Recent Advances in Dielectric Properties-Based Soil Water Content Measurements

Remote Sensing, Journal Year: 2024, Volume and Issue: 16(8), P. 1328 - 1328

Published: April 10, 2024

Dielectric properties are crucial in understanding the behavior of water within soil, particularly soil content (SWC), as they measure a material’s ability to store an electric charge and influenced by other minerals soil. However, comprehensive review paper is needed that synthesizes latest developments this field, identifies key challenges limitations, outlines future research directions. In addition, various factors, such salinity, temperature, texture, probing space, installation gap, density, clay content, sampling volume, environmental influence measurement dielectric permittivity Therefore, aims address gap critically analyzing current state-of-the-art properties-based methods for SWC measurements. The motivation increasing importance precise data applications agriculture, monitoring, hydrological studies. We examine time domain reflectometry (TDR), frequency (FDR), ground-penetrating radar (GPR), remote sensing (RS), capacitance, which accurate cost-effective, enabling real-time resource management health through measuring travel electromagnetic waves reflection coefficient these waves. can be estimated using approaches, TDR, FDR, GPR, microwave-based techniques. These made possible loss factor with SWC. available further synthesized on basis mathematical models relating apparent providing updated their development, applications, monitoring. It also analyzes recent calibration models, algorithms, challenges, trends estimating By consolidating advances highlighting remaining article guide researchers practitioners toward more effective strategies

Language: Английский

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Room for improvement: A review and evaluation of 24 soil thermal conductivity parameterization schemes commonly used in land-surface, hydrological, and soil-vegetation-atmosphere transfer models

Earth-Science Reviews, Journal Year: 2020, Volume and Issue: 211, P. 103419 - 103419

Published: Oct. 29, 2020

Effective thermal conductivity of soils (λeff) is a critical parameter for agriculture, environment science, and engineering. Functions to estimate λeff from readily available soil properties, known as (STC) schemes, are needed by land-surface models (LSMs), hydrological models, soil-vegetation-atmosphere transfer (SVAT) study the land surface energy balance, heat flux, regime under various climates geographic regions. The selection STC scheme can result in large differences temperature estimates LSMs, sometimes masking effects climate change. Therefore, accurate critically important LSM estimates. Although number schemes have been incorporated no has systematically evaluated their performance. objectives this were review evaluate employed LSMs comparing (1) predicted measured STCs (2) modelled (LST) using Community Land Model at three selected sites corresponding LST data moderate resolution imaging spectrometer (MODIS). In total, 24 collated 38 mainstream SVAT, models. They divided into categories based on model types: one physically-based scheme, eight linear/non-linear regression 13 normalized schemes. We also include two that express function matric potential (ψ, hereafter referred (ψ) schemes). first types with compiled dataset consisting 439 unfrozen frozen measurements 16 soils. simultaneously separate or independent studies. Results showed none could be used accurately predict all types. performance largely depended size (number samples) characteristics (e.g., types) comparison. Some work well certain soils, but care should taken larger scale applications. simulated varied when compared MODIS LST. general, performed better medium- coarse-textured than fine-textured However, discrepancies observed estimated different medium recommend modelers mindful inherent bias hence overall predictions. Orchestrated efforts urgently part hydrology, climatology communities develop more extensive systematic database development evaluation improved wider

Language: Английский

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Water Migration and Segregated Ice Formation in Frozen Ground: Current Advances and Future Perspectives

Frontiers in Earth Science, Journal Year: 2022, Volume and Issue: 10

Published: Feb. 10, 2022

A characteristic of frozen ground is a tendency to form banded sequences particle-free ice lenses separated by layers ice-infiltrated soil, which produce frost heave. In permafrost, the deformation surface caused segregated harms engineering facilities and has considerable influences on regional hydrology, ecology, climate changes. For predicting impacts permafrost degradation under global warming transformation environmental, establishing appropriate mathematical models describe water migration behavior in soil necessary. This requires an essential understanding formation ground. article reviewed mechanisms soils their model construction introduced effects environment included landforms, hydrological patterns, ecosystems. Currently, potential been widely accepted characterize energy state liquid water, further study direction flux moisture migration. Models aimed dynamics have successfully predicted macroscopic processes ice, such as rigid segregation model, used developed. However, some difficulties theoretical basis microscope physics still need study. Besides, how lens landscape another interesting challenge that helps understand interaction between environment. final this review, concerns overlooked current research summarized should be central focus future

Language: Английский

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Effect of freeze–thaw process on heat transfer and water migration between soil water and groundwater

Journal of Hydrology, Journal Year: 2022, Volume and Issue: 617, P. 128987 - 128987

Published: Dec. 16, 2022

Language: Английский

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Miscellaneous methods for determination of unfrozen water content in frozen soils

Journal of Hydrology, Journal Year: 2024, Volume and Issue: 631, P. 130802 - 130802

Published: Jan. 28, 2024

Language: Английский

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A Novel Heat Pulse Method in Determining “Effective” Thermal Properties in Frozen Soil

Water Resources Research, Journal Year: 2024, Volume and Issue: 60(12)

Published: Dec. 1, 2024

Abstract Accurate and fast measurements of thermal properties are frequently required for characterizing the heat‐water dynamics in frozen soil. Measuring soil without inducing ice thaw has proven challenging with conventional heat pulse (HP) methods. In this study, based on an Infinite Line Source (ILS) semi‐analytical model that applies a constant temperature lower than freezing point at source to prevent initiation soil, we propose novel HP‐based approach measure properties, applicable temperatures below or above 0°C. Laboratory experiments numerical modeling were utilized validate applicability optimization strategies measurement. We found proposed effectively maintained maximum spatial therefore estimated bulk quartz sand contents. An optimized measurement strategy was monitor variations 2–4 cm away from center probe after 60 s. This progress can largely facilitate determination multi‐phase ‐component such as conductivity, flux, content cold areas across science, hydrology, engineering, climate science.

Language: Английский

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A theoretical model for estimating the thermal conductivity of granular geomaterials with low porosity

International Communications in Heat and Mass Transfer, Journal Year: 2024, Volume and Issue: 152, P. 107230 - 107230

Published: Jan. 16, 2024

Language: Английский

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Impact of snow thermal conductivity schemes on pan-Arctic permafrost dynamics in the Community Land Model version 5.0

˜The œcryosphere, Journal Year: 2025, Volume and Issue: 19(4), P. 1539 - 1558

Published: April 14, 2025

Abstract. The precise magnitude and timing of permafrost-thaw-related emissions their subsequent impact on the global climate system remain highly uncertain. This uncertainty stems from complex quantification rate extent permafrost thaw, which is influenced by factors such as snow cover other surface properties. Acting a thermal insulator, directly influences energy fluxes can significantly regime. However, current Earth models often inadequately represent nuanced effects in regions, leading to inaccuracies simulating soil temperatures dynamics. Notably, Community Land Model (CLM5.0) tends overestimate snowpack conductivity over resulting an underestimation insulating capacity. Using scheme better adapted for typically found we seek resolve insulation assess influence simulated Evaluation using two Arctic-wide temperature observation datasets reveals that new reduces cold-soil bias (root-mean-square error, RMSE = 3.17 2.4 °C, remote sensing data; 3.9 2.19 situ data), demonstrates robustness through sensitivity analysis under lower tundra densities, addresses overestimation default CLM5.0. improvement highlights importance incorporating realistic processes land enhanced predictions dynamics response change.

Language: Английский

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Evaluation of soil thermal conductivity schemes incorporated into CLM5.0 in permafrost regions on the Tibetan Plateau

Geoderma, Journal Year: 2021, Volume and Issue: 401, P. 115330 - 115330

Published: July 15, 2021

Language: Английский

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Comparative analysis of seven machine learning algorithms and five empirical models to estimate soil thermal conductivity

Agricultural and Forest Meteorology, Journal Year: 2022, Volume and Issue: 323, P. 109080 - 109080

Published: July 13, 2022

Language: Английский

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