Author(s): Geraldo Wilson Junior; Cid Da Silva Carcia Monteiro
Linked Author(s): Geraldo Wilson Junior
Keywords: Movement of sediments and pollutants; Stochastic Processes; Radioactive and Fluorescent Tracers; SPICON
Abstract: The Stochastic Theory has shown that the sediment particles 2-D trajectories ω (x, z, t) result from the combination of random 1-D series of movement periods: (i) an alternating series of downstream longitudinal displacements intercalated by time periods when the particle does not move in this direction or sense; (ii) an alternating series of descendent vertical displacements intercalated by periods when the grain does not move towards the bed. These series are defined by Mobility Functions: λx1; λz1; λt1 and λt2, which analytical expressions describe the instantaneous and punctual movements of single particles. Thus, the bed and suspended load are both described by the same Stochastic Theory. The Objectives of this article are to present: (1) the 2-D longitudinal and vertical models; (2) the experimental devices used for the study of bed and suspended longitudinal movements with vertical transfers; and (3) the importance of temporal and spatial intensity functions, in the Stochastic Processes models’ creation. Experimental results obtained in open channel flows with radioactive and fluorescent tracers were used, where the mobile bed layer behaves: (i) as a reflective barrier of fine sediments of varying concentrations and of different sizes; (ii) as a source for bed load movements of uniform sand; (iii) as a barrier of sediment absorption; and (iv) as a simultaneous barrier of absorption and reflection of sediments. A software SPICON - Stochastic Processes with Instantaneous and CONtinuous injections was developed to study the Homogeneous Poisson Models.
Year: 2020