Learning the Esri stack: ArcGIS Pro, Model Builder, Arcpy

You can't solve a problem if you can't define the problem.  In our case, we are interested in determining the percentage of the total, black, and white population in Maryland within 1, 3, and 5 miles of a vaccination site in each county?  By understanding this, we can consider which counties have the highest saturation of vaccination sites, and what counties have the lowest?

In this video we'll take a deeper dive into what we are attempting to do, where we got our data, and some issues we'll have to be aware of throughout the project - just like a real world project!

There are so many ways to solve a problem using GIS.  For our solution, we'll cover 9 steps.  Now, maybe some people can do it in 7 steps.  Maybe others will take 12.  Either way, it is going to take a lot of steps - just like GIS projects you work with at your own organization.   Before taking on a multi-step process, it is good to define what those steps are, the tools we need to use, and the order we need to accomplish our tasks. 

This is an important video because pretty soon we'll be getting deep into the weeds of how ArcGIS Pro works, and if you don't know what our overall objective is, you may feel a little lost. 

Overview

Over the next few hours, you will work alongside me, learning to use the ArcGIS Pro GUI to determine the percent of the total, black, and white population within 1, 3, and 5 miles of a vaccination site in Maryland. We will work through the command structure within ArcGIS Pro to solve our multi-step process.

You will immediately see the tradeoff of how accessible the commands are, but you will also get an appreciation for the number of steps you have to follow as well. If you decide to change a requirement, you may find yourself back at square one, running through the steps again. Also, you'll notice that you have to perform the same number of steps whether you are seeking a solution for the population within 1, 3, or 5 miles.

As you recall, we defined 9 steps to complete our project. In this first step, you will bring our geodatabase into the ArcGIS GUI and save your project so you can return to it at a later time, should you need a break. 

This video will show you how to perform basic spatial analysis to select the census blocks within 1 mile of the vaccination centers. You will also join the population data with the census blocks. After completing the entire module, you will be able to perform the same tasks for the 3 and 5 mile criteria.

In this video, you will summarize the total, white, and black populations for each county, as well as summarize the populations for only those census blocks within 1 mile of a vaccination site. You'll conclude the lesson by joining both summary tables together in order to calculate the population percentages in the next video.

In this video, you will add new fields to the summary table you created and then calculate the percentages for the total, white, and black populations within 1 mile of a vaccination center. You'll complete the project by joining the results with the County layer so that you can display your completed results.

As a special bonus, you'll follow this video to replace a simple as-the-crow-flies distance with actual driving distances. You'll notice that the percentages of the population within 1 mile of a vaccination center change because measuring distances along a street does not travel quite as far as a simple Euclidean distance due to natural barriers like forests, water, and farm fields. You should also be impressed with how easy it is to leverage Esri solutions in the cloud such as creating service area using distances and driving times.

Overview

In this section, you'll work alongside me, learning to use the ArcGIS Pro Model Builder to determine the percent of the total, black, and white population within 1, 3, and 5 miles of a vaccination site in Maryland. We will work through how to build a model to solve our multi-step process.

You will immediately see the tradeoff from the last section when we ran multiple commands. Using Model Builder is going to be a bit more effort, but once the model is built, we can rerun it with different parameters, or even give it to a colleague to run with their own data. Imagine you have a friend in another State looking to perform the same analysis - you can simply hand them this model, and with some minor modifications, they'll be able to run it with their data.

Here we will have a short introduction to what Esri's Model Builder tool is, and what it does.  I've also got a completed model so that you can simply run it and see how it works.  I like showing people results at the beginning so that they understand where the rest of the training will go.  But, don't short-circuit your learning.  Force yourself to actually work through the remaining steps.  By doing so, you'll have a hands-on experience in building a model, and that will improve your skills and knowledge of the tool.

Creating models in ArcGIS Pro can be a tedious and interactive set of steps as you create parts of the model, and check the result for accuracy. This next section is broken into two main parts. In this video, you will begin to create the model, and about halfway through, you'll debug your model to make sure the steps you've created are producing the results that you expected.

Once you are satisfied that the first part of you model is working correctly, you can complete the model with the remaining steps. When completed, you'll have a fully working model that produces the results of our task. In addition, you will also be able to rerun the model using different parameters.

In this video, you will take your final model and begin adding even greater sophistication and flexibility. Namely, you will create variables and parameters to prompt the user for input and run the model just like you would with any ArcGIS Pro geoprocessing tool. Also, you will learn how easy it is to swap out your selection of census blocks using straight-line Euclidean distances with a more realistic scenario of calculating distances using travel along streets.

If you can do this, you are on your way to being able to maximize your potential (and salary) in providing interactive solutions to Esri clients. 

Introduction

This video is designed for people who have not written programs on a computer. So, before we attempt to write scripts for ArcGIS Pro with Python, it will be good to get a basic understanding of what scripting is, and how it works in Python. For those of you without any background in scripting, the thought of writing a computer program is probably very intimidating. So, for this video, we simply want to help you understand what Python is, how to start typing code, and also gain some knowledge about variables, data structures (Lists in Python), conditional statements, and flow of control within a script.

For those of you who have written computer programs before, the video will still have value, as there are a number of nuances in Python that you might not be aware of.

Python in ArcGIS Pro

Now that you've had some experience typing in Python commands, we are going to explore how to interact with ArcGIS Pro commands using Python. We'll take a single example of buffering the vaccination centers to illustrate how Python connects to ArcGIS Pro, how to use the help files to interpret the programming interface, and how to set important environmental variables in your script. At the end of this video and the previous one, you'll be ready to dive back into solving our problem using Python.

Writing Python code to solve our problem

In this video, you are going to begin entering the specific Arcpy commands to solve our problem. To do this, you'll revisit the model that we created, and for each function, you'll find the corresponding Arcpy function to enter, along with the proper syntax.