• Beucher, Amelie Marie
• Greve, Mogens Humlekrog
• Adetsu, Diana Vigah
• Koganti, Triven

Abstract

Peatlands are important Carbon (C) reserves and they provide a wide range of ecosystem services.Over the years, draining their water table to meet energy and agricultural needs has led to increased release of greenhouse gases (GHGs) and dissolved C loss contaminating potable water, thus turning them into C-sources. Globally, different initiatives are put forward to safeguard, properly manage, and restore the peatlands to reduce GHG emissions and enhance C sequestration. However, a comprehensive characterization of peat inventory providing details on the spatial extent, thickness, and water table levels is required to accomplish this. The conventional methods involving handheld probes and boreholes are labor-intensive and provide only localized and discrete measurements. Proximal soil sensing methods provide an effective alternative solution. In Denmark, we are testing the suitability of electromagnetic induction (EMI), ground penetrating radar (GPR), and gamma ray radiometric on-the-go methods across a variety of peatland types, especially for estimating peat thickness. Electrical resistance tomography is being used along dedicated transects for controlled experiments. While EMI proved superior in a minerotrophic fen, GPR provided unequivocal results in an ombrotrophic bog. Gamma-ray sensing is not only suitable for delineating the peatland boundaries but can provide insights into the peat thickness gradient. Our results suggest that no single technique is a silver bullet and the sensor choice should be based on the knowledge of the peatland type. If unsure, we recommend performing EMI surveys ahead of GPR surveys for optimal cost benefit. This is because EMI can also be very useful in predicting the GPR success rate. Future work entails developing fully drone-borne sensors for improving scale and accessibility.

Topics

• impedance spectroscopy
• Carbon
• silver
• experiment
• tomography