热示踪法在非饱和土壤水力参数反演中的研究

Unsaturated soil hydraulic parameters are important in characterizing soil water movement. The accurate determination of these parameters is the precondition of rational assessment for water, solute and heat transport in soils. Due to the low cost and convenience in temperature measurement, heat tracing method has been widely used in measuring the heat characteristics and water flux in unsaturated soils. Most existing researches are based on the one-dimensional homogeneous assumption. Therefore, it’s challenging to use these methods when dealing with practical heterogeneous soils. Based on numerical simulation and experimental studies, this project will develop efficient inversion methods, including the probabilistic collocation-based ensemble Kalman filter and Bayesian analysis, to estimate heterogeneous unsaturated soil hydraulic parameters by assimilating the temperature measurements in flow and heat transport. This project will also compare the information value in different types of measurements and evaluate corresponding measuring techniques, and develop the optimal monitoring method. This project will improve the quantification of water and heat transport in soils, and provide both theoretical and technique support for agricultural soil water management.

土壤非饱和水力学参数，是描述土壤水运动规律的重要参数。它们的精确获取是对土壤中水、盐和热运移进行准确评估的前提。由于温度测量的廉价和方便性，热示踪法已经广泛用于测量非饱和土壤的热特性和水分通量。已有的研究大多基于一维均质假定，在处理具有非均质性的实际问题时，遇到较大挑战。本项目通过数值模拟与试验研究相结合的手段，发展基于随机配点法的卡曼滤波和贝叶斯分析方法等高效的反演方法，对水热运移中的温度信息进行数据同化，反演出非均质的非饱和土壤水力参数。研究还将比较不同类型数据的信息价值以及各自监测手段的优缺点，发展最优监测设计方法。本项目的实施有助于更准确地量化土壤水热运移过程，为农业土水管理提供理论依据和技术支持。

土壤非饱和水力学参数，是描述土壤中物质运移和能量传输规律的重要参数。它们的精确获取是对土壤中水、盐和热运移进行准确评估的前提。由于温度测量的廉价和方便性，热示踪法已经广泛用于测量非饱和土壤的热特性和水分通量。已有的研究大多基于一维均质假定，在处理具有非均质性的实际问题时，遇到较大挑战。本项目通过数值模拟与试验研究相结合的手段，发展了基于数据驱动模型的卡曼滤波和贝叶斯分析方法等高效的反演方法，对土壤中的温度、压力和浓度等信息进行数据同化，反演出非均质的非饱和土壤水力参数。研究还比较了不同类型数据的信息价值以及各自监测手段的优缺点，发展最优监测设计方法。本项目的研究成果有助于更准确地量化土壤物质运移和能量传输过程，为农业土水管理提供理论依据和技术支持。