Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)

Knowledge on peat volumes is essential to estimate carbon stocks accurately and to facilitate appropriate peatland management. This study used airborne electromagnetic and radiometric data to estimate the volume of a bog. Airborne methods provide an alternative to ground-based methods, which are lab...

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Main Authors: Bernhard Siemon, Malte Ibs-von Seht, Stefan Frank
Format: Article
Language:English
Published: MDPI AG 2020-01-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/12/2/203
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author Bernhard Siemon
Malte Ibs-von Seht
Stefan Frank
author_facet Bernhard Siemon
Malte Ibs-von Seht
Stefan Frank
author_sort Bernhard Siemon
collection DOAJ
description Knowledge on peat volumes is essential to estimate carbon stocks accurately and to facilitate appropriate peatland management. This study used airborne electromagnetic and radiometric data to estimate the volume of a bog. Airborne methods provide an alternative to ground-based methods, which are labor intensive and unfeasible to capture large-scale (&gt;10 km<sup>2</sup>) spatial information. An airborne geophysical survey conducted in 2004 covered large parts of the Ahlen-Falkenberger Moor, an Atlantic peat bog (39 km<sup>2</sup>) close to the German North Sea coast. The lateral extent of the bog was derived from low radiometric and elevated surface data. The vertical extent resulted from smooth resistivity models derived from 1D inversion of airborne electromagnetic data, in combination with a steepest gradient approach, which indicated the base of the less resistive peat. Relative peat thicknesses were also derived from decreasing radiation over peatlands. The scaling factor (&#181;<sub>a</sub> = 0.28 m<sup>&#8722;1</sup>) required to transform the exposure rates (negative log-values) to thicknesses was calculated using the electromagnetic results as reference. The mean difference of combined airborne results and peat thicknesses of about 100 boreholes is very small (0.0 &#177; 1.1 m). Although locally some (5%) deviations (&gt;2 m) from the borehole results do occur, the approach presented here enables fast peat volume mapping of large areas without an imperative necessity of borehole data.
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spelling doaj.art-074852aadf8d4beeae52f5b2fa9cd8472022-12-22T04:15:01ZengMDPI AGRemote Sensing2072-42922020-01-0112220310.3390/rs12020203rs12020203Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)Bernhard Siemon0Malte Ibs-von Seht1Stefan Frank2Federal Institute for Geosciences and Natural Resources (BGR), 30655 Hannover, GermanyFederal Institute for Geosciences and Natural Resources (BGR), 30655 Hannover, GermanyState Authority for Mining, Energy and Geology (LBEG), 30655 Hannover, GermanyKnowledge on peat volumes is essential to estimate carbon stocks accurately and to facilitate appropriate peatland management. This study used airborne electromagnetic and radiometric data to estimate the volume of a bog. Airborne methods provide an alternative to ground-based methods, which are labor intensive and unfeasible to capture large-scale (&gt;10 km<sup>2</sup>) spatial information. An airborne geophysical survey conducted in 2004 covered large parts of the Ahlen-Falkenberger Moor, an Atlantic peat bog (39 km<sup>2</sup>) close to the German North Sea coast. The lateral extent of the bog was derived from low radiometric and elevated surface data. The vertical extent resulted from smooth resistivity models derived from 1D inversion of airborne electromagnetic data, in combination with a steepest gradient approach, which indicated the base of the less resistive peat. Relative peat thicknesses were also derived from decreasing radiation over peatlands. The scaling factor (&#181;<sub>a</sub> = 0.28 m<sup>&#8722;1</sup>) required to transform the exposure rates (negative log-values) to thicknesses was calculated using the electromagnetic results as reference. The mean difference of combined airborne results and peat thicknesses of about 100 boreholes is very small (0.0 &#177; 1.1 m). Although locally some (5%) deviations (&gt;2 m) from the borehole results do occur, the approach presented here enables fast peat volume mapping of large areas without an imperative necessity of borehole data.https://www.mdpi.com/2072-4292/12/2/203peatlandbogfenpeat thicknessvolume mappingairborne electromagnetic surveyairborne gamma-ray surveyem inversion
spellingShingle Bernhard Siemon
Malte Ibs-von Seht
Stefan Frank
Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
Remote Sensing
peatland
bog
fen
peat thickness
volume mapping
airborne electromagnetic survey
airborne gamma-ray survey
em inversion
title Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
title_full Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
title_fullStr Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
title_full_unstemmed Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
title_short Airborne Electromagnetic and Radiometric Peat Thickness Mapping of a Bog in Northwest Germany (Ahlen-Falkenberger Moor)
title_sort airborne electromagnetic and radiometric peat thickness mapping of a bog in northwest germany ahlen falkenberger moor
topic peatland
bog
fen
peat thickness
volume mapping
airborne electromagnetic survey
airborne gamma-ray survey
em inversion
url https://www.mdpi.com/2072-4292/12/2/203
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