Mapping Peat Thickness Using a Portable Gamma-Ray Sensor

Activity: Talk or presentation typesLecture and oral contribution

Description

Peatlands being excellent storage for terrestrial Carbon (C) play a crucial role in regulating climate and water and provide several important ecosystem services. Over the years, peatlands are heavily altered particularly by draining the water table for meeting energy and agricultural needs. This led to increased release of greenhouse gases (GHGs) into the atmosphere and dissolved C loss contaminating potable water. Climate change concerns have sparked interest in reducing the emission of GHGs from drained and degraded peatlands to counteract global warming. Comprehensive characterization of peat inventory providing details on the spatial extent, thickness, and water table depth is required to estimate the C stocks – for climate budgeting, improved land use planning and deciding appropriate management strategies. The conventional handheld probing for peat depth (PD) determination is labour-intensive and provides only localized and discrete measurements. Besides, these measurements can be inaccurate at times necessitating the evaluation of rapid alternative methods. Gamma-ray radiometric in general showed promise for delineating the spatial extent of peatlands. However, the use of this technique for estimating PD remains questionable as earlier studies made use of readily available airborne datasets of a coarser resolution. With technological advances, portable gamma-ray spectrometers that can provide on-the-go measurements of radionuclide concentrations are finding new applications in soil mapping. Given this, here, we explored the suitability of such a gamma-ray sensor for mapping PD at a highly variable (0 – 7.3 m) peatland area in Denmark. Further, we tested the suitability of different processing methods and evaluated the support extended by the readily available terrain attributes. Our results suggest that gamma-ray sensing can stand alone potentially predict the PD down to 4 m, beyond which other covariates can supplement in improving the prediction accuracy.
Period8 Feb 2023
Event titleSoil Mapping for a Sustainable Future - 2nd joint Workshop of IUSS
Event typeConference
LocationOrleans, FranceShow on map
Degree of RecognitionInternational