土地退化评价与监测技术路线的研究

在对 90年代后期国内外土地退化评价与监测主要进展分析基础上 ,归纳出了绝对、相对和差异三种退化的评价思想 ;直接运用图象处理软件 ,通过监督非监督分类选择几个基于RS、GIS的指标 ,给定不同的权重综合地确定土地退化类型和程度的两种技术监测路线。最后 ,结合中国的实际情况 ,以沙质荒漠化为例提出了在绝对退化思想指导下 ,通过确定土地退化生态基准的时空尺度 ,建立监测区内典型土地退化类型与程度的标准信息资源库 ,GIS数据与RS数据相融合的土地退化评价与监测的技术路线框架。

Technical Framework on Monitoring and Assessing of Land Degradation

Based on the review of the advance on monitoring and assessing of sandy desertification at home and abroad since the late 1990s, the paper draws an outline of theories and technical lines after conducting desertification evaluation in several regions. Three of theories are important, respectively representing absolute, relative and diversity degradation, they are global assessment of human induced soil degradation(GLASOD), the assessment of the status of human induced soil degradation in South and Southeast Asia(ASSOD), and the theory put forward by Moscow State University and Russia Academy of Science(RUSSIA). Two technical lines are either using image processing software through supervised and unsupervised classifications or selecting different weighed indicators from RS and GIS. Combining the situation in China and under guidance of absolute degradation theory, the paper puts forward the technical framework for monitoring and assessing sandy desertification of China, which include the definition of degradation baseline with temporal and spatial scale, the establishment of indicators database based on 3S for the typical desertified land of all levels and the integration of computer image processing, GIS and ES.