摘要
利用NOAA/AVHRR NDVI时间序列数据,分析1981-2003年古尔班通古特沙漠不同分区NDVI时空变化的特征。结果表明：23年来,古尔班通古特沙漠NDVI整体上呈波动上升趋势。NDVI增加区域略大于减小区域,且20世纪90年代NDVI增加幅度小于80年代。沙漠不同的植被、沙地类型可能造成了NDVI年内变化特征的空间差异性。沙漠中部和西部年内NDVI最高,呈单峰型;东南部最低,呈低值型;北部植物生长季期间NDVI变化非常平缓,为平稳型。从年内尺度看,水分和热量条件对沙漠植被生长的年内变化起着重要作用。从年际尺度看,降水对NDVI年际变化影响较大,降水丰沛的年份植被茂盛,反之植被稀少、生长缓慢;气温对植被生长的影响不明显。在空间分布上NDVI具有明显的纬向水平地带性分布规律：44.7°～45.6°N NDVI较高,在0.15以上,45.6°N以北和44.7°N以南的地区NDVI较低,其值小于0.15。
In this paper, the spatio-temporal change characteristics of NDVI in the Gurbantonggut Desert during the period from 1982 to 2003 are analyzed using the NOAA/AVHRR NDVI time series data. The results reveal that, during the past 22 years, the NDVI in the Gurbantonggut Desert was generally in an increase trend in a fluctuation way. Moreover, the area of the regions where the NDVI was increased was slightly larger than that of the regions where the NDVI was decreased, and the increase extent of NDVI in the 1990s was lower than that in the 1980s. The spatial otherness of monthly NDVI variation is possibly caused by the different desert vegetarian and sandlot types. The NDVIs in the central and western parts of the desert were the highest, and their curves were unimodal, while the NDVI in the southeastern part was low, and it changed gently in the northern part in the growth season of vegetation. Measuring from the monthly scale, precipitation and heat conditions played an important role in monthly growth of desert vegetation; from the annual scale, precipitation was much more influential for annual variation of NDVI. Plants grew luxuriantly in the years with high precipitation, but the vegetation was sparse and grew Slowly in the years with less precipitation. Comparatively, the effect of air temperature on vegetation growth was not so obvious. In addition, there was an obvious horizontal latitudinal zonation of NDVI in spatial distribution, NDVI was high and higher than 0.15 in the zone of 44.7°N -45.6°N, but is was low and lower than 0.15 in the zone north from 45.6°N and south from 44.7°N.
出处
《干旱区研究》
CSCD
北大核心
2009年第5期686-693,共8页
Arid Zone Research
基金
国家自然科学基金项目(40701148)
科技部社会公益研究专项(2005DIB6J113)共同资助
关键词
古尔班通古特沙漠
NDVI
植被类型
时空变化
降水
气温
Gurbantonggut Desert
vegetation
NDVI
spatiotemporal change
precipitation
air temperature.
