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Mount Timpanogos Watershed
Lab Objectives
Download a DEM in an area of interest
Delineate a watershed
Use flow accumulation to approximate a stream network
Calculate stream order
Experiment with 3D analyst tools
Methods
I downloaded a 10m DEM from UT AGRC and I decided to focus on Mount Timpanogos, UT. I chose Mount Timpanogos because its close to home and its one of my favorite paces. I used fill, flow direction, flow accumulation, hillshade, slope, aspect, snap pour point and watershed delineation tools during this project.
The outlet, or pour point, is the point on the surface at which water flows out of an area. It is the lowest point along the boundary of a watershed. My pour point is not very visible on my map but its at the end of the stream order 5 right where it says provo on the base map map.
Once that was done with that I found the threshold which was 16,000 for me when the "stream networks roughly matched the USGS network. Then I used the reclassify tool using 16,000 as the minimum. After that I calculated the stream order of my watershed.
Stream Order
Stream ordering is a method of assigning a numeric order to links in a stream network. Head water streams get a value of 1 and when two 1 order stream comes together it becomes a 2 order and that process keeps continuing.
(The image on the left is a visually representation of this concept but is not associated to Mount Timpanogos Watershed)
The table above shows the total length in meters and the percentages of each stream order. This order is a method for identifying and classifying types of streams. As the stream order increases the total length decreases.
Improvements
The watershed I choose was quite big so trying to find a good threshold was really hard. If I ever do a project like this again in the future I would choose a smaller watershed so its easier to see and visualize. That way the threshold would be more accurate and it would be easier to follow the stream order. This lab made me use a lot of tools I have never used or heard of before so it was really cool working with a new concept and seeing how well the results came out.
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