An unconventional approach to modeling spatial and temporal variability of local shear stress in stream segments

Measuring and especially modeling the spatial and temporal variability of local bottom shear stress in streams are major issues in concepts of hydraulic engineering and cotic ecology and becomes very complicated with increasing channel complexity and/or decreasing channel size. Using Fliesswasserstammtisch (FST) hemispheres, an unconventional method for near-bottom flow measurements, we determined the parameters of shear stress frequency distributions of German mountainous streams by a maximum likelihood procedure. The resulting model is robust and generates information on the spatial and temporal variability of local shear stress in stream segments from easily obtained input variables (discharge, mean stream width and depth).