中文摘要：

基于2001—2015年MODIS NDVI遥感数据反演了呼伦贝尔沙地近15年来植被覆盖度和沙漠化土地的空间格局与变化.结果表明：2001年以来呼伦贝尔沙地土地沙漠化总体有所减弱,但年际变化显著.其中：2001—2007年沙漠化土地以扩张为主;2007—2013年随植被覆盖缓慢恢复,沙漠化逐渐逆转;2013—2015年沙漠化有所加剧.降水量年际变化是该区沙漠化逆转或加剧最重要的驱动力.在气候变化背景下,未来几十年内该区沙漠化具有正过程发展趋势.

英文摘要：

Spatial and temporal changes in vegetation coverage and desertification in Hulun Buir sandy land over the past 15 years were examined from MODIS NDVI remote sensing data. Desertification was found to be weakened from 2001 overall but with remarkable annual variations. Land desertification expanded from 2001 to 2007. Gradual reversal of desertification was found from 2007 to 2013, after slow recovery in vegetation coverage. Such process intensified slightly from 2013 to 2015. Annual fluctuations in precipitation were the most important driving force for desertification reversion or exacerbation. Due to climatic changes, sandy de- sertification in Hulun Buir sandy land is likely to be exacerbated in the next few decades.