基于EM38电导率仪土壤水分探测研究  

EM38 for Soil Moisture Content Estimation in the Farming-pastoral Ecotone in Inner Mongolia

作　　者：蒋志云[1,2] 李小雁[1,2] 张志华[1,2] 张思毅[1,2] 李柳[1,2] 

机构地区：[1]北京师范大学地表过程与资源生态国家重点实验室,北京100875 [2]北京师范大学资源学院,北京100875

出　　处：《干旱区研究》2015年第1期48-55,共8页Arid Zone Research

基　　金：国家自然科学杰出青年基金项目(41025001);国家自然科学基金重点项目(41130640);教育部创新团队(IRT1108);中央高校基本科研业务费专项资助

摘　　要：通过在内蒙古农牧交错带退耕地开展EM38电导率仪监测实验,结合土壤水分观测系统及土壤样品分析,探测土壤水分。结果表明:土壤水分与土壤表观电导率(ECa)具有显著相关性(r=0.822**,P<0.01),两者的变化趋势一致;同时,验证了表观电导率的深度响应函数,指出土壤水分可近似替代土壤电导率对土壤表观电导率的贡献,即土壤水分是决定土壤表观电导率变化的主要因素。建立土壤水分与土壤表观电导率间的线性回归模型并进行模型验证,模型预测结果较可靠(R2=0.65)。EM38电导率仪探测退耕地土壤水分具有可行性,探测结果可为揭示农牧交错带土壤水文过程及土壤—植被系统演化过程提供方法与数据支持,并为该地区土壤管理提供科学的决策依据。Em38,electromagnetic induction sensors,has been widely used for monitoring and mapping soil by measured apparent electrical conductivity（ ECa）. Using the Em38,this study estimated soil moisture content of a semi-arid grassland,which was returned from grain plots,in the typical steppe of Inner Mongolia,China. Firstly,we selected a sample site at the grassland and installed the ECH2O system for monitoring the soil volumetric moisture and temperature. Then we collected the soil samples for analyzing the soil physicochemical properties,such as soil bulk density,soil soluble salinity,and conducted the Em38 measuring experiment for vertical and horizontal dipole configurations to investigate the main factors which affect the ECa. Em38 was put in different heights above the ground at the experimental sites in 2012 and the vertical and the horizontal ECawere recorded. Soil cores（ 0-80 cm,10 cm interval） were collected for soil moisture content measurement to testify the depth response function proposed by Mc Neill（ 1980）. The study verified the relationship of the soil moisture content with the ECaat the grassland. Based on the experimental results of Em38 and the data analysis of soil moisture content and soil physicochemical properties,there was a significant correlation between the soil moisture content and the soil apparent electrical conductivity,which was measured by Em38 sensor with horizontal dipole configuration（ r = 0. 822^＊＊,P〈0. 01）. A linear regression model was established according to correlation between the soil moisture and ECh.The model could be used to predict the average soil moisture content of a soil profile and the results were relatively reliable（ R^2= 0. 65,k = 0. 821）. However,the vertical distribution of the soil moisture content would affect the ECameasurements and the regression model. Therefore,it is necessary to investigate the distribution of vertical soil moisture content before using the Em38 for soil moisture predicting. The results could be helpful for providi

关 键 词：土壤水分 EM38 电导率 退耕地 农牧交错带 内蒙古 

分 类 号：S152.7[农业科学—土壤学]