Swiping (apologies to Dora the Explorer) is a simple way to show the difference between two layers or highlight changes over time. I’ve found that this neat trick is very effective in grabbing people’s attention or getting a reaction from them. It’s a common feature you can see in webmaps using Leaflet and Mapbox. This functionality is also available in desktop GIS like GRASS through the Map Swipe and QGIS via the MapSwipe Tool plugin

If you don’t know how to install plugins yet, you can check-out this post for QGIS 2 and this post for QGIS 3.

The Plugin

You can install the MapSwipe Tool plugin via Plugins -> Manage and Install Plugins.

• Name: MapSwipe Tool plugin
• Funtion: Allows for the selected layer to be swiped.
• Description: This plugin is a map tool for swipe active layer. The active layer, or group, will appear above all others. This plugin is developed of collaborative form with IBAMA [1] and APPLIED TECHNOLOGY CO., LTD [2].
  [1] http://www.ibama.gov.br
  [2] http://www.apptec.co.jp
• Author: Hirofumi Hayashi and Luiz Motta
• Code Repository: https://github.com/lmotta/mapswipetool_plugin

How to use

The plugin is used in a very straightforward manner. For my example below, I’m using two XYZ maps (Google Satellite and Bing VirtualEarth). The plugin works for both vector and raster layers.

1. Select the layer that you want to swipe on the Layers panel.

   

2. Activate the plugin by clicking the MapSwipe Tool icon in the Plugins toolbar or via Plugins -> Map swipe tool -> Map swipe tool. Note that this will unselect/disable your layer as well.

   
   

3. Drag your mouse to swipe the selected layer. You can swipe horizontally or vertically.

   

4. Once finished, click the icon again to deactivate the plugin.

   

That’s it. You can use the MapSwipe Tool on your next mapping project. #HappyMapping!