Branched networks are common in nature; examples are the forms assumed by blood distribution systems, leaf veins, plant roots and branches, lightning, crystal growth, and river basins. This somewhat peculiar solution to the transport of mass and energy is prevalent in such a variety of phenomena that it may point to a commonality of controlling principles. The search for these principles, which has occupied hydrologists and geomorphologists for a long time, has centered on such questions as: Why do river channels branch? 1990. American Geophysical Union. All Rights Reserved.
