EM38在黄河三角洲地区土壤盐渍化快速检测中的应用研究

Application of electromagnetic induction EM38 to rapid analysis of soil salinization in the Yellow River Delta

针对目前黄河三角洲地区存在的土壤盐渍障碍问题,以该地区典型地块为研究对象,电磁感应仪EM38检测与田间采样相结合,分析土壤电导率的剖面分布特征,建立磁感式表观电导率与土壤电导率间的回归模型,并对运用电磁感应仪EM38划分土壤盐渍剖面类型进行探讨。结果表明:研究区表层土壤盐分具有较强的表聚性与变异强度,剖面各土层电导率间存在着关联性;土壤电导率与磁感表观电导率EMh、EMv间呈极显著的相关关系和对数相关关系,EMh对浅层土壤电导率的解译精度较高,对深层土壤电导率、EMv的解译精度要高于EMh;利用电磁感应仪EM38可将研究区土壤盐渍剖面准确划分为表聚型、底聚型与均匀型三种类型,其中表聚型与底聚型是研究区最主要的盐渍剖面类型,进一步的统计分析证明了采用电磁感应仪EM38对土壤盐渍剖面的分类结果具有较高的精度与可信度。该结果对研究黄河三角洲地区土壤盐渍化的发生机理、预测与评估该地区土壤盐渍化的发生发展具有重要参考意义。

Taking into account the problem of soil salinization existing in the Yellow River Delta at present, the profile distribution patterns of soil electrical conductivity was analyzed with the application of EM38 and field sampling method, which was performed in typical field of the Yellow River Delta. Regression models between soil electrical conductivity and electromagnetic conductivity were established and the classification of soil saliniza- tion profile types by using EM38 was further discussed. The results indicated that soil salinity at surface layer exhibited top enrichment and strong spatial variation across the study area, and soil electrical conductivity at all layers was correlated with each other. Soil electrical conductivity showed correlation and logarithmic correlation with electromagnetic conductivity EMh and EMv, significantly, the interpretation accuracy between EMh and soil electrical conductivity at upper layers was relatively high while the interpretation accuracy between EMv, and soil electrical conductivity at deeper layers was higher than EMh. Soil salinity profiles were precisely classified into inverted, normal and uniform types with the use of EM38, and the predominant salinity profile types in the study area were inverted and normal. The further statistical analysis proved that the classification results of soil salinity profiles by using electromagnetic induction EM38 were of high precision and reliability. The research results were of great significance for the mechanism, prediction and evaluation of the occurrence and development of soil salinization in the Yellow River Delta.