I thought that people would enjoy this beautiful map that I have been working on this holiday season. It is a visualization derived from an SRTM digital elevation model based on a multi-scale topographic position analysis. This is one that you really have to click to enlarge to fully appreciate. I have spent hours lost in the detailed galactic colouring of this map!
I’m working on a paper right now in which I describe a new form of local topographic position analysis and the map above is one of the resulting visualizations. It shows prominent features at the small (blue channel), medium (green channel), and large (red channel) scales. A prominent feature is one that is either significantly above or below the surrounding landscape at the scale of interest. There’s actually a fair amount of analysis (and coding!) involved but if you’re really interested and can’t wait for me to finish the paper, send me an email. Here is a similar map but covering parts of British Columbia, Canada:
And this is the multi-scale topographic position map derived from SRTM data for the Northern Territory of Australia:
Personally, I think that these visualizations are remarkable for their ability to characterize the structure of the surface geology of a region but I’m sure that there are many other interesting applications as well. Interpreting the images takes a bit of experience but the following interpretation key can help:
Leave your comments below and, as always, best wishes and happy geoprocessing.
****UPDATE (May 27, 2015)****
This work was eventually written up as a manuscript and has recently been accepted for publication by the journal Geomorphology. The citation is:
Lindsay, J.B., Cockburn, J.M.H., and Russell, H.A.J. In press. ‘An integral image approach to performing multi-scale topographic position analysis’ Geomorphology, 245, DOI: 10.1016/j.geomorph.2015.05.025.
This article can be downloaded for free until July 18, 2015 from the following link:
And the submitted draft is available here.