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NT Remote Communities Storm Tide Study and Inundation Mapping



NT Remote Communities Storm Tide Study and Inundation Mapping


Systems Engineering Australia Pty Ltd

Issued by

Northern Territory. Department of Land Resource Management


E-Publications; E-Books; PublicationNT; J1507-PR001B




Made available via the Publications (Legal Deposit) Act 2004 (NT).; 'This report documents tropical cyclone (TC) storm tide hazard analyses that will provide the basis for reliable risk analyses of major remote towns and indigenous communities on the West Coast, Arnhem Land and Tiwi Islands.' - Introduction


This Storm Surge Study Report was produced with funding provided by the Northern Territory and Australian Governments through the Natural Disaster Resilience Program. 'Numerical Modelling and Risk Assessment' - on cover.; Made available via the Publications (Legal Deposit) Act 2004 (NT).

Table of contents

Executive summary -- Introduction -- The study localities -- Methodology to assess the storm tide hazard -- Simulation model results -- Conclusion -- References -- List of Appendices A-C.




Storm surges; Storm surges; Cyclones; Maps; Mathematical models

Publisher name

Northern Territory Government

Place of publication





vi, 62, 4,3,8 pages : colour illustrations, colour maps ; 30 cm.

File type



Attribution International 4.0 (CC BY 4.0)

Copyright owner

Northern Territory Government



Parent handle


Citation address


Page content

NT Department of Land Resource Management NT Remote Communities Storm Tide Study and Inundation Mapping J1507-PR001B 40 Systems Engineering Australia Pty Ltd July 2016 depth and then combined with the combined surge and tide time history. This is repeated for 10,000 years of synthetic storms and each storm surge time history is resampled with a further five phase-offset tide sequences to provide a 50,000 y data set. The exceedance statistics of the combined total water level at each site for each TC event then forms the basis of the probabilistic storm tide level predictions. An example of the model output is shown below in Figure 3-15. Figure 3-15 Example SEAsim visualisation of the 1000 y ARI total storm tide variability near Milingimbi and Galiwinku. In principle, the model applies a linear superposition of surge, tide and wave setup estimates. However, in shallow water locations in conjunction with a large tidal range, there can be non-linear surge-tidewave interactions. In the case of wave interactions, the parametric model analyses take a conservative view by being based on a minimum near-coast water depth equivalent to Mean High Water Springs (MHWS). In respect of surge-tide interactions, the model allows a linear modulation that will slightly attenuate the reference MSL surge magnitude for higher tides and amplify it for lower tides. The assigned modulation factors in the modelled regions here are nominal values referenced to LAT of +10% and to HAT of -5% based on sensitivity testing of historical events using the hydrodynamic model.