Drainage network simulation

Abstract A program is written to generate a drainage network on an arbitrary land surface based on the principle that water runs down the steepest slope. The drainage network includes not only stream lines but also lakes which are formed within any closed topographic depressions. The drainage network simulation is performed on a rough slope which is composed of a number of random elevations superimposed on a smooth slope. Horton analysis then is made on the drainage pattern of simulated slope. The result agrees generally with the laws of linear relationships between the stream order and the logarithms of drainage area, stream number, and stream length. A slightly higher bifurcation ratio is observed due to lakes and multiple junctions. Differing the roughness and minimum discharge, different landform, and drainage pattern also can be simulated. This new drainage network simulation method can be performed on a digitized elevation data of any area and may offer an opportunity for a greater understanding of actual stream networks.