基于宽波段遥感光谱混合分解的干旱区土地退化监测评价理论和技术方法探讨

土地退化遥感监测可以服务于政策制定、修复优化、效果评价以及安全预警,亟需建立和完善土地退化理论知识和遥感方法技术体系相结合的框架体系。在借鉴国内外干旱区土地退化(荒漠化)相关理论的基础上,以生态系统服务为连接,以植被-生境互动为核心,构建了生物-物理-社会经济系统耦合的干旱区土地退化监测理论框架。其次,围绕提出的理论框架,基于光谱混合分解端元空间的一致性、稳定性、包容性优势,以宽波段遥感为例建立干旱区遥感监测评价技术方法体系,主要包括当地环境知识挖掘、旱地生态系统景观要素提取、地表(生物物理)参数遥感反演与定标、旱地生态系统结构分析与制图、旱地生态系统功能量化与评价和旱地生态系统与社会经济综合模型七个部分。所建立的理论框架和技术体系可以为干旱区不同区域和尺度间土地退化遥感监测评价和对比分析提供参考。

Theory and Technology of Land Degradation Monitoring and Evaluation in Arid Area based on Linear Spectral Mixture Analysis Using Wide-band Remote Sensing

Remote sensing monitoring of land degradation can serve policy formulation, restoration optimization, effect evaluation and security early warning, and it is urgent to establish and improve the basic theoretical framework and technical system. Based on the theory of land degradation (desertification) in arid areas in China and abroad, this paper establishes the theoretical framework of remote sensing monitoring of land degradation in arid areas coupled with bio-physical-socio-economic systems, taking ecosystem services as the link and vegetation-habitat interaction as the core. Secondly, based on the proposed theoretical framework and the consistency, stability, inclusiveness and applicability of remote sensing monitoring, a technical method system for remote sensing monitoring and evaluation in arid areas is established with wide-band remote sensing as an example, which mainly includes five parts: local environmental knowledge mining, multi-season spectral mixture decomposition, dryland ecosystem structure analysis and mapping, quantification and evaluation of dryland ecosystem function and dynamic monitoring of dryland ecosystem degradation process. The theoretical framework and technical system can provide reference for remote sensing monitoring, evaluation and comparative analysis of land degradation in different regions and scales in arid areas.