Build the map

First, you'll add the house sites and Lake Junaluska feature layer, change the basemap, and create a web map.

Add layers

Web map layers are the way geographic data is organized and combined to create maps. These layers are also the basis for geographic analysis. Seeing location-based information on a map is the foundation of understanding and making decisions. In this section, you will add the layers required to build the map.

  1. Sign in to your ArcGIS organizational account.
    Note:

    If you don't have an organizational account, you can sign up for an ArcGIS free trial.

  2. On the ribbon, click the Map tab.

    Click the Map tab.

    Note:
    Depending on your organizational and user settings, you may have opened Map Viewer, formerly known as Map Viewer Beta. ArcGIS Online offers two map viewers for viewing, using, and creating maps. For more information on the map viewers available, please see this FAQ.

    This lesson uses Map Viewer Classic.

  3. If necessary, on the ribbon, click Open in Map Viewer Classic.

    Open in Map Viewer Classic

    Map Viewer Classic opens.

  4. On the ribbon, click Add and choose Search for Layers.

    Select Search for Layers.

  5. At the top of the Search for Layers pane, select ArcGIS Online from the drop-down menu. In the Find box, type IGIMG_Viewshed and press Enter.

    ArcGIS Online filter and IGIMG_Viewshed search

  6. Add the House_Sites layer by Teach_with_GIS to the map.

    Add House_Sites layer to the map.

  7. Similarly, search for the IGIMG_lake layer and add it to the map.

    Add IGIMG_lake layer to the map.

    Next, you will give it a descriptive name.

  8. In the Contents pane, click More options and choose Rename.

    Rename IGIMG_lake to Lake Junaluska.

    The Rename window appears.

  9. In the Rename window, type Lake Junaluska and click OK.
  10. Zoom out so you can see the entire lake with the three house sites.

    Zoom out to view the entire lake with the three house sites.

Next, you will change the basemap to Imagery Hybrid.

Change the basemap

Map Viewer Classic offers a basemap gallery that can be used to change the basemap in web maps created in ArcGIS Online. In this section, you will change the default Topography basemap to the Imagery Hybrid basemap.

  1. On the ribbon, click Basemap and select Imagery Hybrid from the drop-down menu.

    Change the basemap to Imagery Hybrid.

  2. On the ribbon, click the Save button and choose Save.

    The Save Map window appears.

  3. In the Save map window, enter the following information:
    • For Title, type Viewsheds for House Sites.
    • For Tags, type viewshed, house sites, Lake Junaluska, North Carolina.
    • For Summary, type Research map of house viewsheds near Lake Junaluska, NC.

  4. Click Save map.

    Save map details

The red dots on your map represent potential house sites, but by looking at the map, you can't tell which house will correspond to which viewshed. The solution is to add simple labels, which you will do in the next section.

Create labels

The way you draw your layers helps to describe and identify features, but sometimes you need more than just a particular symbol or color to convey what you want to say with your map. This is when labeling features can help. You will create labels for the House Sites layer.

  1. In the Contents pane, for the House Sites layer, click More Options and select Create Labels.

    Create Labels

  2. In the Label Features pane, set the following parameters:
    • If necessary, check Label Features.
    • For Text, select OBJECTID.
    • For Font, click Bold, check Halo, and change the Halo font size to 5.

    Label Features pane

  3. Click OK.

    The house sites are labeled as 1,2, and 3, which makes it easier to correlate which viewsheds they correspond to once the viewsheds are created.

    Map view after change in label settings

  4. Answer the following question:

    Question 1: How did changing the basemap from Topographic to Imagery Hybrid help your understanding of the Lake Junaluska area?

    Note:

    Possible answers are listed at the end of the lesson.

In the next section, you will create viewsheds for each of the house sites.


Create viewsheds for each house site

Now that you've identified and labeled the house sites surrounding Lake Junaluska, your next step is to calculate their viewsheds. The Create Viewshed tool uses Esri's World Elevation services to determine which areas are visible from specified observer points.

Create viewsheds

In this section, you'll select one house site at a time using the Filter tool and create corresponding viewsheds.

  1. In the Contents pane, for the House Sites layer, click the Filter button.

    Filter button on the House Sites layer

    The Filter: House_Sites window appears.

  2. In the Filter: House_Sites window, construct an expression saying OBJECTID is 1. Click Apply Filter.

    Applying filter for house 1

    Notice how the first house site is the only one that appears on the map. Next, you will use the House Sites layer to access the Create Viewshed tool.

  3. In the Contents pane, for the House Sites layer, click the Perform Analysis button.

    Perform Analysis button for House Sites layer

  4. In the Perform Analysis pane, click Find Locations and choose the Create Viewshed tool.

    Create Viewshed tool

    In the Create Viewshed pane, you’ll create a setting representing a 6-foot-tall person standing in a one-story house that is 10 feet in height. This makes the height of the observer at 16 feet. (This height represents a person standing in a home with a raised foundation, as is often the case with rural homes in hilly areas.) Also, since you’re interested in the lake view, you’ll limit the viewing distance to 1 mile.

  5. In the Create Viewshed pane, verify the following:
    • For Point features that represent observer locations, select House_Sites.
    • For Visibility settings (optional), set Height of observer locations to 16 Feet and Maximum viewing distance to 1 Miles.
    • For Result layer name, type House 1 lake view_Your initials.
    • Uncheck Use current map extent.
  6. Click Run Analysis.

    Create Viewshed pane settings

    Now, you have a map showing the view that a person standing in House 1 would see.

    House 1 viewshed result

  7. Answer the following question:

    Question 2: Why do you think House 1 has such a limited view of Lake Junaluska?

    Tip:

    Uncheck the House 1 lake view layer and zoom in to the imagery surrounding the house.

    Next, you will repeat steps 1 through 7 for house sites 2 and 3.

  8. In the Contents pane, for the House Sites layer, click Filter.

    The Filter: House_Sites window appears.

  9. In the Filter: House_Sites window, edit the expression to OBJECTID is 2. Click Apply Filter.

    Applying filter for house site 2

  10. Open the Create Viewshed tool again and, using the same settings as House 1, create a layer named House 2 lake view.

    House 2 viewshed result

    Having the viewsheds of each home represented by the same color is confusing. To avoid this, you will change the House 2 view layer color for easier comparison.

  11. In the Contents pane, for theHouse 2 lake view layer, click the Change Style button.

    Change Style button for House 2 lake view

  12. In the Change Style pane, for Step 2 – Select a drawing style, click Options.

    Change Style pane options

  13. Click Symbols.

    Click Symbols.

  14. In the Symbols pane, select a light and contrasting color for the House 2 lake view layer. Click OK.

    Select a contrast color.

  15. Click OK again and click Done. Now you can see both viewsheds.

    House 1 and 2 viewshed results

  16. Using the previous steps, create a viewshed for House 3. Remember to edit the filter expression to OBJECTID is 3, rename your House 3 lake view layer, and change the color of the viewshed.

    You have created a viewshed for all three house sites, but you have only one house site on the map. In the next step, you will remove the filter in the House Sites layer to show all three house sites.

  17. In the Contents pane, for the House Sites layer, click the Filter button. Click Remove Filter.

    Remove Filter

    Your map should now look similar to this one.

    Map with all the viewsheds

  18. Answer the following:

    Question 3: Assuming you're 6 feet tall, and you're building a three-story home, how would that change the settings on your Create Viewshed tool? Would that improve your view of Lake Junaluska?

In the next section, you will narrow down the areas which can be seen from the house sites.


Intersect views of the lake

Which proposed house site has the best view of the lake? Now that you've created the viewsheds, you will isolate which section of the lake can be seen from each house site.

Create intersect views of the lake

The Overlay Layers tool combines two layers into a single layer using one of three methods: Intersect, Union, or Erase.

In this section, you will use the Intersect method. The resultant of the two layers that intersect is the portion of features that are overlapped in the two input layer (in this case, Lake Junaluska and the viewshed layers).

  1. In the Contents pane, for the Lake Junaluska layer, click the Perform Analysis button.

    Perform Analysis button

  2. In the Perform Analysis pane, click Manage Data, and choose Overlay Layers.

    Overlay Layers

  3. In the Overlay Layers pane, set the following parameters:

    • For Choose input layer, select Lake Junaluska.
    • For Choose overlay layer, select House_1_lake_view.
    • For Choose overlay method, select Intersect, and for Output, select Areas.
    • For Result layer name, type House 1 Lake Junaluska_Your Initials.
    • Click Run Analysis.

    Overlay Layers settings

    A new layer, House 1 Lake Junaluska, is added to the top of the Contents pane. The light blue polygons on Lake Junaluska represent that portion of the lake visible from House 1. This is what you want to discover since you’re specifically buying a dream home with the most expansive view of the lake. Uncheck the House 1 lake view layer to declutter your map.

  4. Next, you’ll create Lake Junaluska viewsheds for House 2 and House 3. Repeat steps 1 through 3 for both house sites 2 and 3. Remember to select House 2 lake view for the Overlay layer, change the result layer name to House 2 Lake Junaluska_Your Initials, and once the analysis has run, uncheck the House 2 lake view layer. Then repeat for house site 3.

    Viewshed overlay results

    Note:

    You may want to change the color of the intersections to more clearly see each house site’s view. Use the Change Style button for the layers. To make it even easier to see which house site has the most expansive view of Lake Junaluska, you can uncheck the box next to each layer. This will allow you to see each house site’s lake view by itself and compare the three house sites.

  5. Answer the following questions:
    • Question 4: Do the lake views of House 2 surprise you? If you had to pick now, would you prefer House 1 or House 2?
    • Question 5: You now know the lake views of the three houses under consideration. Which house has the view you most prefer?
    • Question 6: Real estate listings of the Lake Junaluska area show vacant lots in the $45,000 to $60,000 range. Assuming the locations in this lesson were vacant lots, how much would you be willing to pay for the land containing House 1, House 2, and House 3?

Possible answers

Below are possible answers to the questions throughout the lesson:

  1. How did changing the basemap from Topographic to Imagery Hybrid help your understanding of the Lake Junaluska area?

    You were able to see the homes and development, which gave you a much more realistic view of Lake Junaluska.

  2. Why do you think House 1 has such a limited view of Lake Junaluska?

    According to the Imagery Hybrid basemap, House 1 appears to be surrounded by terrain that limits the line of sight between the house and the lake.

  3. Assuming you’re 6 feet tall, and you’re building a three-story home, how would that change the settings on your Create Viewshed tool? Would that improve your view of Lake Junaluska?

    You would change your Height of observer location to 36 feet (three stories equal 30 feet and a 6-foot-tall homeowner; 30+6=36). Yes, that additional height would increase your view of the lake.

  4. Do the lake views of House 2 surprise you? If you had to pick now, would you prefer House 1 or House 2?

    Answers could vary.

  5. You now know the lake views of the three houses under consideration. Which house has the view you prefer?

    House 3 has the most expansive view of Lake Junaluska, but answers could vary.

  6. Real estate listings of the Lake Junaluska area show vacant lots in the $45,000 to $60,000 range. Assuming the locations in this lesson were vacant lots, how much would you be willing to pay for the land containing House 1, House 2, and House 3?

    Answers could vary.

In this exercise, you created three viewsheds that intersected with Lake Junaluska. Using the Create Viewshed and Overlay Layers tools, you discovered information that left you better informed about selecting the location of your dream home.

You can share your lessons and any other educational resources with us through our Learn ArcGIS Contributor program. Contact us with your idea.