View source for Analytical models for bar patterns and braiding threshold

<Forecasterlink type="getToolInfoBox" code="26" />
=Analytical models for bar patterns and braiding threshold=
==Type==
Hydromorphological models

==Basic principles==
Linearized fundamental equations for conservation of water mass and water flow momentum, time-averaged over all turbulent fluctuations, spatially averaged over water depth (2DH) or nor spatially averaged (3D). Linearized parameterized relation for effect of helical flow on bed shear stress direction.
Linearized equilibrium sediment transport predictor or advection-relaxation equation for sediment transport. Linearized empirical relation for effect of sloping beds on sediment transport magnitude and direction. Linearized Exner equation for conservation of sediment mass.

==Outputs==
Number of bars per cross-section, bar length, bar stability.

==Rivertypes==

<Forecasterlink type="getRivertypesForTool" code="26"/>
==Related Pressures==

<Forecasterlink type="getPressuresForTool" code="26"/>
==Related Measures==

<Forecasterlink type="getMeasuresForTool" code="26" />


==Useful references==
===Selected software systems===
REGMEANDER

===Theoretical background===
Blondeaux P. and Seminara G. (1983): Bed topography and instabilities in sinuous channels. In: River Meandering, Proc. Conf. Rivers 1983, New Orleans, Ed. C.M. Elliott, ASCE, 1984, pp.747-758.

Colombini M., Seminara G., Tubino M. (1987): Finite-amplitude alternate bars. J. Fluid Mech., 181, pp.213-232.
http://dx.doi.org/10.1017/S0022112087002064

Crosato A. and Mosselman E. (2009): Simple physics-based predictor for the number of river bars and the transition between meandering and braiding, Water Resources Res., AGU, 45, W03424.
http://onlinelibrary.wiley.com/doi/10.1029/2008WR007242/abstract

Struiksma N., Olesen K.W., Flokstra C., de Vriend H.J. (1985): Bed deformation in curved alluvial channels. J. Hydr. Res., IAHR, 23, (1), pp.57-79.
http://www.tandfonline.com/doi/abs/10.1080/00221688509499377#.UZN6d8pIXoY

===Sample applications===


[[Category:Tools]][[Category:Hydromorphological models]]