基于主动微波遥感的土壤盐分定量反演研究

项目名称： 基于主动微波遥感的土壤盐分定量反演研究

项目编号： No.41301363

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 吴月茹

作者单位： 中国科学院寒区旱区环境与工程研究所

项目金额： 25万元

中文摘要： 土壤盐渍化是土地退化的主要类型之一，已成为关系到社会经济、生态环境及现代农业可持续发展的重大科学问题。主动微波遥感对土壤介电常数变化的高敏感性，使其在定量监测土壤含盐量方面有着独特的优势，尤其是多维度合成孔径雷达（SAR）。然而，由于对盐渍土的介电行为及盐分对土壤散射的影响机理并不清晰，目前尚未形成成熟、稳健、通用的微波遥感反演土壤盐分的算法。本项目拟通过室内控制试验配制一定水盐含量的标准土壤样品，在实测介电常数及土壤理化参数基础上，对传统的介电混合模型（Dobson）进行改进和扩展，发展适用于盐渍土的介电混合模型，使其能够更好的刻画盐渍土的介电行为特征。基于此，采用时间序列的SAR数据，借鉴土壤水分反演的方法，在消减粗糙度对SAR观测信号影响的前提下，采用AIEM理论辐射传输模型, 实现土壤盐分的主动微波遥感定量反演，发展盐分的微波遥感反演算法，并根据地面同步实测数据对其精度进行评价。

中文关键词： 微波遥感；介电常数；土壤盐分；土壤含水量；定量反演

英文摘要： As one main type of land degradation, soil salinization has being to be a critical scientific issue which plays an important impact on socio-economic, ecological environment and modern agriculture development. The strong correlation between radar backscattering coefficient and soil dielectric constant makes the active microwave remote sensing, especially the multi-dimensional synthetic aperture radar (SAR), to be a promising tool to quantitatively monitor soil salinity amount. However, till now, due to the lack of the knowledge of the dielectric properties of saline soil and the effect of salt on the soil backscattering coefficient, a universal algorithm and model for soil salinity retrieval had still not yet been developed. This project aims to revise the imaginary part of the dielectric constant in Dobson's model based on the understanding of the dielectric property of saline soil, via the measurement and analysis of dielectric properties of the soil samples with different moisture and salt content under the controlled experiment in laboratory. Then, with the help of the soil moisture inversion method and the AIEM model, by reducing the effect of soil roughness on SAR image and using multi-phase SAR images, we will finally develop a soil salt inversion algorithm for active microwave remote sensing data (SAR).

英文关键词： Microwave remote sensing；Dielectric constant；Soil salinity；Soil water content；Quantitative retrieval