Using ArcGIS Online and Open Data


by Albert Lin

April 11, 2016

ArcGIS is a geospatial tool that helps you create maps to visualize spatial data. Typically, subscriptions to the desktop version of ArcGIS are very expensive, and the software requires a significant amount of training to gain competency. However, by leveraging the power of preformatted open data sets and Esri’s streamlined and free edition of ArcGIS Online, you can begin creating maps in no time. This guide will walk you through signing up for ArcGIS Online and connecting data from the Western Pennsylvania Regional Data Center’s open data portal.

Signing up and accessing ArcGIS Online

Signup for ArcGIS isn’t very straightforward. Ignore references to free trials and purchasing and click “sign in” in the upper right corner. Select the “Create an account” tab on the next page and go through the application.

 Once signed in, click your account dropdown in the upper right corner and select “ArcGIS Online” to access the application.

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Navigating ArcGIS Online

From the main menu, you will be able to access the main application by selecting “Map”, access shared content in Groups, and also see all of your previously saved content.

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In the application, the main menu allows you to add layers, save your map, and access sharing features. Layer-specific options are located on the sidebar.

Finding and Connecting Data to ArcGIS Online

You can upload shapefiles and CSVs to ArcGIS Online, but you are limited to 1,000 features in your upload file in the free edition. This probably won’t be a problem you run into often, but could be an issue if you are trying to upload a file that has geocoded police incident reports, or similarly large files. The easiest way to access open data files with geospatial data on the Regional Data Center is to look for datasets with the Esri REST filetype.

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These datasets will have an “ArcGIS Open Dataset” filetype that will link you to the City of Pittsburgh GIS page by clicking “Download”. From here, you can open up the filte directly into ArcGIS Online by clicking “Open in ArcGIS”. This will bring in the shapefile as a new “layer” directly into ArcGIS Online. You can think of a layer as an overlay with the data that you are interested that sits on top of a map projection.

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From there, you can begin directly manipulating your data in a new layer.

Basic Functionality

You can access layer options by selecting the “Change Style” button, represented by the shape icon, under a layer heading. This allows you to edit the data attribute you want to display from the shapefile that you are using. Note that each attribute displayed will require its own shapefile, so if you want to show multiple data attributes from the same shapefile, you’ll want to duplicate the layer.

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Using the “Change Style” menu, you can change the data attribute, select your draw style, and edit the draw style options. For example, if you are setting gradient shading to show density, you can set manual breakpoints for the shading.

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You can access other layer options under the ellipses icon, such as visibility and transparency, copying a layer, renaming, and editing labels and popups.

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Sharing Options

When you are done with your map, you can share your results via the “share” button in the upper right. Here, you will be able to add your map to groups, obtain a direct link that you can then use in emails, obtain HTML code to embed your map in websites, or use prebuilt web apps. Some of the prebuilt web apps, like story maps, allow you to create interactive maps to show changes and trends.

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Web Apps

Esri also has some great built-in Web Apps that you can use to create interactive maps using pre-made templates. You can show multiple maps or multiple layers on a single map to display analysis in an attractive and presentable format. This is great for telling a story with your data, such as displaying change over time.

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Click here to see a basic example generated with SNAP data to show population change in Pittsburgh neighborhoods between 1960 and 2010.

Additional resources