Satellite remote sensing for change detection on land-sea interaction and its effect on coastal heritage assets

Coastal infrastructure is an essential part of the built and the natural environment that is prone to natural and anthropogenetic hazards. The coastal regions require continuous monitoring to understand the extent and scale of environmental changes, and their impact can affect coastal heritage, roads and the built environment. Various approaches were implemented to monitor these assets with in-situ monitoring techniques and expert observations. Unprecedented remote sensing data could help with continuous monitoring and terrestrial observations. In this study, Light Detection And Ranging (LiDAR) data and Interferometric Synthetic Aperture Radar (InSAR) observations are used to investigate morphological changes along the coast. The focus is to explore changes along the coastline of the Isles of Scilly, UK. LiDAR data are used and digital terrain models (DTM) from 2007 and 2020 observations are produced. The change in morphology is estimated by applying a raster difference between the two dates. The results show a significant change along the coast that is aligned with the coastal heritage designated at risk by Historic England. Sentinel-1 interferograms from the Looking Inside Continents from Space (LiCSAR) archive are utilised and velocity and time series are estimated for the island. The velocity map and the time series show patches of uplift/subsidence but are limited by the resolution of the data. The results have proven agreement in most locations although they need further validation with other on-site observations. Moreover, for SAR observations, high-resolution data is inevitable to resolve small-scale changes in coastal heritage.