Monitoring coastal subsidence using InSAR and airborne LiDAR around Eagle Point, Texas
Abstract
Coastal areas are unique ecosystems that offer habitats for many species and provide important services to human society. Land subsidence occurring over the coastal areas are exacerbating various environmental and ecological problems, such as coastal flooding, wetland loss. Mapping spatial variability of coastal subsidence could contribute to risk management strategies. This study attempts to integrate satellite interferometric synthetic aperture radar (InSAR) and airborne LiDAR methods to investigate the spatiotemporal pattern of land subsidence around Eagle Point, Texas, a region known for its fast rate of relative sea-level rise in recent decades. Results showed that the line-of-sight velocities were up to -33 mm/year in the period of 2006-2011 based on ascending ALOS-1 PALSAR-1 images. The vertical velocities were up to -34 mm/year in the period of 2016-2021 based on both ascending and descending Sentinel-1 images. A 1-m map of land surface difference was derived from subtraction analysis of multi-temporal airborne LiDAR datasets. The comparison of InSAR and airborne LiDAR results indicated that local subsidence rates could vary significantly below the spatial resolution of InSAR results, indicating a valuable role for airborne LiDAR results in extending InSAR results to parcel and building levels and explaining subpixel variabilities. Subsidence results were further linked to the patterns of land cover. Results illustrated that subsidence was stronger in vegetated areas than in developed areas over the study area. Overall, this study demonstrated the unique benefits of combining InSAR results with other geospatial datasets to characterize coastal subsidence.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.G42D0246Z