cyclone pam post inundation assessment survey...
TRANSCRIPT
Cyclone PAM
Post Inundation Assessment
Survey using UAV
Herve Damlamian, Cyprien Bosserelle,
Amrit Raj, Zulfikar Begg, Jens Kruger.
Tropical Cyclone PAM
Tuvalu:• AU$ ~14M
• 25% of TV 2013 GDP
• 41% population affected
• 90% damage on crops in 3 Islands,
30% damage on crops in 4 Islands
Vanuatu:• 16 death
• 65,000 people displaced
• >50% population affected (166,000)
• 17,000 buildings affected
• AU$ ~619M – Damage and Loss
• 64.1% of GDP
• Livelihood of more than 80% of
rural population affected.
Other countries affected: New
Caledonia, Solomon Island,
Kiribati, New-Zealand.
Preliminary Wave model of Cyclone Pam
Post Disaster Assessment
Survey
• Rapid Damage Assessment
– Collect high resolution images to assess
building damage.
• Extreme Wave Inundation and Impact Assessment
– Collect Inundation data from an extreme wave
event.
– Assess use of UAV for Post disaster inundation
impact assessment.
Post PAM Inundation Assessment
3D Shoreline Mapping
• Generate high resolution Topography of coastal areas:
– Setting up temporary tide gauge.
– Setting up Bench Marks in Targeted areas.
– Using RTK GPS System to Establish GCPs.
– UAV mapping with 90% overlap
• Compare with LIDAR data (2012)
Methodology
Preliminary Wave model of Cyclone Pam, Efate
Point Cloud: Takara Village, NE Efate
Inundation Extent and Run-up
240m Inundation extent
7m run-up (Above TGZ)
Debris line
Debris line
3D Shoreline Change
• ORTHOPHOTO
• DTM
Prior Cyclone
PAMLIDAR DATA (2012)
After Cyclone
PAMUAV DATA (2015)
Example: Map of Change
Takara Village, NE Efate
UAV limitation in dense vegetation
Erosion
Accretion
Erosion
AccretionOnesua
Epike
Epau
Paonagisu
Common Shoreline Pattern
2015 Beach profile
2012 Beach profile
Emerged Holocene Reef Terrace
2015 Beach profile
2012 Beach profile
Erosion
Accretion
Erosion
Accretion
2015 Beach profile
2012 Beach profile
Before CycloneAfter Cyclone
Spurs and Grooves
Impact Exacerbated
by Human Activity
Prior Cyclone
PAMLIDAR DATA
(2012)
After Cyclone
PAMUAV DATA (2015)
Erosion (Red) / Accretion (Blue)
Cross
Section
Erosion
Accretion
Conclusion:
• This study highlights the benefit of using UAV for post inundation survey.– One dataset: Inundation extent, Run-up, coastal changes (m3)
– Identified Shoreline Change Pattern vs Geomorphology:• River (present or Ancient)
• Salient
• Uplifted Holocene reef terrace
• Uniform sandy beach
- Improve our understanding on extreme wave inundation and coastal impact on fringing reef.
- Improve future inundation risk assessment study, inundation and impact forecast work.
• Combined with Tide Gauge and RTK system, UAV + photogrammetrytechnology has proven to be a credible alternative to LIDAR forTopography data collection. However there are limitations… (DSM toDTM conversion, processing time,…).
Vinaka
and
special
thanks to
Ministry
of Land,
Vanuatu