Essential Raster Geoprocessing

SUMMARY

Links: Terrain Analysis Using ArcGIS Pro, Oso Landslide (from course materials)

Time: Altogether the training and exercises took about 2 hours to complete.

Insights: The Terrain Analysis training helped me to understand the practical applications of using hillshade, viewshed, and the many different ways elevation rasters can be used. I had immediately thought of commercial applications (where to place buildings) when studying, and understanding how it can be applied to other situations like finding optimal habitats or locations for agricultural endeavors was interesting to me. While simple, I also enjoyed seeing how transparency effected the cartographic value of the map and I’m looking forward to being more conscious of that in the future.

Stack Profile Flow

1.      Add both DEMS and hillshades to map so you can visually identify changes in the landscape.

2.      Using the Geoprocessing pane, search for Stack Profile (3D Analyst Tools).

3.      Click the pencil icon to the right of the dropdown under Input Line Features and select Line.

4.      Click the drop down under Profile Targets and select both DTMs.

5.      Using the hillshades as a guide, draw a line across the feature whose elevation you would like to analyze.

6.      Click Run.

Training Questions

-        Raster Resolution:

o   Oso_ DTM14

  x = 3

  y = 3

  unit = feet

  Resolution: 3x3 ft

  Projected coordinate system: NAD 1983 HARN StatePlane Washington South FIPS 4602 (US Feet)

o   Oso_ DTM13

  x = 3

  y = 3

  unit = feet

  Resolution: 3x3 ft

  Projected coordinate system: NAD 1983 HARN StatePlane Washington North FIPS 4601 (US Feet)

-        In the table that is generated what does the FirstDist column represent? FirstZ?

The data in the FirstDist column represents the distance to the first vertex in the profile segment.

The data in the FirstZ column represents the height of the first vertex in the profile segment.

-        Can you put both profiles on the same chart? Why might you want to do this?

By using the Split By option, I split the data by its source name, since I wanted to be able to differentiate between the elevation profiles of both DTMs. This way I can compare the elevation profiles before and after the landslide in this specific instance.

-        What is Cut Fill calculating? What does it show? Why might this be useful for the Oso Landslide? How might you make the results better? Open the attribute table—What do the negative values for volume mean?

Cut Fill calculating compares two rasters of the same area and creates an output raster that shows the change in properties in its attribute table from one to the other. In the case of the Oso Landslide, I compared the DTM from before the landslide to the DTM from after it so I could see the difference in the attribute values. One thing that could have improved was the resolution of the DTMs to provide better data. The negative values for volume indicate areas that have been filled by material.

ESRI TERRAIN ANALYSIS USING ARCGIS PRO CERTIFICATE

MAP SCREENSHOTS