cyclone pam post inundation assessment survey...

Cyclone PAM

Post Inundation Assessment

Survey using UAV

Herve Damlamian, Cyprien Bosserelle,

Amrit Raj, Zulfikar Begg, Jens Kruger.

herveda@spc.int

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