High-Resolution Classification of South Patagonian Peat Bog Microforms Reveals Potential Gaps in Up-Scaled CH4 Fluxes by use of Unmanned Aerial System (UAS) and CIR Imagery

South Patagonian peat bogs are little studied sources of methane (CH4). Since CH4 fluxes can vary greatly on a small scale of meters, high-quality maps are needed to accurately quantify CH4 fluxes from bogs. We used high-resolution color infrared (CIR) images captured by an Unmanned Aerial System (U...

Authors: Lehmann, Jan Rudolf Karl
Münchberger, Wiebke
Knoth, Christian
Blodau, Christian
Nieberding, Felix
Prinz, Torsten
Pancotto, Verónica A.
Kleinebecker, Till
Division/Institute:FB 14: Geowissenschaften
Document types:Article
Media types:Text
Publication date:2016
Date of publication on miami:01.06.2016
Modification date:16.04.2019
Edition statement:[Electronic ed.]
Source:Remote Sending 8 (2016) 3, 173, 1-19
Subjects:closed chamber; object-based image analysis; OBIA classification; methane; peatland; RPAS; UAV
DDC Subject:550: Geowissenschaften, Geologie
License:CC BY 4.0
Language:English
Notes:Finanziert durch den Open-Access-Publikationsfonds 2015/2016 der Westfälischen Wilhelms-Universität Münster (WWU Münster).
Format:PDF document
ISSN:2072-4292
URN:urn:nbn:de:hbz:6-95279681708
Permalink:http://nbn-resolving.de/urn:nbn:de:hbz:6-95279681708
Other Identifiers:DOI: 10.3390/rs8030173
Digital documents:remotesensing-08-00173.pdf

South Patagonian peat bogs are little studied sources of methane (CH4). Since CH4 fluxes can vary greatly on a small scale of meters, high-quality maps are needed to accurately quantify CH4 fluxes from bogs. We used high-resolution color infrared (CIR) images captured by an Unmanned Aerial System (UAS) to investigate potential uncertainties in total ecosystem CH4 fluxes introduced by the classification of the surface area. An object-based approach was used to classify vegetation both on species and microform level. We achieved an overall Kappa Index of Agreement (KIA) of 0.90 for the species- and 0.83 for the microform-level classification, respectively. CH4 fluxes were determined by closed chamber measurements on four predominant microforms of the studied bog. Both classification approaches were employed to up-scale CH4 closed chamber measurements in a total area of around 1.8 hectares. Including proportions of the surface area where no chamber measurements were conducted, we estimated a potential uncertainty in ecosystem CH4 fluxes introduced by the classification of the surface area. This potential uncertainty ranged from 14.2 mg·m−2·day−1 to 26.8 mg·m−2·day−1. Our results show that a simple classification with only few classes potentially leads to pronounced bias in total ecosystem CH4 fluxes when plot-scale fluxes are up-scaled.