Open AccessProspects of Debris Flow Studies from Constitutive Relations to Governing Equations
Author(s) -
Shinji Egashira
Publication year - 2011
Publication title -
journal of disaster research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.332
H-Index - 18
eISSN - 1883-8030
pISSN - 1881-2473
DOI - 10.20965/jdr.2011.p0313
Subject(s) - sediment , debris flow , erosion , geotechnical engineering , flow (mathematics) , flux (metallurgy) , deposition (geology) , debris , sediment transport , geology , sorting , constitutive equation , shear stress , mechanics , geomorphology , materials science , physics , mathematics , oceanography , thermodynamics , algorithm , finite element method , metallurgy
The author thinks keys to debris flow studies lie in 1) sediment sorting in debris flow body, 2) phase shifting to or from fluid to solid, 3) difference between sediment concentration and flux sediment concentration, 4) constitutive relations and 5) governing equations employed in numerical simulation. In discussing 3)-5), the author stresses that 1) Eq. (1) predicts the spatial average sediment concentration of the flow body well from debris flow to bed load, and thus it should be prized, 2) researchers must be careful for the difference between sediment concentration and flux sediment concentration and for different flow structures over erodible and rigid beds, and realizes that 3) many problems associated with governing equations such as bed shear stress, erosion and deposition rates and correction parameters for sediment transport still remain to be solved.