古尔班通古特沙漠旱生植物时空分布特征

根据2000—2016年MODIS NDVI数据提取旱生植物的时空格局,并结合MODIS地表温度数据和TRMM降水数据,我们分析了古尔班通古特沙漠旱生植物的空间分布和变化特征。结果表明:(1) 2000—2016年间,古尔班通古特沙漠旱生植物覆盖的年际波动明显,但整体呈现缓慢上升趋势;(2)沙漠中旱生植物覆盖空间分布具有明显的地区差异性,位于南部靠近农田地区的覆盖最高,中东部地区次之,西北部最少;(3)古尔班通古特沙漠反映旱生植物长势的NDVI值与温度及降水呈现正相关,降水对NDVI的影响大于温度,并且NDVI与温度或降水之间存在明显的滞后效应,降水与NDVI之间的滞后效应更强。

Spatio-temporal distribution of xerophytes in the Gurbantunggut Desert

The spatial distribution and variation of xerophytes in the Gurbantunggut Desert were analyzed based on the normalized difference vegetation index (NDVI) extracted from the moderate resolution imaging spectroradiometer (MODIS) data from 2000 to 2016 combining MODIS surface temperature and TRMM precipitation data. The results showed that:(1) during 2000-2016, the coverage of xerophytes in the Gurbantunggut Desert fluctuated inter-annually, but steadily increased overall; (2) the spatial distribution of xerophytes in the desert showed obvious regional differences. The coverage was higher in the southern farmland area, lower in the central and eastern part, and lowest in the northwestern part; (3) the NDVI values reflecting the growth of xerophytes in the Gurbantunggut Desert was positively correlated with temperature and precipitation, and the effect of precipitation was greater than that of temperature. An obvious hysteresis effect existed between the NDVI value and temperature or precipitation, and was stronger between the NDVI value and precipitation.