新疆典型沙尘暴源区绿洲土地荒漠化的动态变化分析

Dynamic analysis of desertification land in the typical source regions of sandstorm in Xinjiang

利用1990年到2005年遥感数据资料,基于NDVI计算了博尔塔拉河、精河流域绿洲土地荒漠化程度,分析了该地区土地荒漠化的历史演变特征。结果显示：1）1990-2000年期间,土地荒漠化呈加剧态势;2）2000-2005年期间,土地荒漠化逆转形势明显,恶化程度有所降低;3）1990-2005年的16年间,虽然研究区的荒漠化形势在近几年有了一定程度的改善,但除了重度荒漠化面积有所减少外,其他荒漠化类型均为增加趋势,这极有可能成为重度荒漠化的潜在危机。研究表明：影响研究区绿洲荒漠化的主要自然因素是年降水量和年蒸发量,而人口剧增带来的水土资源开发强度增大则是主要人文因素。

Based on the remote sensing data and NDVI,we calculated the desertification degree and analyzed the characteristics of its historical evolution from 1990 to 2005.The results showed that：（1）The oasis desertification degree became severity from 1990 to 2000.（2）The oasis desertification degree was better than before from 1990 to 2000.（3）Although the desertification degree was better than before in recent five years,other styles of desertification were on the increase besides heavy desertification from 1990 to 2005.That will be the potential thread to become the heavy desertification.This paper also showed that the main natural influencing factors on oasis land desertification are precipitation and evaporation.The population growth and land and water resources exploitation are the main humanity influencing factors.