Quantitative retrieval of soil salt content based on measured spectral data
Quantitative retrieval of soil salt content based on measured spectral data
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基于实测光谱数据的土壤含盐量定量反演
DOI：
10.3724/sp.j.1226.2016.00507
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发表时间：
2018-11
影响因子：
1
通讯作者：
ChangZhen Yan
中科院分区：
文献类型：
--
作者：
HanChen Duan;Tao Wang;Xian Xue;CuiHua Huang;ChangZhen Yan
以石羊河下游的民勤绿洲为研究区域，利用高光谱数据和室内土壤盐分数据，分析了该区域盐渍土的光谱反射率及其变化特征，阐明了土壤光谱反射率及其变化与土壤盐分含量的关系。此外，我们筛选了敏感波段。基于实测光谱数据建立了土壤盐分含量的多元线性回归模型，并利用野外实测数据对模型的精度进行了验证。结果表明，不同盐渍化程度土壤的光谱曲线总体形状一致，盐渍化土壤在可见光和近红外波段的反射率高于非盐渍化土壤。经过微分变换后，光谱反射率与土壤盐分含量的相关系数明显提高。基于盐渍土光谱反射率倒数对数的一阶微分变换模型在462和636 nm波段的精度和稳定性最高，决定系数为0.603，均方根误差为5.407。该模型为区域土壤盐渍化的定量提取和监测提供了很好的参考。
Choosing the Minqin Oasis, located downstream of the Shiyang River in Northwest China, as the study area, we used field-measured hyperspectral data and laboratory-measured soil salt content data to analyze the characteristics of saline soil spectral reflectance and its transformation in the area, and elucidated the relations between the soil spectral reflectance, reflectance transformation, and soil salt content. In addition, we screened sensitive wavebands. Then, a multiple linear regression model was established to predict the soil salt content based on the measured spectral data, and the accuracy of the model was verified using field-measured salinity data. The results showed that the overall shapes of the spectral curves of soils with different degrees of salinity were consistent, and the reflectance in visible and near-infrared bands for salinized soil was higher than that for non-salinized soil. After differential transformation, the correlation coefficient between the spectral reflectance and soil salt content was obviously improved. The first-order differential transformation model based on the logarithm of the reciprocal of saline soil spectral reflectance produced the highest accuracy and stability in the bands at 462 and 636 nm; the determination coefficient was 0.603, and the root mean square error was 5.407. Thus, the proposed model provides a good reference for the quantitative extraction and monitoring of regional soil salinization.