基于高密度电阻率成像法的陇中半干旱区土壤含水量监测研究

发布时间：2018-05-11 16:13

本文选题：电阻率成像 + 土壤含水量　；参考：《中国生态农业学报》2016年10期

【摘要】：土壤含水量是影响半干旱区农作物生长的重要因素。为了准确测定土壤含水量的变化动态以指导农业高效用水,近年来,利用地球物理测量方法研究高分辨率的水流入渗,已经越来越受到欢迎和重视。本文以陇中半干旱区玉米田为例,通过在土壤表面布置电极,利用高密度电阻率成像法(ERT)对降雨前后土壤二维剖面进行电阻率数据测量,实现对土壤二维剖面电阻率值和含水量监测,解释不同条件下土壤含水量变化的原因,建立陇中半干旱区农田土壤电阻率和含水量之间的相关关系。结果表明:降水入渗使得二维剖面土壤电阻率整体呈明显降低趋势,反演得到的电阻率图像局部电阻值"高-低-高"的变化过程,与一次降水过程前后"干-湿-干"的循环过程一致。土壤含水量实测值与估计值之间有较为显著的线性关系(R2=0.651 8,n=96)。在0~2.0 m深度范围内,总体估计偏差较小,为0.74%;土壤含水率的估计精度较高,为2.64%。0~0.5 m土层(H1)含水量监测探头分布密集,数据采集较为准确,故H1层估计精度略高于0.5~2.0 m层(H2)。相比之前利用实测工具进行野外测量,ERT测量方法精度较高。本文提供了一个高分辨率的土壤结构二维分布与水分运移过程的图像,同时为实现精确和高效的农业用水管理提供一种新途径。
[Abstract]:Soil moisture content is an important factor affecting crop growth in semiarid area. In order to accurately measure the dynamic changes of soil moisture in order to guide agricultural efficient water use, in recent years, geophysical methods have been used to study high-resolution water infiltration, which has been more and more welcomed and paid more and more attention. In this paper, the soil resistivity data of 2-D soil profile before and after rainfall were measured by placing electrodes on the soil surface and using high density resistivity imaging (ERT), taking the maize field in the semi-arid region of central Gansu as an example. The resistivity value and water content of two-dimensional soil profile were monitored to explain the reasons of soil water content change under different conditions and to establish the correlation between soil resistivity and water content in semi-arid farmland in the middle of Gansu Province. The results show that the soil resistivity of 2-D profile is obviously decreasing due to precipitation infiltration, and the local resistivity value of the obtained resistivity image is changed from "high to low to high". It is consistent with the cycle of "dry-wet-dry" before and after a precipitation process. There was a significant linear relationship between the measured values and the estimated values of soil water content. In the range of 0 ~ 2.0 m depth, the overall estimation deviation is small (0.74), and the estimation accuracy of soil moisture content is high, which is 2.64. 0 ~ 0. 5 m soil layer and 2. 64 ~ 0. 5 m soil layer. The water content monitoring probe is distributed intensively and the data collection is more accurate, so the accuracy of H1 layer estimation is slightly higher than that of 0. 5 ~ 2. 0 m layer. The accuracy of the field measurement method is higher than that of the previous field measurement method. In this paper, a high resolution image of two-dimensional distribution of soil structure and water transport process is provided, and a new way to achieve accurate and efficient agricultural water management is provided.
【作者单位】：兰州大学资源环境学院/西部环境教育部重点试验室;山东农业大学水利土木工程学院;
【基金】：国家自然科学基金项目(41471023,41202174)资助~~
【分类号】：S152.7

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