Integration of Multi-Gas Sensors and Aerial Thermography Into UAVs for Environmental Monitoring of a Landfill

Landfills are a significant source of atmospheric emissions associated with the decomposition of organic waste; however, conventional monitoring methods typically have limited spatial coverage. This study evaluated the use of a UAV-based system for the spatial characterization of gases associated with biogas emissions at a municipal landfill. A DJI Matrice 350 RTK platform equipped with a Sniffer4D Mini2 multigass station and a Zenmuse H20T thermal camera was used. Four flight campaigns were conducted at a height of 20 m, with an acquisition frequency of approximately 1 Hz, recording CxHy as an indirect indicator of CH₄, as well as CO₂, CO, NO₂, O₃, SO₂, O₂, temperature, and relative humidity. The results showed a marked transition around 13:10 h, characterized by a simultaneous increase in CH₄ equivalent and CO₂, along with a decrease in NO₂, O₃, and SO₂. Furthermore, CH₄ equivalent and CO₂ exhibited the highest positive correlation among the variables (r = 0.96). The maps obtained using ordinary kriging revealed more heterogeneous patterns, while the qualitative thermal orthophoto confirmed the site’s surface variability. Taken together, the results demonstrate that the integration of multigass sensors and aerial thermography on UAVs is viable for the spatial monitoring of landfills.