Model help:BedrockAlluvialTransition
BedrockAlluvialTransition
This is used to calculate aggradation and degradation with a migrating bedrock-alluvial transition at the upstream end.
Model introduction
This program computes fluvial aggradation/degradation with a bedrock-alluvial transition. The bedrock-alluvial transition is located at a point sba(t) which is free to change in time. A bedrock basement channel with slope Sb is exposed from x = 0 to sba(t); it is covered with alluvium from x = sba(t) to x = sd, where sd is fixed. Initially sba = 0. The bedrock basement channel is assumed to undergo no incision on the time scales at which the alluvial reach responds to change. In computing bed level change on the alluvial reach, the normal (steady, uniform) flow approximation is used. Base level is maintained at x = sd, where bed elevation h = 0. The Engelund-Hansen relation is used to compute sediment transport rate, so the analysis is appropriate for sand-bed streams. Resistance is specified in terms of a constant Chezy coefficient Cz.
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
| Symbol | Description | Unit |
|---|---|---|
| qw | water discharge per unit width during floods | m^2 / s |
| If | intermittency factor for floods (0 < I <= 1) | - |
| qtf | volume sediment feed rate per width at upstream end during floods | - |
| D | grain size of alluvium | mm |
| Cz | Chezy resistance coefficient | - |
| Sb | slope of bedrock coefficient | - |
| Sinit | initial slope of alluvial region | - |
| M | number of spatial intervals | - |
| dt | time step | yr |
| Mtoprint | number of steps to printout | - |
| Mprint | number of printout | - |
Output
| Symbol | Description | Unit |
|---|---|---|
| x | - | |
| eta |
Notes
Any notes, comments, you want to share with the user
Numerical scheme
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
