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17      <td>
18        <H1>Tsunami Inundation Models for the GOSFORD region</H1>
19      </td>
20    </tr>
21  </table>
22  <hr>
24  <a name="modifications"><h2><b>Modifying a simulation</b></h2></a>
26  Here we talk about how you change a simulation.  Why would you need to change a simulation?  Well,
27  you might have some better elevation data, you want to run the simulation on a finer mesh in certain
28  areas, or maybe you want to see the result for different events.
29  <p>
30  First we describe the uses of the script files you might change, then we walk through a few examples
31  of changes you might make.
32  <p>
34  <a name="project_files"><h3><b>The project scripts</b></h3></a>
36  In the <b>project</b> directory are the scripts that control the simulation.  These scripts are:
37  <table class="code">
38    <tr><td><font color="red"></font></td><td>Defines the input data used, where to place output, etc.</td></tr>
39    <tr><td><font color="red"></font></td><td>Builds a PTS file of all elevation data specified by <font color="red"></font></td></tr>
40    <tr><td><font color="red"></font></td><td>Prepares the simulation before actually running it</td></tr>
41    <tr><td><font color="red"></font></td><td>Runs the simulation</td></tr>
42  </table>
44  <a name=""><h4><b></b></h4></a>
46    This file is the heart of the simulation. The project script introduces all files that are necessary to run all accompanying scripts.
47    By changing one of the variables in this script the output could be completely different.
48    For further details on changing parameters see <a href="#change">Making changes to a simulation</a>.
50<!--  This file is the heart of the simulation.  Here we specify many things, including the tide level, the simulation
51  start and stop times, input data files, and so on.  Because we are using python as the programming language in
52  these files, we can use the power of the language to speed up our development.  We use this by <i>parameterising</i>
53  data as much as possible.
54  <p>
55  Parameters that you might change
56  As an example, let's look at the <b>scenario_name</b> variable we define in <font color="red"></font>:
57  <table class="code">
58    <tr><td>scenario_name = 'hobart'&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;# name of the scenario</td></tr>
59  </table>
60  <p>
61  We define this variable solely to quickly change other input filenames.  Where we want a different input files for
62  a different scenario,
63  depending on whether we want a 'small' or 'large' model, we build the filenames using the <b>model</b> variable.
64  Some examples are:
65  <p>
66  <table class="code">
67    <tr height="25"><td>bounding_polygon_filename = 'bounding_polygon_'+ model + '.csv'</td></tr>
68    <tr height="25"><td>land_initial_conditions_filename = [['initial_conditions_' + model +'.csv', 0]]</td></tr>
69    <tr height="25"><td>landward_boundary_filename = 'landward_boundary_'+ model +'.csv'</td></tr>
70  </table>
71  <p>
72  We must, of course, ensure that there are input files <font color="red">bounding_polygon_small.csv</font>
73  and <font color="red">bounding_polygon_large.csv</font>, and so on.
74  <p>
75  Now, if we need to change the simulation model from 'small' to 'large', we need only change the
76  value of the <b>model</b> variable, and all the input files that depend on the model will change.
77  This speeds up development and make errors less likely.  If you want to add another model to the two
78  we show above, just set <b>model</b> to 'medium' and create appropriate input files with the string
79  'medium' in the filename. -->
81  <a name=""><h4><b></b></h4></a>
83  This script combines all input elevation files into one PTS file.
84  We have provided you with the PTS file used to create the outputs on this DVD.
85  If you would like to change the elevation see <a href="#change">Making changes to a simulation</a>.
86  <p>
88  <a name=""><h4><b></b></h4></a>
90  This script is used to transform data into a specific format for <font color="red"></font>,
91  if required, and to generate warning messages if you are missing data.
92  <p>
94  <a name=""><h4><b></b></h4></a>
96  This script runs a tsunami inundation scenario.  It relies on the parameters set in <font color="red"></font>
97  as well as the PTS and STS files.
98  An STS file has been generated for each event listed in the boundaries directory. For further details on events see
99  <a href="#change">Making changes to a simulation</a>.
100  <p>
102  <a name="change"><h3><b>Making changes to a simulation</b></h3></a>
104  There are many parameters that you can change within the <font color="red"></font> script,
105  but the following four parameters are those most commonly changed.
106  <p>
108  <a name="tide"><h4><b>Tide</b></h4></a>
110  The <b>tide</b> parameter is used to change the mean stage of the simulation.  When <b>tide</b> is set to 0
111  the initial water level will be at Mean Sea Level.  If you increase the <b>tide</b> value the water level will become deeper.
112  However land is masked out using initial conditions.  Within ANUGA <b>tide</b> is modelled as a constant.
113  <p>
115  <a name="events"><h4><b>Events</b></h4></a>
117  The <b>event_number</b> variable contains the event number that initiates the tsunami we are modelling.
118  You can change <b>event_number</b> to any event number in the anuga/boundaries directory.
119  As we said above, a new STS file must be generated for <font color="red"></font> to work.
120  <p>
121  The event numbers correspond to a quake ID from the probabilistic tsunami hazard map of Australia.
122  <table class="code">
123    <tr><td><pre>event_number = 51436    # 1 in 10000 yr event from New Hebrides</pre></td></tr>
124  </table>
125  <p>
127  <a name="elevation"><h4><b>Elevation</b></h4></a>
129  Elevation data can be changed in the <font color="red"></font> elevation script.
130  Elevation data can be read as either a point file, comma delimited, or as an ASCII grid file
131  (ASC) with an accompanying projection file (PRJ). All elevation input must be projected in the correct UTM zone.
132  <p>
134  A header for a CSV file has the format:
135  <table class="code">
136    <tr><td><pre>x,y,elevation</pre></td></tr>
137  </table>
138  <p>
140  An ASC file header has the format:
141  <table class="code">
142    <tr><td><pre>ncols         868
143nrows         856
144xllcorner     418933.86055096
145yllcorner     5151810.6668096
146cellsize      250
147NODATA_value  -9999</pre></td></tr>
148  </table>
149  <p>
151  The header of a PRJ file has the format:
152  <table class="code">
153    <tr><td><pre>Projection    UTM
154Zone          55
155Datum         D_GDA_1994
156Zunits        NO
157Units         METERS
158Spheroid      GRS_1980
159Xshift        500000
160Yshift        10000000
162  </table>
163  <p>
165  The elevation filenames must be listed in either <b>point_filenames</b> or <b>ascii_grid_filenames</b>
166  depending on their format. Point files need to have their extension shown however the ascii grid files have the .asc extension assumed:
167  <table class="code">
168    <tr><td><pre>point_filenames = ['SD100031996_jgriffin_clip.csv',
169                   'tomaga_offshore_AHD_MGA_1997.csv',
170                   'gosford_BBHD_MGA_1995.csv',
171                   'gosford_AHD_MGA_2000.csv']
173ascii_grid_filenames = ['sd100031996_p',
174                        'sd100031996_p2',
175                        'sd100031996_p3',
176                        'sd100031996_p4']</pre></td></tr>
177  </table>
178  <p>
180  For further information on ANUGA file formats please see the ANUGA User Manual, section 6.1.
181  <p>
183  <a name="interior_regions"><h4><b>Interior regions</b></h4></a>
185  The <b>interior_regions</b> parameter allows you to change the mesh of the model.
186  <p>
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