Plan and profile curvature map created from DEM in ArcMap. How to interpret the concave and convex, then convergence and divergence curvatures from the negative and positive values.
I found these two links really helpful, try:
http://blogs.esri.com/esri/arcgis/2010/10/27/understanding-curvature-rasters/
http://www.ian-ko.com/ET_Surface/UserGuide/Raster/ETG_RasterCurvature.htm
At the same time, you may have a look into this paper:
Rana, Sanjay. "Use of plan curvature variations for the identification of ridges and channels on DEM." Progress in spatial data handling. Springer Berlin Heidelberg, 2006. 789-804.
Hope that helps.
you should be classify profile and plan curvature based on the following values:
concave: 0.001 or upper bound value)
Hello!
I was reading this exchange of information and there is something I do not manage to get my hear around. If the reply of Hamid Reza Pourghasemi holds true, negative values should indicate a concave surface.
Yet, from Esri's webpage (http://blogs.esri.com/esri/arcgis/2010/10/27/understanding-curvature-rasters/) fig. 16.20 (profile curvature), a concave curvature should be indicated by positive values. Is that an error on Ersi's webpage part?
From a commonsene standpoint, I would lean to agree with Hamid Reza Pourghasemi...
Best
Dear Alverti
in Plan curvature: Convex (+), Concave (-)
BUT
Profile curvature: Concave (+), Convex (-)
Best
Hello,
I have a question related to the profile curvature values.
In an article I was reading (reference provided at the bottom of this question), scholars have found a negative correlation between profile curvature and soil moisture (see articles' pages 274-75).
Now, it is my understanding that (judging from the fact that the correlation is negative) when profile curvature has negative values (i.e., convex), the moisture should be high, and vice versa.
Now, what I am wondering is how can a convex (sloping) terrain hold more moisture than a concave one? May be I am missing something here....
Thanks for any elucidation.
Reference:
Famiglietti, J., Rudnicki, J., & Rodell, M. (1998). Variability in surface moisture content along a hillslope transect: Rattlesnake Hill, Texas. Journal of Hydrology, 210(1-4), 259–281. doi:10.1016/S0022-1694(98)00187-5
Dear researchers,
Thank you for your response.
The answer given by the Dr. Hamid is for plan and profile curvatures.
If we use combo-curvature (which is combination of plan and profile curvature how would be the classification ?
Ramesh for the Combo-curvature, according to ESRI: A positive curvature indicates the surface is upwardly convex at that cell and a negative curvature indicates the surface is upwardly concave at that cell. See this link
http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Curvature
Strange, in a more recent link the positive profile curvature is a concave cell but I really don’t understand how a convex surface decelerates the flow and the concave one will accelerate it.
It´s what they are saying in this link … additionaly i’m currently trying to cite someone on this matter and I’m just more confused. I know other software’s use different signs but the logic of the acceleration in a concave cell I still don’t get it!?? Can someone please clarify this to me?
http://desktop.arcgis.com/en/arcmap/10.3/manage-data/raster-and-images/curvature-function.htm
Thanks for the information, I am starting to learn about this topic in order to implemet a methodology in my field (archaeology, rockart) and I find this line really usefull!
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