Coastal change detection
Satellite(s)Landsat TM, ETM; | Monitoring elementLand/water surface reflectance, SAR backscatter. |
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Description techniqueKonko et al. (2018) pre-processed both optical and radar data. Normalized Difference Water Index (NDWI) calculations were then used to improve the discrimination of aquatic and terrestrial areas. | Accuracy / ResolutionOverall accuracy: 87%. |
Case study
https://gitlab.com/envirosattools/documentation/-/wikis/coastal | |
Also fits domainFreshwater. | |
Benefits
| Limitations
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Applicability for NorthlandYes. Approaches combining optical and radar satellite imagery data would allow for a better cartographic performance and would very likely be useful for coastal hazard mapping and coastal erosion monitoring in Northland. Applications are already developed for Whatipu Beach, Auckland NZ (EnviroSatTools 2021). Techniques applying optical data will be limited in coverage and temporal granularity by the persistent cloud cover in the region, particularly during the winter months. Mature cloud-masking techniques are directly available for open access multispectral data (e.g. Landsat and Sentinel-2). When using commercial data, care must be taken to ensure that there is sufficiently cloud free imagery available, as cloud masking is not as mature, and ordering a large volume of imagery to ensure complete cloud free coverage between multiple observations can become cost prohibitive. | |
Publication referencesKonko, Y. , Bagaram, B. , Julien, F. , Akpamou, K. and Kokou, K. (2018) Multitemporal Analysis of Coastal Erosion Based on Multisource Satellite Images in the South of the Mono Transboundary Biosphere Reserve in Togo (West Africa). Open Access Library Journal, 5, 1-21. doi: 10.4236/oalib.1104526. | |
Other comments or informationDu et al. (2015) suggested to take full advantage of the 10-m information provided by Sentinel-2 images to produce a 10-m spatial resolution MDNWI maps, by downscaling the 20-m resolution SWIR band to 10-m based on pan-sharpening. | |
Other references Aryastana P, Ardantha IM, Candrayana KW. 2018. Coastline change analysis and erosion prediction using satellite images. MATEC Web Conf. 197:13003. Du Y, Zhang Y, Ling F, Wang Q, Li W, Li X. 2016. Water Bodies’ Mapping from Sentinel-2 Imagery with Modified Normalized Difference Water Index at 10-m Spatial Resolution Produced by Sharpening the SWIR Band. Remote Sensing. 8(4):354. Hasan M, Karmaker S, Rahman M. 2020. Geomorphological change assessment of south western coastal region: a case study of Mongla Upazila, Bagerhat, Bangladesh. Journal of Applied Water Engineering and Research. 9. doi:10.1080/23249676.2020.1831977. https://www.tandfonline.com/doi/full/10.1080/23249676.2020.1831977 |