Our project started with an intent to correlate water with geology and vegetation, which proved to be impossible using remote sensing. We decided then to locate vegetation with topography and its effect on vegetation types.
Our goals for this project became to determine where vegetation is in comparison to topography of Cache Valley quadrangles. We did this by clipping from the Cache Valley image and put a grid system on it. From there we clipped portions of six grids with the coordinates of 413711137, 413711145, 414511137, 414511145, 415211137, and 415211145. These six sections are representative of the terrain and vegetation we wanted to investigate because of its diversity.
To get the files of the coordinates, we copied the files from /auto/gisclass/data/(coordinates)dem.Z. Then we uncompressed the file with the command uncompress coordinates dem.Z. We folded the file so that it would be readable to the page, using the command Fold -1024 coordinatesdem > new name. We went into arc and made it a grid file. To merge the grid files we used the commands Latticemerge and named our output file. We saved our grid files as imagine files. Then we were able to topographically analyse the images in imagine interpreter. This gave us our starting point and we could produce the rest of our files from this base image.
This is the vegetation file (Figure 1), that was already made in arc info. We imported it and it became the base vegetation file that we would compare with our topographic analysis tools. It was already classified with vegetation types and this facilitated the project.
(Figure 1)
This is an image of our quadrangles with their respective Slope facing Aspect to show the topography and the direction the slopes. We classified these directions as North = 316-45 degrees (Green), East = 46-135 degrees (shown in gold), South = 136-225 degrees (shown in purple), and West = 226-315 degrees (shown in Blue). The chart shows the way we divided the circle in degrees.
(Figure 2)
These next images, Figures 3 and 4, show the North and South facing slopes with their respective vegetation. You can see how the vegetation is different on opposite facing slopes.
1. North = 316-45 degrees (Figure 3) 2.South = 136-225 degrees (Figure 4)
These images, Figures 5 and 6, show the comparison between East and West facing slopes and their respective vegetation types.
3. East = 46-135 degrees (Figure 5) 4. West = 226-315 degrees (Figure 6)
We had to recode each direction (create a file for each aspect) to find out which vegetation type was pertinent to that direction. The vegetation image was already classified so we made the information into chart form to see with each direction which vegetation type is most prevelant, using the top three percentages. The chart shows that there is distinct vegetation types with each aspect. For instance the sagebrush and juniper was much more prevelant to the South and West facing slopes. Agriculture showed up in every aspect due to the Valley.
We compared slope in degrees with our vegetation image. The angle of slope in degrees is determined by recoding the files with the degrees desired.
1. Slopes of 5-15 degrees (Figure 7) 2. Slopes of 16-32 degrees (Figure 8)
3. Slopes of 33-45 degrees (Figure 9)
The next analysis we used was Level Slice. It shows elevation Countours. We recoded the colors by 15 meters shown in Figure 10.
(Figure 10)
Vegetation of three distinct elevation areas, described as Valley, Bench and Peaks is what we showed in Figure 11. These were the three basic areas which showed different vegetation types according to elevation.
(Figure 11)
This last image is of Shaded Relief overlayed with the Landsat image of Cache Valley. It shows everything including vegetation, agriculture, topographic relief and cultural aspects of our quadrangles.(Figure 12)
There was a distinct difference with the vegetation concerning the different variables of elevation, slope degrees and slope facing aspect. With elevation the vegetation of the valley differed greatly from the higher mountain peaks. The bench area showed a combination of valley and mountain vegetation with a distinct difference according to the slope angles. The slope aspect files showed a difference in the types of vegetation that grow on the slopes, according to the amount of sun received which also affects the amount of potential evaporation.