I would like to collate a library of terrain types and features, suitable as reference material for generating small scale artificial versions (for gaming or concept art). For example, I might wish to view a typical part of the Mojave Desert, or section of forest on the bank of a river in Yellowstone National Park, or part of the Florida Everglades, and use that to get a sense of typical height differences, surface types, plant cover - anything that would help visualise the area on a computer without needing to visit it in person.
I am interested in features important at a human scale that might affect navigating through an area, viewing it or otherwise experiencing it. I am also interested in collating a wide variety of terrain types in many small examples, as opposed to highly-detailed coverage of a single large area. So I am not looking for a map directly, but enough details to characterise real-world natural terrain.
The following properties of any data source would be interesting:
Area covered can be relatively small e.g. 100m x 100m, because I am looking for reference data for terrain types, not specific maps.
Digital Elevation Map at 30cm/point or better
Ground type map at 30cm/point or better, or scientific data for inferring this in context (e.g. spectrographic)
Plant ground cover classified by species or broader types (grasses, shrubs, trees).
Aerial photography with suitable resolution to cover human-scale features (e.g. 30cm per pixel)
I am not expecting to find all this neatly packaged for all possible types of natural location in a single data source (although that would be great). I am expecting instead to need to spend time and effort finding and extracting data I want from detailed surveys made for other purposes, where original data has been openly published.
Searches I have done often turn up DEMs of suitable quality (example: USGS Lake Mead), but I rarely find other data sources on the small-scale high-resolution I am interested in. I am not sure whether that is because the data sources do not exist, or because I don't know where or how to go looking.
Update: I am aware that "natural" is wooly term here. I mean to exclude building or structural plans and surveys, that is all. I would probably consider non-intensive farmland as "natural" for my purposes.