[2950] | 1 | The calculated run-up height and resulting inundation ashore is determined by |
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| 2 | the input topographic and bathymetric data, the forcing terms, the |
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| 3 | initial and boundary conditions, as well as the cell resolution. It |
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| 4 | would be ideal if the data adequately captures all complex features |
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| 5 | of the underlying bathymetry and topography and that the cell |
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| 6 | resolution be commensurate with the underlying data. Any limitations |
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| 7 | in terms of resolution and accuracy in the data will introduce |
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| 8 | errors to the inundation maps as well as the range of model approximations, |
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| 9 | including the cell resolution. |
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| 10 | |
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| 11 | A number of sources have supplied data for this study. With |
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| 12 | respect to the onshore data, the Defence Imagery and Geospatial |
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| 13 | Organisation (DIGO) supplied the DTED (Digital Terrain Elevation |
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| 14 | Data) Level 2 data which has been authorised for Australian Tsunami |
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| 15 | Warning System use only. This data has a resolution of 1 second |
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| 16 | (about 30 metres), produced from 1:50 000 contours, elevations and |
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| 17 | drainage. The Department of Land Information (DLI) has provided a |
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| 18 | 20m DEM and orthophotography covering the NW Shelf. As the 30m |
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| 19 | DTED Level 2 data is bare earth we have chosen to use this as |
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| 20 | the onshore data set. |
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| 21 | |
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| 22 | With respect to the offshore data, the Department of Planning and |
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| 23 | Infrastructure have provided state digital fairsheet data around |
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| 24 | Onslow. This data covers only a very small geographic area. (Note, |
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| 25 | similar data has also been provided for Broome.) The Port Hedland |
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| 26 | Port Authority has provided digital data from a multibeam survey of |
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| 27 | the Port Hedland channel. The Australian Hydrographic Office |
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| 28 | fairsheet data has also been utilised. |
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| 29 | |
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| 30 | In summary, |
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| 31 | |
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| 32 | \begin{center} |
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| 33 | \begin{tabular}{|l|l|}\hline |
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| 34 | Data & Detail \\ \hline |
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| 35 | DIGO DTED Level 2 & Onshore, 1 second $\approx$ 30m \\ \hline |
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| 36 | DLI & Onshore, 20m DEM and orthophotography \\ \hline |
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| 37 | \hline DPI & Offshore, fairsheet data around Onslow \\ \hline |
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| 38 | \hline Pt Hedland Port Authority \hspace{.3in} & Offshore, |
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| 39 | digital multibeam survey |
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| 40 | \\ \hline |
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| 41 | \end{tabular} |
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| 42 | \end{center} |
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| 43 | |
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| 44 | The coastline has been generated from the DIGO DTED Level 2 and modified |
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| 45 | using the aerial photography and the two detailed surveys provided |
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| 46 | by WA Department of Planning and Infrastructure. |
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| 47 | |
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| 48 | The extent of the |
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| 49 | data used for the tsunami impact modelling can be seen in the |
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[3024] | 50 | following figure. The study area covers approximately 100km of coastline |
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| 51 | and extends offshore to the 100m contour line and inshore to approximately 10m |
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| 52 | elevation. |
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[2950] | 53 | |
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| 54 | |
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| 55 | \begin{figure}[hbt] |
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| 56 | |
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| 57 | \centerline{ \includegraphics[width=100mm, height=75mm]{../report_figures/pt_hedland_data_extent.png}} |
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| 58 | |
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| 59 | \caption{Data extent for Pt Hedland scenario. Offshore data shown in blue and onshore data |
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| 60 | in green.} |
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| 61 | \label{fig:pt_hedland_data_area} |
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| 62 | \end{figure} |
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| 63 | |
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| 64 | Section \ref{sec:metadata} outlines the metadata for data used for |
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| 65 | this study. |
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| 66 | |
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| 67 | |
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| 68 | |
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| 69 | |
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