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Knowledge and management of hydraulic processes including flow pattern, sediment transport, and flood level prediction in natural rivers require proper understanding of interactions between flood flow and vegetation in floodplains. This study examined the flow structures and turbulence parameters in an asymmetric non-prismatic compound channel with different vegetation densities in divergent floodplain. Due to existence of vegetation, the bed shear stresses in the middle and end of the divergence floodplain decrease 78.5% and 86%, respectively. Also, the depth-averaged velocity in vegetated floodplain diminishing by about 60% and 69%. The results revealed that the production and dissipation of Reynolds shear stresses and the formed shear layer depend on the vortex shedding frequency formed behind each single rod and is very unstable. Finally, some equations were presented to estimate friction factor based on rod Reynolds number, calculate the frequency of the vortices generated behind the elements and the local drag coefficient. [ABSTRACT FROM AUTHOR]

In the present research, the application of a proposed, modified, central force optimisation method for multi-objective optimisation of water distribution systems is examined. This new method is based on a central force optimisation algorithm in which the non-dominated sorting plus crowding distance calculator mechanisms produce optimal Pareto solutions in objective functions trade-offs. Minimising pipe-sizing cost and maximising new reliability measures are considered as objective functions. The method is written in Matlab and linked with Epanet water distribution software. Employing the method to solve the Kadu and Khorramshahr water distribution networks shows its capability to produce well-distributed optimal Pareto solutions for cost and reliability. Also, by utilising a fuzzy ranking method, a best compromise solution for two objectives can be extracted from the optimal Pareto set. [ABSTRACT FROM AUTHOR]