Terrain Modelling: Shortest Path, Drain Patterns, and Interspersed Contours

摘要

A computational approach to the task of generating contour-true and drain-consistent cartographic terrain surfaces from given grid-digitized contour lines is proposed and demonstrated for a still somewhat limited class of such contours. This approach is as follows: Consider all grid points located between two adjacent contours, and for each such grid point determine a shortest path towards the lower contour with respect to a grid metric that penalizes proximity to either contour. ne pattern of these shortest paths is interpreted as a drain (ridge) pattern or network. This pattern contains the major drain (ridge) lines as implied by the contour information and thus permits the extraction of such features directly from grid-digitized contours. In a further development, the pattern is utilized to construct a grid elevation matrix by prorating elevations along its paths. An alternate drain (ridge) pattern derives naturally from that elevation matrix. This suggests an iterative procedure, alternating between extracting a drain (ridge) pattern from a grid elevation matrix and then generating a new elevation matrix from such a pattern. This procedure will be described and demonstrated. It will be considered as a method for interspersing contour lines of intermediate elevations.... Automated cartography, Blocked drain, Digitized contour drainage network, Interspersed contour, Elevation matrix, Interpolation, Drain pattern, Surface generation, Terrain modeling.