季节性形变盐渍化评价指数

Seasonal Deformation Salinization Index

摘要: 现有的盐渍土遥感监测多依赖多光谱信息的专题处理与指数反演方法，受限于土壤光谱响应特征的综合性以及“异物同谱”等问题，客观精准的定量评价仍难以实现。为此，本文提出了一种新型的季节性形变盐渍化评价指数，借助高精度的时序形变信息实现对土壤盐渍化程度的评价。实验于甘肃敦煌地区选取了2018年1月至2020年1月共74景Sentinel-1A影像数据，使用SBAS-DInSAR方法求取时序形变信息以构建季节性形变盐渍化评价指数，联合现有的定量评价方法(如修正的盐渍化评价指数、盐分指数、归一化植被指数)开展综合的比较分析。研究结果表明：季节性形变盐渍化评价指数可以较好的完成对硫酸盐渍土的定量评价；与传统多光谱方法相比，季节性形变盐渍化评价指数与土壤盐渍化程度相关系数的绝对值最大(R = −0.2611)且曲线拟合结果明显优于其他方法(其拟合结果与土壤盐渍化程度的决定系数最大为0.3358，而其他方法最大仅为0.2085)，验证了季节性形变盐渍化评价指数相对于多光谱指数独特的优势。

Abstract: The existing remote sensing monitoring of saline soil mostly relies on the thematic processing and index inversion methods of multispectral information. However, due to the comprehensive characteristics of soil spectral response and the “same spectrum of foreign objects”, it is still difficult to achieve objective and accurate quantitative evaluation. Therefore, a new seasonal deformation salinization evaluation index is proposed in this paper to realize the quantitative evaluation of soil salinization with the help of high-precision time-series deformation information. In this study, 74 Sentinel-1A images were selected from January 2018 to January 2020 in Dunhuang, Gansu Province, and the SBAS-DinSAR method was used to obtain the temporal deformation information to con-struct the seasonal deformation salinization evaluation index. Combined with existing quantitative evaluation methods (such as modified salinization evaluation index, salinity index and normalized vegetation index), comprehensive comparative analysis was carried out. The results show that the seasonal deformation salinization index can complete the quantitative evaluation of sulfate soil. Compared with the traditional multispectral method, the absolute value of correlation coefficient between seasonal deformation salinization evaluation index and soil salinization degree was the largest (R = −0.2611), and the curve fitting result was significantly better than that of other meth-ods (the maximum coefficient of correlation between fitting result and soil salinization degree was 0.3358, while the maximum coefficient of other methods was only 0.2085). The seasonal deformation salinization evaluation index has a unique advantage over the multispectral index.