Changeset 2800

Timestamp:

May 4, 2006, 5:03:08 PM (19 years ago)

Author:

sexton

Message:

report updates

Location:

production/scenario_reports/report_end_FY06

Files:

• data.tex (modified) (4 diffs)
• introduction.tex (modified) (1 diff)
• tsunami_scenario.tex (modified) (1 diff)

production/scenario_reports/report_end_FY06/data.tex

@@ -1 @@
-The runup height and resulting inundation ashore is determined by
+The calculated run-up height and resulting inundation ashore is determined by
 the input topographic and bathymetric data, the forcing terms, the
 initial and boundary conditions, as well as the cell resolution. It
 would be ideal if the data adequately captures all complex features
 of the underlying bathymetry and topography and that the cell
-resolution be commensurate with the underlying data. Errors in any
-of these areas will affect the accuracy of the final model result.
+resolution be commensurate with the underlying data. Any limitations
+in terms of resolution and accuracy in the data will introduce 
+errors to the inundation maps as well as the range of model approximations,
+including the cell resolution.
 
 A number of sources have supplied data for these two studies. With
@@ -14 +16 @@
 (about 30 metres), produced from 1:50 000 contours, elevations and
 drainage. The Department of Land Information (DLI) has provided a
-20m DEM and orthophotography covering the NW Shelf. This data set is
-not bare earth and as a result, we have chosen to use the 30m DTED
-Level 2 data due to its bare earth thingo.
+20m DEM and orthophotography covering the NW Shelf. As the 30m
+DTED Level 2 data is bare earth we have chosen to use this as
+the onshore data set.
 
 With respect to the offshore data, the Department of Planning and
@@ -26 +28 @@
 fairsheet data has also been utilised.
 
-The coastline has been generated from the DIGO DTED2 and modified
+In summary,
+
+\begin{center}
+\begin{tabular}{|l|l|}\hline
+Data & Detail \\ \hline 
+DIGO DTED Level 2  & Onshore, 1 second $\approx$ 30m) \\ \hline 
+DLI & Onshore, 20m DEM and orthophotography \\ 
+\hline DPI & Offshore, fairsheet data around Onslow \\ 
+\hline Pt Hedland Port Authority \hspace{.3in} & Offshore,
+digital multibeam survey
+\\ \hline
+\end{tabular}
+\end{center}
+
+The coastline has been generated from the DIGO DTED Level 2 and modified
 using the aerial photography and the two detailed surveys provided
-by WA Department of Planning and Infrastructure. The extent of the
+by WA Department of Planning and Infrastructure. 
+
+\input{data_issues}
+
+The extent of the
 data used for the tsunami impact modelling can be seen in the
 following two figures.
@@ -51 +71 @@
 these studies.
 
-In summary,
 
 
-\begin{center}
-\begin{tabular}{|l|l|}\hline
-Data & Detail \\ \hline DIGO DTED Level 2  & Onshore, 1 second
-($\approx$ 30m) \\ \hline DLI & Onshore, 20m DEM and
-orthophotography \\ \hline DPI & Offshore, fairsheet data around
-Onslow \\ \hline Pt Hedland Port Authority \hspace{.3in} & Offshore,
-digital multibeam survey
-\\ \hline
-\end{tabular}
-\end{center}
 
-
-\input{data_issues}

production/scenario_reports/report_end_FY06/introduction.tex

@@ -3 +3 @@
 (FESA)
 as part of the Collaborative Research Agreement with Geoscience Australia.
-The report describes the methods, assumptions and results of tsunami inundation
-scenarios for two areas in the North West shelf region of the West Australian
-coastline, namely Onslow and Pt Hedland.
+FESA recognises the potential vulnerability of the Western Australia
+coastline to tsunamigenic earthquakes originating from 
+the Sunda Arc subduction zone. There is
+historic evidence of such events and FESA has sought to assess
+the relative risk of its urban and regional communities to the tsunami
+threat and develop detailed response plans.
 
-Describe why this work is being done – exposure, vulnerability –
-understand impact and risk to tsunami hazard.
-
+This report is the first in a series of studies to assess the relative
+risk to the tsunami threat. The methods, assumptions and results of a
+single tsunami source scenario is described for two areas in the 
+North West shelf region, namely Onslow and Pt Hedland. The return
+period of this particular scenario is unknown, however it
+can be be classed as a plausible event. Future studies
+will present a series of scenarios for a range of return events to 
+assist FESA in developing appropriate plans for a range of event impacts.
 
 The software tool, ANUGA, has been used to develop the inundation extent
 and associated water height at various points in space and time.
-ANUGA has been developed by GA and ANU to solve the nonlinear shallow water
+ANUGA has been developed by GA and the Australian National University
+(ANU) to solve the nonlinear shallow water
 wave equation using the finite volume technique (described in [1]).
 An advantage of this technique is that the cell resolution can be changed

production/scenario_reports/report_end_FY06/tsunami_scenario.tex

@@ -1 @@
-need to say something about the event, i.e. Mw 8.5 event initiated
-along the Java Trench (get from David)
+The tsunamigenic event used for this study is one used
+to develop the preliminary tsunami hazard assessment which 
+was delivered to FESA in September 2005 (ref Burbidge, D. and
+Cummins, P. 2005). In that assessment, a suite of
+tsunami were evenly spaced along the Sunda Arc subduction zone and there
+was no consideration of likelihood. Other sources were not considered, such
+as intra-plate earthquakes near the WA coast, volcanoes, landslides
+or asteroids. The preliminary assessment argued
+that the maximum magnitude of earthquakes off Java is at least 8.5 and
+could potentially be as high as 9.
+
+Current studies underway in GA are building probabilistic
+models to develop a more complete tsunami hazard assessment
+for the Sunda Arc subduction zone. (This is
+due for completion in late 2006.) In the preliminary assessment for
+example, it was argued that while Mw 7 and 8 earthquakes are expected
+to occur with a greater frequency, they are likely to pose a comparatively
+low and localised hazard to WA. 
+
+FESA are interested in the ``most frequent worst case scenario''. Whilst
+we cannot determine what that event may be, the Mw 8.5 event provides
+a plausible worst case scenario. 
+
+The following figure is taken from the preliminary assessment and
+shows the maximum wave height up to the 50m contour for a Mw 8.5 event off
+the coast of Java. It is this event which provides the source to the
+inundation modelling presented in the following section.
+
+
 
 \begin{figure}[hbt]
 
-  %\centerline{ \includegraphics[width=75mm, height=75mm]{figures/.eps}}
+  \centerline{ \includegraphics[width=75mm, height=75mm]{mw85.jpg}}
 
-  \caption{Source zones of influence}
-  \label{fig:source}
+  \caption{Maximum wave height (in cms) for a Mw 8.5 event off the 
+coast of Java}
+  \label{fig:mw85}
 \end{figure}