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Record W4379531583 · doi:10.1061/jhtrbp.hzeng-1226

A Field-Verified Model to Estimate Landfill Methane Flux Using Surface Methane Concentration Measurements under Calm Wind Conditions

2023· article· en· W4379531583 on OpenAlexaff
Hiroshan Hettiarachchi, Erfan Irandoost, J. Patrick A. Hettiaratchi, Dinesh Pokhrel

Bibliographic record

VenueJournal of Hazardous Toxic and Radioactive Waste · 2023
Typearticle
Languageen
FieldEnvironmental Science
TopicLandfill Environmental Impact Studies
Canadian institutionsUniversity of Calgary
Fundersnot available
KeywordsMethaneFugitive emissionsGreenhouse gasFlux (metallurgy)Environmental scienceContext (archaeology)Landfill gasEnvironmental engineeringSoil scienceMethane gasAtmospheric sciencesChemistryGeology

Abstract

fetched live from OpenAlex

A significant portion of anthropogenic greenhouse gas emissions––that are suspected of contributing to global warming––are emitted from landfills accepting biodegradable organic waste. Thus, the assessment of fugitive methane emissions from landfill surfaces has become an important and integral part of determining the overall carbon budgets of individual countries. Quantifying fugitive methane emissions from landfills using indirect methods, such as predictive mathematical models, which has been the norm for a long time, have proven to be ineffective for current needs. In recent years, attention has shifted to direct measurements, such as the flux chamber method, which is also costly and labor intensive, considering the vast areas covered by landfill surfaces. However, collecting surface methane concentration (SMC) data through an instantaneous emission measurement technique is relatively simple and inexpensive. Although the SMC is only a qualitative indicator of the methane flux of a landfill, recent literature on this topic has pointed to a potentially strong correlation between SMCs and methane flux. In this context, establishing a simple but robust model, capable of estimating methane surface flux using SMC values, was the primary aim of the research described here. In this study, we investigated the correlation between SMCs and methane flux across the soil–atmosphere boundary in a small-scale test cell under a partially controlled environment. The data collected from the test cell were used to propose a linear regression model that suggested that the methane flux under calm wind conditions could be simply predicted as 1.264 times the SMC. This model was then verified in a field lysimeter, which consisted of material similar to what is found in a landfill biocover. The model was able to predict the methane flux at the field lysimeter with an absolute average error of 40%. This error margin is quite reasonable because, as per the literature, error margins as high as 190% are not uncommon in estimating the methane flux at landfills using other commonly adopted methods.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.278
Threshold uncertainty score0.683

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.054
GPT teacher head0.327
Teacher spread0.273 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designBench or experimental
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations3
Published2023
Admission routes1
Has abstractyes

Explore more

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