In:
SOIL, Copernicus GmbH, Vol. 8, No. 2 ( 2022-12-07), p. 733-749
Abstract:
Abstract. To meet the sustainable development goals and enable sustainable
management and protection of peatlands, there is a strong need for improving
the mapping of peatlands. Here we present a novel approach to identify peat
soils based on a high-resolution digital soil moisture map that was produced
by combining airborne laser scanning-derived terrain indices and machine
learning to model soil moisture at 2 m spatial resolution across the Swedish
landscape. As soil moisture is a key factor in peat formation, we fitted an
empirical relationship between the thickness of the organic layer (measured
at 5479 soil plots across the country) and the continuous SLU (Swedish University of Agricultural Science) soil moisture
map (R2= 0.66, p 〈 0.001). We generated categorical maps of
peat occurrence using three different definitions of peat (30, 40, and 50 cm
thickness of the organic layer) and a continuous map of organic layer
thickness. The predicted peat maps had a higher overall quality (MCC = 0.69–0.73) compared to traditional Quaternary deposits maps (MCC = 0.65)
and topographical maps (MCC = 0.61) and captured the peatlands with a
recall of ca. 80 % compared to 50 %–70 % on the traditional maps. The
predicted peat maps identified more peatland area than previous maps, and
the areal coverage estimates fell within the same order as upscaling
estimates from national field surveys. Our method was able to identify
smaller peatlands resulting in more accurate maps of peat soils, which was
not restricted to only large peatlands that can be visually detected from
aerial imagery – the historical approach of mapping. We also provided a
continuous map of the organic layer, which ranged 6–88 cm organic layer
thickness, with an R2 of 0.67 and RMSE (root mean square error) of 19 cm. The continuous map
exhibits a smooth transition of organic layers from mineral soil to peat
soils and likely provides a more natural representation of the distribution
of soils. The continuous map also provides an intuitive uncertainty estimate
in the delineation of peat soils, critically useful for sustainable spatial
planning, e.g., greenhouse gas or biodiversity inventories and landscape
ecological research.
Type of Medium:
Online Resource
ISSN:
2199-398X
DOI:
10.5194/soil-8-733-2022
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2834892-8
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