Raster smoothing

I am an italian student. I'm using ArcMap 10. For my thesis I need to simulate a debris avalanche, but in my elevation raster the avalanche deposit is included so I'd need to take it off to simulate on a pre-avalanche-like surface. Unfortunately the only data I have is the average (and supposed uniform) thickness of the deposit of 24m. I removed this thickness from my raster using raster calculator ("my raster" - "raster of tickness created from polygon to raster"). What I obtained is a raster without that thickness, but like a valley with sub-vertical walls! I need to smooth these edges to make it look more realistic (now it looks like a print with the shape of the deposit). Which tool can use? What I was able to find is the Filter tool which smooth these edges too mildly or the Smooth Line tool which could work on the contour lines. Is there a tool to smooth directly the raster?

Thank you,

Michele

• possible duplicate of What raster smoothing/generalization tools are available? – Aaron Jun 14 '13 at 13:59
• @Aaron That's a good call; those methods can be applied to answer this question. But IMHO there may be better answers available which address some special aspects here. The present problem might better be characterized as "fairing" a raster into another rather than just "smoothing" or "generalization," although it does share aspects of the latter two. A good answer would use knowledge of the shapes of debris deposits. It would also increase the thickness in the middle to compensate for the thinning at the edges, maintaining the average at 24 meters. – whuber Jun 14 '13 at 14:43
• Any chance you can post an image of your raster? – Radar Jun 14 '13 at 17:11
• @Radar This is kind of the reverse of How to build an artificial dam?, which has some illustrations: given the result, which is a raster showing a dam, how could one reproduce the original DEM that doesn't have the dam? The dam (which is just an artificial "deposit" of geological materials anyway) plays the role of the avalanche deposit. This analogy helps make it clear why some knowledge of the likely 3D shape of the avalanche deposit (or the terrain beneath it) is critical to a good solution. – whuber Jun 14 '13 at 17:42
• Agreed - if you want to remove a 3D object from 3D space you need to know the dimensions of the object. An example image would help me wrap my head around the geometry of the object to be removed (although I can make an educated guess as to what slide deposit would look like - I'm a bit concerned it may not be as uniform as the original post states). – Radar Jun 14 '13 at 18:19

1 Answer

I think you need the Raster Generalization option: http://www.esri.com/software/arcgis/extensions/spatialanalyst/key-features/raster

Take a look at this also: Performing Raster Noise Reduction and Edge Smoothing?

• Although these sound like applicable methods, they do not seem to address this particular question. Could you please explain how you think they would be applied here? – whuber Jun 14 '13 at 14:43