3

I would like to make a map of sinkholes. I have a DTM ARC/INFO ASCII GRID of Asiago Plateau and and I'm using grass gis. Does anyone know what is the correct form in grass gis?

  • Please take a look at this page why sink filling is not needed in GRASS GIS: grasswiki.osgeo.org/wiki/… – markusN Nov 18 '14 at 9:36
  • Thanks, I read. I understood that it was necessary to consider the areas highlighted as a fault. I was not happy with the result and so looking at the DEM I saw that large sinkholes could be seen by eye. The area that I have analyzed is not large and karst features are well developed. From a DEM with cells to 5 meters I could not expect much more. – Filippo Nov 18 '14 at 21:09
  • Fortunately I'm a caver and I can make out the sinkholes from rough terrain. – Filippo Nov 18 '14 at 21:18
2

In general, to create a map of sinkholes using a DEM, you would first fill the topographic depressions (sinkholes) then difference the original DEM from the filled DEM. This gives you 'depth in sink' but if you simply want a Boolean sink map, reclass the depth map such that 1 is assigned to all values greater than 0. The tool in GRASS GIS to fill depressions is called r.fill.dir. As an aside, in ArcGIS there is a convenient tool that maps sinks in one step by using the Sink tool and in the open-source GIS Whitebox GAT, for which I am a developer, you can use the similarly named Sink tool to achieve the same result.

  • @Filippo That's great. I'm glad you got solved. – WhiteboxDev Nov 14 '14 at 14:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.