Review status: this discussion paper is a preprint. It has been under review for the journal Natural Hazards and Earth System Sciences (NHESS). The manuscript was not accepted for further review after discussion.
Debris flow sediment control using multiple herringbone water-sediment separation structures
Xiangping Xie1,2,Fangqiang Wei3,Xiaojun Wang1,Hongjuan Yang1,and James S. Gardner4Xiangping Xie et al.Xiangping Xie1,2,Fangqiang Wei3,Xiaojun Wang1,Hongjuan Yang1,and James S. Gardner4
Received: 23 Oct 2016 – Accepted for review: 24 Oct 2016 – Discussion started: 25 Oct 2016
Abstract. Single herringbone water-sediment separation structures (HWSS) have limited sediment control effectiveness in debris flows. A series of such structures in a debris flow channel to form a multiple structure system (M-HWSS system) should be more effective in debris flow mitigation. Hydraulic model tests reveal that a M-HWSS system does perform better in coarse sediment separation and has better stability in differing debris flow situations. The mean particle size of discharged sediment is gradually and significantly decreased down channel by M-HWSS system. The separated sediments are moderately sorted and this can be improved by optimizing the structure design parameters and increasing structure numbers. The fraction separation ratio (λi), coarse separation ratio (λc) and total sediment separation rate (Pt) are suggested parameters to express the sediment control effectiveness. All are closely related to the herringbone opening width and the input sediment grain size distribution. The quantitative relationships among them are proposed. On the basis of the tests, conclusions and guidelines for effective M-HWSS design include: (1) three structures in the M-HWSS located in succession upstream, midstream and downstream, each with substantially different in sediment control functions, (2) a structure's performance is strongly influenced by that of the preceding one so that every structure is designed to fully implement the sediment control function, especially for those in the upstream and midstream, (3)the suggested herringbone opening width in a structure should be set at the percentile of d50 ~ d84 of the input sediment grain size distribution so that 20 ~ 60 % of the effective separation rate can be achieved.
How to cite. Xie, X., Wei, F., Wang, X., Yang, H., and Gardner, J. S.: Debris flow sediment control using multiple herringbone water-sediment separation structures, Nat. Hazards Earth Syst. Sci. Discuss. [preprint], https://doi.org/10.5194/nhess-2016-340, 2016.
This research was mainly focus on the sediment control effects of multiple herringbone water-sediment separation structures. We basically use hydraulic model tests to do this research. By statistic analysis, sediment control effects by series of them. We basically use hydraulic model tests to do this research. By statistic analysis, sediment control effects were qualitatively and quantitatively described. Preliminary implications were concluded for future research.
This research was mainly focus on the sediment control effects of multiple herringbone...