Sharpen Your GIS Skills: A Comprehensive Spatial Analysis Challenge in ArcGIS Pro

Welcome to “Sharpen Your GIS Skills: A Comprehensive Spatial Analysis Challenge in ArcGIS Pro,” where we invite you to rekindle and advance your geospatial expertise. This tutorial is tailored for those who have a foundational understanding of GIS but seek to deepen their proficiency in spatial analysis using ArcGIS Pro. Here, we bypass the basic step-by-step instructions and instead present you with a series of thought-provoking challenges. These exercises are designed to test and enhance your skills in managing spatial data, understanding map datums and projections, and performing complex spatial queries and analyses. Whether you’re brushing up your abilities after a hiatus or looking to refine your existing skills, this tutorial will guide you through the intricacies of ArcGIS Pro, reinforcing your capabilities in this powerful geospatial software.

What You Should Know

At this time, you should already have a level of practical experience with GIS. This tutorial assumes that you learned the following skills:

  • Organizing folders and files into a standardized workspace.
  • Acquiring data from public sources.
  • Using Esi Help Documentation to figure out unfamiliar tools.
  • Repair broken links to data sources.
  • Locate and read metadata for specific datasets.
  • Check the spatial reference system, datums, and map projections for specific datasets.
  • Check the spatial reference of the map window in ArcGIS Pro.
  • Add XY data to the map window in ArcGIS Pro.
  • Perform a table-join operation.
  • Add a new field to an attribute table.
  • Calculate geometry on a field in the attributes table.
  • Use the field calculator to solve problems.
  • Symbolize data using graduated colors, symbols, and data classification methods (natural breaks, quantile, equal intervals, etc.)
  • Perform both attribute and spatial queries to select features on a map.
  • Export selected features to create new map layers.
  • Perform vector overlay and proximity operations (clip, intersect, buffer, etc.)

Setting up Your Workspace

By now, you should be familiar with file management protocols for GIS. In a typical workflow, you work on geospatial data using a local hard drive. When done, you compress your data and back up your work to your cloud storage so that you can retrieve the files from anywhere. For this tutorial, use the desktop as your local hard drive location.

On the computer desktop, create a project folder named “Geospatial_Review.” Be sure there are no spaces. You may use underscores instead of spaces. Create the following three subfolders inside this folder: original, working, and final.

This diagram represents a basic folder structure used in this book.
Figure 1.1: This diagram represents a basic folder structure used in this book.

As the name indicates, use the original folder for storing original, unaltered data. As you are working on a project, if, for some reason, your working version of the data gets lost or corrupted, you can go back to your original folder and find a fresh copy of the data. Use the working folder for data you create or alter while working on your project. Use the final folder for storing any output you produce as a result of your work, such as images, maps, tables, or reports. Setting up the standard folder structure for a project is good practice and a habit you want to develop.

Skill Drill: Download and Decompress Data

Welcome to your first skill drill. Recall that a skill drill is a prompt designed for you to demonstrate skills you have already learned. In the following steps, navigate to a Google Drive download page and download a .7z file for extraction. You have already learned how to do this from previous coursework and have performed these steps multiple times in the past. You will also need to complete these steps many times in future assignments. It is time for you to show your skills.

Use the following link to navigate to Google Drive:

Use the download button on the Google Drive page to download the 7zip file provided (Figure 1.2). Copy the file to your original folder and use the 7zip software to decompress the .7z file. You should already be familiar with 7zip from previous coursework. You may need to install 7zip on your computer if you work from home. Otherwise, it should already be installed and ready to use.

The Google Drive download page.
Figure 1.2: Navigate to the Google Drive download page.

Open an ArcGIS Project File

Once you have decompressed the contents of the 7z file, locate the ArcGIS Project File named Geospatial Review (Figure 1.3). Double-click to open the file.

A view of the workspace folder as seen in Microsoft Windows File Explorer.
Figure 1.3: The default icon for an ArcGIS Project file looks like a blue briefcase.

ArcGIS Pro launches, and if it is your first time working in ArcGIS Pro, you may be prompted to sign in (Figure 1.4).

An image of the ArcGIS Pro sign in options.
Figure 1.4: Follow the prompts under “Your ArcGIS organization’s URL.”

Skill Drill: Repairing Broken Links

It is time for your next skill drill. In this section, you must repair broken links to data sources. You’ll encounter this problem many times in the future, so solving the problem is necessary. Except for the default basemap, the Map pane should be empty of layers. You should see red exclamation points preceding each layer in the Contents pane (Figure 1.5). Repair the broken links to the data sources using the procedures you learned in previous tutorials.

Red exclamation points in the Contents pane.
Figure 1.5: The red exclamation points in the Contents pane indicate broken links to data sources.

Hint: Clicking the red exclamation points gets you started.

Datums, Projections, and Spatial Reference Systems

Previously, you learned that geospatial scientists model the surface of Earth by transforming the irregular non-geometrical shape of the geoid surface model into a smooth, mathematically defined surface model called the reference ellipsoid. You also learned that because the geoid and the reference ellipsoid are not an exact match, multiple reference ellipsoids are used today, each optimized for different regions of Earth.

You were also taught that combining a reference ellipsoid with a network of carefully surveyed control points establishes a geodetic datum. Geodetic datums are standard reference points or reference ellipsoids that serve as a base for calculating positions on and above the surface of the Earth. You also learned that geodetic datums provide a starting point for map projection creation. A map projection is a geometric transformation of the round Earth onto a flat plane using mathematical equations. Transforming a spherical object onto a flat plane distorts area, shape, distance, direction, and continuity. These are known as the five preserved properties because some map projections can maintain one or more of these characteristics accurately. However, no map projection can retain all five of these qualities at the same time.

Want to learn more? Check out this tutorial on how to understand spatial errors in map datums and projections.

Finally, you learned about different spatial reference systems, including geographic and projected coordinate systems. A geographic coordinate system (GCS) is a coordinate-based spatial reference system using latitude and longitude. An important fact to remember is that a geographic coordinate system is ellipsoid-based, which makes it useful for defining a location on the earth’s surface. However, a geographic coordinate system makes measuring distances and areas complicated. A projected coordinate system solves this problem by using map projections to transform a spherical system, like latitude and longitude, into a flat two-dimensional grid. Projected coordinate systems use feet or meters to measure distances and areas, making them ideal for calculations. Such systems include the Universal Transverse Mercator (UTM) and State Plane Coordinate (SPC) systems.

In the following skill drills, you will review how to check the datums, projections, and spatial reference systems using ArcGIS software.

Skill Drill: Verify the spatial reference information

After repairing the broken links, three datasets are displayed on the data frame. Previously, you learned that in ArcGIS Pro, the map pane uses project-on-the-fly for display purposes. Even though the layers in the Contents pane might use different projections and coordinate systems internally, ArcGIS Pro tries to line them up on the screen using the coordinate system defined in the Map pane properties. This means you can change the projection in the Map pane to alter the map’s appearance onscreen without modifying the original data files.

Using the skills you learned earlier, open a blank Microsoft Word document, and record the answers to the following questions as they apply to the current map document and data frame.

Hint: Though it may look a little different, you should be able to find the information you need by looking at the map properties and the properties of the individual layers.

1. What datum does the current Map pane use to project on the fly?

2. What map projection does the current Map pane use to project on the fly?

3. What geographic coordinate system (GCS) does this Map pane use?

4. What projected coordinate system (PCS) does this Map pane use?

5. Which layer in the Contents pane uses the same projected coordinate system as this data frame?

6. Which layer in the Contents pane has a projected coordinate system different from this data frame?

7. Which layer in the Contents pane does not have a projected coordinate system?

8. If you wanted to create a California layer that used different spatial reference systems, datums, and projections, which tool In ArcGIS Pro would you need to use?

9. If you wanted to create a CA hypsometric tiff file that used different spatial reference systems, datums, and projections, which tool In ArcGIS Pro would you need to use?

Skill Drill: Inspect the Metadata

To complete the following skill drill, your metadata settings must be set to the correct style in the ArcGIS Pro options. Click on the Project tab on the upper left side of the screen (Figure 1.6).

Map ribbon
Figure 1.6: The Project tab takes you to many global options for ArcGIS Pro.

Next, click on Options (Figure 1.7).

ArcGIS Pro options link
Figure 1.7: The options link is on the left side of the screen.

Select Metadata on the list. Under Metadata style, choose ISO19139 Metadata Implementation Specification. Uncheck the box under Delete metadata content. You will need the geoprocessing history to answer the next question (Figure 1.8).

Metadata options window
Figure 1.8: Be sure that your settings match the image.

To return to your map, click the back arrow on the upper left of the Project window. For the next few questions, open the metadata for each file. Search through the metadata to find the answers. In your Microsoft Word document, record the answers to the following questions using the information in the metadata.

10. What was the last geoprocessing tool used on the file CA_hypsometric.tif?

11. what does the attribute COUNTYFP stand for in the California counties shapefile?

12. Who is the source for the description of the COUNTYFP attribute?

13. In the United States shapefile, what is the geographic extent (north, south, east, west) in decimal degrees latitude and longitude?

Working with Database Tables

As you learned previously, a significant component of geospatial data resides in a database. Understanding a database’s elements, structure, and organization helps one work with geospatial data more effectively. A database is a collection of individual entities stored in a highly structured way. Entities are unique objects or features represented in the database. One of the roles of a database is to ensure that each of these entities remains unique and separate from other entities. When working with geospatial data, entities are usually composed of geographic units such as cities, counties, states, and countries. Entities also have attributes. Attributes describe the properties of entities. For example,  an attribute for a specific county might include the total area in square miles.

You also learned that a database stores entities and attributes as tabular data. When discussing databases, one refers to a row in the table as a record and a column as a field. Each field has a unique name in the table’s top row called a header row. Each field also has an attribute type. An attribute type describes the nature of the attribute in the manner in which the database stores it in memory. Attribute types typically include numbers, strings, and dates. A string is a data type that represents text.

Skill Drill: Performing a Table Join

Start by right-clicking the Folders in the Contents pane and adding a folder connection. Connect your workspace folder, Geospatial Review, so that it appears in the Catalog window. You’ll need to do this to access your original and working subfolders.

Navigate to the National Historical Geographic Information System (NHGIS) website using your learned skills. Download a CSV table containing county-level data that relates to Sex by Age for the years 2006-2010 (Figure 1.9). Save the file to your original folder and decompress the zipped folder.

NHGIS search filters for the sex by age dataset.
Figure 1.9: Use the filters to narrow down the list of source tables.

Previously, you learned that a table join is when you establish a one-to-one relationship between two tables using a common attribute field. In this step, you must create a table join between the California counties layer and the csv table containing the sex-by-age data. The joining of the two tables requires a key. As you learned earlier, a key is a common field that exists on both tables and is used to associate them together. The NHGIS provides an attribute field that serves as a key called GISJOIN (Figure 1.10).

California counties attribute table
Figure 1.10: The CSV and California Counties attribute tables have a GISJOIN field.

After performing a table join, export the layer as a new shapefile called Sex_by_age.shp. Save the new shapefile to your working folder. When done, add the new shapefile to the map.

Hint: Right-clicking on the California counties layer in the Contents pane will get you started for the table join and exporting the data.

Skill Drill: Data Classification

Recall from previous tutorials that a CSV file is one of the simplest forms of GIS data. It consists of a single table. As a result, it does not contain the metadata you would typically find in GIS data. Instead, the NHGIS stores the metadata in a separate text file called a codebook. This text file is located in the same folder as the CSV file. Locate the codebook file, which stores the metadata, and use it for the next few steps.

Previously, you learned that data classification is used to simplify and understand numeric data. It is possible to identify patterns and trends or alter data by creating a subset of specific classes through classification. Classification is mostly organizing data in groups. One undertakes classification by creating a series of class intervals, a range of values that do not overlap.

In ArcGIS Pro, symbolize the Sex by Age layer using graduated colors. To get to the Symbology pane, click Feature Layer on the ribbon. Then click the Symbology button and choose Graduate Colors (Figure 1.11).

ArcGIS Pro symbology options for graduated colors
Figure 1.11: By default, the Symbology pane appears on the right side of the screen.

Use the field representing the male population as the primary value to base the classification. Use the field that represents the total population to normalize the data. Use the quantile method of classification and seven classes. The result should be a choropleth map that displays the percentage of males per capita using seven class intervals.

ArcGIS Pro symbology pane settings
Figure 1.12: Your results may appear slightly different based on your color scheme.

In your Microsoft Word document, record the answers to the following questions.

14. Which California counties fall into the highest class interval?

15. Which California counties fall into the middle-class interval?

16. Which California counties fall into the lowest class interval?

Hint: For questions 14-16, consider changing the colors of the highest, middle, and lowest class intervals. Also, please turn on the labels to make it easier to identify the counties.

Skill Drill: Using the Field Calculator

Open the attribute table for the Sex by Age layer and locate the Shape_Area field. Perform a Calculate Geometry operation to update the field to display square kilometers.

Hint: Right-clicking on the field name “Shape_Area” will get you started.

Next, add a field to the attribute table called FemPerSqKm. Change the field type to Long Integer. Leave all other default settings (Figure 1.13). Close the add fields window and save the changes.

ArcGIS Pro add field window
Figure 1.13: The long integer field type represents a large number with no decimal places.

Use the Field Calculator on the FemPerSqKm field. Divide the field that represents the female population by the Shape_Area field. The result should be the female population density of each county expressed as females per square kilometer.

Hint: You can access the field calculator by right-clicking the FemPerSqKm field name in the layer attribute table.

In your Microsoft Word document, record the answers to the following questions.

17. Which California county has the highest female population density?

18. How many females per square kilometer does this county have?

Hint: You will find the answers to questions 17-18 in the attribute table.

Adding XY Data

As you learned in a previous step, a CSV is one of the plainest forms of geospatial data. As mentioned before, each column of data gets separated by a comma, and the first row in the table contains the field names. When adding XY data with geographic coordinates, the two columns, latitude, and longitude, are necessary to place this information on a map. The longitude in decimal degrees is the X coordinate, and the latitude in decimal degrees is the Y coordinate. ArcMap reads these numbers, the latitude, and longitude values in decimal degrees, to figure out where to place the points on the map.

Skill Drill: Downloading and adding XY data to the map

Using the Chrome browser, navigate to the Northern California Earthquake Data Center (NCEDC) website. Enter the following search parameters:

Output format: NCSN catalog in CSV format

  • Start Time: 2002/01/01
  • End Time: 2019/08/31
  • Min Magnitude: 5.0
  • Min Latitude: 32
  • Min Longitude: -114
  • Max Latitude: 47
  • Max Longitude: -130
  • Event Types: Earthquakes
  • Under Output Mechanism, select Send output to an anonymous FTP file on the NCEDC

When you are ready, click Submit request. In the Chrome browser, the results load in a new tab. Under output can be downloaded from, click the link next to the word URL (Figure 1.14)

NCEDC download link
Figure 1.14: Access the data products for this tutorial through the Northern California Earthquake Data Center

The next page displays the data in CSV format (Figure 1.15). You need to save the results to your original folder.

NCEDC results page
Figure 1.15: CSV stands for comma-separated values. As you can see on the page, each value gets separated by a comma.

In the Chrome browser, hit Ctrl S to save. Browse to your original folder. For the filename, enter earthquakes.csv. Next, to Save as type, choose All files. When you are ready, click Save. In Microsoft Windows, navigate to your original folder and open the Earthquake 2017 CSV to view the results. By default, a CSV file should open in Microsoft Excel (Figure 1.16).

Earthquake data on an Excel sheet
Figure 1.16: GIS data table must be in a particular format. The top row must contain the field names.

When opened in Microsoft Excel, the CSV file appears as a table. The commas in the data create fields.  Each record represents a single earthquake. In this instance, the top row is different from the remaining records. It is made up of field names. When working with geospatial data, this format is critical. The first row of any geospatial data table must contain the field names to work correctly. Go ahead and close the CSV file in Microsoft Excel.

Using the skills you learned previously, add the earthquake CSV to the map document as XY data (Figure 1.17).

ArcGIS Pro add data options
Figure 1.17: The Add Data button has several options for adding data to the map.

Make sure you use the correct spatial reference system for this data. Most readers make mistakes here. Many people assume that latitude and longitude coordinates are universal. They are not. There are many different spatial reference systems available when you make maps. Different datums use distinct values for latitude and longitude.  ArcMap does not know from which spatial reference system the latitude and longitude values come. Instead, it tries to guess. The mistake many make is that they allow ArcMap to guess incorrectly. These latitude and longitude values come from a spatial reference system called GCS WGS 1984, which uses the World Geodetic System of 1984 as the datum. Check to make sure that the Geographic Coordinate System is GCS WGS 1984. If not, manually set the spatial reference information for the earthquake data in the XY Table to Point dialog box. Be sure to save the shapefile to your working folder.

ArcGIS Pro Geoprocessing Pane XY Table to Point options.
Figure 1.18: Your Add XY Data window should look like the image above.

Skill Drill: Attribute and Spatial Queries

In your Microsoft Word document, record the answers to the following questions.

19. How many earthquakes above a 5.5 magnitude occurred within 100 miles of Humboldt County?

Hint: First, select Humboldt County and create a new layer (Figure 1.19). Then use the Select by Location tool on the Map tab for the spatial query.

ArcGIS Pro Select by Location options
Figure 1.19: You must create a separate layer for Humboldt County to perform a spatial query on the earthquakes.

Proximity and Overlay Operations

As you learned through previous readings, spatial operations tend to fall into two primary categories, proximity, and overlay. Proximity operations for spatial analysis share similar characteristics for spatial queries in evaluating distances from features. An overlay operation is a spatial operation in which two or more datasets are superimposed on one another to assess the relationship between features that occupy the same geographic space. Overlay operations also share common elements with the other spatial query operations. The primary difference is that overlay operations use a spatial query to create new datasets.

As you learned earlier, buffering is a proximity operation that creates a buffer. A buffer is a zone around the map feature with an area calculated using distance or time. Buffering may be applied to point features, line features, or polygon layers. However, the output will always be a polygon layer. Intersect is an overlay operation that preserves overlapping areas. The output will only contain regions of all overlapping layers (Figure 1.20). The resulting features retain the attribute information from each map layer.

Circles and stars overlap and intersect
Figure 1.20: The shapes in this diagram, a star, and a circle, represent two map layers. When performing an intersect operation, the output contains only the overlapping areas.

Skill Drill: Buffer and Intersect

Using the skills you learned, create a 500-kilometer buffer around the earthquake with the highest magnitude. You can locate tools using the Tools button on the Analysis tab (Figure 1.21). This button opens the Geoprocessing pane, where you can search for tools by name.

ArcGIS Pro tools button
Figure 1.21: You can search for tools using the Tools button to open the Geoprocessing pane.

Hint: Start with an attribute selection to create a layer for the earthquake with the highest magnitude. Then use the buffer tool.

Intersect the buffer with the Sex by Age layer using the Intersect tool. Save the output to your working folder as a shapefile called earthquake_intersect.shp. Add the shapefile to the map.

Hint: Use your skills and Esri Help documentation to find the Intersect tool and learn how to use it.

Uncheck the boxes for the rest of the shapefiles to make the new layer visible. Take a moment to open the attribute table of the earthquake intersect layer. An intersect operation will alter the area of the output features but will not update the attribute table. As a result, you need to update the Shape_Area field in the attribute table using Calculate Geometry. Be sure to use square kilometers as the unit.

Hint: If the Calculate Geometry option is greyed out, add a new field in the attribute table named “area_km.” Be sure the type is set to double. Then right-click on the field name and run Calculate Geometry.

In your Microsoft Word document, record the answers to the following questions.

20. How many counties are within 500 kilometers of the earthquake with the highest magnitude?

21. On the earthquake intersect layer, use the updated areas within each county to calculate males per square kilometer and females per square kilometer. Which county has the greatest difference between the number of males per square kilometer and the number of females per square kilometer?

22. Which counties have the least difference between the number of males per square kilometer and the number of females per square kilometer?

Hint: Questions 20-22 are the hardest of all. They require several different steps to get the answer. However, the skills you use here repeat the skills you mastered earlier in this tutorial.

Similar Posts