Lab 9| Digital Landscapes
Introduction
In this assignment you be introduced to some of the basic of terrain modeling – working with Digital Elevation Models (DEM), contours, slope, aspect, and hillshades.
Instructions
Based on the topic from this week’s lecture and reading, you will be using ArcGIS software to create a variety of terrain models to analyze a particular landscape.
Deliverables
Follow the instructions below to complete the exercises. Answer the questions throughout the lab (numbered). Your lab document should be typed, well organized, and submitted based on the “How To” guidelines provided in the course syllabus.
PART I
Digital Elevation Model
· Open TerrainAnalysis.mxd from the Lab9 folder
· Go to Customize (on the main menu bar) and click on Extensions. When the pop-up window appears, check ‘Spatial Analyst’ and click close.
· There is a DEM of Vancouver, WA. Go into the symbology tab (in the properties) and choose a color ramp to represent more ‘real-world’ colors.
· Under the Display tab in the properties, change the transparency to 50%.
Create a Hillshade
A hillshade (also referred to as Shaded relief) is a technique where a lighting effect is added to a map based on elevation variations within the landscape. It generally is intended to mimic the sun's effects - illumination, shading and shadows - on hills and canyons. This is a good way to get a 3D effect and making canyons look like canyons, and hills to look like hills. It assists in creating a visual effect of the terrain.
· Open ArcToolbox. Go into Spatial Analyst tools and expand the Surface toolset. **All the tools you need for the remainder of the lab can be found in this folder.**
· Double-Click on Hillshade. Use the Couv_DEM as the input raster. Name the output raster CouvHill and save it to your flashdrive. Accept all other defaults. Check the screenshot below and click OK.
· Go into layout view. Turn on the DEM and place it over your hillshade. Add your name and a title, and export your map as a .jpg.
1 | Insert your Hillshade map into the lab document.
2 | Why would you add a hillshade to the map?
3 | Provide one example where you would want to use a hillshade.
Create a Slope Layer
· In ArcToolbox go to the Slope tool (under Spatial Analyst tools>Surface).
· Use the Couv_DEM as the input raster. Name the output raster CouvSlope and save it to your flashdrive. Accept all other defaults. Check the screenshot below and Click OK.
· Go into layout view. With only your slope layer turned on, add your name and a title, and export your map as a .jpg.
4 | Insert your Slope map into the lab document.
5 | What is Slope?
6 | What can you tell about this landscape based on the results of the Slope Analysis?
7 | Provide one example of when you would use Slope in GIS or another geospatial technology.
Create an Aspect Layer
· In ArcToolbox go to the Aspect tool (under Spatial Analyst tools>Surface).
· Use the Couv_DEM as the input raster. Name the output raster CouvAspect and save it to your flashdrive. Check the screenshot below and Click OK.
· Go into layout view. With only your aspect layer turned on, add your name and a title, and export your map as a .jpg.
8 | Insert your Aspect map into the lab document.
9 | What is Aspect?
10 | What is located in the area that is designated as “Flat”? (hint: you can add a basemap)
11 | Provide one example of when you would use Aspect in GIS or another geospatial technology.
Create Contours
· In ArcToolbox go to the Contour tool (under Spatial Analyst tools>Surface).
· Use the Couv_DEM as the input raster. Name the output raster CouvContour and save it to your flashdrive. Set the Contour Interval to 10 (this is in meters). Accept all other defaults. Check the screenshot below and Click OK.
· Go into layout view. With your Contour layer (top layer) and your DEM on the map, add your name and a title. Change the color of the Contours if they are not easily visible. Export your map as a .jpg.
12 | Insert your Contour map into the lab document.
13 | What are contour lines?
14 | What is the GIS file type of the newly created Contour file?
15 | Provide one example of when you would use contour lines in GIS or another geospatial technology.
Viewshed Analysis
· In ArcToolbox go to the Viewshed tool (under Spatial Analyst tools>Surface).
· Use the Couv_DEM as the input raster. Use the ViewshedPt as the input point. Name the output raster CouvView and save it to your flashdrive. Accept all other defaults. Check the screenshot below and Click OK.
· Go into layout view. With your Viewshed, ViewshedPt, and contours (with a 50% transparency) on the map, add your name and a title. Change the colors of the Viewshed results to make it easy to read. Export your map as a .jpg.
16 | Insert your Viewshed map into the lab document.
17 | What is a Viewshed?
18 | Explain the results of this analysis.
19 | Provide one example of when you would use Viewshed in GIS or another geospatial technology.
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