This tool calculates the total curvature, which is the curvature of the surface itself and not the curvature of intersecting lines (e.g. profile and plan curvatures). Curvature is a second derivative of the topographic surface defined by a digital elevation model (DEM). Total curvature can be positive or negative, with zero values indicating that the surface is either flat, or that the convexity in one direction is perfectly balanced by the concavity in the opposite direction (e.g. a saddle point). The user must specify the name of the input DEM and the output raster image. Whitebox reports curvature in degrees multiplied by 100 for easier interpretation. The Z Conversion Factor is only important when the vertical and horizontal units are not the same in the DEM. When this is the case, the algorithm will multiply each elevation in the DEM by the Z Conversion Factor. If the DEM is in the geographic coordinate system (latitude and longitude), with XY units measured in degrees, an appropriate Z Conversion Factor would be a value of approximately 0.000003, although this will vary somewhat by latitude. If the XY units of the raster are set to degrees or the projection set to geographic coordinates, the tool will automatically calculate an appropriate value for the Z Conversion Factor.
The algorithm uses the same formula for the calculation of total curvature as presented by Gallant and Wilson (2000).
The following is an example of a Python script that uses this tool:
wd = pluginHost.getWorkingDirectory()
inputFile = wd + "DEM.dep"
outputFile = wd + "curv.dep"
zFactor = "1.0"
args = [inputFile, outputFile, zFactor]
pluginHost.runPlugin("TotalCurv", args, False)
This is a Groovy script also using this tool:
def wd = pluginHost.getWorkingDirectory()
def inputFile = wd + "DEM.dep"
def outputFile = wd + "curv.dep"
def zFactor = "1.0"
String[] args = [inputFile, outputFile, zFactor]
pluginHost.runPlugin("TotalCurv", args, false)