基于EM38-MK2的南疆干旱区表观电导率反演土壤水分研究  

Inversion of Soil Water in an Arid Area of Southern Xinjiang by Using EM38-MK2 Apparent Electrical Conductivity

作　　者：齐威 刘新路 吴家林[1] 冯春晖 王佳文 迟春明[1] 彭杰[1] QI Wei;LIU Xin-lu;WU Jia-lin;FENG Chun-hui;WANG Jia-wen;CHI Chun-ming;PENG Jie(College of Plant Science,Tarim University,Alar 843300,China)

机构地区：[1]塔里木大学植物科学学院,新疆阿拉尔843300

出　　处：《土壤通报》2020年第3期521-528,共8页Chinese Journal of Soil Science

基　　金：国家重点研发计划项目(2018YFE0107000);新疆生产建设兵团中青年创新领军人才项目(2020CB032)共同资助。

摘　　要：土壤水分含量是农田进行定额灌溉的基本参数,南疆地处干旱区,土壤水资源稀缺,实现田间定额灌溉更利于充分利用土壤水分。EM38-MK2快速和高效获取土壤水分含量数据,适时监测土壤水分含量,可成为农田精准灌溉的重要途径。用EM38-MK2测定轻度、中度和重度3个不同程度盐渍化区域土壤0~0.75 m和0~1.5 m的表观电导率,结合同步采集的0~20 cm、20~40 cm、40~60 cm、60~80 cm和80~100 cm土壤剖面剖面及室内测定含水量数据,对比三个不同盐渍化程度表观电导率反演土壤含水率模型精度,比较分区模型和全区模型的反演精度,分析土壤盐分含量对反演土壤含水率精度的影响。结果表明,用EM38-MK2对土壤含水率反演效果在轻度盐渍化表现最好,中度盐渍化次之,重度盐渍化较差。不同深度土层的分区模型精度均高于全区模型精度,分区模型R^2为0.73~0.88,RMSE低于全区模型,全区模型各层的RPD均低于1.5,不具备预测能力。土壤盐分含量对土壤水分的反演有影响,并且随土壤盐分含量的增加,反演精度下降。Soil moisture content is a basic parameter of the evaluation for fixedirrigation for farmland,Southern Xinjiang is located in an arid area,where soil water resources are scarce.In order to achieve fixed field irrigation,it is more conducive to making full value of soil moisture.and the rapid and efficient acquisition of soil moisture data by using EM38-MK2,which become important way for precision irrigation of farmland.The apparent conductivity of soil in salinized regions with mild,moderate and severe degrees was determined by using EM38-MK2 geodetic conductivity instrument,and the water content data at 0-20 cm,20-40 cm,40-60 cm,60-80 cm and 80-100 cm soil depths were collected synchronously.Comparing the accuracy of inversion of soil moisture content model with apparent conductivity of three different salinization degrees,the inversion accuracy of local model and global model was compared,and the effect of soil salinity on soil moisture inversion accuracy was analyzed.The results show that the inversion effect of EM38-MK2 on soil moisture content is the best in mild salinization,followed by moderate salinization,and worse in severe salinization.The local model accuracy of soil layers at different depths is higher than global model accuracy.The local model R^2 is 0.73-0.88,RMSE is lower than global model,and RPD of each layer of the global model is lower than 1.5,which does not have the predictive ability.Soil salt content has an effect on the inversion of soil moisture,and as the soil salt content increases,the inversion accuracy decreases.

关 键 词：土壤水分 土壤盐渍化 反演模型 表观电导率 

分 类 号：S152.7[农业科学—土壤学]