I selected a section of USGS elevation data for Oahu, Hawaii because of the volcanic nature of the land.
The height of the area extends from 21.63* N to 21.28* N. Also, the width of the area spans from -158.23*E to -157.75*E. The total area is 2128.8 km^2. As you can see the elevation levels out quickly on the edges, this is because there is water there around the island.The raster is made up of 1860 columns and 1275 rows. Each cell is 0.000277* repeating in both dimensions. Also the RF scale is 1:239,084. The original coordinate system was latitude and longitudinal, but the map was projected using a UTM projection in order to add linear units to the map for calculating the slope data. The 1983 North American Datum was used.
Map 1: Shaded Relief Model
The shaded relief model is a color-ramped DEM layered over a color-ramped hillshade model. This combination creates a sort of topographic effect.
Map 2: Slope Model
The slope model indicates steeper slopes with more intense colors. This model makes it easy to observe mountainous features, but could also be inverted to emphasize flat areas.
Map 3: Aspect Model
The aspect model is a display of the directions of each face of hills. This technique is helpful in interpreting from the map what the actual shapes of features look like in the real world.
3D Elevation Map
This is a color-ramped 3D model of Oahu. Having 3 dimensions allows us to analyze location based data in addition to Digital Elevation Models, without the other 3 techniques. This gives us the most accurate picture of the land features but is difficult to use for quantitative analysis.
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