What Problem Does This Solve?
In multi-scale systems it is increasingly easy to get lost because of the lack of clues to orient oneself.
When to Use This Pattern
This pattern can occur quite frequently when navigating map applications horizontally (at the same zoom level) or vertically (across multiple zoom levels). Possible reasons for not knowing where you are including missing reference features like states or county lines but especially at larger scales missing or hardly visible labels and features like landmarks.
What’s the Solution?
The first step to avoid the desert fog problem is to provide clear and legible labels.
Additionally one can provide well known man-made (landmarks, highways) or natural (rivers, mountains) features are shown so that users can recognize their location and locate themselves in relation to these features.
Application designers may also consider adding
- Home Button to reset back to a well-known extent
- Overview Map to see the current location in relation to the whole
- Visual cues like grid lines
Why Use This Pattern?
A core design principle is user control. The best apps find the correct balance between enabling users and avoiding unwanted outcome, make people feel like they’re in control by keeping interactive elements familiar and predictable. Being aware of the desert fog problem helps to consider and implement familiar and predictable controls that enable users to orient themselves and navigate unfamiliar geographical areas.
 Human Interface Guidelines, Apple, https://developer.apple.com/ios/human-interface-guidelines/overview/themes