Automated accuracy assessment for ridge and valley polylines using high-resolution digital elevation models

For better understanding of geologic and geomorphic processes responsible for the formation of ridges and valleys widely distributed over the Earth’s surface, accurate delineation of the features is very important. This paper intro duces an automated method for accuracy assessment of ridge and valley polylines using high-resolution digital elevation models (DEMs) derived from light detection and ranging (LiDAR) data and software implementation of a Python add-in toolbar for Esri’s ArcGIS1. Compared with existing methods that use two input polyline layers for comparison, the new method automatically extracts reference points from the DEM on-the-fly. In addition to producing statistical results of positional accuracy following the National Standard for Spatial Data Accuracy, the method also identifies locations where inaccuracies occur, so that the polylines can be edited and reevaluated. Two data sets from New Mexico and Colorado are also used as samples to demonstrate the application of the geographic information system (GIS) add-in. The results suggest that the free GIS add-in can be widely used by geoscientists.