基于分布式温度信息的土体含水率多尺度估算方法  

Multi-scale estimation method for soil moisture content based on distributed temperature information

作　　者：顾凯[1,2] 张博 姜霖 王勇 施斌 GU Kai;ZHANG Bo;JIANG Lin;WANG Yong;SHI Bin(School of Earth Sciences and Engineering,MNR Key Laboratory of Earth Fissures Geological Disaster,Nanjing University,Nanjing 210023,China;Frontiers Science Center for Critical Earth Material Cycling,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学地球科学与工程学院自然资源部地裂缝地质灾害重点实验室,江苏南京210023 [2]教育部关键地球物质循环前沿科学中心,江苏南京210023

出　　处：《岩土工程学报》2024年第12期2661-2667,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金面上项目(42277124,41977217);江苏省基础研究计划自然科学基金面上项目(BK20231216);教育部关键地球物质循环前沿科学中心青年教师独立团队项目(0206-14380148);中央高校基本科研业务费国际合作项目(0206-14380119)。

摘　　要：土体水分迁移过程及其规律是岩土工程、地质工程等领域的重点研究内容之一,准确掌握土体含水率时空演化是开展上述研究的重要前提。基于分布式光纤温度感测技术(fiber optic distributed temperature sensing,FO-DTS),开展了原位测试,记录了浅地表(0~0.5m)不同深度土体自然温度信息,基于半通滤波算法提取振幅、相位信息,结合一维瞬态热传递方程解析解提出了土体含水率估算的新方法。研究结果表明:①基于FO-DTS的高时空分辨率温度信息能够有效估算浅表土体不同深度的含水率;②该方法能够反映复杂天气变化条件下(阴、晴、雨、寒潮等)浅表土体含水率的复杂响应;③降水事件对浅表土体含水率的影响程度随着深度衰减,土体含水率的变化具有一定的滞后性。利用分布式光纤温度感测技术实现基于自然温度信息的含水率估算新方法具有高空间分辨率、易拓展、低能耗的特点,可实现0~10km内多尺度浅地表含水率快速估算,对浅地表-大气相互作用、地质和岩土工程防灾减灾具有重要意义。The soil water migration is one of the key types of researches in geotechnical engineering and geological engineering,and it is an important prerequisite to accurately monitor the spatial-temporal evolution of soil moisture content.Based on the fiber optic distributed temperature sensing(FO-DTS)technology,a high spatial and temporal resolution in-situ monitoring test is conducted to illustrate the proposed method and its feasibility.The continuous natural temperature information of the soil at different depths on the shallow surface(0~0.5 m)is recorded.The amplitude and phase are extracted from the natural temperature data based on the half-pass filtering algorithm,and the soil moisture content is then estimated based on the analytical solution of the one-dimensional transient heat transfer equation.The results show that:(1)The natural temperature information obtained by the FO-DTS technology can be effectively used to estimate the moisture content of shallow soil at different depths.(2)The proposed method can accurately reflect response of the soil moisture under influences of complex weather changes(cloudy,sunny,rain,cold wave,etc.)in the shallow environment(0~0.5 m).(3)The rainfall effects on the change of shallow soil moisture decays with depth and lags in time.The new method,which owns the advantages of high-resolution monitoring,easy expansion and low energy consumption,can realize the rapid content estimation of soil moisture in multi-scale shallow subsurface environment within the range of 0~10 km.This study should be meaningful for the researches on shallow surface-atmosphere interaction,natural hazards and disaster prevention and mitigation in geotechnical engineering.

关 键 词：FO-DTS 自然温度信息 土体含水率 多尺度 

分 类 号：TU43[建筑科学—岩土工程]