J. Garbrecht et Lw. Martz, THE ASSIGNMENT OF DRAINAGE DIRECTION OVER FLAT SURFACES IN RASTER DIGITAL ELEVATION MODELS, Journal of hydrology, 193(1-4), 1997, pp. 204-213
Drainage direction assignment over Bat surfaces in raster Digital Elev
ation Models (DEM) has been a stubborn problem for DEM processing meth
ods. A new approach that improves upon current methods of Bat surface
treatment is presented, The approach is based on the recognition that
in natural landscapes drainage is generally away from higher and towar
ds lower terrain, To produce such a drainage, DEM elevations of a flat
surface are modified to impose two gradients: one away from higher te
rrain, and one towards lower terrain. Subsequent processing of the DEM
produces a drainage pattern over the flat surface that is topographic
ally consistent and exhibits Row convergence properties, The proposed
approach is not restricted by the shape of the flat surface, the numbe
r of outlets on its edge, or the complexity of the surrounding topogra
phy. A comparison with the drainage pattern of an established method t
hat displays the 'parallel flow' problem shows significant improvement
s in producing realistic drainage patterns. The proposed approach exte
nds automated DEM processing to digital landscapes for which existing
methods cannot provide adequate flow directions over flat surfaces to
conduct a drainage analysis. The necessary algorithmic details for imp
lementation of the approach are provided. (C) 1997 Elsevier Science B.
V.