Understanding geological evolution of chalk cliffs and coastal processes using InSAR
File(s)
Author(s)
Mider, Malgorzata
Type
Thesis
Abstract
A tenth of the world’s population lives in coastal zones (Evans, 2004), where human activity and rising global sea levels intensify the erosion and flooding. To enable the coastal area to remain viable for human use, reliable and repeatable methods of monitoring are necessary, along with better understanding of geological processes that can be encountered in such areas. Current monitoring methods are often expensive, requiring specialist equipment, which can prove problematic when trying to gain access to the coast, work can be weather and/or tide dependant.
Space-borne Synthetic Aperture Radar Interferometry (InSAR) is increasingly used to monitor ground motions related to natural and anthropogenic geohazards with up to millimetre accuracy. The European Space Agency (ESA) satellites, Sentinel-1A and 1B, provide freely available detailed data with repeat time of 6 days.
The aim of this research was to investigate and understand use of InSAR data for monitoring and analysis of geological processes affecting coastal zones. The focus of the research is downwearing and erosion of the shoreline, cliff collapse and rotational landslides. Permanent Scatterer Interferometry (PSI) technique was used on Sentinel-1 data to measure surface deformation and relate to these coastal processes and mechanisms.
The UK chalk coast was selected for the research sites, the results show that identifying evidence of vertical cliff collapses was very challenging and the results were inconclusive, mainly due to the vegetation present, leading to a loss of coherence. Platform downwearing can be successfully monitored both at a local and regional scale, and large scale coastal, rotational landslides can also be successfully monitored. This has been performed to sub-millimetre accuracy and allowed for the natural processes to be interpreted.
The effectiveness of the PSI methodology as a monitoring tool for coastal environments has been shown, especially when coupled with conventional monitoring methods.
Space-borne Synthetic Aperture Radar Interferometry (InSAR) is increasingly used to monitor ground motions related to natural and anthropogenic geohazards with up to millimetre accuracy. The European Space Agency (ESA) satellites, Sentinel-1A and 1B, provide freely available detailed data with repeat time of 6 days.
The aim of this research was to investigate and understand use of InSAR data for monitoring and analysis of geological processes affecting coastal zones. The focus of the research is downwearing and erosion of the shoreline, cliff collapse and rotational landslides. Permanent Scatterer Interferometry (PSI) technique was used on Sentinel-1 data to measure surface deformation and relate to these coastal processes and mechanisms.
The UK chalk coast was selected for the research sites, the results show that identifying evidence of vertical cliff collapses was very challenging and the results were inconclusive, mainly due to the vegetation present, leading to a loss of coherence. Platform downwearing can be successfully monitored both at a local and regional scale, and large scale coastal, rotational landslides can also be successfully monitored. This has been performed to sub-millimetre accuracy and allowed for the natural processes to be interpreted.
The effectiveness of the PSI methodology as a monitoring tool for coastal environments has been shown, especially when coupled with conventional monitoring methods.
Version
Open Access
Date Issued
2021-12
Date Awarded
2022-06
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Lawrence, James
Mason, Philippa
Ghail, Richard
Sponsor
Skempton Scholarship
CDT
Grant Number
EP/L016826/1
Publisher Department
Civil and Environmental Engineering
Publisher Institution
Imperial College London
Qualification Level
Masters
Qualification Name
Master of Philosophy (MPhil)