Spatio-temporal characterization of water dynamics in a vertical profile of unsaturated soil, utilizing the temperature measurement in heated fiber optics

• Grant number: 23/08756-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2023
• End date: July 31, 2027
• Field of knowledge: Physical Sciences and Mathematics - Geosciences
• Principal Investigator: Edson Cezar Wendland
• Grantee: Luis Eduardo Bertotto
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The soils play an essential role in the ecology of the planet. Soil unsaturated zone (UZ) properties and processes, in particular, are important for the energy and hydrological cycles. In recent years, UZ studies have been highlighted by the use of distributed temperature sensing (DTS), which use fiber optic cables (FOC) as sensors and allow data collection with high spatial and temporal resolution. In these studies, the actively heated fiber optic method (AHFO) is used, in which the FOC monitors the soil thermal response to the application of a heat pulse. Thus, an AHFO-DTS system is composed, in which the heat pulse raises the temperature of the FOC and of the surrounding medium (in this case, the soil), which is monitored by the DTS. This increase in temperature is related to different properties of the soil. Therefore, the objective of this research project is to evaluate the behavior of soil moisture content and water infiltration and percolation processes in a vertical profile of unsaturated soil, through the use of an AHFO-DTS system. For this, an apparatus is proposed where a metallic alloy kept in contact with the external coating of a FOC will be heated, in order to generate the thermal disturbance of the soil. This apparatus will allow the collection of data with high spatial and temporal sampling resolution. Hence, it will be possible to implement an AHFO-DTS system at laboratory level, in a soil column, and at field scale, in an area with a typical soil of tropical regions. It is expected that the results obtained with the execution of this project will allow a better understanding of the spatio-temporal dynamics of water in vertical profiles of unsaturated soil, as well as highlight the use of temperature as a tracer for UZ studies, through the use of the DTS technology. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BERTOTTO, LUIS EDUARDO; REIS, ALAN; COBALCHINI, ERICK RUBENS OLIVEIRA; SCHWAMBACK, DIMAGHI; UCHOA, JOSE GESCILAM SOUSA MOTA; WENDLAND, EDSON CEZAR. Heated fibre optics to monitor soil moisture under successive saturation-drying cycles: An experimental approach. European Journal of Soil Science, v. 75, n. 4, p. 17-pg., 2024-07-01. (15/03806-1, 19/24292-7, 23/08756-9, 21/14016-2)

SCHWAMBACK, DIMAGHI; BRANDAO, ABDERRAMAN R. AMORIM; BERTOTTO, LUIS EDUARDO; BERNDTSSON, RONNY; ZHANG, LINUS; WENDLAND, EDSON; PERSSON, MAGNUS. Quantifying Soil Loss in the Brazilian Savanna Ecosystem: Current Rates and Anticipated Impact of Climate Changes. LAND DEGRADATION & DEVELOPMENT, v. N/A, p. 18-pg., 2024-10-14. (15/03806-1, 19/24292-7, 23/08756-9, 21/14016-2)