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Coastal process modelling for evaluating EbA strategies to

climate change in the Pacific F. Andutta, S. Lee, G. Fraive, R. Tomlinson, B. Mackey

Griffith Centre for Coastal Management (GCCM) and Griffith Climate Change Response Program (GCCRP)

EcoAdapt - The benefits of ecosystem-based approaches for climate change in Least Developed

Countries

Priority themes are: (1) Adapting to a rapidly changing climate in coastal

regions, (2) Information & knowledge management for

adaptation and resilience planning.

You will find here an overview of the coastal process modelling component to be applied for the EcoAdapt

Project.

A few simple questions to merge concepts of coastal oceanography and EbA were defined. i. What is the general coastal circulation in the region and how will this change under future climate? ii. How to assess coastal flooding in the Pacific Islands, and how this may change under a number of future climate scenarios? iii. Are there new scientific questions to be defined in advance regarding EbA and coastal oceanography? iv. Are EbA feasible and coast-effective solutions for most islands of the Pacific?

Why EbA strategies?

4

+

-

X Environmental friendly

X Mitigation of coastal erosion

X Inexpensive maintenance

X sustainable

X Duration of EbA strategies under a climate change?

Artificial Coral Reef

Artificial Reef Artificial reefs and coral reefs relate to different ecosystems.

Differences between some models TUFLOW (friendly-GUI)

source: http://www.tuflow.com

Flood packages: Mike flood, Delft3D, ADCIRC, SMS, etc

SLIM C++ based code

FVCOM F90/95 based code

source: http://fvcom.smast.umassd.edu

source: http://sites.uclouvain.be/slim/

Essential features for the coastal model component: i. I am setting up initially Finite-Volume Coastal Ocean Model FVCOM

and Second-generation Louvain-la-Neuve Ice-ocean Model SLIM.

ii. We aim to use high resolution of topography and bathymetry for simulations of storm surge.

iii. Good descriptions of the sediment distribution, and thus better representation of the roughness coefficient applied into the models.

iv. Tides from Topex with verification and validation.

v. Wind forcings from CFSR or another reliable wind model.

vi. Boundary forcings from HYCOM and Mercartor, which will be compared against measurements in the coastal zone.

Efate

Tanna

Global Etopo data (topography and bathymetry) Horizontal resolution (~2 Km)

We will obtain higher

resolution bathymetry around the islands and

inside the bay.

Mele Bay in Efate

We will be using an unstructured mesh in simulations with FVCOM and SLIM3D

Mele Bay

HR topography from SRTM 30 m grid (closer view)

SRTM vertical accuracy??

10m!!!!

What are the implications?

The wave hindcast evaluated the wave conditions around Efate between 1979 and 2013. (http://gsd.spc.int/wacop/)

Four seasons

Period Direction Height

buoy

Wave climate hindcast of Efate (CSIRO model)

Wave climate using buoy measurements (Efate)

Bottom stress from SGW model can be applied into sediment transport model. However, extreme events must be considered!!!!!

Period, Direction, Height

The wave hindcast evaluated the wave conditions around Tanna between 1979 and 2013. (http://gsd.spc.int/wacop/)

Four seasons

Period Direction Height

Wave climate hindcast of Tanna (CSIRO model)

(Mellor et al., 2008) Incorporated into FVCOM, but under analysis. The structure used in FVCOM is different

from orthogonal curvilinear models. Therefore, interpolations may caused some errors.

Finite-Volume approach

source: ntl.bts.gov

Hydro-sed-wave model

Partitioning of your mesh (MPI) MPI using METIS Libraries in FVCOM and SLIM

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Efate-model (tidal currents)

Tanna-model (tidal currents)

Tanna-model (tidal currents)

Tanna-model (tidal currents)

Tanna-model (tidal currents)

Tanna-model (tidal currents)

Tanna-model (tidal currents)

Thanks for watching Questions ?

Acknowledgement to Tamara Rouse and you all for your time!