WSEAS Transactions on Environment and Development
Print ISSN: 1790-5079, E-ISSN: 2224-3496
Volume 8, 2012
Determination of Small Size Bedload Sediment Transport and its Related Bedform under Different Uniform Flow Conditions
Authors: ,
Abstract: A laboratory study has explored to determine the influence of current uniform flow conditions on bedload of different small size sediment particle beds and its bed formations. The influence of uniform flow and its related near bed turbulent flow conditions on bedload sediment transport and its related bedform in relatively low, mild and steep slopes channel has been experimentally investigated. Four sediment particle sizes were evaluated in the experimental study: (1) fine sand (0.2 mm), coarse sand (1.6 mm), very coarse sand (2.8 mm), and fine grain (4.4 mm). A traditional experimental technique was developed to enable accurate performance for sediment particle transport measurement. The technique of estimating the transport rate of sediment particles is based on the trap measuring device. The trap was assessed for their efficiency by observation and photograph method. This enables the measurement of the area of the movable sediment particles to be determined by the collection of the particles in traps. The traps with an inlet width of 29 cm, a length of 15 cm and a height of 6 cm were selected to collect sediment particles. The sediment transport rates were then predicted using well known sediment transport equations. This paper presents results from the laboratory study of the effects of various uniform flows on the bedload and its related bedform of the bimodal small sediment particle beds. The experiments are based on near bed turbulent flow forces on the bed resistance. The results show that the bedload and its related bedform are occurred by increasing the value of bed slope and the ratio of water depth to sediment particle size. The results obtained from the bedload and its related bedform present clearly the difference of four used material, which are necessary for computing the risk for different values of the particle Reynolds number.