Full Stack Cartography – Think Like a Designer for Better Maps
This episode features Alan McConchie, a leading cartographer at Stamen. The discussion centers on mapping and visualization; and explores the usefulness of adopting a design-first thinking approach to the map making process. Alan has over 8 years experience making maps that are as beautiful as they are useful. Together, we will gain a deeper insight into full stack cartography, and how we can leverage it in our own work.
Spatial Data Visualization vs. Non-Spatial Data Visualization
Although they are both ultimately design tasks, there are some distinct differences between spatial and non-spatial data visualization. For one, there is lesser liberty in spatial visualizations than there is in non-spatial data visualization. Unlike in the latter where the designer can take liberty in choosing where to place objects and what shapes to use, spatial visualizations usually have to maintain location integrity. If the locations in a map are distorted, the map will be misleading and fail to serve its purpose. The flexibility in maps is mainly found in the choice of the symbology, color ramps, and fonts used. Even these areas are often guided by standard cartography rules, so it’s important to make the most of the creative space provided if you want your maps to stand out from the rest.
What is Full Stack Cartography?
Full stack cartography is seeing the world as a challenge of design, and how it can be effectively mapped for a particular use case, or to communicate your topic of interest. To back it up a bit, full stack is the idea of taking your entire workflow, and all of the areas of your system that it touches into consideration together. Full stack cartography incorporates design thinking into the map making process right from the beginning, throughout the process, and until the end. Writing the code and scripts used to process the map data is heavily guided by the use case of the end product.
Ideally, every decision, at each stage of the process should contribute towards making the end product the best it can be for its use case. All the decisions made when making a map are important; from how the data is stored in a database, to how it is processed, to how the end product is displayed. The ripple effect of all these decisions throughout the process can make achieving the end goal easier (if done right), where ignoring them can make the process more difficult, inefficient, and altogether frustrating.
Why Are Base Maps Pre-Generated?
A base map is a pre-generated background map that provides context to other map layers that are overlaid on top of it. They generally contain generalized land uses, streets, water features, and building footprints, amongst other landmarks. Pre-generating base maps makes loading web maps faster, and more efficient, by leveraging imagery tiles. Since creating base maps is a complicated process that usually requires a huge amount of data, generating them on the go every time is computationally intensive and slow for devices with low to standard computing power – which is the case for the majority of users.
In order to improve the user experience even further, base maps are divided into many small pieces, called map tiles, so that a browser does not have to load the entire base map, but rather only loads the pieces (tiles) of the area that a viewer is interested in. This is faster and more efficient than loading the full dataset.
How Do Map Tiles Work?
Using map tiles is a popular and common technique for displaying maps on the web. After generating a map, it is divided into many small pieces (usually square shaped, be sure to look into Hex Tiles); which, when joined, form a seamless single map.
Tiling maps improves the user experience by reducing the size of the dataset that a browser has to load when displaying a map. Less data to load means displaying a map is faster, and uses less bandwidth. This is significant as web maps are already data and display intensive due to the many additional features and layers that need to be loaded alongside the base map, especially if those layers contain a lot of attribute data. To view an area of a map, the browser will only load the tiles that cover that area. When a user pans the map, more tiles that cover that area are returned. Previously loaded tiles may be cached so returning to your previous extent will be faster than if the map was loaded fresh.
How Are Map Tiles Created?
After creating a map, tiles can be generated using map tiling tools or services such as Mapbox Tiling Service. Tiles can be in a vector or raster format. The tiles are generated for different zoom levels to allow users to zoom in or out of a map as they may need. At higher zoom levels, the map tiles are further split into smaller equal tiles that display more details. Each zoom level has its pre-generated tiles that are easily loaded to a browser upon request. Most programs, like ArcGIS, have a default tiling scheme and thus create tiles for specific zoom levels that are most optimized for their viewers. If, however, you want your map to be drawn at different intervals, you can create and publish a custom tiling scheme.
Creating map tiles includes deciding which details will be included in the tiles, and which will be filtered out. In order to improve efficiency even further, cartographers try to reduce the size of data stored in each tile as much as possible. Some simplification is applied in the lower zoom levels to exclude details that may not be visible or useful in that zoom level. For instance, an application to show bike trails in a park may only display the trail lines at lower zoom levels, but then include the attributes like the trail names, or topographic lines at higher zoom levels. A cartographer decides which details to include at each zoom level and cuts out what is not required to avoid storing unnecessary data in the tiles. Having light weight tiles makes them even more efficient, fast, and useful for many mobile applications.
Styling Map Tiles
After deciding what map details appear at each zoom level, it’s time to decide how they should look. The tiles only contain the shapes and attributes of the map features. In order to apply styles such as colors and textures, a stylesheet is used. The stylesheet defines how the data stored in the tiles will be displayed. Design tools such as Mapbox Studio, or the open source option Maputnik, can change the color, line thickness, and other styling characteristics of a feature and display them instantaneously for review.
What is a “Good Map” in Cartography?
A good map may mean different things in different use cases, and to different people. Generally, a good map is one that finds the right balance between beauty and usefulness. No doubt we all love a beautiful map, but if it is too beautiful then users spend more time admiring it than actually using it. This is not a good map as it does not successfully and efficiently convey its message. Keeping the distractions to a minimum is one important trait of a good map.
Design-first thinking helps to create good maps that are useful, as well as visually appealing. Everything from the choice of colors, to fonts, to avoiding emphasis on less important features will contribute to whether a map is successful in its application. The ultimate measure of a good map is how well the map serves its intent. This of course includes making it visually appealing so that people are willing and able to use it in the first place.
Is Cartography Changing?
In the world of cartography, a lot has changed already. The tools used to make maps decades ago are not the ones being used today. The way maps are displayed today is different from how they were displayed in the past as well. The way maps are used have evolved too, and this is why the approach to cartography has also evolved over the years.
Today, maps are not only created for humans but for machines as well. For instance, self-driving cars need maps for navigation, and have to process a lot of simultaneous inputs.
In the future, more changes can be expected as further advancements are realized. Technology is getting better by day and soon we may see even more new products in cartography. For one, since personalization is a big thing these days, we may start seeing more personalized maps. This will come hand in hand with the loss of privacy that seems commonplace, and even expected nowadays. The developments seen in indoor mapping suggest we will soon see seamless outdoor-to-indoor navigation.
There is much we can expect from the future. In order to avoid being surprised, get involved now.