民勤绿洲土壤盐分组成与光谱特征  

Soil salt components and their spectral characteristics in Minqin Oasis of Northwest China

作　　者：张建明[1] 齐文文[2,3] 

机构地区：[1]兰州大学资源环境学院,兰州730000 [2]中国科学院地理科学与资源研究所,北京100101 [3]中国科学院大学,北京100049

出　　处：《生态学杂志》2013年第10期2620-2626,共7页Chinese Journal of Ecology

基　　金：国家重点基础研究计划项目(2009CB825102)资助

摘　　要：基于野外采样和实验室分析,研究了民勤绿洲土壤的可溶盐特征。结果表明,表层土壤中阴离子以氯离子和硫酸根离子为主,阳离子以钙离子和镁离子比重较大;民勤表层土壤中硫酸盐矿物居多,硫酸根离子易与阳离子结合形成硫酸盐化合物,而且硫酸根离子与钙、镁离子的相关系数达0.918、0.933,说明土壤中硫酸根离子与钙离子、镁离子是主要的结合方式。采用线性方程拟合土壤浸提液电导率和土壤全盐量的关系,精度较高。通过表层土壤的光谱测量和光谱特征分析,发现反射率一阶微分和反射率对数一阶微分两种变换形式与土壤全盐量的相关性最强。利用多元逐步线性回归方法,以反射率对数一阶微分为自变量的回归方程效果最佳,预测方程的决定系数达到0.789。Based on field sampling and laboratary analysis, this paper studied the characteristics of soil soluble salts in Minqin Oasis of Northwest China. The dominant anions in the surface soil were Cl- and SO42-, and the main cations were Ca2＋ and Mg2＋. The correlation coefficients of the SO42- with the Ca2＋ and Mg2＋ were 0.918, and 0.933, respectively, illustrating that the SO42- was mainly combined with the Ca2＋ and Mg2＋. There was a higher precision when using linear equation to fit the relationships between the soil electrical conductivity and soil total salt content. Through the measuremnt of surface soil extract spectra and the analysis of surface soil spectral characteristics, it was found that the two transformations of firstorder differentiation of reflectivity and logarithmic reflectivity had the strongest correlations with the soil total salt content. The soil total salt content was further predicted by multiple linear regressions, and the regression equation with the firstorder differentiation of logarithic reflectance as the independent variable had the best effect, with the determination coefficient （R2） being 0.789.

关 键 词：民勤绿洲 土壤全盐量 电导率 土壤光谱特征 光谱微分处理 

分 类 号：S156.4[农业科学—土壤学]