How to create a model gridded bathymetry?
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How to create a model gridded bathymetry?
Contents
Step 1 - Extract Ocean bathymetry data from ETOPO 2'
Google Earth
Make sure you have Google Earth correctly configured!!
- Obtain the ETOPO 2' extraction domain limits by reading the Max and Min values of Longitude and Latitude for your domain from Google Earth.
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/091fbeaa-1c4a-445a-a501-970eec891e3c/2008-09-25_1729.png)
Etopo data file
- The internet address where to download the data is http://www.ngdc.noaa.gov/mgg/global/global.html;
- Download the ETOPO2V2 raw binary data to use with the ConvertToXYZ program OR, if possible, rather use the intranet address which is \\kepler\DataCenter1\DataCenter\DadosBase\Oceanografia\Batimetria\Etopo\Etopo2\Data
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/c8db4980-a1dd-4215-b82f-d61475fc9169/2008-09-25_1734.png)
A sample configuration file ConvertToXYZ.dat is:
<begin_window> FILE_TYPE : 2 INPUT_FILENAME : \\kepler\DataCenter1\DataCenter\DadosBase\Oceanografia\Batimetria\Etopo\Etopo2\Data\etopo2.dat OUTPUT_FILENAME : SLouisCoast_ETOPO2.xyz TOP : 17 BOTTOM : 14 LEFT : -18 RIGHT : -14 MAXIMUM : 1 MINIMUM : -9999 WRITE_AS_BATHYMETRY : 1 CONVERT_TO_HDF5 : 0 <end_window>
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/2c6039ac-06d7-4190-a22b-e0bb3b1cc69f/2008-09-25_1738.png)
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/eccf1818-ac75-4528-b819-a059a410fdc2/2008-09-25_1755.png)
- Sample of XYZ data extracted from ETOPO 2'. How the bathymetry XYZ file should look like.
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/2ec3a00d-857b-4116-8d2d-c0f7116e325d/2008-09-25_1812.png)
MOHID GIS
- Open new project in Mohid GIS
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/be419508-098a-402f-8c0a-a1f3e1bae1d6/2008-09-25_1758.png)
- Give name and location to new project, then save
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/7ceffc83-b6ae-4bba-95cd-d8cea4b7434b/2008-09-25_1759.png)
- Add new data item
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/2711bd08-8603-410d-bdee-b5a4a47ac7e9/2008-09-25_1801.png)
- Select data item and open
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/82f96607-836d-4a02-9327-966830d2f8d1/2008-09-25_1803.png)
- Right-click data, zoom select, right-click, properties
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/2c754098-c707-4bd3-80f6-cbb0fc595df4/2008-09-25_1805.png)
- Click on settings to set the colar palette and color range
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/b9d0d1ac-5387-4260-9ac0-687282513d1e/2008-09-25_1817.png)
- Choose min depth (negative if above sea level), max depth and color palette
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/a0295c41-2935-4a63-a69f-7765c0b0ecaa/2008-09-25_1820.png)
- IMPORTANT: Click Save All from the Data Items menu. Otherwise you risk to loose all your work!
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/fa43bb14-6b40-41c5-8fcb-7f8427e8c905/2008-09-25_1837.png)
Step 2 - Create a coast line
Create coast line in Google Earth
- Create a polygon shaped like the line of the coast
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/6ea1a270-cb13-4060-9084-ab8717058c2e/2008-09-25_2015.png)
- Right-click on polygon, then "save as"
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/3320aa3b-f3c0-4bf9-a8a0-573b1c4dd2ce/2008-09-25_1832.png)
- Save the file in Kml format (NOT in Kmz format)
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/ee02f2ac-7d98-455a-8109-dfd34b64ffe1/2008-09-25_1834.png)
Run Kml2mohid
- Get the Kml2Mohid program, edit a batch file, and run the program
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/4ed24f90-dd2b-49bb-8a12-4c94c4212ab4/2008-09-25_1847.png)
- Successfully run Kml2Mohid program.
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/629db22c-73c4-4ef8-81b4-b73f94f0216a/2008-09-25_1852.png)
- Sample polygon (.xy) file
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/f775b5a4-096d-4c4c-b7a1-1912a64d9834/2008-09-25_1854.png)
Import coastline polygon in Mohid
- Click Data Items menu, then select Add Data Items...
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/cf323931-065d-413d-861b-d0b629894908/2008-09-25_1858.png)
- Select folder, select polygon file type, select file and click open
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/034730fe-19e5-4f29-bfbc-aee611411d29/2008-09-25_1901.png)
- Right-click polygon data, then select Properties
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/08500fa8-23c6-48b0-bd03-a03c0dc9e025/2008-09-25_1905.png)
- Click on settings
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/8e606f02-8ad9-46ab-b2eb-82d72164b322/2008-09-25_1907.png)
- Select Constant and choose a color
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/7dbec8eb-e7e3-45ef-b785-58035f416da1/2008-09-25_1908.png)
- Very important: Save All from the Data Items menu
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/8b3323bb-0fef-47b8-afa5-acabdc5cf8dd/2008-09-25_1957.png)
- General look of ETOPO points data layer and coastline polygon layer
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/2173549d-71f1-42a5-a79b-4609575e2baa/2008-09-25_2020.png)
Step 3 - Create the model domain regular grid in MOHID GIS
Define the grid
- Choose bottom-left origin for the model domain
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/14187bbb-1bb9-4f88-9cdc-c24ea63fc7bc/2008-09-25_2032.png)
- Choose model domain grid resolution with Google Earth
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/bd31b051-8358-4bce-8408-3861318924b3/2008-09-25_1942.png)
- Click on Data Item menu, then select New Data Item
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/caf030f5-a5d3-45cb-80ea-08bc2f9e2b39/2008-09-25_1917.png)
- Select Simple Grid, then click on Browse
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/1bbe5e5f-021c-4e4c-b308-7891c341223b/2008-09-25_1920.png)
- Give name, select Grid file as file type, click on Save
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/65818878-26de-493d-b0fa-34282d0c9fa6/2008-09-25_1921.png)
- Click Ok
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/5881fb84-70d9-4fae-b857-a8e7ae15f315/2008-09-25_1924.png)
- Right-click the Grid layer, then select Properties from the menu
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/4fa42c28-082c-421a-aae1-98615bb100e9/2008-09-25_1925.png)
- Define origin, define resolution, define grid size, choose Simple Geographic coordinates type (and NOT Geographic as seen in the figure. CAUTION!)
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/8ee49234-c066-47cd-b82b-47f52bc5a465/2008-09-25_1930.png)
- Very important: Save All from the Data Items menu
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/8b3323bb-0fef-47b8-afa5-acabdc5cf8dd/2008-09-25_1957.png)
- General look of a bathymetry points data from ETOPO, a coastline and land polygon, and a model domain grid
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/b7936c41-8f29-4838-9993-bdff4cb7abad
/2008-09-25_1938.png)
Create Digital Terrain from Mohid GIS
- Click on menu Tools, select Create Digital Terrain ...
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/26403c0a-f816-4b63-bc0c-404821742e3b/2008-09-25_1947.png)
- Select grid layer, data points layers, land polygon layers. Then click Browse
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/17deee31-bb92-4934-8e6b-1572057c6071/2008-09-25_1949.png)
- Choose Options menu, select Triangulation, select All points, click on Run
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/10fe5ab0-8df2-47e5-9eba-306956653b30/2008-09-25_1953.png)
- Successful Done message
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/bd17559d-c349-47be-b0f1-29096dd98a08/2008-09-26_1609.png)
Admire the result
You can now proceed to create a model simulation after you create the tidal gauges
![](http://content.screencast.com/users/GRiflet/folders/Jing/media/4d8b4943-0201-4a20-908d-88beb0327c03/2008-09-25_2022.png)
Next steps
Previous steps
About the screen capturing tool
The screen capturing tool used for this tutorial was the Jing Project.