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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 45 Systems Engineering Australia Pty Ltd July 2016 4.2 Site-Specific Storm Tide Level Components by the Year 2100 The following site-specific storm tide results are presented in Figure 4-4 to Figure 4-6, showing all of the storm tide components for each of the nine sites as a function of ARI: Total Storm Tide Level (m AHD) Tide + Surge (m AHD) Surge (m) Wave Setup (m) Astronomical Tide (m AHD) Significant Wave Height16 (m) Together with: HAT Year 2100 (m AHD) Dune Crest (m AHD) These figures contrast the relative contribution of each of the storm tide components (refer Section 1.4) in estimating the total water level hazard at each site17. It can be noted that the Astronomical Tide component asymptotes to the HAT level at about the 100 y ARI rather than the expected 18.6 y tide nodal period. This is because the simulation only generates tides when there is an active tropical cyclone. It can be seen that Wave Setup is not a significant contributor at any of the Study sites. This is mainly due to their generally protected exposure within estuaries but is also predicated on nominal values for beach slopes. More rigorous analyses should be undertaken if specificallyreliable beach slope data becomes available. 4.3 Mapped Total Storm Tide Levels by the Year 2100 Examples are presented in Figure 4-7 to Figure 4-15, showing the mapped extents of the Total Storm Tide Water Levels for each of the ARI events listed in Table 4-1 applied to the available aerial LiDAR limits. The colour legend indicates the relevant event ARI, noting that for some sites the 100 y ARI level is close to or less than the indicated HAT level (refer Table 4-2) and has therefore been obscured by the HAT extent. As noted previously, detailed public domain mapping is being undertaken separately by NT DLRM based on these GHD-supplied surfaces. 16 These values are not directly suitable for use in structural design. 17 Note that the various ARI curves are not additive in water level.