Simulation of bedload transport in headwater area of the Lubina River (Moravskoslezské Beskydy Mts)

This paper is focused on modeling of bedload transport in mountain headwater streams in the Moravskoslezské Beskydy Mts. Based on field mapping of part of the Lubina River (length: 1014 m; catchment area 1.06 km2; average slope: 0.06 m.m-1) data for simulations of bedload transport were prepared for modeling of discharge Q2 and Q20 (the latter according to the flood discharge in May 2010). Several combinations of equations and calibration parameters values were used. Values of flow velocity, flow discharge, bedload discharge and accumulated bedload transport were simulated at 17 channel cross-sections. In total, 247-466 m3 (630-1188 tons) of bedload were transported during Q20 flood in study part of Lubina River according to the model. During Q2 discharge the model supposed almost zero bedload discharge except the upper part of study area (0.73-2 m3.hod-1). Settings of calibration parameter has the highest impact on resulted values; the choice of transport equations does not lead to significant differences in modelled values. Validation was not executed due to the absence of directly measured data of bedload transport; only comparison to amount of transported material in the nearby watercourse (the Velký Škaredý Stream) was possible. The model TOMSED represents a good solution for simulation of bedload transport in mountain headwater streams due to relatively accurate results when compared to other models.