Work

Analysis of soil thermal property measurements in double-layered soils with the heat pulse sensor vertically crossing a soil horizon interface

Year: 2026

Type: article

Abstract: • Soil layer properties affect HP measurements when the soil horizon interface is less than 15 mm from the thermocouple. • A PCPC model that considers soil horizon interface and layer properties effects on HP measurements was proposed. • The PCPC model accurately estimate the double-layered soil thermal properties based on HP measurements. The growing demand for studying coupled hydrothermal transport processes in layered soils comes with a need for accurate estimations of thermal properties using the heat pulse (HP) sensor. In the case where a HP sensor is installed vertically in a double-layered soil with the sensor crossing a soil horizon interface, its measurements are affected by different upper and lower layered properties. This study combined laboratory and numerical experiments to quantify the effect of the soil horizon interface on HP measurements, and to develop a parameterized cylindrical perfect conductor (PCPC) model that accounts for the interface position and layered properties. Results indicated that the effect of the layered soil properties on HP measurements depended on the soil horizon interface position, specifically when the soil horizon interface was within 15 mm vertically above or below the thermocouples in the HP sensor. A sigmoid function was used to quantify the effects of soil layer properties and soil horizon interface position on HP measurements. The developed PCPC model, based on the sigmoid function, exhibited strong agreement with the numerical simulations, yielding soil thermal property estimates all within a maximum relative error of −3.1%. The PCPC model effectively captured the combined effects of soil horizon interface and thermal properties of soil layers on the HP measurements in a double-layered soil system. This model provides a theoretical basis for the inversion of soil thermal property in such a double-layered soil environments with a HP sensor vertically crossing a soil horizon interface.

Source: Geoderma

DOI: 10.1016/j.geoderma.2026.117680

Authors: Wei Peng, Lin Liu, Meng Tian, Xiaomeng Yao

Institutions: Hebei Normal University, China Agricultural University, Henan Academy of Sciences

Language: English

Topic: Soil and Unsaturated Flow

Subfield: Civil and Structural Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,320

Funders: National Natural Science Foundation of China, Hebei Normal University, Department of Education of Hebei Province, Natural Science Foundation of Hebei Province