Tributary valley impoundment by trunk river floodplain development : a case study from the KwaZulu-Natal Drakensberg foothills, eastern South Africa

Auteur(s) et Affiliation(s)



Description :
This paper investigates the origin and geomorphic evolution of Stillerust Vlei, a wetland system (a floodplain and adjacent impounded tributary valley) located northwest of Durban in the temperate submontane foothills. The investigation confirms that many floodplain wetlands in eastern South Africa are located upstream of resistant rock barriers (dolerite intrusions) that cross river courses and form stable local base levels. In addition, the study examines how local levee and alluvial ridge accretion on the floodplain of Stillerust Vlei has impounded a small tributary valley, and drawing on observations of similar wetlands in the region, the paper explains the origin and geomorphic evolution of wetlands in floodplain-abutting valleys, and associated streams that commonly become discontinuous toward their confluence with the trunk (floodplain) river. Controls on the origin and geomorphic evolution of Stillerust Vlei are placed within the context of slope-channel decoupling and (dis)connectivity in sediment delivery, illustrating that wetlands are environments of deposition providing potential habitat for a diversity of biota.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2008, vol. 33, n°. 13, p. 2029-2044, nombre de pages : 16, Références bibliographiques : 1 p.

Date :
2008

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley