Topographic ruggedness index

The topographic ruggedness index (TRI) is a measure of local topographic relief. The TRI calculates the root-mean-square-deviation (RMSD) for each grid cell in a digital elevation model (DEM), calculating the residuals (i.e. elevation differences) between a grid cell and its eight neighbours.

Grid cells containing NoData values in any of the input images are assigned the NoData value in the output raster. The output raster is of the float data type and continuous data scale.

See Also:

• Difference From Mean Elevation

Scripting:

The following is an example of a Python script that uses this tool:

wd = pluginHost.getWorkingDirectory()
inputFile = wd + "DEM.dep"
outputFile = wd + "output.dep"
zFactor = "1.0"
args = [inputFile, outputFile, zFactor]
pluginHost.runPlugin("TopographicRuggednessIndex", args, False)


This is a Groovy script also using this tool:

def wd = pluginHost.getWorkingDirectory()
def inputFile = wd + "DEM.dep"
def outputFile = wd + "output.dep"
def zFactor = "1.0"
String[] args = [inputFile, outputFile, zFactor]
pluginHost.runPlugin("TopographicRuggednessIndex", args, false)


Credits:

• John Lindsay (2012)

Reference:

• Riley, S. J., S. D. DeGloria and R. Elliot (1999). A terrain ruggedness index that quantifies topographic heterogeneity, Intermountain Journal of Sciences, vol. 5, No. 1-4,1999.