coastline monitoring - imt atlantiquerecherche.imt-atlantique.fr/data/bretel/pres2 - lafon.pdf ·...
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Coastline monitoring Virginie Lafon
Cyril Mallet
S. Capo, A. Dehouck
E. Maneux, A. Michot
C. Proisy, R. Walker First BreTel Workshop
May 31 – June 1st 2012 Saint Malo, France
30/05/2012 First BreTel Workshop 1
30/05/2012 First BreTel Workshop 2
About the coastlines
Geomorphology Substrate type
Bedrock, sand beach, tidal flats, salt marsh and mangrove …
Forcing
Evolution
Forecast Population
Management strategy
About the monitoring
• Sandy beaches and dunes – Shallow water sandbank – Dune foot
• Rocky coasts – Cliff foot
• Maritime wetlands – Salt marsh contour
• Mangrove wetlands • Articificial coasts
– Dykes, seawalls …
– Waterline (lakes, internal
seas)
• Terrestrial acquisition – DGPS
– Theodolite
– Scanner 3D
– Photo / video surveys
• Airborne RS – Pictures (RGB + NIR)
– Hyperspectral imagery
– Lidar
• Satellite RS – MS / Hyperspec Imagery
– SAR Imagery
Survey indicators Monitoring approaches
From the :
30/05/2012 First BreTel Workshop 3
30/05/2012 First BreTel Workshop 4
Dune foot monitoring
X JNGCGC, NEREUS publication, 2010
Radiometric calibration / Image mosaic
Unsupervised /Supervised classification
Sobel filtering
Raster facies / polylines
Validation (DGPS)
Mean coastline positionning error : 10 m (2 m resolution space image)
Partnership
30/05/2012 First BreTel Workshop 5
Dune foot forecast and management strategy
Hazard mapping - Weak - Medium - Strong
NEREUS publication, 2012
30/05/2012 First BreTel Workshop 6
Demonstrators of operational services
• Automatic detection
• Change detection analysis
• Conservation status analysis
• Dune erosion / restoration
Window on GMES publication, 2012
30/05/2012 First BreTel Workshop 7
Shallow water bathymetry
Réflectance image (rXS1)
depth (z) in 3 steps
SP -
16/04/2010
Sem
i an
aly
tical
mo
del Empirical
calibration
Sentinel-2 Preparatory Symposium, 2012
30/05/2012 First BreTel Workshop 8
Sandbank monitoring
Breaching
30/05/2012 First BreTel Workshop 9
Integrated analysis
55 m
55 m
14 m
2000 2003 2005
- 04/2009 - 04/2010 - 09/2010
30/05/2012 First BreTel Workshop 10
Oyster farming / oyster banks
THR Satellite data
Texture analysis +
Segmentation
30/05/2012 First BreTel Workshop 11
Polder monitoring
• Polder evolution survey
• Island breaching and flooding monitoring – Mecanism study
K2 18/03/2009 K2 05/03/2010 K2 15/03/2010
• Evolution scenarii proposition • 3-year project (2012 -> 2015)
30/05/2012 First BreTel Workshop 12
Mangrove monitoring
SAVI-based automatic detection
30/05/2012 First BreTel Workshop 13
Conclusions
• Satellite imagery allows locating the coastline over large muddy sandy, rocky littoral (with / without vegetation cover)
• Satellite imagery allows describing time (historical) / space evolution of the coastline
• Satellite observation constitute a powerful and low cost solution for coastline surveying at a national scale
• Also, medium- to long-term satellite-based observations participate to evolution processes analysis and they provide numerical simulation validation cases
• Automatic operational services are being demonstrated e.g. in Aquitaine
30/05/2012 First BreTel Workshop 14
Thank you for
your attention
Scale
+1 m
0 hydro
- 1 m
- 2 m
- 3 m