Author(s): Raquel Duque, Juan Manuel Moreno-Murillo, Jaime Ivan Ordoñez
Linked Author(s): Raquel Duque
Keywords: Continental Deltas; Distributive Drainage Systems; Natural Hazards;
Abstract: The Arauca river, which serves as part of the international geographical boundary between Colombia and Venezuela, in the eastern plains area between the two countries, originates high up, in the Ritacuba peaks of the Sierra Nevada of Cocuy, in the Colombian Andes, at over 5,300 meters above sea level. Entering the immense extension of the plains, it generates a large distributive drainage system that gives rise to a continental delta still in formation. The avulsive nature of the system has generated distributive channels that have facilitated lateral migration, generating deposition and redistribution of flows along large lobes of sediments. This peculiar behavior creates a particular morphological arrangement in the flat lands, which generate marshes, “esteros” and wetlands with an impressive variety of live forms. The volumes of sediment transported are high, generating major morphological changes in relatively short periods, favoring lateral movement of the river, diffusion, avulsion, and the creation of new channels with the closure of previous ones, generating extensive and largely compartmentalized flooding. This paper presents some of the morphological and hydrodynamic characteristics of this type of drainage systems.