title: Longitudinal and transverse dispersion coefficients in braided rivers.
abstract: The dispersion characteristics of braided rivers are presently unclear. The comprehensive flow structure in a physical braided river model was measured and was used to estimate its dispersion coefficient tensor. The largest values of the longitudinal and transverse dispersion coefficients occurred in the separation zone in two anabranches. The separation zone disappeared in a small diversion angle model of braided rivers where the coefficients were smaller. As for the sectional transverse distribution, the two coefficients varied markedly and an interesting negative correlation between them appeared in several sections. The dispersion coefficients increased with upstream flow rates. Comparison between the coefficients for different anabranch widths revealed higher values in wider sections. Finally, the values of the laboratory tests were compared with those in a real braided river, and relatively larger coefficients were found in natural rivers. The findings of this paper could be helpful in understanding the dispersion characteristics and in estimating pollutant concentration in braided rivers.
authors: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China E-mail: zulinhua@hhu.edu.cn; National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing 210098, China.
authors: Li
authors: L
authors: Gu
authors: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China E-mail: zulinhua@hhu.edu.cn.
authors: Zinan
authors: Z
authors: Jiao
authors: Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China E-mail: zulinhua@hhu.edu.cn; National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing 210098, China.
authors: Zulin
authors: Z
authors: Hua
mesh_terms: D004784:Environmental Monitoring / Q000379:methods; D045483:Rivers / Q000737:chemistry*; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical