Using heat maps

Heat maps can be created from point layers of types that allow configuration of symbology. This includes layers from ArcGIS Server dynamic map services, tables from Spatial Data Service endpoints, and SharePoint lists. For more information on the different layer types and their capabilities, refer to the Layer types topic.

About heat maps

When a layer contains a large number of point features, showing each feature individually on the map is often not useful. In this scenario, point features often overlap, making it difficult to distinguish between features. Even when they do not overlap, it is usually difficult or impossible to visually extract meaningful information when hundreds or thousands of points are shown all at once.

One approach to resolving this issue is to generate a heat map. A heat map represents the geographic density of point features on a map by using colored areas to represent those points. The areas will be largest where the most points are concentrated together. Also, areas of high density, or hot spots, will be symbolized with the color chosen to represent "hot" areas. While heat maps in general can also incorporate one or more attributes into how they are calculated, the ArcGIS Map Web Part only takes into account geographic location. So heat maps in the Map Web Part provide an effective way to visualize where the point features in a given layer are most concentrated.

Creating a heat map

  1. Choose the point layer on the Map Contents panel that you would like to generate a heat map from. For instructions, see The Map Contents panel.
  2. Click the Add button in the Heat Map group on the Symbols tab of the ribbon:
    Heat Map Add button
    A heat map is calculated and automatically added to the map. The heat map also becomes the selected layer, so the Intensity and Color Scheme buttons are enabled:
    Intensity and Color Scheme buttons enabled
  3. Click the Intensity button to open the intensity slider. Use the slider to increase or decrease the heat map's intensity:
    Heat Map Intensity slider
  4. Click the Color Scheme button and use the resultant color picker to modify the colors for the heat map.
8/12/2011