Model help:AgDegNormalSub
AgDegNormalSub
This program is used to calculate the evolution of upward-concave bed profiles in rivers carrying uniform sediment in subsiding basins.
Model introduction
This module computes the time evolution of a river toward steady state as it flows into a subsiding basin. The subsidence rate s is assumed to be constant in time and space. The sediment is assumed to be uniform with size D. A Manning-Strickler formulation is used for bed resistance. A generic relation of the general form of that due to Meyer-Peter and Muller is used for sediment transport. The flow is computed using the normal flow approximation. The river is assumed to have a constant width.
Model parameters
Uses ports
This will be something that the CSDMS facility will add
Provides ports
This will be something that the CSDMS facility will add
Main equations
A list of the key equations. HTML format is supported; latex format will be supported in the future
Notes
All sediment transport is assumed to occur in a specified fraction If of time during which the river is in flood. The volume bed material transport rate per unit width during floods is denoted as qt; the upstream feed value is denoted as qtf.
Sediment is deposited not only on the channel as it aggrades, but across a wider depositional zone as the channel migrates and avulses in response to aggradation. It is assumed that for each unit of bed material load that deposits across the depositional zone, L units of wash load deposit; here L (>= 0)is a user-specified parameter.
Channel sinuosity, denoted as W (>= 1), and the ratio of channel width to depositional width, denoted as rB (>=1), are also user-specified. The initial condition is specified in terms of a constant initial bed slope SI.
In performing this calculation, the following parameters must be specified: L = reach length; M = number of spatial intervals, so that the spatial step length = L/M; dt = time step length; Ntoprint = number of time steps to a printout; Nprint = number of printouts in the calculation. The calculation assumes that the bed elevation at the downstream end of the domain is fixed.
Examples
An example run with input parameters, BLD files, as well as a figure / movie of the output
Follow the next steps to include images / movies of simulations:
- Upload file: http://csdms.colorado.edu/wiki/Special:Upload
- Create link to the file on your page: [[Image:<file name>]].
See also: Help:Images or Help:Movies
Developer(s)
References
Key papers
