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Depicting Small-Scale Ground Contours

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#1
CharlieG

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I've been looking for an easy way to depict small-scale ground contours such as one would be dealing with on a golf course. The target audience is people who have no idea how to read a topo map. I stumbled across something in a paper I found online.

Number 1 - A relatively standard depiction of topographic lines
Number 2 - What I found in the aforementioned paper online
Number 3 - What I found to be easiest to decipher at a glance

(note, the image should be animated, if not I'll have to find another way of showing it.)

Attached File  Topo_depiction.gif   238.2KB   90 downloads


The end goal is to represent the ground contours of a golf course, so fairly small scale. I'm hoping that in looking at it, they'll be able to tell where their ball will bounce and roll when it hits the ground. Below is an image I did of a golf course depicted using method 3 shown above.

Attached File  Wilshire_CC_for_post.jpg   499.44KB   148 downloads


Let me know if this seems to work, or if there are better ways to depict ground contour for the untrained eye.

Thanks much,

Charlie

#2
David Medeiros

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Just for reference, what you are working with here is actually a large scale map (large details but small area), not a small scale map. I think what you mean is "small area".

For the effect itself, I personally don't like the shadow effect. It creates a stepped appearance to the contours and makes the terrain look very unnatural. A contour line is a slice of elevation and the terrain is assumed to slope between contours relative to the contour interval and the distance between contours (rise / run). Your example tells me that there is no slope on the golf course.

Coloring the contours technically says the same thing, but with non shadowed contours can be useful in emphasizing the relative elevations at a glance. So maybe try this thechnique without the shadows and use a compact range of color values.

You could use a shaded relief image instead, created from a surface derrived form your contours or using a high res elevation model for the area. If the SR is too coarse or lacks detail you can use it under the contours, letting the contours emphasize the finer changes in the terrain and the SR adding a sense of slope.

GIS Reference and Instruction Specialist, Stanford Geospatial Center.

 

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#3
DaveB

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There is a discussion of the line thickness method and related ideas in Imhof's Cartographic Relief Presentation, starting on page 149.
You might also be interested in this article by Pat Kennelly and Jon Kimerling

Your example map looks a little busy with various lines, including the contour lines, lines around the green areas, etc. I'm thinking shaded relief, with lighter contour lines if they help, would work better.

I like that you are looking around and experimenting with different techniques. Too often we can get in a rut and go back to the same tools and techniques again and again.
Dave Barnes
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#4
M.Denil

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The big drawback to the Tanaka shaded contour method is that it leads people to expect a layer cake / stair stepped / terraced landscale, especially as the contours get sparse. This is exacerbated at large scales like this, where people expect features to be human sized, and not simply conventional.

Using this system, a lot of intermediate contours and a smaller line size variation with a less solid black would help.

Both Tanaka techniques (shaded contour and oblique contour) need a LOT of line work to give a good representation, and your map has more than enough heavy handed linework already. The outlines on the green areas (fairways ?, forested screens?) and the stupendous black line across the middle (road? Highway? Anaconda?) are unnecessarily prominant.

These terrain depiction methods require a very subtle balance of contrast to work well. They can produce a very persuassive and easily read depiction, but that balance is critical. Good luck with it: it is a lot of work to get that balance right, but can be very rewarding.

M.Denil




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