TDRによる土壌凍結深の計測に関する基礎的研究

TDR测量土壤冻结深度的基础研究

• 批准号: 05760184
• 负责人: 堀野 治彦
• 金额: $ 0.58万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Encouragement of Young Scientists (A)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05760184/
• 关键词: TDR; 凍結深; 誘電率; 電磁波; 含水率

周知のように,寒冷地においては,土壌の凍結・凍上によって構造物や作物への被害が生じているが,こうした被害に対応するためには,土壌の凍結深を簡易に精度よく測定することが必要となる。これまでは,主にメチレンブルー凍結深計や土中に埋設した温度計による計測がなされてきたが,これらの方法では,過冷却状態を正しく評価したり,瞬間的な値を得ることは困難であった。そこで本研究では,土壌の体積含水率thetaを誘電率epsilonより求めるTDR(Time Domain Reflectometry)の原理を,土壌の凍結深計測に応用することを考え,当初の計画どおり,豊浦標準砂,マサ土を用いてTDRによる(1)土壌水分量計測実験,(2)凍結深計測実験を行った。その結果,まず(1)の実験より,得られたepsilon-thetaのキャリブレーション曲線は,精度のよいthetaの測定に利用可能なこと,脱水・給水過程間で特にヒステリシスが認められないことなどが明らかになり,TDRの測定原理・精度を確認することができた。次に,(2)の実験より,TDRによる凍結深の測定値を,定規によるそれと比較したところ,1.蒸留水でthetaを調整した土壌の凍結深は,平均絶対誤差が,theta【similar or equal】0.2の試料で0.28cm,theta【similar or equal】0.1の試料で0.34cm内の高精度で計測できた,2.塩類化土壌を想定し,2,000ppmの塩水でthetaを調整した試料では,同じく平均絶対誤差が,theta【similar or equal】0.2の場合に0.17cm内とさらに精度良く凍結深の計測ができた,3.thetaが小さくなるとTDRによる測定値には誤差が増加し,計測システムの性能上,theta【similar or equal】0.07を下回るような水分量の少ない土壌でなお,現場でのTDRによる凍結深計測試験も,現在実行中である。

It is well known that in the cold, the soil is cold, it is cold. The main equipment is used to measure the temperature of buried buildings in the earth, temperature measurement, temperature In this study, the moisture content of soil mass, the moisture content of soil mass, the electrical energy rate of soil, the principle of TDR (Time Domain Reflectometry), the principle of soil moisture content, the water content of soil, the moisture content of soil, the water content of soil, the moisture content of soil, the water content of soil, the moisture content of soil, the water content of soil, the moisture content of soil, the moisture content of The results show that: (1) the results show that: (1) the epsilon-theta test results show that the accuracy of the curve, the accuracy of the theta measurement and the dehydration process of the dehydration water are very sensitive, and the principle accuracy of the TDR test confirms the accuracy of the test. For the second time, (2) the measurement of the depth of the TDR, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of the depth, the accuracy of the measurement, the measurement of Steamed and retained water, theta, soil temperature, soil depth, average temperature difference, theta [similar or equal] 0.2%, theta [similar or equal] 0.1%, 0.34cm high precision calculation precision, 2. This is the same as the average error, theta [similar or equal] 0.2, theta [similar or equal] 0.2, 0.17cm precision, precision, depth, 3.theta, 3.theta, TDR, measurement, temperature, performance, performance, accuracy, accuracy, Theta [similar or equal] 0.07The next time you need to reduce the amount of water, you will need to pay more attention to the amount of water you need. You will need to pay more attention to the situation in the future. Now you are in the line of work.