Evaluation of Ground-Based Spectral Imaging Capabilities for Detecting and Quantifying Landfill Methane Emissions

Methane (CH₄) is the second most important anthropogenic greenhouse gas, contributing significantly to climate change. Landfills are major anthropogenic sources of methane, but these emissions are subject to significant uncertainty. Due to their substantial mitigation potential, accurate and independent detection and quantification of landfill methane emissions is vital for assessing emission mitigation efforts. This thesis evaluates the capabilities of ground-based spectral imaging for detecting and quantifying the methane emissions of the Pinto landfill near Madrid, Spain. The Pinto landfill is one of the landfills with the largest methane emissions in Europe. Over the course of two weeks in the summer of 2024, hyperspectral images were collected from a distance of 2 km to 7 km and with a scanning frequency of approximately one minute. A matched filter was used to retrieve methane column enhancements from the 2.3-µm spectral region of these observations. Various matched filters were compared, and the lognormal matched filter (LMF) was found to perform best. Therefore, it was used for all retrievals in this thesis. Diffuse enhanced methane concentrations were detected over the landfill on both days analyzed, with concentrations decreasing with altitude and increasing throughout the day. The hot and dry summer climate in Madrid causes a lot of dust in the atmosphere. Dust clouds shorten the light path and thus appear as negative methane enhancements, affecting the amount of detected methane in an image. Observing the movement of a dust cloud enables the calculation of the transport wind velocity. A one-box model was used to derive emission rates using wind data from a co-deployed wind lidar. There is a strong correlation between the emission rates and the wind velocity, indicating that the short-term emission rate variability stems from the wind variability and suggesting inaccuracies in the model. Temporally averaged emission rates range from 1 t/h to 5 t/h and are of the same order of magnitude as those found in previous studies and as those listed in emission registers, although uncertainties remain high.

Level thesis:degree_level

master

Grantor dc:publisher

Universität Heidelberg

Year

2025

Author dc:creator

• Resch, Lennart

Contributors dc:contributor

• Butz, André

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/37764

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:37764