Characterizing subsidence in used and restored peatland with Sentinel SAR data

Abstract

Peatland is a fragile ecosystem in the tropical region which is prone to subsidence. Until now, there is still lack of procedure to rapidly assess a tropical peatland subsidence in a large area. Our objective was to compare subsidence in a used and restored zone in a peatland hydrological unit using synthetic aperture radar data from Sentinel-1A products (SAR data) in South Sumatra, Indonesia from the period of 2014–2021. The subsidence rate of used peatland estimated by the D-InSAR procedure were in the range of 28–80 cm year−1 in the early period of its utilization and becoming less for the consecutive year (16–48 cm year−1). Meanwhile, the subsidence rate based on the field surveys was in the range of 4–50 cm year−1 in the early period of peatland utilization. The subsidence rate in the used peatland zone (agriculture and plantations) was higher than that in the restoration zone for all SAR data pairs used in our study. The SAR data is a potential tool for the assessment, monitoring and differentiating subsidence rates among different peatland uses in a large area. This tool will help the Directorate of Peat Ecosystem Degradation Control, Directorate General of Environmental Pollution and Degradation Control, and Ministry of Environment and Forestry to plan for better peatland management and restoration.