Reconstructing of anastomosing river

Auteur(s) et Affiliation(s)



Description :
Intensive hydro technical works were conducted in the middle course of the Obra River (Poland) at the beginning of the nineteenth century. The natural river course (functioning before the major construction works) was transformed into 3 artificial canals. Ground-penetrating radar investigations, ground-truthed with coring and remote sensing surveys, were conducted to reconstruct the course taken by the river prior to the hydro technical works. This work demonstrated that the Obra formerly had an anastomosing planform. Radiocarbon dating indicated that the earliest of the retraced channels were active before 9000 BP. The retraced river system was formed in a proglacial stream valley perpendicularly cut by remains of subglacial tunnels, now partly filled with lakes. The planform consisted of one or two major channels and a number of secondary channels formed by avulsions. During the last 2000 years, some of the avulsions may have been caused by anthropogenic interventions. Valley sections with meandering anabranches, anastomosing patterns with traces of a lateral migration and traces of a transition from meandering to anastomosing planform were distinguished.


Type de document :
Article de périodique

Source :
Geografiska annaler. Series A. Physical geography, issn : 0435-3676, 2014, vol. 96, n°. 2, p. 195-216, nombre de pages : 22, Références bibliographiques : 64 ref.

Date :
2014

Editeur :
Pays édition : Suede, Stockholm, Svenska sällskapet för antropologi och geografi