基于驻波率原理的森林枯落物和土壤含水率测量方法

发布时间：2018-05-01 04:36

本文选题：森林枯落物 + 土壤含水率　；参考：《农业机械学报》2017年12期

【摘要】：枯落物含水率测定在森林水文学、碳循环、林火蔓延以及火险等级评估等研究中具有重要作用。本文提出了一种基于驻波率(SWR)原理的森林枯落物含水率测量方法,所设计的SWR水分传感器具有复用双环式探头结构,可分时测量枯落物或土壤的含水率和电导率。实验结果表明,传感器输出电压与半分解、全分解枯落物和土壤含水率呈现良好的线性关系。与商品化TDR水分传感器相比,SWR传感器测量枯落物和土壤含水率的平均绝对误差较小,且在厚度小于10 cm的枯落物含水率测量以及测量成本方面具有明显优势。在对枯落物含水率进行长期原位测定时,SWR传感器可通过测量电导率判断半分解的枯落物是否随时间推移而完全分解,以便及时调整传感器水分测量的标定曲线,最大程度降低因枯落物成分改变对传感器测量精度造成的影响,为准确测量森林地表枯落物含水率奠定基础。
[Abstract]:The measurement of moisture content of litter plays an important role in the study of forest hydrology, carbon cycle, forest fire spread and fire risk assessment. In this paper, a method for measuring the moisture content of forest litter based on standing wave rate (SWR) principle is proposed. The designed SWR water sensor has a dual-loop probe structure, which can be used to measure moisture content and conductivity of litter or soil in different time. The experimental results show that there is a good linear relationship between the output voltage of the sensor and the semi-decomposition, the total decomposition of litter and the soil moisture content. Compared with commercial TDR water sensor, the average absolute error of litter and soil moisture content measured by TDR sensor was smaller than that of commercial TDR water sensor, and it had obvious advantages in measuring litter moisture content and measuring cost when thickness was less than 10 cm. When the moisture content of litter is measured in situ for a long time, the SWR sensor can judge whether the half-decomposed litter is completely decomposed with time by measuring the conductivity, in order to adjust the calibration curve of moisture measurement in time. The effect of the change of litter composition on the accuracy of sensor measurement was minimized, which laid the foundation for accurate measurement of moisture content of forest surface litter.
【作者单位】：北京林业大学工学院;北京林业大学城乡生态环境北京实验室;
【基金】：国家自然科学基金项目(31500588) 国家重点研发计划项目(2017YFD0600901) 中央高校基本科研业务费专项资金项目
【分类号】：S714

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