Assessing river dynamics from 2D hydraulic modelling and high resolution grain-size distribution

Auteur(s) et Affiliation(s)

VERDÚ, J.M.

Catalan Water Agency, Provença, Barcelona, Espagne

BATALLA, R.J.

Dep. of Environment and Soil Sciences, Univ., Lleida, Espagne

Catalan Inst. for Water Research, Girona, Espagne

Forest Sciences Center of Catalonia, Solsona, Espagne

MARTÍNEZ-CASASNOVAS, J.A.

Dep. of Environment and Soil Sciences, Univ., Lleida, Espagne

Description :
A new approach is proposed to study gravel riverbed stretches at high resolution. During a two-year period, flood events in the River Isábena (Central Pyrenees) were reproduced using a steady-state 2D hydraulic model (Hydro2de) with the aim of studying gravel riverbed dynamics. The parameters included detailed grain size at 1.5 x 1.5 m resolution, topographic data and field measurements along an 11 km stretch. Discharge data were obtained from 2 gauging stations and velocity and maximum water width were measured at 15 control cross-sections. Observed and modeled results show good agreement. Additionally, shear stress for several discharges and related critical shear stress were compared for the whole river stretch. The initiation of sediment motion occurred at a lower discharge in the lower stretches than in the middle and upper stretches, where the mean grain size was coarser. This matched riverbed erosion measures. Results were obtained at 1.5 × 1.5 m resolution, showing a good potential as bases for subsequent fluvial applications (i.e. entrainment, channel scour).

Type de document :
Article de périodique

Source :
Zeitschrift für Geomorphologie, issn : 0372-8854, 2014, vol. 58, n°. 1, p. 95-115, nombre de pages : 21, Références bibliographiques : 27 ref.

Date :
2014

Editeur :
Pays édition : Allemagne, Stuttgart, Gebruder Borntraeger

Langue :
Anglais