Module 2.1: Surfaces – TINs and DEMs

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TIN is a vector-based representation of the elevation compared to DEM which is represented as a raster from square pixel/grid squares. The most common used are DEM which is publicly available for the world at around 30m resolution which can also derive a TIN data as TIN is a type of derived DEM. 

DEM visualizes a much softer edges (see left image), feather edge as what we can call it in Photoshop,  compared to TIN that has pointy edges or very defined/jagged edges (see right image). 



Any DEM or TIN is as good input data that can help user to assess elevation, slope and suitability areas. TIN is more accurate in terms of you can take not of sudden change in elevation depending on how close your sampling points are, but DEMs provides real world view of the elevation compared to TIN especially if you have a high-resolution raster imagery of the DEM, which sometimes is hard to find unless captured by a drone. The advantages of DEM is its inability to adapt to areas of differing relief complexity unlike TIN that allows extra data points to use in complex areas. In addition, TINs are vectors compared to DEMs that are often in raster format – when you calculate its contour lines DEMs take more disk usage and renders slower than TINs. 


With ArcGIS Pro, it's easy to geoprocess raster/DEM data compared to TIN as tool are readily available for DEM. Overall, you can use either of the two depending on which form suits your needs better and what processes will you use it for.





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