The occurrence of obtuse junction angles and changes in channel width below tributaries along the Mekong River, south-east Asia

Auteur(s) et Affiliation(s)



Description :
SPOT-5 imagery from Google Earth was used to identify and catalogue junction geometries and downstream changes in channel width below tributary junctions along a 2200 km reach of the Mekong River. Of the 284 junctions identified, 30% were found to be obtuse. Meander extension of the incoming tributary and deflection of the tributary across bedrock shoulders were found to be the dominant geomorphological causes of the obtuse tributary junctions. The relationship between the width of the tributary channels and the width of the mainstem upstream and downstream of the confluences was analysed. It was observed that, over the whole reach, a slight narrowing occurred immediately below tributary junctions. The geological control observed suggests that complex factors play important roles in determining changes to channel width across large systems and that simple cause-effect relationships do not hold in such complicated geological settings.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2011, vol. 36, n°. 12, p. 1563-1576, nombre de pages : 14, Références bibliographiques : 2 p.

Date :
2011

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