Abstract
Although the Sand dunes screen the coastal cities from the sand dunes hazards and their infrastructures from rising sea levels and storms, they might threaten and hide the surrounding developmental projects. Thus, imaging these coastal dunes' internal anatomy and dynamics are crucial to protect the environment. In this study, the Optical and Synthetic Aperture Radar (SAR) images were processed and integrated with field observations and surveys to extract information about the past, current, and future behavior of coastal dunes in the Nile Delta-Northwest sector. A conventional change detection method using the supervised Landsat-8 images for the years 2015 and 2017 were generated to show a rapid change in the sand dune cover, where the high-resolution images of Google Earth were used to digitize the dune crests and measure its encroachment rate, which has been reached about 4 m/year with the NW–SE direction. The full-polarimetric ALOS/PALSAR-2 images from the years 2015 and 2017 show very low coherence for the sand dunes, which means these dunes are dynamic, where the changes in both power and phase imbalances of different dune fields during the investigated years (2015 and 2017) show high differences in values, which reached 40 dB and 0.06°, respectively. Finally, the extracted radar facies from the field survey show two successive groups of coastal sand dunes show a decline in the heavy minerals content to a level that might threaten the properties at the shoreline due to sea level rise and wave storms if mitigation actions are not taken place soon.
Original language | English |
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Title of host publication | Springer Proceedings in Earth and Environmental Sciences |
Publisher | Springer Nature |
Pages | 385-394 |
Number of pages | 10 |
DOIs | |
State | Published - 2023 |
Publication series
Name | Springer Proceedings in Earth and Environmental Sciences |
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Volume | Part F1684 |
ISSN (Print) | 2524-342X |
ISSN (Electronic) | 2524-3438 |
Funding
The authors would like to thank JAXA for providing the ALOS/PALSAR-2 satellite images free of charge (through the ALOS-2 6th RA PI-3131 agreement). In addition, we would like to thank the USGS for providing Landsat-8 as well as Google Earth. This work is dedicated to the soul of Professor Fikry Khalaf from Port-Said University, for the valuable discussion before he passed away in early 2021. This research received no external funding.
Keywords
- Coastal dunes
- Egypt
- Future threats
- Remote sensing
- SAR