Lab 6 Spatial Analysis

DEMs and Spatial Analysis

 

The above is a digital elevation model of Mars taken from the Viking space probe in 2001. though most of what is done on ArcGIS stays here on planet Earth, this image illustrates the amazing potential for DEM analysis on many levels. From planetary topology to city wide planning, this is both a useful tool and a fascinating one to use for many purposes.

Shaded Relief Map

Slope Map

Aspect Map

3D Image

The region I chose is a mountainous area of Central California, centered on Banner Peak (37.6966, -119.195142) in the Sierra Nevada mountain range. The extent of this map is as follows - 

Top: 37.9449999993

Bottom: 37.416666666

Left: -119.676944444

Right: -118.788888889

The datum used for this map is North American 1983 (NAD83). It has proven to be quite an interesting subject area for digital elevation model analysis. The first time I came into contact with this area was about a year ago when I did a trans-sierra hike that went through the region. I know first hand how inaccessible and rugged this terrain is. DEMs can be very helpful in understanding the topography of an area from a more interactive and useful perspective. At times looking at topographic maps can be helpful, but may not fully give understanding to what is where in terms of slope, elevation, and how everything interacts with one another. There are also many other practical uses to DEM analysis, if you need to know how much land area has a south facing slope this could be quite useful to you. I can think of several industries where this would be indispensable knowledge, the cellular network companies, like AT&T, may want to understand how towers will transmit data; or a vineyard might want to buy land with optimal sunshine for prolonged growing time. Aspect maps could be used for all of these tasks and many more. Slope maps are very useful as well, if a company is looking for a place to put a ski resort they may look to one of these for an idea of how steep gradients are and where; or if a forest service is going to do controlled burns they would need to know how steep the terrain is to keep it from becoming an inferno. These maps hold a great deal of useful information for a varying array of applications.