How to produce an orographic map of Sri Lanka using CDT

 What is Orography?

"Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as oreography, orology or oreology) falls within the broader discipline of geomorphology."
- Wikipedia, the free encyclopedia

For more Information:

Producing Orographic map of Sri Lanka 

Step 1: Download Digital Elevation Model of the Sri Lanka

- First of all, we have to download a netCDF file for the digital elevation model of the Sri Lanka. 


Downloading the Digital Elevation Model


- You Can See a window as follows. Input the Maximum and Minimum Longitude and Latitude in shown no 1 as follows. Then give the path to save netCDF file. (It stores in Documents file as default.)


- If we follow the steps correctly, it shows that files are downloading in the bottom of the CDT.


Step 2: Download the Country Administrative Boundaries.

 - In this step We have to download a shape map of Sri Lanka.

Downloading the shape map of Sri Lanka


- Select the Region and the country in appeared window. In the "Select level subdivisions", you can download the map which you want by selecting the level. (1-District-wise, 2-Division-wise). Then select the path to save the file and then click "Download".



Note: It is easy to download and keep shape files of all levels. Then you can use whenever you want. So that you have to follow this step for each level.

Step 3: Plot netCDF data

- Go to the following path to open the Plot NetCDF Data pane.


- Give the path of the NetCDF file by using shown button below.

Plot NetCDF Data pane


- When we download the digital elevation model, two files are downloaded. We can see those files as follows.


Choosing the .nc file


- Choose the following inputs in the appeared window and click "OK". 


Data Import Options


Note: If you choose DEM_2 file in the previous step, the window of "Data Import Options" will be little bit different than this. Choose "X" as Longitude and "Y" as Latitude in the appeared window 

- Now you can see that the selected file has appeared in the selection list.



1- You can change the file and make other changes (Ex: adding title; changing color scale etc.) by clicking "Options". Also after doing all changes you can click "Plot" to visualize the map.
2- In this you can provide maps with outside or blanked outside the country boundary.
3- In this place you can add a shape map of the country to the orographic map. 

Step 4: Save images of the Orographic maps

- Go to the following path.
        File → Save image as...

- You can see a window as follows.


- You can make changes of the images by using this window. The maps which shown below has 1000px width, 1000px height and 120 resolution.
 
 

Examples of some Orographic maps produced using CDT

- Following are some examples of Orographics maps produced using CDT.

District Level (Blanked outside the country boundaries)

District Level (with outside the country boundaries)
 
Division Level (Blanked outside the country boundaries)

Division Level (with outside the country boundaries)
















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