遥感技术在中国土地荒漠化监测中的应用进展

The Application of Remote Sensing Technology to Land Desertification Monitoring

土地荒漠化已成为一个全球性的重大环境问题,也是我国面临的严重生态环境问题。遥感技术以其信息量大、获取速度快、覆盖范围广、受人力物力的限制小等优点,在过去的30多年中,已逐渐成为土地荒漠化监测的重要数据来源和技术手段。本文首先概述了土地荒漠化遥感监测中使用的遥感数据源,综述了各类卫星遥感影像、影像的不同季相、波段和各类植被指数的选择等;讨论了土地荒漠化信息遥感提取的多种方法,综合比较不同遥感提取方法的优缺点,进而分析土地荒漠化遥感监测中多采用计算机自动分类与人工手动分类结合的原因。最后,指出遥感技术在土地荒漠化监测中存在的一些问题,并提出土地荒漠化遥感监测中综合指标与综合方法集成研究等发展方向。

Land desertification has been a worldwide environmental problem. It is also a serious eco-environmental problem in China. Because of the advantage of large amount of information, short cycle and broad scope of data, less restrictions on the human and material resources and so on, remote sensing has become an important technology to monitor land desertification in the past 30 years. Firstly, we summarize the research progress in monitoring land desertification using remote sensing data, including different satellite remote sensing imageries, how to choose the time and bands of the imageries and how to choose the vegetation indexes. Then, we discuss about the methods to extract information of land desertification from remote sensing imageries, which ineludes artificial visual interpretation, supervised classification, unsupervised classifcation, hierarchical decision tree classification and neural network classification. Also we comprehensively compare the strength and weaknesses of each method. Furthermore, we analyze the reasons why both computer automatic classification and artificial classification are widely used in monitoring land desertification. We identify the problems in the remote sensing technology application to land desertification monitoring. Finally, we put forward the development prospects in the application of remote sensing to monitoring land desertification, such as the integration of aggregative indicators and methods and so on.