GIS5935: Mod4 TINs and DEMs

 In this lab, I explored how different elevation models—TINs (Triangulated Irregular Networks) and DEMs (Digital Elevation Models)—represent terrain and how they can be applied in GIS analysis. The exercises emphasized both visualization and analysis, showing the strengths and limitations of each model.

In Part A, I draped a radar image over a TIN of Death Valley, then exaggerated the vertical scale to better highlight subtle landforms. This helped illustrate how 3D visualization can reveal relationships between surface features and elevation patterns.


In Part B, I worked with a DEM to build a ski run suitability map. By reclassifying elevation, slope, and aspect, then combining them with weighted values, I created a raster showing areas most suitable for ski runs. Displaying the result in 3D with appropriate symbology highlighted how terrain factors interact in real-world site selection.


In Part C, I experimented with TIN symbology, adjusting slope, aspect, edges, and contours to better understand how TINs represent terrain data through triangular facets. This showed how flexible TINs are in visualizing different terrain properties.


Finally, in Part D, I created my own TIN from elevation points and compared its contours with those generated from a DEM using spline interpolation. The TIN produced sharper, more angular contours tied to the point distribution, while the DEM resulted in smoother, more continuous lines. The differences were greatest in areas with sparse data and smallest in areas with dense points, with the DEM generally providing a more natural representation of terrain.




Overall, this lab demonstrated how TINs are powerful for working directly with irregular elevation points, while DEMs are more effective for continuous terrain modeling and analysis. Both models are valuable tools in GIS, depending on the project’s goals.

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