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为了方便快捷地同步监测盐渍化土壤的水、盐含量,本文以新疆典型盐渍化灌区为研究对象,基于高光谱技术、运用便携式光谱仪获取不同质地的土壤水盐含量光谱曲线,采用一阶微分、二阶微分、连续统去除的数据处理方法对土壤原始光谱进行变换.结果表明:对原始光谱数据的变换有利于土壤属性指纹波段的提取,不同质地水盐含量的变换方法并不相同,在壤土中质量含水量为0%和10%时的水盐光谱曲线使用连续统去除方法、15%含水量使用一阶微分、19%含水量使用二阶微分,砂土中0%含水量使用连续统去除方法、10%、15%和19%含水量水盐光谱曲线使用二阶微分处理后,有利于特征波段的提取;对筛选出的变换数据采用偏最小二乘回归方法构建水盐反演模型,壤土盐度小于6.38 m S·cm~(-1)、砂土小于5.94m S·cm~(-1)时,模型建立的建模数据集决定系数(R_(cal)~2)、内部交叉验证(R_(cv)~2)和外部检验数据集决定系数(R_(val)~2)均大于0.65(P<0.05);壤土水分含量小于16%、砂土小于12%时模型反演精度较高.研究结果可为盐渍化土壤水盐含量同步监测提供阈值参考.
In order to synchronously monitor the water and salt content of salinized soils conveniently and quickly, this paper takes the typical salinized irrigation area of Xinjiang as the research object, and obtains the spectral curve of soil water and salt content of different textures by using portable spectrometer based on hyperspectral technology. The results show that the transformation of the original spectral data favors the extraction of fingerprint bands in soil attributes, and the transformation methods of water and salt content in different textures are not the same. The water-salt spectral curve at 0% and 10% mass water content in loam was determined using the continuum removal method with 15% moisture content using first-order differential, 19% moisture using second-order differential, and 0% moisture in sand using Continuous removal method, 10%, 15% and 19% moisture content of the water and salt spectral curve using second-order differential processing is conducive to the extraction of characteristic bands; partial least squares regression method for the selected transformation data to build water and salt anti When the salinity of loamy soil is less than 6.38 m S · cm -1 and the sand content is less than 5.94 m S · cm -1, the coefficient of determination (R cal ~ 2) , Internal cross-validation ( R cv 2 and R val 2 were greater than 0.65 (P <0.05), the soil moisture content was less than 16%, and the model inversion accuracy was higher when the sand content was less than 12% The results can provide a reference for the simultaneous monitoring of water and salinity in salinized soil.