Lessons learned from a UAV survey and methane emissions calculation at a UK landfill

Area of Science:

• Environmental Science
• Atmospheric Science
• Geospatial Analysis

Background:

• Accurate methane emission quantification from landfills is vital for greenhouse gas inventories and climate change mitigation.
• Traditional methods (e.g., gas production models, manual measurements) suffer from significant uncertainties and high costs.
• Bridging this gap requires innovative, cost-effective, and accurate measurement techniques.

Purpose of the Study:

• To evaluate the challenges and applicability of the Unmanned Aerial Vehicle (UAV)-based mass balance method for quantifying methane emissions from a large, heterogeneous landfill source.
• To provide guidance on key methodological aspects, including background methane concentration, data interpolation, and sampling strategies.
• To assess the feasibility of UAV-based wind measurements and emission plume characterization.

Main Methods:

• A case study was conducted at a landfill site in Bury, Manchester, UK, during summer 2022.
• Unmanned Aerial Vehicles (UAVs) equipped with methane and wind sensors were utilized for site surveys.
• The UAV-based mass balance method was applied to quantify methane flux, considering background concentrations and plume characteristics.

Main Results:

• The study quantified methane flux from the landfill site at 150.7 kg h⁻¹.
• A 1 standard deviation uncertainty range of 83.0 kg h⁻¹ to 209.5 kg h⁻¹ was determined for the methane flux.
• Challenges related to UAV wind measurements and spatial characterization of emission plumes were addressed.

Conclusions:

• The UAV-based mass balance method shows promise for accurate landfill methane emission quantification, despite inherent challenges.
• Methodological guidance is provided for optimizing UAV surveys, including background concentration definition and sampling strategies.
• This research contributes to improving greenhouse gas inventories and informing climate change mitigation strategies through enhanced methane emission monitoring.