Basic GIS Analysis with ArcGIS Pro

Introduction

During the past training sessions you learned about ArcGIS Online, a web-based GIS platform and how Geographic Information Systems (GIS) enables you to think more spatially about the phenomena you are studying. You used GIS to plan evacuation strategies and share your findings with the people who make decisions. Now that you know more about GIS and spatial data, you are ready to do some basic spatial analysis! Let's do this!!

Getting Started with ArcGIS Pro

We will now get ourselves familiar with ArcGIS Desktop. ArcGIS Pro is a powerful single desktop GIS application and a feature-packed software developed by ESRI. ArcGIS Pro supports data visualization; advanced analysis; and authoritative data maintenance in 2D, 3D, and 4D. It supports data sharing across a suite of ArcGIS products such as ArcGIS Online and and enables users to work across the ArcGIS system through Web GIS. We will cover a small spectrum of tools and capabilities within ArcGIS Pro today.

Opening the Software & Logging In

Go to the Start menu and open ArcGIS Pro. On top right side of the interface click Sign.

In the ArcGIS Sign In page click on Your ArcGIS organization's URL option and type Clemson in the box. Then click Continue.

Click on Clemson University. Now log into your Clemson account. This is the same as your iRoar account.

Create a New Project

Check the box for Create a new folder for this project. Click ok.

In the Location box, make sure you navigate to your desired project location.

In front of Name, type Hurricane_evacuation_analysis

When you start ArcGIS Pro, you see a list of the project templates you can use to create projects. To build a 2D map, select the Map template.

ArcGIS Pro Interface

ArcGIS Pro is a ribbon-based application. Many commands are available from the ribbon at the top of the ArcGIS Pro window; more advanced or specialized functionality is found on panes (dockable windows) that can be opened as needed.

Along the top of the screen is the ribbon. The ribbon has a set of core tabs—Map, Insert, Analysis, View, Edit, Imagery, and Share—that are always present when a map view is active. Each tab has its own set of tools, organized in groups. The application also responds contextually to your work. Tabs on the ribbon change depending on the type of item you're working with.

Catalog

On the right-hand side is the Catalog pane. When you create or open a project, one of the first panes you see is the Catalog pane. The catalog view is open and active if you create a new project using the Catalog blank project template provided with ArcGIS Pro. The Catalog pane and the catalog view allow you to access all items associated with a specific project in one place, whether they are available from a local or network computer, ArcGIS Online, or an ArcGIS Enterprise portal. In other words, it shows the organization of your project and the items you can access, such as databases, toolboxes, and connections to folders and network drives.

Content

On the left-hand side is the Contents pane. This shows all the layers present in the map view, scene view, or layout view that is active. You can turn layers on and off, reorganize layers in the map, and interact with map layers from this pane.

Panes can be hidden temporarily to clean up your view. They can also be moved to different locations based on your preferences. Click the Auto-Hide button in the Contents pane (the pushpin). The pane will collapse to the side of the interface. Clicking on it will open it temporarily. Click the Auto-Hide button once again to show the pane.

Adding and Exploring Data

With ArcGIS Pro, you can create maps and scenes (3D version of maps) by adding data from your own computer, from a local network, or from a package, such as a map or project package. You can also add data from your ArcGIS Online or another portal such as ArcGIS Living Atlas of the World.You can find map layers to meet many of your needs in ArcGIS Living Atlas of the World, a curated collection of global geographic information. Maps and layers from ArcGIS Living Atlas can be added directly to ArcGIS Pro.

Let's add hurricane evacuation routes.

On the ribbon, click the View tab. In the Windows group, click Reset Panes

and click Reset Panes for Mapping (Default).At the top of the Catalog pane, click the Portal tab.My Favorites —Items you have marked as favorites in the portal software application: in this case, ArcGIS Online.My Groups —Items shared with groups of which you are a member.My Organization —Items from My Content and items shared by other members of your ArcGIS organization. This would be all content within Clemson University that is shared. ArcGIS Online —Items shared publicly on ArcGIS Online as well as items in My Organization and My Content. Living Atlas —Curated items shared through ArcGIS Living Atlas of the World.Click the Living Atlas tab .In the search box, type Hurricane Evacuation Routes and press Enter.The search returns a single result. Right click on the layer and click on Add to Current Map. Now let's add demographic data. In the search box, clear any existing search text and type ACS Vehicle Availability Variables. Press Enter. Add the first result to your map: ACS Vehicle Availability Variables - Boundaries

Notice that this layer adds three layers to your map. Can you tell their difference?

Hint: Zoom in and out on your map.

My Content

—Maps, layers, and other items you have added to the active portal.

This ensures that the Contents and Catalog panes are open and that other panes are closed.

Under the Portal tab are six tabs you can use to add data:

Viewing Attribute Table

You see that by clicking on a feature in the map a pop-up window opens with a snapshot of attribute data. You can also open the attribute table to see the entire database, query it, and perform calculations. To open the attribute table for our counties:

Right-click the County layer in the Contents pane and click Attribute table. The table opens underneath the Map view. Examine the fields. What kind of information do you see in this?

If you have gone too far away, click on Bookmarks in the Navigate group and go back to SC extent.

Data Creation | Geocoding Your Data

Geocoding is the process of transforming a description of a location—such as a pair of coordinates, an address, or a name of a place—to a location on the earth's surface. You can geocode by entering one location description at a time or by providing many of them at once in a table. The resulting locations are output as geographic features with attributes, which can be used for mapping or spatial analysis.

You can quickly find various kinds of locations through geocoding. The types of locations that you can search for include points of interest or names from a gazetteer, like mountains, bridges, and stores; coordinates based on latitude and longitude or other reference systems, such as the Military Grid Reference System (MGRS) or the U.S. National Grid system; and addresses, which can come in a variety of styles and formats, including street intersections, house numbers with street names, and postal codes.

This process requires a table that stores the addresses you want to geocode and an address locator or a composite address locator. This tool matches the addresses against the locator and saves the result for each input record in a new point feature class. When using the ArcGIS World Geocoding Service, this operation consumes credits.

Now, we will geocode the addresses of hurricane shelters. Here is the original file.

Preparing Your Data

Before you can import tabular data into ArcGIS, you must make sure it is in a file type and a format that ArcGIS can recognize and your field names are clean and matching geocoding categories. First, we will format our data fields, and then we will save it correctly.

In this case, we had to export the addresses from PDF to Excel. Addresses must be correctly formatted in order to display correctly in ArcGIS and fields cannot start with a number or contain special characters except for underscore (_). Read carefully the rules for field names:

Create a bookmark to mark the extent of South Carolina.

You can perform many operations on the fields by right-clicking on them.

Right-click the Total Households column and select Sort descending. What is the county with the highest number of households?

Click the X to close the table.

2D: Navigation

On the Map tab, the Explore tool allows you to move around the map as well as get more information about features.

Click the Explore tool. Then click and drag the map to a different location. You can zoom in and out using the mouse wheel.

When creating spreadsheets, make sure fields are fewer than 255 characters. ArcGIS reads the first 255 field characters. Fields with more than 255 characters are converted to BLOB fields and are not readable. Abbreviate, manually truncate, or split any fields longer than 255 characters.
Check the numeric field type before and after importing Excel data. ArcGIS typically converts spreadsheet numeric fields to double precision (Double), which may not meet your needs. If necessary, create new fields of the desired type and calculate values into them.
Check the format for date fields. ArcGIS uses the Lotus date/time format. In this format, the calendar date is represented by a whole number value that represents the number of days since January 1, 1900, plus one day (due to a bug in Lotus 123 and carried over to Excel). Time is represented as the decimal portion of a 24-hour day.

If date/time data is important, format the input spreadsheet using a standard Excel date/time format. We only have the year information, so we can skip this step.

Follow ArcGIS field naming rules when creating Excel column names.

Column/Field names may not consist solely of reserved words (date, value, name, text, and year). Do not use these words in field names. See the list of reserved words. ArcGIS typically adds a trailing underscore to reserved word field names added by copying and pasting from other sources.

Once you have formatted your data, you will save it using a file type that ArcGIS can recognize. The following file types can be used in ArcGIS. All of these file types can be read by Microsoft Excel:

.csv
.txt
.xls

Click on File, Save As, Name: shelters_formatted.xlsx. Click Save. For the sake of time, we have prepared a formatted version for you ready to use.

Create a folder in your project folder and call it Data. Copy the excel file in the Data folder.

In your Catalog pane, right-click on Folders and click Refresh.

Click on the little rectangle next to the excel file to open all the sheets in that excel file.

Right-click on Formatted and click on Add to Current Map.

Geocoding addresses in ArcGIS

Geocoding is the process of transforming a description of a location, such an address or a name of a place, to a location on the earth’s surface. The resulting locations are output as geographic features with attributes, which can be used for mapping or spatial analysis. In order to geocode addresses, we need an address reference dataset and an address locator. The reference dataset contains a database with the location of addresses for a particular region or locality. The address locator is the entity that specifies the method to interpret a particular type of address input, relate it with the reference dataset and deliver a matching option back to the user interface. This picture illustrates an example of how the process works →

If the Geoprocessing pane is not open, on the Analysis tab, click Tools

to open the Geoprocessing pane.

On the Geoprocessing pane, type geocode addresses in the search box. The first search result is Geocode Addresses tool

You can also find this tool under Geocoding Tools. Click on the tool to open it.

Attention:

Using ArcGIS World Geocoding Service is only for the purpose of small number of records and we do not recommend using it for large datasets (more than 1000 records). Instead, we use the address locators that are available for us as part of our subscription to ESRI software.

To do so, either browse to CCGT drive :\\Geocoding_Data_2020\Geocoding Data and click on USA_StreetAddress.loc, or use Clemson USA Geocoder. You must be signed in to be able to see this option.

For Input Table, click on the dropdown and select Formatted$. For Input Address Locator, click on Clemson USA geocoder

For Output Feature Class, Type Shelters

Make sure all the address fields correspond with the ones in the Clemson USA Geocoder.

Address or Place → Address

City → City

County → County

ZIP → Zip

Click Run to geocode the table. You should see the blue ribbon moving.

When the geoprocessing tool is done running, click on View Details to view the results. You can see that we have:

On your Content pane, right-click on Shelters and click Zoom To Layer. You should see the extent below:

Extraction Tools

GIS datasets often contain much more data than you need. There are several methods available to reduce or extract data from larger, more complex datasets. The extraction tools are used to:

Select a portion of your data

Clip your data to a specified boundary

Selecting South Carolina

We will now start with Select tool. When you added ACS Vehicle Availability Variables - Boundaries, three layers were added to your map: State, County, and Tract. We will now select South Carolina from the States list.

In ArcGIS Pro, Selection > Select By Attributes

Under Input Rows, select ACS Vehicle Availability Variables - Boundaries\State

Click New expression and set the Name parameter to be equal to South Carolina.

Click Ok. Zoom out to the extent of the US. You should see the borders of South Carolina highlighted.

Right-click on the State, and go to Data > Export Features. Put the Output Name SC_Border and click OK.

Go to Hurricane_evacuation_analysis.gdb and drag and drop the SC_Border layer to your map. What is the difference between this layer and the layer that was automatically added to your map once you exported the selected feature?

Finding Census tracts that are within South Carolina: Using the Clip tool

In the previous section, you added the census tracts in the United States to your map. We are only interested in the ones in South Carolina, i.e. South Carolina is our Area of Interest (AOI) and we only want to work with the data in our AOI.

We are going to clip the Tract to the state boundary.

Under the Analysis tab, click on Tools.

Under Geoprocessing search tab, type clip into the bar and press enter. Click on the Clip (Analysis Tools).

Another way to find clip, is to go on the Analysis tab, click on Tools, and select Toolboxes. Under Analysis Tools, expand Extract and click on Clip.

For Input Features or Dataset, navigate to Tract.

Set the Clip Features to SC_Border.

Save the output as Tract_SC in the Hurricane_evacuation_analysis.gdb.

Click on Run.

Compare the attribute tables between the original data set and the new feature class.

Overlay Tools: What's on top of what?

One of the most basic questions asked in GIS is ‘What's on top of what?’ For example:

What land use is on top of what soil type?

What parcels are within the 100-year floodplain? ("Within" is just another way of saying "on top of.")

What roads are within what counties?

What wells are within abandoned military bases?

In GIS, these ‘What's on top of what?’ questions are answered with the use of overlay tools. We are going to use Overlay toolset to answer some spatial questions.

Identifying schools in counties with substantial flood risk:

To Identify schools that are in counties with substantial flood risk, we will add Flood Factor risk statistics layer to our map.

At the top of the Catalog pane, click the Portal tab and then on Living Atlas In the search box, type Flood Factor risk statistics and press Enter. This layer will add 4 sublayers to your map at the ZIP code, county, congressional district level and state levels. You can remove or turn off all except for Counties.

The search returns 4 result. Right click on the layer that says Full Dataset at the end and click on Add to Current Map.

Now let's add schools. In the search box, clear any existing search text and type schools. Press Enter. Add the first result to your map: Public Schools

Now we will select all the counties in which the Average Flood Factor risk score for all properties is above the mean.

Let's first symbolize our Counties layer to better visualize this phenomenon. Right-click on Counties and then click Symbology.

In front of Field, choose avg_risk_score_all, which is Average Flood Factor risk score - all properties

In front of Classes, choose 5

For Color scheme, choose Yellow to Red

If you click on Histogram, you will see a distribution of your data. What is the mean of counties flood risk across the US?

Now, we will isolate the counties that are in South Carolina AND have Average Flood Factor risk score above 2.

Right-click on Counties and click on Properties > Definition Query

Click New definition query

Set the query as the picture to the left and click OK.

Turn off the schools layer to see the results. How many counties in South Carolina have above the average flood risk?

Turn the school layer back on!

Turn off the original school layer to see the results. How many schools did you find in these counties?

Proximity Analysis: What is near what?

One of the most basic questions asked of a GIS is ‘what's near what?’ For example:

How close is this shelter to a hospital or a grocery store?

What is the distance between two locations?

What is the nearest or farthest feature from something?

What is the distance between each feature in a layer and the features in another layer?

What is the shortest street network route from some location to another?

Now, we will use the Intersect tool to determine which schools fall within counties with higher than average flood risk.

Under the Analysis tab, click on Tools.

Under Geoprocessing search tab, type Intersect into the bar and press enter. Click on the Intersect (Analysis Tools).

Another way to find Intersect is to go on the Analysis tab, click on Tools, select Toolboxes. Under Analysis Tools, expand Overlay and click on Intersect.

Set the Input Features to Counties and the Public Schools layers.

Name the Output Feature Class Schools_High_Flood_Risk and save it in the Hurricane_evacuation_analysis.gdb. Leave the other defaults and click Run.

In this exercise, we are going to look into two different spatial questions using proximity tools.

Identifying hospitals within 0.5 mile of evacuation routes

Turn off all the layers except for your basemap and Hurricane_Evacuation_Routes.

The same way you added Schools layer, look for a layer that has information on hospitals. This time, we will look in ArcGIS Online . Add the layer to your map.

Under Map tab, go to Selection group and click Select by Location.

For Input Feature select Hospitals_SC

Select Within a distance for Relationship

Set the Selecting Features to Hurricane_Evacuation_Routes

Choose New selection for Selection type.

Click Run.

How many hospitals are within 05 mile of the evacuation routes?

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