Characterization and prediction of methane spatial heterogeneity within and beyond a flux tower footprint
department or school: Arts, Faculty of
department or school: Geography, Department of
data provider: DSpace
degree campus: UBCV
creator: Ng, Darian Chi Yung
issued: 2023-08-21T21:09:02Z
issued: 2023
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Freshwater wetlands are effective nature-based solutions to climate change for their unique ability to sequester atmospheric carbon for extended periods of time. However, they simultaneously emit large amounts of methane gas (CH₄). CH₄ is a highly potent greenhouse gas, and its spatial heterogeneity in wetlands is not yet fully understood. This study is the first of its kind and explores a novel approach to characterizing and predicting the spatial distribution of CH₄ fluxes (FCH₄) within a single flux tower footprint using a combination of remote-sensing via the Landsat 8 satellite and eddy covariance (EC) Footprint-weighted Flux Maps. There were two research objectives: 1) to determine whether there exist significant relationships correlating remote-sensing with within-footprint FCH₄, and 2) to investigate the potential of extrapolating and upscaling these relationships to predict FCH₄ beyond the flux tower. The Normalized Difference Vegetation Index (NDVI), Water Index (NDWI), Moisture Index (NDMI), and Land Surface Temperature (LST) remote-sensing products were collected from Landsat 8, and EC data from four wetland sites, MBPPW1, MBPPW2, US-Myb, and US-WPT were used for the Flux Maps. Hierarchical clustering was used on the Flux Maps to identify distinct FCH₄ features, and then applied to Landsat 8 to process the data for use in two stages of regression analysis. The first stage used simple linear regression to assess the relationships between FCH₄ and the four remote-sensing indices. The second stage used multiple linear regression (MLR) to model the spatial distribution of FCH₄. The simple linear regression analysis demonstrated strong relationships between remotely-sensed surface conditions and FCH₄, and found stronger FCH₄ from open water at MBPPW2 and US-WPT, and stronger FCH₄ from the emergent vegetation at US-Myb. MBPPW1 demonstrated a limitation of this approach requiring sites to have strong FCH₄ signals. The MLR models supported the feasibility of ups…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/85560
note: CHARACTERIZATION AND PREDICTION OF METHANE SPATIAL HETEROGENEITY WITHIN AND BEYOND A FLUX TOWER FOOTPRINT by Darian Chi Yung Ng B.Sc., The University of British Columbia A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Geography) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2023 © Darian Chi Yung Ng, 2023 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Characterization and prediction of methane spatial heterogeneity within and beyond the flux tower footprint. Submitted by Darian Chi Yung Ng in partial fulfillment of the requirements for the degree of Master of Science in Geography Examining Committee: Dr. Sara Knox, Assistant Professor, Geography, UBC Co-supervisor Dr. T. Andrew Black, Professor, Land and Food Systems, UBC Co-supervisor Dr. Camilo Rey-Sanchez, Assistant Professor, Marine Earth and Atmospheric Sciences, North Carolina State University Supervisory Committee Member Dr. Brett Eaton, Professor, Geography, UBC Additional Examiner iii Abstract Freshwater wetlands are effective nature-based solutions to climate change for their unique ability to sequester atmospheric carbon for extended periods of time. However, they simultaneously emit large amounts of methane gas (CH4). CH4 is a highly potent greenhouse gas, and its spatial heterogeneity in wetlands is not yet fully understood. This study is the first of its kind and explores a novel approach to characterizing and predicting the spatial distribution of CH4 fluxes (FCH4) within a single flux tower footprint using a combination of remote-sensing via the Landsat 8 satellite and eddy covariance (EC) Footprint-weighted Flux Maps. There were two research objectives: 1) to determine whether there exist significant relationships correlating remote-sensing with within-footprint FCH4, and 2) to …
has type: Thesis/Dissertation
date issued: 2023-11
is shown at: 10.14288/1.0435517
language: eng
degree discipline: Geography
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Knox, Sara
contributor: Black, T. Andrew
type: Text
identifier URI: http://hdl.handle.net/2429/85560