Effects of Soil Moisture on Simulated Methane Flow Under Varying Levels of Soil Compaction

Publikation: Bidrag til bog/antologi/rapportKonferencebidrag i proceedingsForskningfagfællebedømt

  • M. M.T. Lakshani
  • T. K.K.C. Deepagoda
  • T. J. Clough
  • J. R.R.N. Jayarathne
  • S. Thomas
  • N. Balaine
  • Elberling, Bo
  • K. Smits

Soil density plays an important role in regulating the migration of greenhouse gases from terrestrial soils to the atmosphere. Soil moisture is one of the main soil physical controls determining the fate and transport of gases in soils. This study investigated the transport of methane (CH4) originating from a simulated CH4 source within a variably compacted pasture soil. Simulations were carried out for dry and variably saturated soils. Steady-state methane flow was simulated as a density-dependent, multiphase flow considering a multicomponent mixture of CH4, water vapor and air, under different soil moisture conditions. We used measured soil–water characteristic (SWC) and gas diffusivity data at five density levels (1.1, 1.2, 1.3, 1.4, and 1.5 Mg m−3) to parameterize predictive models. Permeability was estimated using an existing SWC-based saturated hydraulic conductivity function. Results show a distinct effect of soil density on CH4 concentration profiles within the soil. Clear effects of soil moisture on CH4 transport could also be seen in differentially compacted soils. Relatively smaller CH4 concentrations were observed in dry soils where permeability, gas diffusivity, and air-filled porosity were higher. With increasing density, the profile-accumulated concentrations >0.3% increased up to 200 times under the dry condition. In moist soils, on the other hand, smaller air-filled porosity and higher moisture-controlled tortuosity resulted in reduced permeability and gas diffusivity, yielding high CH4 concentrations in the soil profile with only a maximum fivefold increase in the accumulated concentration with increasing density.

OriginalsprogEngelsk
Titel12th International Conference on Structural Engineering and Construction Management - Proceedings of the ICSECM 2021
RedaktørerRanjith Dissanayake, Priyan Mendis, Kolita Weerasekera, Sudhira De Silva, Shiromal Fernando, Chaminda Konthesingha
Antal sider12
ForlagSpringer Science and Business Media Deutschland GmbH
Publikationsdato2023
Sider271-282
ISBN (Trykt)9789811928857
DOI
StatusUdgivet - 2023
Begivenhed12th International Conference on Structural Engineering and Construction Management, ICSECM 2021 - Kandy, Sri Lanka
Varighed: 18 dec. 202119 dec. 2021

Konference

Konference12th International Conference on Structural Engineering and Construction Management, ICSECM 2021
LandSri Lanka
ByKandy
Periode18/12/202119/12/2021
NavnLecture Notes in Civil Engineering
Vol/bind266
ISSN2366-2557

Bibliografisk note

Funding Information:
We gratefully acknowledge the funding from the Asia-Pacific Network for Global Change Research (APN) grant (CRRP2020-07MY-Deepagoda). The New Zealand Government and New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) under the Livestock Emissions and Abatement Research Network (LEARN) are also acknowledged.

Funding Information:
Acknowledgements We gratefully acknowledge the funding from the Asia-Pacific Network for Global Change Research (APN) grant (CRRP2020-07MY-Deepagoda). The New Zealand Government and New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) under the Livestock Emissions and Abatement Research Network (LEARN) are also acknowledged.

Publisher Copyright:
© 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

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