Modelling Potential Rates of Natural Subsidence using Geological and PSI
Ground Motion Data: An Experiment in Europe and Great Britain
Abstract
Sixteen of the world’s largest cities, with populations of over 10
Million, are located within 100 km of the coast (as are sixteen European
cities, with populations of over 1 Million). The need to understand the
contribution that the lowering of the ground surface, through natural
geological phenomena, can make to estimates of relative sea level change
is especially relevant to these lowland areas, which are usually the
most geologically susceptible to subsidence. In this work, the
methodology developed within the SubCoast EC-FP7 project was exploited
to create a combined natural sub-sidence potential percentage change
value for each lithology of the OneGeology dataset for Europe.
Calibration of potential volume changes against ground motion statistics
extracted from interpreted Persistent Scatterer Interferometry (PSI) and
geohazard mapping datasets allowed for the deriva-tion of potential
ground motion rates for the coastline of Europe. By utilising this
subsidence po-tential methodology and combining it with the British
Geological Survey (BGS) geology (superficial and bedrock) 1:50,000 scale
dataset, a nation-wide dataset of potential natural subsidence rates was
produced for Great Britain, providing information for all lithologies of
the country. By incorporating the most current and up-to-date PSI data,
the potential subsidence rates could be re-calculated, and a more
detailed, calibrated polygon dataset could be created in the future.
SubCoast was a collab-orative research project funded by the EU, the aim
of which was to assess the combined impact of sea level rise and coastal
subsidence as measured with satellite radar interferometry.