Raster Analyses: Terrain and Habitat; 3D Visualizations
A. Terrain Modeling
Our first task is to set up our terrain with a stretch type that best represents the terrain of
the state of Delaware. We experimented with three alternatives in order to establish the best one.
Comparing the three stretch types shown in the figures above, I have chosen the Minimum-Maximum option
as the most appropriate display of the given data.
Our next task is to identify the terrain that would be flooded by a 10-ft sea rise event.
The results can be seen in the map below, where the flood zone is highlighted in red.
We then used the Spatial Analyst's Surface Analysis tools to create a Hillshade surface of the area and
also overlaid the DEM surface to enhance the hillshade effect.
We then created a map that displayed the slope of the terrain where the slope is represented in degrees.
The next map created was an aspect map of the terrain using the default color scheme.
A contour map was then created at an interval of 25ft.
B. Habitat Analysis
We are given the following criteria to identify prime habitat areas for the endangered pickled strumpet.
A. Slope of 2 degrees or less and
B. EITHER freshwater wetland with an elevation greater then 16 ft
OR forrest within 250 meters of stream and
C. At least 200 meters from primary roads and
At least 100 meters from all other roads and
At least 100 meters from all rail lines
A. The map below displays the area that is satisfied by criteria a, slope less then or equal to 2 degrees highlighted in red.
B. The freshwater wetlands that have an elevation greater then 16 feet can be seen in the maps below
The forrest within 250 meters of streams can be seen in the maps below
Since the criteria specifies that the habitat must be EITHER freshwater wetland with elevation of greater then 16ft
OR forrests within 250 meters of streams, we combine the two conditions into a map that satisfies this criteria below
C. The maps below show the satisfaction of the road distance criteria
All of the road conditions satisfied can be seen in the map below, the areas that satisfy all three road conditions are highlighted in red.
Criteria A B and C are can be combined to determine appropriate areas for pickled strumpet habitats
and can be seen in the map below highlighted in red
Some of these areas are not large enough to be able to sustain a habitat for the pickled strumpet,
therefore, we need to identify core polygons that are an appropriate size (at least 22,500 square meters large).
These core polygons can be seen below in red.
An air photo of some core polygons, outlined in green, can be seen below
The fifteen biggest polygons were then identified to further narrow down the habitat search.
Below is a map of the fifteen biggest possible habitat locations.
A projection of some of the largest polygons (orange) on possible habitat areas (red) can be seen below
The core polygons were then ranked based on their area and compactness. The top polygons can be seen in the
maps below with information about their priority ranking, area and elevation above sea level.
When ranking the polygons, I took into consideration the polygons areas and compactness, for I believe those two factors to be
the most significant on the ability for the area to be a suitable habitat. The way that I made these two factors comparable,
since one is a fraction and the other is a large area, was by increasing the compactness by a factor of 1000 and summing the two
variables. This sum was then sorted ascendingly, with the largest sum having the top priority.
One organization that may support this effort is the Delaware Division of Fish and Wildlife. They have a Natural Heritage and
Endangered Species Program that takes funds from congress to establish habitats to satisfy the state's conservation needs.
This strategy would implemnt legal prohibitions on disturbing the esablished habitat, also this organization provides landowner
incentive programs to those who own land in the areas a habitat could be created.
Oblique-angle view of the piedmont region of the county
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