vegetation cover in the semi-arid and arid regions of China during 1982—2006

The spatial-temporal changes of climate(temperature and precipitation) and vegetation cover in the semi-arid and arid regions of China during 1982—2006 were analyzed based on global temperature and precipitation data from Climatic Research Unit(CRU) and the Normalized Difference Vegetation Index(NDVI) from NOAA/NASA.The results show that the climate trends to be warm-wet in general,although the precipitation decreases in some areas of the inland semi-arid and arid regions of China,which are consistent with the previous studies.Under the warm-wet climatic background,the vegetation cover increases in most areas(>1%.(10a)-1),especially in the northwestern Xinjiang Autonomous Region and the southeastern Qinghai province.However,the vegetation cover decreases slightly in the partial areas (0~-1)%.(10a)-1] such as the southern and eastern Xinjiang Autonomous Region and the northwestern Gansu province.In addition,it is found that the increases in both precipitation and temperature,which sequentially prolongs the growing season,significantly improve the vegetation cover of Urumqi city during the past 25 years.