Basic Mapping With ArcGIS Online

The dominant company in geographic information systems is ESRI, which was one of the pioneers of GIS in the late 1960s. If you do GIS professionally, you will probably be working with ESRI software.

Historically, ESRI's flagship software product has been ArcMap, a desktop GIS program that is feature rich, but also buggy, bloated, and difficult to use. This software is still dominant in enterprise GIS - the GIS done by government agencies and large companies. Accordingly it is also the software you will probably learn to use in an introductory GIS class in preparation for a professional GIS career.

ArcMap

However, with information technology increasingly oriented around the internet, ESRI has branched out into an online, cloud-based product called ArcGIS online, which is available by subscription, and which can be used to create web maps and perform some types of spatial analysis.

ArcGIS Online

ArcGIS Online makes web map creation comparatively easy by providing online access to a flexible visualization and analysis tool, as well as easy access to both public and proprietary data.

Getting ArcGIS Online

You can get an ArcGIS Online account in one of three ways.

Enterprise Account

If your school or employer has an ESRI site license, you can get an account from your instructor or IT staff. The video below shows how to log in to ArcGIS Online using an enterprise account such as that used at Farmingdale State College:

Basic Mapping With ArcGIS Online

ArcGIS For Personal Use

You can purchase an annual license from ESRI for personal use (as opposed to commercial use) for $100 that includes not only authorization for their desktop products (ArcMap and ArcGIS Pro) but also ArcGIS Online. The ArcGIS Online subscription comes with a limited number of credits, although you can purchase more as needed for a significant cost.

ArcGIS For Personal Use

Free Public Accounts

ESRI provides free public accounts that provide basic capabilities to give you a feel for what ArcGIS Online can do. Public accounts include no proprietary data or analysis tools, which limits users to creating simple maps.

ArcGIS For Personal Use

Living Atlas Layers

ESRI's Living Atlas of the World is a collection of open and proprietary data that is made available in ArcGIS Online. Living Atlas layers cover a wide variety of topics.

Creating a Map

  1. Select Map from your ArcGIS Online home page
  2. Click the Add button and Browse Living Atlas Layers
  3. Search for your topic of interest. For this example we will use 2016 Median Household Income
  4. For polygon layers, adjusting the transparency to 25% will permit the base map to be visible and give geographic context to your layer so you know where things are
  5. Zoom the map to your area of interest
  6. View the legend to see what the colors or symbols mean
  7. With many layers, you can click on a region to display a pop-up displaying information about that region
Creating a Living Atlas Map

Generalization

Web maps are designed so that you can zoom in or zoom out, and those different zoom levels are numbered, from one showing the whole world, to 21 or greater, which shows building-level detail.

Many Living Atlas layers provide different levels of cartographic generalization based on the zoom level. This optimizes the amount of data displayed at different scales, so maps do not appear either too cluttered, or too lacking in detail to be meaningful. With this median household income layer:

Layer Generalization

Adding Map Notes

Map notes are layers of annotations that can be used to point out specific locations or features on a map.

  1. Select Add, Add Map Notes
  2. Give the map notes layer a meaningful name
  3. Pan to the area you want to annotate
  4. Select the type of note you want to add in the left pane, then click on the map to add it
  5. Give the annotation a meaningful name and, if needed, annotation text
  6. When you are done adding notes, click the edit button to stop editing
  7. If you later want to add additional map notes to an existing map notes layer, select the layer in the Contents pane and click the Edit button
Adding Map Notes

Finding Latitudes and Longitudes

If you need the latitude and longitude in ArcGIS Online, you can use the Location tool and click on the map to find the latitude and longitude. Those latitudes and longitudes can be pasted into Google Maps if you want to find neighborhood names or get or share street views of a location.

Finding Locations

Sharing a Map

Sharing controls who can see your map.

  1. Zoom to the view that you want visitors to see when they first open your map
  2. Save (or Save As) your map under a meaningful name. Include tags such as the name of the layer or the location being mapped
  3. Click the Share button. ArcGIS Online is oriented around creating maps for the web, so you will usually want to share with Everyone.

  4. You can then copy the provided link to include in an e-mail or assignment submission

Note that depending on the authorization provided by your account administrator, Living Atlas layers may not be accessible to people outside of your organization and will throw a warning message. You can view such layers by logging in when viewing the map.

Sharing an ArcGIS Online Map

Starting a New Map

When you are done editing a map, if you want to close the existing map and start a new map, save the existing map, and then click the New Map link at the top left.

Starting a New ArcGIS Online Map

Reopening a Map

Maps that you save are listed on your Content page in ArcGIS Online. To reopen the map for modification or revision, select the link on your content list and then Open in Map Viewer.

Sharing an ArcGIS Online Map

Mapping Points From CSV Files

Comma-Separated Variable files are spreadsheet files that can be saved from any desktop spreadsheet program (like Excel) or from Google Sheets.

Capturing Latitude and Longitude With What's Here in Google Maps

CSV files that contain addresses or latitudes/longitudes can be imported as layers in ArcMap. Latitudes and longitudes can be captured using the What's Here tool in Google Maps.

  1. Right click on the location where you want the latitude and longitude
  2. Select What's Here
  3. Click on the latitude/longitude in the pop-up box
  4. Copy the latitude/longitude from the right pane. Always use the decimal format (smaller numbers on the bottom) rather than the degrees-minutes-seconds format (larger numbers on the top with the additional symbols)
Latitudes and Longitudes With What's Here in Google Maps

Categorical Pictogram Maps

For this example, we use a spreadsheet of houses of worship in the Farmingdale area.

  1. Download as CSV your spreadsheet as a .csv file. In a spreadsheet program, you can Save As with a type of Text CSV
  2. In ArcGIS Online, Add, Add Layer from File
  3. a
  4. If you have named your location fields latitude and longitude, the app will automatically map your points as dots. If you misspell latitude or longitude, or you want to map your points from addresses or other types of names, you will be given a dialog box asking what fields to use for what types of locations
  5. For categorical variables, you will probably want the Types (Unique symbols) drawing style
  6. For Options click on the icons under each categor to choose and size appropriate pictograms
  7. If desired, add labels to the bubbles by clicking on the ellipsis on the layer and selecting Create Labbels. Choose a label alignment where there is the least amount of overlap and contention for your particular set of locations
  8. Consider changing the base map to something unobtrusive if the base map conflicts visually with the points
Mapping a Categorical Variable From a CSV File

Quantitative Bubble Maps

For quantitative variables, Counts and Amounts (Size) can be used to create bubble maps.

  1. Download as CSV your spreadsheet as a .csv file. In a spreadsheet program, you can Save As with a type of Text CSV
  2. In ArcGIS Online, Add, Add Layer from File
  3. For Choose an attribute to show, select your quantitative variable
  4. For quantitative variables, you will probably want the Counts and Amounts (Size) drawing style
  5. If desired, add labels to the bubbles by clicking on the ellipsis on the layer and selecting Create Labbels. Choose a label alignment where there is the least amount of overlap and contention for your particular set of locations
  6. Consider changing the base map to something unobtrusive if the base map conflicts visually with the points
  7. Save the map with a meaningful name
  8. Share the map with Everyone (public) and copy the shared link that you can e-mail or submit for an assignment
  9. If you are embedding the map on a web page, you can also get iframe code from the sharing dialog
Mapping a Quantitative Variable From a CSV File

Mapping Shapefiles

Many organizations, including federal, state and local governments, make data available to the public as shapefiles, which is an old file format developed by ESRI in the 1990s that is still commonly used for sharing data. A shapefile is actually multiple files, but shapefiles are often packaged as single .zip files for easier distribution.

For this example, we use this shapefile state election data.

Mapping a Shapefile