Articles | Volume 15, issue 9
Hydrol. Earth Syst. Sci., 15, 2821–2837, 2011
Hydrol. Earth Syst. Sci., 15, 2821–2837, 2011

Research article 09 Sep 2011

Research article | 09 Sep 2011

Sediment transport modelling in a distributed physically based hydrological catchment model

M. Konz1, M. Chiari2, S. Rimkus1, J. M. Turowski3, P. Molnar1, D. Rickenmann3, and P. Burlando1 M. Konz et al.
  • 1Institute of Environmental Engineering, ETH Zurich, Wolfgang-Pauli-Str. 15, 8093 Zurich, Switzerland
  • 2Institute of Mountain Risk Engineering, University of Natural Resources and Life Sciences, Peter Jordanstr. 82, 1190 Vienna, Austria
  • 3Mountain Hydrology and Torrents, Swiss Federal Research Institute, WSL, Zürcherstr. 111, 8903 Birmensdorf, Switzerland

Abstract. Bedload sediment transport and erosion processes in channels are important components of water induced natural hazards in alpine environments. A raster based distributed hydrological model, TOPKAPI, has been further developed to support continuous simulations of river bed erosion and deposition processes. The hydrological model simulates all relevant components of the water cycle and non-linear reservoir methods are applied for water fluxes in the soil, on the ground surface and in the channel. The sediment transport simulations are performed on a sub-grid level, which allows for a better discretization of the channel geometry, whereas water fluxes are calculated on the grid level in order to be CPU efficient. Several transport equations as well as the effects of an armour layer on the transport threshold discharge are considered. Flow resistance due to macro roughness is also considered. The advantage of this approach is the integrated simulation of the entire basin runoff response combined with hillslope-channel coupled erosion and transport simulation. The comparison with the modelling tool SETRAC demonstrates the reliability of the modelling concept. The devised technique is very fast and of comparable accuracy to the more specialised sediment transport model SETRAC.