Monitoring tropical peat related settlement using ISBAS InSAR, Kuala Lumpur International Airport (KLIA)

Abstract

Rapid population growth in South-East Asia has placed immense pressure upon lowland regions both to supply food and employment and space for residential, commercial and infrastructure development. This pressure has led to sites on tropical peatland previously considered unsuitable for development to be revisited. One such site, the KLIA2 terminal and runway, Kuala Lumpur International Airport which opened in May 2014 at a cost of 3.6 billion MYR has been beset by well documented subsidence problems. Coverage of the tropics by the Sentinel-1 satellite constellation presents an opportunity to monitor the ongoing subsidence at KLIA 2, identify potential knowledge gaps and help inform more sustainable infrastructure development in tropical peatland regions. Our results show that the ISBAS InSAR method produces reproducible ground deformation maps which can clearly identify the patterns of deformation across both urban infrastructure and adjacent rural plantations and tropical peat swamp. This is particularly well defined around the terminal building at KLIA-2 where different ground preparation and foundation design have resulted in stable terminal buildings and subsidence of surrounding pavement. Deformation is greatest in the runway area where alternate bands of uplift and subsidence presumably accompany the greatest loads associated with landing aircraft. In contrast, areas where peat replacement was the primary form of ground preparation, ground motion is stable, however this comes at high economic and environmental cost.

National geohazards mapping in Europe: Interferometric analysis of the Netherlands

“…Examples of such projects include ESA-Terrafirma (2003 -2012) (Adam et al, 2009), EU-FP7-Subcoast (2010 -2013) (Gruijters & van der Krogt, 2013), EU-FP7-PanGeo (2011 -2014) (Capes, 2012) and EU-FP7-PROTHEGO (2015 -2018) (Themistocleous et al, 2016). Satellite-based interferometric synthetic aperture radar (InSAR) has played a central role in all of these projects as it is capable of measuring and monitoring a wide range of geohazards including landslides (Bayer et al, 2017), tectonics (Colesanti et al, 2003) and volcanology (Hooper et al, 2004), in addition to ground motion associated with anthropogenic activity such as oil and gas operations (Castelletto et al, 2013), carbon capture and storage (Rohmer et al, 2015), mining (Gee et al, 2017), civil engineering works (Marshall et al, 2018) and groundwater abstraction (Boni et al, 2015).…”

InSAR Time Series Analysis of L-Band Data for Understanding Tropical Peatland Degradation and Restoration

“…The potential of InSAR to measure peat height changes has been explored [20][21][22][23][24][25][26][27]. For example, in 2011, using four scenes of European Remote Sensing (ERS, C-band) tandem pairs (1 day interval) from October 1997 to January 2000 and the four-pass (four SAR images) InSAR method, a subsidence rate of 2 cm/year was estimated for Central Kalimantan, Indonesia [21].…”

“…Using Intermittent Small Baseline Subset (ISBAS) DInSAR algorithm, ERS C-band images (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000) and Sentinel-1 C-band (2015-2016), Alshammari et al, [25] detected subsidence and uplift change over peatland areas in the northeast of Scotland, UK. Using 161 Sentinel-1 SAR (C-band) images and ISBAS method, Marshall et al, [24] also measured the deformation patterns of tropical peat swamp around Kuala Lumpur International Airport. Fiaschi et al, [32] detected uplift signal of up to 8.9 mm/year and subsidence signal of up to −11.6 mm/year in Irish peatlands by using 124 Sentinel-1A/B images acquired from 4 May 2015 to 1 March 2018 and PS-InSAR method.…”

“…Fiaschi et al, [32] detected uplift signal of up to 8.9 mm/year and subsidence signal of up to −11.6 mm/year in Irish peatlands by using 124 Sentinel-1A/B images acquired from 4 May 2015 to 1 March 2018 and PS-InSAR method. Although, C-band shows potential in measuring peatlands surface motion, it is likely hard to extract sufficient number of PS points and provide good coverage, particularly over a tropical peatlands area [24]. So far, the application of L-band data and InSAR time series methods for understanding peatlands degradation and restoration in tropical zone is rarely documented in peer-reviewed scientific literature.…”

A Novel Low-Cost, High-Resolution Camera System for Measuring Peat Subsidence and Water Table Dynamics

“…Evidence that peat vertical motion is related to climate and management raises the possibility that it could be used as an effective, and easily measured, proxy for key metrics of peat condition such as water table depth (WTD) and carbon balance, as well as a tool for evaluating restoration outcomes. A number of recent studies have also suggested that this surface motion can be detected remotely using Interferometric Synthetic Aperture Radar (InSAR) data from satellites such as the European Space Agency's Sentinel-1 mission, and the Japan Aerospace Exploration Agency's Advanced Land Observation Satellite-1 (ALOS-1) (Alshammari et al, 2018;Fiaschi et al, 2019;Marshall et al, 2018;Susanti and Anjasmara, 2019;Zhou et al, 2019;Hoyt et al, 2020). This approach offers clear advantages in terms of the cost, spatial scale and frequency at which information can be obtained, especially for large and remote peatland areas.…”