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anuga_work/publications/boxing_day_validation_2008/patong_validation.tex
r7255 r7303 37 37 In this paper a new benchmark for tsunami model validation is 38 38 proposed. The benchmark is based upon the 2004 Indian Ocean tsunami, 39 which provides a uniquely large amount of observational data for model39 which affords a uniquely large amount of observational data for model 40 40 comparison. Unlike the small number of existing benchmarks, the 41 41 proposed test validates all three stages of tsunami evolution - … … 50 50 inundation. Important buildings and other structures were incorporated 51 51 into the underlying computational mesh and shown to have a large 52 influence o finundation extent. Sensitivity analysis also showed that52 influence on inundation extent. Sensitivity analysis also showed that 53 53 the model predictions are comparatively insensitive to large changes 54 54 in friction and small perturbations in wave weight at the 100 m depth … … 70 70 subsequent propagation and inundation of the tsunami, the 71 71 effectiveness of hazard mitigation procedures and the economic impact 72 of such measures and the event itself. Here we focus on modelling of72 of such measures and of the event itself. Here we focus on modelling of 73 73 the physical processes. 74 74 %OLE: I commented this out 23 June 2009 as there was no reference. … … 84 84 geodetic and sometimes tsunami data must be used 85 85 to provide estimates of initial sea floor and ocean surface 86 deformation. The complexity of these models range from empirical to86 deformation. The complexity of these models ranges from empirical to 87 87 non-linear three-dimensional mechanical models. The shallow water wave 88 88 equations, linearised shallow water wave equations, and … … 93 93 94 94 Inaccuracies in model prediction can result in inappropriate 95 evacuation plans and town zoning which may result in loss of life and95 evacuation plans and town zoning, which may result in loss of life and 96 96 large financial losses. Consequently tsunami models must undergo 97 97 sufficient end-to-end testing to increase scientific and community … … 99 99 100 100 Complete confidence in a model of a physical system cannot be 101 established. One can only hope to state under what conditions the101 established. One can only hope to state under what conditions and to what extent the 102 102 model hypothesis holds true. Specifically the utility of a model can 103 103 be assessed through a process of verification and … … 110 110 111 111 The sources of data used to validate and verify a model can be 112 separated into three main categories ;analytical solutions, scale112 separated into three main categories: analytical solutions, scale 113 113 experiments and field measurements. Analytical solutions of the 114 114 governing equations of a model, if available, provide the best means … … 118 118 experiments, typically in the form of wave-tank experiments, provide a 119 119 much more realistic source of data that better captures the complex 120 dynamics of flows such as those generated by tsunami, whilst allowing120 dynamics of flows such as those generated by a tsunami, whilst allowing 121 121 control of the event and much easier and accurate measurement of the 122 122 tsunami properties. Comparison of numerical predictions with field … … 128 128 statements~\cite{bates01}. 129 129 130 Currently, the extent of tsunami 130 Currently, the extent of tsunami-related field data is limited. The 131 131 cost of tsunami monitoring programs, bathymetry and topography surveys 132 132 prohibits the collection of data in many of the regions in which … … 136 136 standards, criteria and procedures for evaluating numerical models of 137 137 tsunami. They propose three analytical solutions to help identify the 138 validity of a model and five scale comparisons (wave-tank benchmarks)138 validity of a model, and five scale comparisons (wave-tank benchmarks) 139 139 and two field events to assess model veracity. 140 140 141 The first field data benchmark introduced by Synolakiscompares model141 The first field data benchmark introduced in \cite{synolakis07} compares model 142 142 results against observed data from the Hokkaido-Nansei-Oki tsunami 143 that occurred around Okushiri Island, Japan on the 12 th ofJuly144 1993. This tsunami provides an example of extreme run up generated from143 that occurred around Okushiri Island, Japan on the 12 July 144 1993. This tsunami provides an example of extreme run-up generated from 145 145 reflections and constructive interference resulting from local 146 146 topography and bathymetry. The benchmark consists of two tide gauge 147 records and numerous spatially 148 modelled maximum run up elevations can be compared. The second149 benchmark is based upon the Rat Islands Tsunami that occurred off the150 coast of Alaska on the 17 th of November 2003. The Rat island tsunami151 provides a good test for real-time forecasting models since t sunami147 records and numerous spatially-distributed point sites at which 148 modelled maximum run-up elevations can be compared. The second 149 benchmark is based upon the Rat Islands tsunami that occurred off the 150 coast of Alaska on the 17 November 2003. The Rat Island tsunami 151 provides a good test for real-time forecasting models since the tsunami 152 152 was recorded at three tsunameters. The test requires matching the 153 153 propagation model data with the DART recording to constrain the 154 tsunami source model and then using it to reproduce the tide gauge154 tsunami source model, and then using it to reproduce the tide gauge 155 155 record at Hilo. 156 156 157 157 In this paper we develop a field data benchmark to be used in 158 158 conjunction with the other tests proposed by Synolakis et 159 al~\cite{synolakis07} to validate and verify tsunami models. Unlike160 the aforementioned tests, the proposed benchmarkallows evaluation of161 model structure during all three distinct ive stages of the evolution162 of a tsunami. The benchmarkconsists of geodetic measurements of the163 Sumatra--Andaman earthquake whichare used to validate the description159 al~\cite{synolakis07} to validate and verify tsunami models. 160 The benchmark proposed here allows evaluation of 161 model structure during all three distinct stages tsunami evolution. 162 It consists of geodetic measurements of the 163 Sumatra--Andaman earthquake that are used to validate the description 164 164 of the tsunami source, altimetry data from the JASON satellite to test 165 165 open ocean propagation, eye-witness accounts to assess near shore 166 propagation and a detailed inundation survey of Patong Bay, Thailand166 propagation, and a detailed inundation survey of Patong Bay, Thailand 167 167 to compare model and observed inundation. A description of the data 168 168 required to construct the benchmark is given in … … 194 194 measurements of coseismic displacements and bathymetry from ship-based 195 195 expeditions, have now been made 196 available.%~\cite{vigny05,amnon05,kawata05,liu05}. 197 In this section we 198 present the data necessary to implement the proposed benchmark 199 corresponding to each of the three stages of the tsunami's evolution. 196 available. %~\cite{vigny05,amnon05,kawata05,liu05}. 197 In this section we present the corresponding data necessary to implement 198 the proposed benchmark for each of the three stages of the tsunami's evolution. 200 199 201 200 \subsection{Generation}\label{sec:gen_data} … … 205 204 commonly caused by coseismic displacement of the sea floor, but 206 205 submarine mass failures, landslides, volcanoes or asteroids can also 207 cause tsunami. In this section we detail the information weused in206 cause tsunami. In this section we detail the information used in 208 207 this study to validate models of the sea floor deformation generated 209 208 by the 2004 Sumatra--Andaman earthquake. … … 213 212 earthquakes on record. The mega-thrust earthquake started on the 26 214 213 December 2004 at 0h58'53'' UTC (or just before 8 am local time) 215 approximately 70 km offshore North Sumatra214 approximately 70 km offshore of North Sumatra 216 215 (\url{http://earthquake.usgs.gov/eqcenter/eqinthenews/2004/usslav}). The 217 216 rupture propagated 1000-1300 km along the Sumatra-Andaman trench to 218 217 the north at a rate of 2.5-3 km.s$^{-1}$ and lasted approximately 8-10 219 218 minutes~\cite{ammon05}. Estimates of the moment magnitude of this 220 event range from about 9.1 to 9.3 ~\cite{chlieh07,stein07}.221 222 The unusually large surface deformation caused by this earthquake s219 event range from about 9.1 to 9.3 $M_w$~\cite{chlieh07,stein07}. 220 221 The unusually large surface deformation caused by this earthquake 223 222 means that there were a range of different geodetic measurements of 224 223 the surface deformation available. These include field measurements of 225 224 uplifted or subsided coral heads, continuous or campaign \textsc{GPS} 226 225 measurements and remote sensing measurements of uplift or subsidence 227 (see~\cite{chlieh07} and references therein). Here we use the the near 228 fieldestimates of vertical deformation in northwestern Sumatra and226 (see~\cite{chlieh07} and references therein). Here we use the the near-field 227 estimates of vertical deformation in northwestern Sumatra and 229 228 the Nicobar-Andaman islands collated by~\cite{chlieh07} to validate 230 229 that our crustal deformation model of the 2004 Sumatra--Andaman … … 249 248 250 249 \subsection{Propagation} 251 Once generated a tsunami will propagate outwards from the source until250 Once generated, a tsunami will propagate outwards from the source until 252 251 it encounters the shallow water bordering coastal regions. This period 253 252 of the tsunami evolution is referred to as the propagation stage. The … … 267 266 The nested bathymetry grid was generated from: 268 267 \begin{itemize} 269 \item Atwo arc minute grid data set covering the Bay of Bengal,268 \item a two arc minute grid data set covering the Bay of Bengal, 270 269 DBDB2, obtained from US Naval Research Labs; 271 \item A3 second arc grid covering the whole of the Andaman Sea based272 on Thai Navy charts no 45 and no362; and273 \item Aone second grid created from the digitised Thai Navy274 bathymetry chart, no 358.which covers Patong Bay and the270 \item a 3 second arc grid covering the whole of the Andaman Sea based 271 on Thai Navy charts no. 45 and no. 362; and 272 \item a one second grid created from the digitised Thai Navy 273 bathymetry chart, no. 358, which covers Patong Bay and the 275 274 immediately adjacent regions. 276 275 \end{itemize} … … 280 279 four grids are shown in Figure~\ref{fig:nested_grids}. The coarsest 281 280 bathymetry was obtained by interpolating the DBDB2 grid to a 27 second 282 arc grid. A subsection of this region was then replaced by 9second283 data which was generated by sub-sampling the 3second of arc grid from284 NOAA. A subset of the 9 second grid was replaced by the 3second281 arc grid. A subsection of this region was then replaced by nine second 282 data which was generated by sub-sampling the three second of arc grid from 283 NOAA. A subset of the nine second grid was replaced by the three second 285 284 data. Finally, the one second grid was used to approximate the 286 285 bathymetry in Patong Bay and the immediately adjacent regions. Any … … 288 287 deleted. 289 288 290 The sub-sampling of larger grids was performed by using {\bf resample} 289 The sub-sampling of larger grids was performed by using {\bf resample}, 291 290 a Generic Mapping Tools (\textsc{GMT}) program (\cite{wessel98}). The 292 gridding of data was performed using {\bf Intrepid} a commercial291 gridding of data was performed using {\bf Intrepid}, a commercial 293 292 geophysical processing package developed by Intrepid Geophysics. The 294 293 gridding scheme employed the nearest neighbour algorithm followed by … … 335 334 336 335 \subsection{Inundation} 337 Inundation refers to the final stages of the evolution a tsunami and336 Inundation refers to the final stages of the evolution of a tsunami and 338 337 covers the propagation of the tsunami in shallow coastal water and the 339 subsequent run-up on 338 subsequent run-up onto land. This process is typically the most 340 339 difficult of the three stages to model due to thin layers of water 341 340 flowing rapidly over dry land. Aside from requiring robust solvers … … 346 345 benchmark the authors have obtained a high resolution bathymetry and 347 346 topography data set and a high quality inundation survey map from the 348 CCOP in Thailand (\cite{szczucinski06}) which can be used to validate 349 model inundation. 347 CCOP in Thailand (\cite{szczucinski06}) to validate model inundation. 350 348 351 349 The datasets necessary for reproducing the results 352 of the inundation stage are available on Sourceforge under the ANUGA350 of the inundation stage are available on Sourceforge under the \textsc{anuga} 353 351 project (\url{http://sourceforge.net/projects/anuga}). At the time of 354 352 writing the direct link is \url{http://tinyurl.com/patong2004-data}. … … 362 360 Bay. This elevation data was again created from the digitised Thai 363 361 Navy bathymetry chart, no 358. A visualisation of the elevation data 364 set used in Patong bay is shown in362 set used in Patong Bay is shown in 365 363 Figure~\ref{fig:patong_bathymetry}. The continuous topography is an 366 364 interpolation of known elevation measured at the coloured dots. … … 375 373 376 374 \subsubsection{Buildings and Other Structures} 377 Human 375 Human-made build and structures can significantly effect tsunami 378 376 inundation. The location and size and number of floors of the 379 377 buildings in Patong Bay were extracted from a GIS data set provided by … … 384 382 \subsubsection{Inundation Survey} 385 383 Tsunami run-up is often the cause of the largest financial and human 386 losses yet run-up data that can be used to validate model runup387 predictions is scarce. Of the two field benchmarks proposed by388 Synolakisonly the Okushiri benchmark facilitates comparison between384 losses, yet run-up data that can be used to validate model run-up 385 predictions is scarce. Of the two field benchmarks proposed in~\cite{synolakis07}, 386 only the Okushiri benchmark facilitates comparison between 389 387 modelled and observed run-up. One of the major strengths of the 390 benchmark proposed here is that modelled run up can be compared to an391 inundation survey which maps the maximum run-up along an entire coast 392 linerather than at a series of discrete sites. The survey map is388 benchmark proposed here is that modelled run-up can be compared to an 389 inundation survey which maps the maximum run-up along an entire coastline 390 rather than at a series of discrete sites. The survey map is 393 391 shown in Figure~\ref{fig:patongescapemap} and plots the maximum run-up 394 of the 2004 tsunami in Patong bay. Refer to Szczucinski et392 of the 2004 tsunami in Patong Bay. Refer to Szczucinski et 395 393 al~\cite{szczucinski06} for further details. 396 394 … … 398 396 Eyewitness accounts detailed in~\cite{papadopoulos06} 399 397 report that most people at Patong Beach observed an initial retreat of 400 the shoreline of more than 100 m followed a few minutes later by a398 the shoreline of more than 100 m followed a few minutes later, by a 401 399 strong wave (crest). Another less powerful wave arrived another five 402 400 or ten minutes later. Eyewitness statements place the arrival time of … … 413 411 which include footage of the tsunami in Patong Bay on the day 414 412 of the Indian Ocean Tsunami. Both videos show an already inundated 415 group of buildings , they thenshow what is to be assumed as the second416 and third waves approaching and further flooding the buildings and417 street. The first video is in the very north filmed from what is413 group of buildings. They also show what is to be assumed as the second 414 and third waves approaching and further flooding of the buildings and 415 street. The first video is in the very north, filmed from what is 418 416 believed to be the roof of the Novotel Hotel marked ``north'' in Figure 419 \ref{fig:gauge_locations}. The second video is in the very south 417 \ref{fig:gauge_locations}. The second video is in the very south, 420 418 filmed from the second story of a building next door to the Comfort 421 419 Resort near the corner of Ruam Chai St and Thaweewong Road. This 422 location is marked ``south'' in Figure \ref{fig:gauge_locations} and420 location is marked ``south'' in Figure \ref{fig:gauge_locations}. 423 421 Figure~\ref{fig:video_flow} shows stills from this video. Both videos 424 422 were used to estimate flow speeds and inundation depths over time. … … 465 463 should reproduce the following behaviour: 466 464 \begin{itemize} 467 \item Reproduce the vertical deformation observed in north-western468 Sumatra and along the Nicobar--Andaman islands ,see469 Section~\ref{sec:gen_data} .470 \item Reproduce the \textsc{jason} satellite altimetry sea surface471 anomalies , see Section~\ref{sec:data_jason}.472 \item Reproduce the inundation survey map in Patong bay465 \item reproduce the vertical deformation observed in north-western 466 Sumatra and along the Nicobar--Andaman islands (see 467 Section~\ref{sec:gen_data}). 468 \item reproduce the \textsc{jason} satellite altimetry sea surface 469 anomalies (see Section~\ref{sec:data_jason}). 470 \item reproduce the inundation survey map in Patong bay 473 471 (Figure~\ref{fig:patongescapemap}). 474 \item Simulate a leading depression followed by two distinct crests472 \item simulate a leading depression followed by two distinct crests 475 473 of decreasing magnitude. 476 \item Predict the water depths and flow speeds, at the locations of474 \item predict the water depths and flow speeds, at the locations of 477 475 the eye-witness videos, that fall within the bounds obtained from 478 476 the videos. … … 489 487 Numerous models are currently used to model and predict tsunami 490 488 generation, propagation and run-up~\cite{titov97a,satake95}. Here we 491 introduce the modelling methodology employed by Geoscience Australia 492 to illustrate the utility of the proposed benchmark. Geoscience 493 Australia's tsunami modelling methodology comprises the three parts; 494 generation, propagation and inundation 495 (Sections~\ref{sec:modelGeneration},\ref{sec:modelPropagation} and 496 \ref{sec:modelInundation} respectively). 489 introduce the three part modelling methodology employed by Geoscience Australia 490 to illustrate the utility of the proposed benchmark. 497 491 498 492 \subsection{Generation}\label{sec:modelGeneration} … … 500 494 There are various approaches to modelling the expected crustal 501 495 deformation from an earthquake at depth. Most approaches model the 502 earthquake as a dislocation in a linear ,elastic medium. Here we use496 earthquake as a dislocation in a linear elastic medium. Here we use 503 497 the method of Wang et al~\cite{wang03}. One of the main advantages 504 498 of their method is that it allows the dislocation to be located in a … … 524 518 subfault. This step is possible because of the linearity of the 525 519 governing equations. For this study, we have made minor modifications 526 to \textsc{edcmp} in order for it to output in a file format527 compatible with the propagation code in the following section butit528 is otherwise thesimilar to the original code.520 to \textsc{edcmp} in order for it to provide output in a file format 521 compatible with the propagation code in the following section. Otherwise it 522 is similar to the original code. 529 523 530 524 In order to calculate the crustal deformation using these codes we 531 thus need to have a model describingthe variation in elastic525 need a model that describes the variation in elastic 532 526 properties with depth and a slip model of the earthquake to describe 533 527 the dislocation. The elastic parameters used for this study are the 534 528 same as those in Table 2 of Burbidge~\cite{burbidge08}. For the slip 535 529 model, there are many possible models for the 2004 Andaman--Sumatran 536 earthquake to choosefrom530 earthquake to select from 537 531 ~\cite{chlieh07,asavanant08,arcas06,grilli07,ioualalen07}. Some are 538 determined from various geological surveys of the site , others solve532 determined from various geological surveys of the site. Others solve 539 533 an inverse problem which calibrates the source based upon the tsunami 540 wave signal, the seismic signal and/or the run up. The source534 wave signal, the seismic signal and/or the run-up. The source 541 535 parameters used here to simulate the 2004 Indian Ocean tsunami were 542 taken from the slip model G-M9.15 fromChlieh536 taken from the slip model G-M9.15 of Chlieh 543 537 et al~\cite{chlieh07}. This model was created by inversion of wide 544 538 range of geodetic and seismic data. The slip model consists of 686 … … 548 542 discussion of this model and its derivation. Note that the geodetic 549 543 data used in the validation was also included by~\cite{chlieh07} in 550 the inversion used to find G-M9.15 , thus the validation is not551 completely independent. However, a successfulvalidation would still544 the inversion used to find G-M9.15. Thus the validation is not 545 completely independent. However, a reasonable validation would still 552 546 show that the crustal deformation and elastic properties model used 553 547 here is at least as valid as the one used by Chlieh … … 558 552 We use the \textsc{ursga} model described below to simulate the 559 553 propagation of the 2004 tsunami in the deep ocean ocean, based on a 560 discrete representation of the initial deformation of the sea floor, 554 discrete representation of the initial deformation of the sea floor, as 561 555 described in Section~\ref{sec:modelGeneration}. For the models shown 562 556 here, we assume that the uplift is instantaneous and creates a wave of … … 565 559 \subsubsection{URSGA} 566 560 \textsc{ursga} is a hydrodynamic code that models the propagation of 567 the tsunami in deep water using a finite difference method on a staggered grid 568 to solve 569 the depth integrated linear or nonlinear shallow water equations in 561 the tsunami in deep water using a finite difference method on a staggered grid. 562 It solves the depth integrated linear or nonlinear shallow water equations in 570 563 spherical co-ordinates with friction and Coriolis terms. The code is 571 564 based on Satake~\cite{satake95} with significant modifications made by … … 596 589 \subsubsection{ANUGA} 597 590 \textsc{Anuga} is an Open Source hydrodynamic inundation tool that 598 solves the conserved form of the depth 591 solves the conserved form of the depth-integrated nonlinear shallow 599 592 water wave equations. The scheme used by \textsc{anuga}, first 600 593 presented by Zoppou and Roberts~\cite{zoppou99}, is a high-resolution … … 620 613 %================Section=========================== 621 614 \section{Results}\label{sec:results} 622 This section presents a validation of the modelling practice of Geoscience Australia against the new proposed benchmarks. The criteria outlined in Section~\ref{sec:checkList} are addressed for each three stages of tsunami evolution. 615 This section presents a validation of the modelling practice of Geoscience 616 Australia against the new proposed benchmarks. The criteria outlined 617 in Section~\ref{sec:checkList} are addressed for each of the three stages 618 of tsunami evolution. 623 619 624 620 \subsection{Generation}\label{modelGeneration} … … 632 628 the areas that were observed to uplift (arrows pointing up) or subside 633 629 (arrows point down) during and immediately after the earthquake. Most 634 of this data comes uplifted or subsided coral heads. The length of635 vector increases with the magnitude of the displacement ,the length630 of this data comes from uplifted or subsided coral heads. The length of 631 vector increases with the magnitude of the displacement; the length 636 632 corresponding to 1 m of observed motion is shown in the top right 637 633 corner of the figure. As can be seen, the source model detailed in … … 646 642 points) is only 0.06 m, well below the typical error of the 647 643 observations of between 0.25 and 1.0 m. However, the occasional point 648 has quite a large error (over 1 m) ,for example a couple644 has quite a large error (over 1 m); for example a couple 649 645 uplifted/subsided points appear to be on a wrong side of the predicted 650 646 pivot line~\ref{fig:surface_deformation}. The excellence of the fit is 651 647 not surprising, since the original slip model was chosen 652 by~\cite{chlieh07} to fit this (and the seismic data) well. However,653 this does demonstratethat \textsc{edgrn} and our modified version of648 by~\cite{chlieh07} to fit this (and the seismic data) well. 649 This does demonstrate, however, that \textsc{edgrn} and our modified version of 654 650 \textsc{edstat} can reproduce the correct pattern of vertical 655 651 deformation very well when the slip distribution is well constrained … … 664 660 based on the slip model, G-M9.15. The black arrows which point up 665 661 show areas observed to uplift during and immediately after the 666 earthquake , those pointdown are locations which subsided. The667 length of increases with the magnitude of the deformation. The arrow662 earthquake; those pointing down are locations which subsided. The 663 length of the arrow increases with the magnitude of the deformation. The arrow 668 664 length corresponding to 1 m of deformation is shown in the top right 669 hand corner of the figure. The cross esmarks show the location of665 hand corner of the figure. The cross marks show the location of 670 666 the pivot line (the region between the uplift and subsided region 671 667 where the uplift is zero) derived from remote sensing. All the 672 observational data come from the dataset collated668 observational data are from the dataset collated 673 669 by~\cite{chlieh07}.} 674 670 \label{fig:surface_deformation} … … 685 681 1335$\times$1996 finite difference points. Inside this grid, a nested 686 682 sequence of grids was used. The grid resolution of the nested grids 687 went from 27 arc seconds in the coarsest grid, down to 9arc seconds688 in the second grid, 3 arc seconds in the third grid and finally 1arc683 went from 27 arc seconds in the coarsest grid, down to nine arc seconds 684 in the second grid, three arc seconds in the third grid and finally one arc 689 685 second in the finest grid near Patong. The computational domain is 690 686 shown in Figure~\ref{fig:computational_domain}. 691 687 692 688 Figure \ref{fig:jasonComparison} provides a comparison of the 693 \textsc{ursga} 689 \textsc{ursga}-predicted sea surface elevation with the JASON 694 690 satellite altimetry data. The \textsc{ursga} model replicates the 695 amplitude and timing of the the wave observed at 2.5 degreesSouth,691 amplitude and timing of the the wave observed at $2.5^0$ South, 696 692 but underestimates the amplitude of the wave further to the south at 697 4 degreesSouth. In the model, the southern most of these two waves698 appears only as a small bump in the cross section of the model shown699 in Figure~\ref{fig:jasonComparison} instead of being a distinct peak693 $4^0$ South. In the model, the southern most of these two waves 694 appears only as a small bump in the cross section of the model (shown 695 in Figure~\ref{fig:jasonComparison}) instead of being a distinct peak 700 696 as can be seen in the satellite data. Also note 701 697 that the \textsc{ursga} model prediction of the ocean surface 702 elevation becomes out of phase with the JASON data at 3 to 7 degrees703 latitude. Chlieh et al~\cite{chlieh07} also observe these misfits and698 elevation becomes out of phase with the JASON data at $3^0$ to $7^0$ North 699 latitude. Chlieh et al~\cite{chlieh07} also observed these misfits and 704 700 suggest it is caused by a reflected wave from the Aceh Peninsula that 705 701 is not resolved in the model due to insufficient resolution of the … … 711 707 \begin{center} 712 708 \includegraphics[width=12.0cm,keepaspectratio=true]{jasonComparison.jpg} 713 \caption{Comparison of the \textsc{ursga} 709 \caption{Comparison of the \textsc{ursga}-predicted surface elevation 714 710 with the JASON satellite altimetry data. The \textsc{ursga} wave 715 711 heights have been corrected for the time the satellite passed … … 720 716 721 717 \subsection{Inundation} 722 After propagating the tsunami in the open ocean using \textsc{ursga} 718 After propagating the tsunami in the open ocean using \textsc{ursga}, 723 719 the approximated ocean and surface elevation and horisontal flow 724 720 velocities were extracted and used to construct a boundary condition … … 752 748 The boundary condition at each side of the domain towards the south 753 749 and the north where no data was available was chosen as a transmissive 754 boundary condition effectively replicating the time dependent wave750 boundary condition, effectively replicating the time dependent wave 755 751 height present just inside the computational domain. Momentum was set 756 752 to zero. Other choices include applying the mean tide value as a 757 Dirichlet type boundary condition but experiments as well as the753 Dirichlet type boundary condition. But experiments as well as the 758 754 result of the verification reported here showed that this approach 759 tends to under 760 wave near the side boundaries whereas the transmissive boundary755 tends to underestimate the tsunami impact due to the tempering of the 756 wave near the side boundaries, whereas the transmissive boundary 761 757 condition robustly preserves the wave. 762 758 … … 785 781 the inundation boundary of the survey is likely to vary significantly 786 782 and somewhat unpredictably. 787 Consequently, an inundation threshold of 10 cmwas selected for inundation783 An inundation threshold of 10 cm therefore was selected for inundation 788 784 extents reported in this paper to reflect 789 the more likely accuracy of the survey and subsequently facilitate a more785 the more likely accuracy of the survey, and subsequently facilitate a more 790 786 appropriate comparison between the modelled and observed inundation 791 787 area. … … 794 790 795 791 796 An animation of this simulation is available on the ANUGAwebsite at \url{https://datamining.anu.edu.au/anuga} or directly from \url{http://tinyurl.com/patong2004}.792 An animation of this simulation is available on the \textsc{anuga} website at \url{https://datamining.anu.edu.au/anuga} or directly from \url{http://tinyurl.com/patong2004}. 797 793 798 794 %\url{https://datamining.anu.edu.au/anuga/attachment/wiki/AnugaPublications/patong_2004_indian_ocean_tsunami_ANUGA_animation.mov}. … … 808 804 \end{figure} 809 805 810 To quantify the agreement between observed and simulated inundation we806 To quantify the agreement between the observed and simulated inundation we 811 807 introduce the measure 812 808 \begin{equation} 813 809 \rho_{in}=\frac{A(I_m\cap I_o)}{A(I_o)} 814 810 \end{equation} 815 representing the ratio $\rho_{in}$ of observed811 representing the ratio $\rho_{in}$ of the observed 816 812 inundation region $I_o$ captured by the model $I_m$. Another useful 817 813 measure is the fraction of the modelled inundation area that falls … … 821 817 \end{equation} 822 818 These values for the two aforementioned simulations are given in 823 Table~\ref{table:inundationAreas}. High value of both $\rho_{in}$ and $\rho_{out}$ indicate s819 Table~\ref{table:inundationAreas}. High value of both $\rho_{in}$ and $\rho_{out}$ indicate 824 820 that the model overestimates the impact whereas low values of both quantities would indicate 825 821 an underestimation. A high value of $\rho_{in}$ combined with a low value of $\rho_{out}$ 826 822 indicates a good model prediction of the survey. 827 823 828 Discrepancies between the survey data and the modelled inundat ed824 Discrepancies between the survey data and the modelled inundation 829 825 include: unknown distribution of surface roughness, inappropriate 830 826 parameterisation of the source model, effect of humans structures on … … 837 833 \subsection{Eye-witness accounts} 838 834 Figure \ref{fig:gauge_locations} shows four locations where time 839 series have been extracted from the model. The two offshore time series835 series have been extracted from the model. The two offshore time series 840 836 are shown in Figure \ref{fig:offshore_timeseries} and the two onshore 841 837 timeseries are shown in Figure \ref{fig:onshore_timeseries}. The … … 856 852 \includegraphics[width=10.0cm,keepaspectratio=true]{gauge_bay_depth.jpg} 857 853 \includegraphics[width=10.0cm,keepaspectratio=true]{gauge_bay_speed.jpg} 858 \caption{Time series obtained from the two offshore locations shown in Figure \protect \ref{fig:gauge_locations}.}854 \caption{Time series obtained from the two offshore locations shown in Figure \protect \ref{fig:gauge_locations}.} 859 855 \end{center} 860 856 \label{fig:offshore_timeseries} … … 865 861 \includegraphics[width=10.0cm,keepaspectratio=true]{gauges_hotels_depths.jpg} 866 862 \includegraphics[width=10.0cm,keepaspectratio=true]{gauges_hotels_speed.jpg} 867 \caption{Time series obtained from the two onshore locations shown in Figure \protect \ref{fig:gauge_locations}.}863 \caption{Time series obtained from the two onshore locations shown in Figure \protect \ref{fig:gauge_locations}.} 868 864 \end{center} 869 865 \label{fig:onshore_timeseries} … … 924 920 and the presence and absence of buildings in the elevation dataset on 925 921 model maximum inundation. The reference model is the one reported in 926 Figure~\ref{fig:inundationcomparison1cm} (right) with friction =0.01,922 Figure~\ref{fig:inundationcomparison1cm} (right) with a friction coefficient of 0.01, 927 923 buildings included and the boundary condition produced by the URSGA model. 928 924 … … 935 931 for tsunami propagation over a sandy sea floor and the reference model 936 932 uses a value of 0.01. To investigate sensitivity to this parameter, 937 we simulated the maximum onshore inundation using thea Manning's933 we simulated the maximum onshore inundation using a Manning's 938 934 coefficient of 0.0003 and 0.03. The resulting inundation maps are 939 935 shown in Figure~\ref{fig:sensitivity_friction} and the maximum flow … … 942 938 friction and that small perturbations in the friction cause bounded 943 939 changes in the output. This is consistent with the conclusions of 944 Synolakis~\cite{synolakis05} who statesthat the long wavelength of945 tsunami tends to mean that thefriction is less important in940 Synolakis~\cite{synolakis05} et al, who state that the long wavelength of 941 tsunami tends to mean that friction is less important in 946 942 comparison to the motion of the wave. 947 943 948 944 %========================Wave-Height==========================% 949 945 \subsection{Input Wave Height}\label{sec:waveheightSA} 950 The effect of the wave -height used as input to the inundation model946 The effect of the wave height used as input to the inundation model 951 947 \textsc{anuga} was also investigated. 952 948 Figure~\ref{fig:sensitivity_boundary} indicates that the inundation 953 949 severity is directly proportional to the boundary waveheight but small 954 perturbations in the input wave -height of 10 cm appear to have little950 perturbations in the input wave height of 10 cm appear to have little 955 951 effect on the final on-shore run-up. Obviously larger perturbations 956 952 will have greater impact. However, this value is generally well … … 966 962 shows the maximum run-up and associated flow speeds in the presence and absence of buildings. It 967 963 is apparent that the inundation is much more severe when the presence 968 of man made structures and buildings are ignored.964 of human made structures and buildings are ignored. 969 965 970 966 \begin{table} … … 992 988 This paper proposes an additional field data benchmark for the 993 989 verification of tsunami inundation models. Currently, there is a 994 scarcity of appropriate validation datasets due to a lack of well 995 documentedhistorical tsunami impacts. The benchmark proposed here990 scarcity of appropriate validation datasets due to a lack of well-documented 991 historical tsunami impacts. The benchmark proposed here 996 992 utilises the uniquely large amount of observational data for model 997 993 comparison obtained during, and immediately following, the 998 Sumatra--Andaman tsunami of 26 thDecember 2004. Unlike the small994 Sumatra--Andaman tsunami of 26 December 2004. Unlike the small 999 995 number of existing benchmarks, the proposed test validates all three 1000 996 stages of tsunami evolution - generation, propagation and 1001 997 inundation. In an attempt to provide higher visibility and easier 1002 accessibility for tsunami benchmark problems the data used to998 accessibility for tsunami benchmark problems, the data used to 1003 999 construct the proposed benchmark is documented and freely available at 1004 1000 \url{http://tinyurl.com/patong2004-data}. … … 1015 1011 1016 1012 A simple sensitivity analysis was performed to assess the influence of 1017 small changes in friction, wave -height at the 100 m depth contour and1013 small changes in friction, wave height at the 100 m depth contour and 1018 1014 the presence of buildings and other structures on the model 1019 1015 predictions. The presence of buildings has the greatest influence on 1020 1016 the simulated inundation extent. The value of friction and small 1021 perturbations in the waveheight at the ANUGAboundary have1017 perturbations in the waveheight at the \textsc{anuga} boundary have 1022 1018 comparatively little effect on the model results. 1023 1019 … … 1058 1054 \includegraphics[width=6cm,keepaspectratio=true]{sensitivity_minus10cm_depth} 1059 1055 \includegraphics[width=6cm,keepaspectratio=true]{sensitivity_plus10cm_depth} 1060 \caption{Model results with wave height at ANUGAboundary artificially1061 modified to asses sensitivities. The reference inundation extent is shown in Figure1056 \caption{Model results with wave height at \textsc{anuga} boundary artificially 1057 modified to assess sensitivities. The reference inundation extent is shown in Figure 1062 1058 \protect \ref{fig:reference_model} (left). The left and right images 1063 show the inundation results if the wave at the ANUGAboundary1059 show the inundation results if the wave at the \textsc{anuga} boundary 1064 1060 is reduced or increased by 10cm respectively. The inundation 1065 1061 severity varies in proportion to the boundary waveheight, but the … … 1105 1101 \includegraphics[width=6cm,keepaspectratio=true]{sensitivity_f0_03_depth} 1106 1102 \caption{Model results for different values of Manning's friction 1107 coefficient shown to asses sensitivities. The reference inundation extent for a1103 coefficient shown to assess sensitivities. The reference inundation extent for a 1108 1104 friction value of 0.01 is shown in Figure 1109 1105 \protect \ref{fig:reference_model} (left). The left and right images -
anuga_work/publications/boxing_day_validation_2008/tsunami07.bib
r7287 r7303 602 602 @INPROCEEDINGS{Watts05, 603 603 AUTHOR = {P. Watts and M. Ioualalen and S. Grilli and F. Shi and J. Kirby}, 604 TITLE = "{Numerical Simulation of the December 26, 2004 Indian Ocean605 Tsunami using a Higher-order Boussinesq Model}",604 TITLE = "{Numerical Simulation of the {D}ecember 26, 2004 {I}ndian {O}cean 605 Tsunami using a Higher-order {B}oussinesq Model}", 606 606 BOOKTITLE = {Ocean Waves Measurement and Analysis 5th International 607 607 Symposium}, … … 714 714 } 715 715 716 @ Unpublished{roberts06,717 author = {Roberts, S.G. and Nielsen, O.M. and Jakeman, J. D. },716 @InProceedings{roberts06, 717 author = {Roberts, S.G. and Nielsen, O.M. and Jakeman, J.~D. }, 718 718 title = "{Simulation of Tsunami and Flash Flood}", 719 note = {Accepted for publication in the refereed proceedings of the International Conference on High Performance Scientific Computing: Modeling, Simulation and Optimization of Complex Processes, March 6-10, 2006, Hanoi Vietnam}, 720 year = {2006} 719 year = {2006}, 720 address = {Hanoi, Vietnam}, 721 month = {March}, 722 booktitle = {International Conference on High Performance Scientific Computing: Modeling, Simulation and Optimization of Complex Processes}, 721 723 } 722 724 … … 801 803 @ARTICLE{grilli06, 802 804 AUTHOR = {Grilli, S.T. and Ioualalen, M. and Asavanant, J. and Shi, F. and Kirby, J.T and Watts, P. }, 803 TITLE = "{Source Constraints and Model Simulation of the December 26, 2004 Indian804 Ocean Tsunami}",805 TITLE = "{Source Constraints and Model Simulation of the {D}ecember 26, 2004 {I}ndian 806 {O}cean Tsunami}", 805 807 JOURNAL = {Journal of Waterways, Port, Ocean and Coastal Engineering}, 806 808 YEAR = {2006}, … … 840 842 @Article{ammon05, 841 843 author = {Ammon, C.J. and Ji, C. and Thio, H. and Robinson, D. and Ni, S. and Hjorleifsdottir, V. and Lay, H. and Lay. T. and Das, S. and Helmberger, D. and Ichinose, G. and Polet, J. and Wald, D.}, 842 title = "{Rupture Process of the 2004 Sumatra-Andaman Earthquake}",844 title = "{Rupture Process of the 2004 {S}umatra-{A}ndaman Earthquake}", 843 845 journal = {Science}, 844 846 year = {2005}, … … 875 877 @Article{roberts00, 876 878 author = {Roberts, S.G and Zoppou, C. }, 877 title = "{Robust and efficent solution of the 2 Dshallow water wave equation with domains containg dry beds}",879 title = "{Robust and efficent solution of the 2{D} shallow water wave equation with domains containg dry beds}", 878 880 journal = {The ANZIAM Journal}, 879 881 year = {2000}, … … 902 904 903 905 @Article{wei95, 904 author = {Wei, G. and Kirby, J.T. and Grilli, S.T. and Subramanya, R. },906 author = {Wei, G. and Kirby, J.T. and F, S.T. and Subramanya, R. }, 905 907 title = "{A fully nonlinear {B}oussinesq model for free surface waves. {P}art 1: Highly nonlinear unsteady waves}", 906 908 journal = {Journal of Fluid Mechanics}, … … 911 913 912 914 @article{ioualalen07, 913 title="{Modeling the 26 December 2004 Indian Ocean tsunami: Case study of impact in Thailand}",915 title="{Modeling the 26 {D}ecember 2004 {I}ndian {O}cean tsunami: Case study of impact in {T}hailand}", 914 916 author={Ioualalen, M. and Asavanant, J. and Kaewbanjak, N. and Grilli, S.~T. and Kirby, J.~T. and Watts, P.}, 915 917 year={2007}, … … 931 933 932 934 @article{satake95, 933 title="{Linear and nonlinear computations of the 1992 Nicaragua earthquake tsunami}",935 title="{Linear and nonlinear computations of the 1992 {N}icaragua earthquake tsunami}", 934 936 author={Satake, K.}, 935 937 journal={Pure and Applied Geophysics}, … … 943 945 author = {Schoettle, E. and Sakimoto, S.}, 944 946 title = "{Modeling the Effects of Coral Reef Health on Tsunami Run-up 945 with the Finite-element Model ADCIRC}",947 with the Finite-element Model {ADCIRC}}", 946 948 howpublished = {\url{http://istim.ce.nd.edu/2007/Posters/Schoettle_poster.pdf}}, 947 949 year = {2007}, … … 977 979 institution = {Pacific Marine Environmental Laboratory}, 978 980 year = {2007}, 979 type = { Tecbical Memorandum},981 type = {{T}echnical {M}emorandum}, 980 982 address = {Seattle, WA, USA}, 981 983 month = {May} … … 993 995 994 996 @article{papadopoulos06, 995 title="{The large tsunami of 26 December 2004: Field observations and eyewitnesses accounts from Sri Lanka, Maldives Is. and Thailand}",997 title="{The large tsunami of 26 {D}ecember 2004: Field observations and eyewitnesses accounts from {S}ri {L}anka, {M}aldives {I}s. and {T}hailand}", 996 998 author={Papadopoulos, G.~A. and Caputo, R. and McAdoo, B. and Pavlides, S. and Karastathis, V. Fokaefs, A. and Orfanogiannaki, K. and Valkaniotis, S.}, 997 999 journal={Earth, Planets and Space}, … … 1034 1036 @article { Gower05, 1035 1037 author = "Gower, J.", 1036 title = "Jason 1 detects the 26 december 2004 tsunami",1038 title = "Jason 1 detects the 26 {D}ecember 2004 tsunami", 1037 1039 journal = "EOS", 1038 1040 volume = "86", … … 1044 1046 @Article{burbidge08, 1045 1047 author = {Burbidge, D. and Cummins, P.R. and Mleczko, R. and Thio, H.K.}, 1046 title = "{A Probabilistic Tsunami Hazard Assessment for Western Australia}",1048 title = "{A Probabilistic Tsunami Hazard Assessment for {W}estern {A}ustralia}", 1047 1049 journal = {Pure appl. geophys.}, 1048 1050 year = {2008}, … … 1054 1056 @Article{thio08, 1055 1057 author = {Thio, H.K. and Somerville, P. and Inchinose, G.}, 1056 title = "{Probabilistic analysis of tsunami hazards in southeast Asia}",1058 title = "{Probabilistic analysis of tsunami hazards in {S}outheast {A}sia}", 1057 1059 journal = {J. 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Res. Lett.}, 1096 1098 year = {2006}, … … 1104 1106 Rachlewicz, G. and Saisuttichai, D. and Tepsuwan, T. and Lorenc, S. 1105 1107 and Siepak, J.}, 1106 TITLE = "{Environmental and geological impacts of the 26 December 2004 tsunami in coastal zone of Thailand - overview of short and long-term effects}",1108 TITLE = "{Environmental and geological impacts of the 26 {D}ecember 2004 tsunami in coastal zone of {T}hailand - overview of short and long-term effects}", 1107 1109 JOURNAL = {Polish Journal of Environmental Studies}, 1108 1110 YEAR = {2006},
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