采用1975年MSS卫星图像、2000年ETM卫星图像为遥感信息源,通过建立科学的沙质荒漠化土地分类体系,并结合地理信息系统方法,对位于农牧交错带生态环境脆弱的陕北长城沿线沙质荒漠化进行了现状及动态变化分析,结果表明,经过20多年来沙质荒漠化防治,现代沙质荒漠化过程得到了明显的逆转,25年间,沙质荒漠化土地面积减少了195.18km²,逆转区的面积比发展区的面积大1280.48km²,为该区能源化工基地的建设提供了良好的生态环境,但是目前该区的沙质荒漠化土地强度依然较大,危害较大的极重度和重度沙质荒漠化土地占到总沙质荒漠化土地面积的35.64%,同时煤炭、油气资源的开发对沙质荒漠化的负面影响具有潜在性和长期性,因此,建立合理的资源开发和环境保护体系具有重要的生态和社会意义。

Using MSS satellite image data in 1975 and ETM image data in 2000 as r emote sensing information source,we studied the status quo and dynamic change of sandy desertification along the Great Wall in northern Shaanxi through building scientific classification system for sandy desertified land in combination with GIS analysis method.The result indicates that after 25 years prevention and con trol,the trend of sandy desertification has been distinctly reversed.Nevertheles s,the sandy desertification intensity was still very high,especially the scale o f severe sandy desertification was large.At the same time,the exploitation of co al,petroleum and natural gas has a long,term and potential negative impact on th e sandy desertification.So we must set up the rational resource exploitation and environmental protection system.