An accurate prediction of the friction coefficient is very important in hydraulic engineering since it directly affects the design of water structures, the calculation of velocity distribution, and an accurate determination of energy losses. However, conventional approaches that are profoundly based on empirical methods lack in providing high accuracy for the prediction of the friction coeffici...

Flow conditions (flow discharge, flow depth, and velocity) in natural streams are mainly determined via the resistance formula such as Manning’s equation. Evaluating accurate roughness coefficient (n), especially rivers with bed form during floods, to obtain more reliable results has always been of interest scholars. The interaction between is very complex since control forms, vice versa. main ...

There is still little experience on the effect of Manning roughness coefficient in coupled hydrological-hydraulic distributed models based solution Shallow Water Equations (SWE), where affects not only channel flow basin hydrographic network but also rainfall-runoff processes hillslopes. In this kind model, takes role concentration time classic conceptual or aggregated modelling methods, as cas...

A simple idealized model to describe the hydraulic resistance caused by vegetation is compared to results from flow experiments conducted in natural waterways. Two field case studies are considered: fixed-point flow measurements in a Green River (case 1) and vessel-borne flow measurements along a cross-section with floodplains in the river Rhine (case 2). Analysis of the two cases shows that th...

Vegetation in riparian zones has a significant influence on resistance, velocity distribution and turbulence intensity. This study experimentally investigated the effect of emergent bending riparian zone vegetation on the flow. The results showed that the frond and stem parts of Acorus calami had different influences on hydraulic features and that the relative depth ratio of water depth h to st...

We quantified the Manning free (uncondensed) counterions fraction θ for dilute aqueous solutions of rodlike polyions: 150 bp DNA fragments, in the presence of a very low concentration of monovalent salt c(salt)<0.05 mM. Conductivity measurements of these solutions for DNA base pair concentration range 0.015≤c≤8 mM were complemented by fluorescence correlation spectroscopy (FCS) measurements of ...

Accurate computation of the roughness coefficient is important in studies open channel flow. To measure and identify hydraulic characteristics flow system, model simulation necessary to study get results properties specify Manning Euphrates River. In this study, reach extended along River from Haditha Dam Ramadi Barrage with a distance 169km. The HEC-RAS was implemented simulate within reach. g...