# Changeset 7401

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Timestamp:
Aug 21, 2009, 5:56:38 PM (13 years ago)
Message:

More comments from Jane and me

File:
1 edited

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Unmodified
 r7399 It consists of geodetic measurements of the Sumatra--Andaman earthquake that are used to validate the description of the tsunami source, altimetry data from the JASON satellite to test of the tsunami source, altimetry data from the \textsc{jason} satellite to test open ocean propagation, eye-witness accounts to assess near shore propagation, and a detailed inundation survey of Patong city, Thailand used to validate the propagation stage in Section \ref{sec:resultsPropagation}. FIXME (Ole): See Phil's second point and email with help from David %DB I suggest we combine with model data to reduce the number of figures. The satellite track is shown in Figure~\ref{fig:satelliteTrack}. \end{figure} FIXME (Jane): legend? Were the contours derived from the final dataset? This is not the entire mode, only the bay and the beach. This is not the entire model, only the bay and the beach. \subsubsection{Buildings and Other Structures} \subsubsection{Inundation Survey} Tsunami run-up is the cause of the largest financial and human Tsunami run-up in built-up areas can be the cause of large financial and human losses, yet run-up data that can be used to validate model run-up predictions is scarce. Of the two field benchmarks proposed predictions is scarce because such events are relatively infrequent. Of the two field benchmarks proposed in~\cite{synolakis07}, only the Okushiri benchmark facilitates comparison between \subsubsection{Eyewitness Accounts}\label{sec:eyewitness data} Eyewitness accounts detailed in~\cite{papadopoulos06} report that most people at Patong Beach observed an initial retreat of the shoreline of more than 100 m followed a few minutes later, by a report that many people at Patong Beach observed an initial retreat (trough or draw down) of the shoreline of more than 100 m followed a few minutes later by a strong wave (crest). Another less powerful wave arrived another five or ten minutes later. Eyewitness statements place the arrival time of the strong wave between 2 hours and 55 minutes to 3 hours and 5 minutes after the source rupture (09:55am to 10:05am local time). FIXME (Ole): We should add observed arrival time and later relate that to the modelled dynamics. \begin{figure}[ht] \begin{center} \includegraphics[width=8.0cm,keepaspectratio=true]{gauge_locations.jpg} \caption{Location of timeseries extracted from the model output.} \label{fig:gauge_locations} \end{center} \end{figure} Two videos were sourced\footnote{The footage is \subsection{Generation}\label{sec:modelGeneration} FIXME (Ole and Jane): Does this need to be so long? There are various approaches to modelling the expected crustal simulating water flow onto a beach or dry land and around structures such as buildings. \textsc{Anuga} has been validated against %a number of analytical solutions and  FIXME: These have not been published %a number of analytical solutions and %FIXME (Ole): Analytical solutions have not been published. Ask Steve. the wave tank simulation of the 1993 Okushiri Island tsunami~\cite{nielsen05,roberts06}. shown in Figure~\ref{fig:computational_domain}. FIXME (Ole): I know that a nested ursga model was trialled for the end-to-end modelling. However, for the study done here, where models were coupled, I didn't think nested grids were used with URSGA - and certainly not down to 1 arc second. Can someone shed some light on this please? \begin{figure}[ht] \begin{center} efficiently increase the simulation accuracy for the impact area. The grid resolution ranged between a maximum triangle area of $1\times 10^5$ m$^2$ near the western ocean boundary to $20$ m$^2$ in the small regions surrounding the inundation region in Patong Bay. Due to a lack of available data, friction was maximum triangle area of $1\times 10^5$ m$^2$ (corresponding to approximately 440 m between mesh points) near the western ocean boundary to $20$ m$^2$ (corresponding to approximately 6 m between mesh points) in the small regions surrounding the inundation region in Patong Bay. The coarse resolution was chosen to be commensurate with the model output from the \textsc{ursga} model (FIXME - this has to be clearly stated in ursga section) while the latter was chosen to match the available resolution of topographic data and building data in Patong city. Due to a lack of available roughness data, friction was set to a constant throughout the computational domain. For the reference simulation, a Manning's coefficient of 0.01 was chosen to Maximum onshore inundation depth was computed from the model throughout the entire Patong Bay region. throughout the entire Patong Bay region and used to generate a measure of the inundated area. Figure~\ref{fig:inundationcomparison1cm} (left) shows very good agreement between the measured and simulated inundation. However \begin{figure}[ht] \begin{center} \includegraphics[width=8.0cm,keepaspectratio=true]{gauge_locations.jpg} \caption{Location of timeseries extracted from the model output.} \label{fig:gauge_locations} \end{center} \end{figure} \begin{figure}[ht] \begin{center} \includegraphics[width=10.0cm,keepaspectratio=true]{gauge_bay_depth.jpg} \includegraphics[width=10.0cm,keepaspectratio=true]{gauge_bay_speed.jpg} The estimated depths and flow rates given in Section \ref{sec:eyewitness data} are shown together with the modelled depths and flow rates obtained from the model in Table \ref{tab:depth and flow comparisons}. The minimum depths shown in the model are clearly lower than expected and an indication that the tsunami model does not predict flow dynamics accurately at this level of detail. However, this comparison serves to check that depths and speeds predicted are within the range of what is expected. and flow rates obtained from the model in Table \ref{tab:depth and flow comparisons}. The predicted maximum depths and speeds are all of the same order of what was observed. However, unlike the real event, the model estimates complete withdrawal of the water between waves at the chosen locations and shows that the model must be used with caution at this level of detail. Nonetheless, this comparison serves to check that depths and speeds predicted are within the range of what is expected. \begin{figure}[ht] \begin{center} \includegraphics[width=6cm,keepaspectratio=true]{sensitivity_f0_0003_depth} \includegraphics[width=6cm,keepaspectratio=true]{sensitivity_f0_03_depth} %\includegraphics[width=6cm,keepaspectratio=true]{sensitivity_f0_0003_depth} %\includegraphics[width=6cm,keepaspectratio=true]{sensitivity_f0_03_depth} \includegraphics[width=12cm,keepaspectratio=true]{friction_comparison_depth} \caption{Model results for different values of Manning's friction coefficient shown to assess sensitivities. The reference inundation extent for a