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Sunday, 20 April 2014

Story of Mauritius

Final Product: Terrain of the Site
Few days ago, a friend of mine called me, "Danesh, can I get a map of my area - middle of Mauritius?" I said yes without asking much detail. Then, he messaged me, could you focus on Plaines Wilhems (state in Mauritius). With this little detail, I hastily pulled out the datasets required for Mauritius. After all, the concept of producing the map is the same but when it comes datasets, it becomes trickier.

For the terrain data, I relied upon ASTER GDEM. When it came to the roads, boundaries, rivers and lakes, I pulled out from DIVA GIS. You would notice how generalized these datasets (DIVA GIS) look in comparison to the terrain data. This map you see above is 1:100 000 and DIVA GIS datasets weren't exactly the best for the scale context.

One of the challenges I faced was capturing the terrain feeling of this area. This area (Plaines Wilhems) is rising plain area with steep cliffs marking its borders in the west. After much experimenting with the colours, I utilized 10 colour classes to give smooth transition of the terrain (hillshading was pixelated at 1:100 000 scale).

Within 3 hours, the map was completed (with all necessary items added) and emailed to my friend.  He was happy and then he asked me, "Can you do a 3D Model?" From my previous experience, I said yes and thinking in 2 days, a  3D Model would fit his requirement. Turned out, there was problems indeed.

Lessons Learnt:

  1. Do you charge a friend? I am no longer a student and now, I am professional. I am entitled to charge you. That's what you think. Of course, there is nothing wrong except you need to know the restrictions found for the datasets. ASTER GDEM strictly made it clear, you cannot commercialize their datasets. From my understanding, I CANNOT CHARGE a single cent on my friend despite spending 3 hours to make a map. DIVA GIS datasets do not seem to have these restrictions. Can anyone clarify what you mean commercialize in geospatial data context?
  2. Learn to get full details. I am happy to hear that my friend actually researched on when sourcing the terrain data. When he struggled, then he came to me. I should have asked him bit more details of the map project (Does he want 2D or 3D?). In heat of my excitement, I overlooked these information
  3. I do not why ArcScene could not read the elevation heights of the terrain datasets. After all, it has an attribute called value (which is elevation cell). I explored what ArcGIS, QGIS and Google Earth could do representing the 3D Model of the site location. However, I told my friend something is wrong with terrain data and I can't help him on that. Fortunately, he saw the site location was largely flat and the 3D Model would be unnecessary
In short, I was excited to this project but there are couple of lessons learnt when it comes to produce maps for people. I just need someone explain to me why terrain data is not being displayed in 3D format in ArcScene!!