Render slope as a directed texture

[Nate-Wessel]

Using elevation contour lines as in the Cincinnati map hasn't worked well for such a flat city. When colors are distinct enough to distinguish between contours, they interfere with easy reading of the colored lines.

My current working hypothesis is that it will be best to assume flatness unless slopes need to be indicated. I've extracted slopes from a smoothed version of the DEM and drawn contours around slopey areas. These are indicated with dark grey against a lighter grey background.

What I want to do now is to somehow indicate the direction of these sloped areas.

[Nate-Wessel]

It has an almost 3d effect which makes me wonder if hillshades would be simpler...