Uncertainty in Digital Elevation Data Used For Geophysical Flow Simulation

Elevation information plays a crucial role in simulations of geophysical flows providing the slope and curvature information required to solve a series of differential equations. Digital Elevation Models (DEMs) used as simulation input diverge in resolution, acquisition time and generation methodology. When more than one elevation data set is available, they can be analyzed to provide an estimate of the uncertainty. This work present a method to estimate elevation uncertainty based on at least two elevation data sets. Cluster analysis of uncertainty is also carried out and a strong correlation between uncertainty and terrain curvature is found. The results of this study can be used to modify the available DEMs along ridge and valley lines, to create a quality of DEM information based on the curvature, and to provide a valuable quality measure for the input and the effect on the geophysical flow model results.