What is a Swipe Map?
In the digital age, maps have evolved far beyond simple paper versions. Among the innovative tools available to visualize geographical data is the "swipe map." This interactive feature offers users a dynamic way to compare two overlapping maps by "swiping" a dividing line across the screen.
But what exactly is a swipe map?
Understanding Swipe Maps
A swipe map is an interactive tool that allows users to compare two different maps by revealing one map underneath the other. Imagine a digital version of peeling back a layer to see what's beneath.
Typically, one map fully displays while hiding the other. Moving the swipe bar reveals the hidden map in real-time. This function is particularly useful for visualizing changes over time, differences between datasets, or comparing various attributes of a geographic area.
The Mechanics of Swipe Maps
Swipe maps are usually embedded within a Geographic Information System (GIS) or mapping platform, such as Mapbox, or Vizualist. They consist of two layers: the base layer and the swipe layer. The base layer is the default map that is fully visible when you first open the map. The swipe layer is the map that you reveal by moving the swipe bar.
The swipe bar is a vertical or horizontal line that you can drag across the screen. Dragging the swipe bar across the screen you reveal and compare the swipe layer with the base layer. This user-controlled interaction offers a seamless and intuitive way to analyze and interpret data.
An Example of a Swipe Map
This Vizualist swipe map compares the 2020 U.S. presidential election results in each state with its urbanity level. In this case, "urbanity" is the percentage of the state’s population living in urban areas.
Note that as you swipe, the darkness of the color indicates the margin of victory for the winning candidate. States with a darker blue show that Joe Biden, the ultimate winner of the 2020 election nationally, won that state by a bigger margin. States with a darker red show a wider margin in that state for the ultimate loser Donald Trump.
Practical Applications of Swipe Maps
Swipe maps have a wide range of applications across various fields. Here are a few examples:
- Urban Planning and Development: Urban planners can use swipe maps to compare current land use with proposed developments. This helps in visualizing potential impacts on the environment, infrastructure, and communities.
- Environmental Monitoring: Researchers can compare satellite images from different years to observe changes in vegetation, water bodies, and urban expansion. This is crucial for tracking deforestation, desertification, and other environmental changes.
- Historical Research: Historians can overlay old maps with current ones to study landscape and cityscape changes over centuries.
- Disaster Management: Swipe maps can assess natural disaster impacts (floods, hurricanes or earthquakes) by comparing before-and-after imagery. This helps in planning recovery efforts and understanding the extent of damage.
Conclusion
Swipe maps are powerful tools that enhance the way we visualize and compare geographical data. Whether you're a researcher, planner, or map enthusiast, swipe maps offer an engaging way to explore changes and differences. By leveraging this tool, you can gain deeper insights and make more informed decisions based on spatial data.
