6 replies to this topic

[Agnar Renolen]

We cartographers like to make maps with nice-looking shaded reliefs.

However, from time to time I come across people who strongly believe that topographic maps used for treking and other outdoor activities should have a traditional cartography with contours and no shaded relief.

We like to think that shaded reliefs makes the maps userfreindly, but do we really know how much?

Does anyone know of surveys examening how much shaded reliefs actualy aids navigation?
It would be very intersting to see this quantified in some way or another.

Agnar

[David Medeiros]

We cartographers like to make maps with nice-looking shaded reliefs.

However, from time to time I come across people who strongly believe that topographic maps used for treking and other outdoor activities should have a traditional cartography with contours and no shaded relief.

We like to think that shaded reliefs makes the maps userfreindly, but do we really know how much?

Does anyone know of surveys examening how much shaded reliefs actualy aids navigation?
It would be very intersting to see this quantified in some way or another.

Agnar

I don't know of any actual studies but I my personal opinion is shaded relief definitely aids map reading on topographic maps that also contain contours. The two representations are fairly complimentary and if executed correctly there should be no loss of clarity on the map between the two (or any other features).

My impression is that individuals who don't like SR on a topo map have never seen it done properly or are imagining the dark SR of some maps under the dark or thick contours of standard USGS topos or similar. Combining a very light SR layer under the contours can speed up terrain recognition tremendously especially in areas with really complex relief.

[Hans van der Maarel]

I agree with David. If done correctly, and in proper balance with contour lines, it can really add a lot of value to a map. I also think (but this is an opinion, not based on any research or facts) that shaded relief is going to be easier to read for novice map users than contour lines.

[rudy]

My personal opinion: relief shading can be very effective at medium and small scale maps but not very effective for very large scale maps - mostly because the detailed data is not there to support it. And do you really want a hillshade on a hill that rises 10m on a 1:1000 scale map?

But in terms of research, I haven't heard of anything that either supports or deos not support the effectiveness of hillshading.

[David Medeiros]

To answer the research question, I have read of studies that found SR to very helpful in terrain recognition. These were not focused on navigation but on how to best communicate mapped information to indigenous populations who in most cases had never seen or used a map before. Various methods of geographic representation were studied for their effectiveness in communication of threat or risk levels for their local terrain involving floods, landslides etc. Contours alone were found to be a very abstract idea for most individuals who had never encountered them before but SR alone and SR with contours was much easier to pick up. The leading method of terrain visualization was a 3d model of the areas, but SR was found to be very effective (and much cheaper than models!).

[Jelf]

Hello Everyone,

In terms of online topographic maps it is possible to let the user select the amount of hill shading they prefer, including none at all. This link displays a 1:24,000 topo of a random spot in the Santa Cruz Mountains of CA. Click Menu ==> Hill shading. The default is 18.
http://www.mappingsu...mp;hillshade=18
Anyone can do their own research with this variable hill shading feature and find out what people prefer.

Joseph, the Gmap4 guy

[P.Raposo]

Hi everyone,

Agnar, while we didn't seek to answer your question directly, Cindy Brewer and I did a study involving user responses to several topographic map designs, some with shaded relief and some not. Users weren't actually hiking, but were asked to read the maps to get landscape/routing information first, and then provide feedback afterward. Our ICC paper is online here.

Also, again not directly related to the question of how shaded relief compares to contours for map readers, this reminds me of something Tom Patterson has written, a great piece about realism in general in maps, with shaded relief being a significant portion of what he was talking about.

The question reminds me also of Tanaka's illuminated contours, which are a beautiful kind of intermediate, even though that might be a little of a stretch
(Tanaka, K. "The Relief Contour Method of Representing Topography on Maps," Geographical Review, Vol. 40, pp. 444-456, 1950.)

Cheers,
Paulo