Topographic Ruggedness Index

The topographic ruggedness index (TRI) was developed by Riley, et al. (1999) to express the amount of elevation difference between adjacent cells of a DEM.  It calculates the difference in elevation values from a center cell and the eight cells immediately surrounding it. Then it squares each of the eight elevation difference values to make them all positive and averages the squares. The topographic ruggedness index is then derived by taking the square root of this average

See Rugosity

Last revision 2/1/2016