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CE547
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The following views were obtained from the site rgis.unm.edu and are based on DEMs of parts of the Rio Grande and Rio Puerco watersheds near Albuquerque, New Mexico. DEMS of Quads 177, 178, and 179 were imported into ArcMap using ArcToolbox and mosaic-ed using the Spatial Analyst extension in ArcView.
Since there were a few "holes" (no data spots) in the DEMs, I "sewed" them together using averages from surrounding cells. Then, I ran through the series of operations in the assignment instructions to generate the flow accumulations, stream grid, watershed grid, etc. Since I had already completed this before the class on "filling, reconditioning, and burning in" missing stream sections, that operation is not included here.
I also played with changing the extent of the calculation area and figured out how it works, but decided to go ahead and show the entire view in the samples below.
Four views are presented below.
In View 1: Streams and Contour I display several layers: the mosaiced dems, then the stream grid. Finally, I created a contour layer to show where the hilly regions are.
View 2: Streams and Flow Direction shows the direction of flow in the areas surrounding the streams. The four colors which apply to the four principal compass points are indicated. The map shows intermediate shades for the secondary compass points, as well; however, you would need to see the original in ArcView to identify these in detail. Surprisingly, the eastern side of the Rio Grande inflow flows primarily north. I am not sure if this is accurate or is due to granularity issues in the data.
View 3: Streams and Watersheds displays the watersheds surrounding the streams. The watersheds are shown in increasing intensities of green; the blue areas do not register as having streamflow.
View 4: Detail: Streams and Watersheds with Outlets is a magnification of a portion of View 3 with the outlet points of subsidiary streams shown as red dots.
