Revisiting geomorphons - with 1 arcsecond SRTM data
Tags: geomorphonscornwallSRTM 1 arcsecond02 Aug 2015 - MawKernewek
I had originally posted maps of DEMs of Cornwall and the Aberystwyth area of mid-Wales processed using Tomasz Stepinski et al.'s geomorphon method.
Since then I have become aware of the 1 arcsecond SRTM data being available, so I have recalculated the geomorphons and present some maps of Cornwall here.
I've also become more aware of the various layer blending methods in QGIS which has allowed me to blend it with a hill-shaded topography layer.
In these maps, the search distance L = 1500m, flatness threshold 1 degree.
Since then I have become aware of the 1 arcsecond SRTM data being available, so I have recalculated the geomorphons and present some maps of Cornwall here.
I've also become more aware of the various layer blending methods in QGIS which has allowed me to blend it with a hill-shaded topography layer.
In these maps, the search distance L = 1500m, flatness threshold 1 degree.
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| West Cornwall. Full resolution image. |
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| SE Cornwall, Tamar valley and Dartmoor. Full-resolution image. |
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| North Cornwall. Full-resolution image. |
Minimum search radius
It is possible to specify an 'inner search radius' that ensures a minimum search radius for the geomorphons. In the maps below, using a minimum search radius of 2 cells (about 50m for this data), this makes the map look a little less noisy: |
| West Cornwall. Full resolution image. |
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| SE Cornwall, Tamar valley and Dartmoor. Full-resolution image. |
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| North Cornwall. Full-resolution image. |