LGRB-BW Relief Parameters: Depth line

A depth line (synonym drain line, valley path) represents the connection line of the deepest points in an open hollow form (valley) on the Earth’s surface. With the assumed water impermeability of the surface of the earth, linear drainage on these lines would occur with continuous irrigation, as is the case with rivers and streams in reality. In geomorphology or relief analysis, drain lines (deep lines) in addition to water sheaths (or culmination or vertex lines) represent the most important rib lines for the structure of the relief. Depth lines form the local erosion base, to which all transport processes (transport of soil material and water and therein loose substances) refer to the slope and/or in the catchment area. [Definition and calculation according to KÖTHE 2001-2008]