通过分析EM38所测的大地电导率与土水比(1∶5)浸提液电导率之间的相关关系,建立以土壤浸提液电导率(EC)为因变量,大地电导率(EM)为自变量的预测模型。在预测模型建立的基础上,对其精度进行了评定,以确保预测模型在土壤盐分含量预测中的可信度。利用EM38所测的大地电导率来预测土壤中盐分含量,进而分析土壤盐分含量的空间变异性。结果表明:研究区土壤盐分的空间变异特征为表聚性、分带性;并且分析了土壤盐分含量的带状走向,其浅层(0~30 cm)的走向与中层(30~60 cm)、深层(60~90 cm)、底层(90~120 cm)盐带走向的夹角在5°以上,而其他各层相差3°以内,尤其是浅层(0~30 cm)土层的盐分含量走向与植被的带状走向一致,较好地拟合了研究区的地貌变化特征。
In this paper,the relationship between the EM38 earth conductivity measurement and soil(1∶ 5) conductivity solution was analyzed,and the prediction models were developed by taking soil solution conductivity as a dependent variable and earth conductivity as an independent variable.In order to ensure the credibility of the models,the credibility of EM data was analyzed.Through correlation analysis between EMh and EMv,the results revealed that the standard mode was consistent with the EM measurement in vertical mode and was capable of reflecting soil salt content,so the data were applicable.An ideal prediction model should be selected in predicting soil salt content.The values of EM38 measurement of earth conductivity could be used to predict soil salt content and analyze the spatial variation of soil salinity.Results showed that the spatial variation of soil salinity in the study area was the salt accumulation in topsoil and zonal.Results showed that the angle of salt zone between the shallow soil layer(0-30 cm) and the moderate(30-60 cm),deep(60-90 cm) and bottom(90-120 cm) soil layers was larger than 5°,but within 3° between it and other soil layers.Especially,the zonal trend of soil salt content in shallow soil layer was consistent with that of vegetation and fitted the change features of landforms in the study area.