Assessing sea level-rise risks to coastal floodplains in the Kakadu Region, northern Australia, using a tidally driven hydrodynamic model

Bayliss, Peter and Saunders, Kate and Dutra, Leo and Melo, Lizandra and Hilton, James and Prakash, Mahesh and Woolard, Fletcher (2016) Assessing sea level-rise risks to coastal floodplains in the Kakadu Region, northern Australia, using a tidally driven hydrodynamic model. Marine and Freshwater Research, NA . NA. ISSN 1323-1650

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Abstract

The low-lying coastal floodplains of the Kakadu Region in tropical northern Australia encompass World
Heritage Kakadu National Park and are highly vulnerable to future sea level-rise (SLR) and extreme weather events, yet
there are no modelling tools to assess potential impacts of saltwater inundation (SWI) on freshwater ecosystems and to
evaluate future management options. A tidally driven hydrodynamic model was developed to simulate the frequency and
extent of SWI in the Kakadu Region for the following four mean SLR scenarios: 0 m (present-day, 2013); 0.14 m (2030);
0.70 m (2070); and 1.1 m (2100). Simulations were undertaken at 60-m spatial resolution using October dry-season tides,
and a digital elevation model (0.10-m vertical resolution) constructed from LiDAR point cloud data was used to resolve
coastal and river-system terrains. Model outputs (maximum extent and frequency of SWI) were used to assess potential
loss of freshwater floodplains for each scenario at a park-wide scale and for three case-study areas that differ in tidal
influence. Results show little loss by 2030 (-3%), a possible threshold effect by 2070 (-42%) and ameliorating after 2100
(-65%). Although freshwater floodplains further from the coast showed least exposure to simulated SLR, indicating
potential refuge areas, all floodplains on Kakadu will be exposed to SWI by 2132 (þ117 years).

Item Type:	Journal Article
Subjects:	G Geography. Anthropology. Recreation > GE Environmental Sciences
Divisions:	Faculty of Science, Technology and Environment (FSTE) > School of Marine Studies
Depositing User:	Fulori Nainoca - Waqairagata
Date Deposited:	28 Jul 2016 23:30
Last Modified:	28 Jul 2016 23:30
URI:	https://repository.usp.ac.fj/id/eprint/9098

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