The fourth module in Special Topics in GIS inroduced the topics of creating, editing, and analyszing TINs and DEMs. The goal was to explore how different elevation data models represent terrain and how these representations can be used in spatial analysis.
One of the portions of this week's lab involved utilizing a DEM to develope a 3D ski run suitibility map. By calculating three critical terrain variables: elevation, slope, and aspect, these layers was reclassified to reflect suitability for downhill skiing. For example, higher elevations scored more favorably, slopes between 20° and 45° were rated highly suitable, and north-facing aspects were given priority. These reclassified layers were then combined in a weighted overlay, where elevation was weighted most heavily, followed by slope and aspect.
The result was a ski run suitability map (shown below), which highlights the best areas for potential ski development. Areas in darker colors represent more favorable conditions, while lighter areas represent less suitable terrain. This exercise not only illustrated how elevation data can be modeled differently with TINs and DEMs, but also how those models support real-world decision making when combined with spatial analysis.
Another portion of the lab provided a point feature class that was used to create a TIN model. Contour lines (100m) were then visualized by modifying the symbology. Next, using the Spline tool, the point feature class was used to create a set DEM based contour lines. The two sets of countour lines were then analyzed and compared. Below is a screenshot shot witht he DEM based contour lines depicted in blue and the TIN based contour lines in grey.
Overall I found this week's module to be very helpful in my understanding of elevation models. We had touched on some of these types of elevation models and tools in previous coursework assignments but being able to apply them to real life analysis has been very beneficial.
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