Model help:DeltaBW
DeltaBW
This is used to Calculate evolution of long profile of a river ending in a 1D migrating delta, using a backwater formulation.
Model introduction
This module is a calculator for 1D Subaerial Fluvial Fan-Delta with Channel of Constant Width. This model assumes a narrowly channelized 1D fan-delta prograding into standing water. The model uses a single grain size D, a generic total bed material load relation and a constant bed resistance coefficient. The channel is assumed to have a constant width. Water and sediment discharge are specified per unit width.The channel is assumed to have a constant width. Water and sediment discharge are specified per unit width. The fan builds outward by forming a prograding delta front with an assigned foreset slope. The code employs a full backwater calculation.
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 / width | m2 / s |
| If | intermittency | - |
| Cz<z> | dimensionless Chezy resistance coefficient | - |
| D | grain size of sediment | mm |
| R | submerged specific gravity of sediment | - |
| λp | bed porosity | - |
| qtf | sediment input rate | - |
| at | coeff in total bed material load relation | - |
| nt | exponent in load relation | - |
| τsc * | critical Shields stress in load relation | |
| εd | water surface elevation of the lake | m |
| ηsl | initial elevation of top of the foreset | m |
| ηbl | initial elevation of bottom of the foreset | m |
| Sfl | initial fluvial bed slope | - |
| Sb | subaqueous basement slope | - |
| sfl | initial length of fluvial zone | m |
| sfmax | maximum length of fluvial zone | m |
| Sa | slope of foreset face | - |
| Δt | time step | days |
| M | number of fluvial nodes | - |
| Mtoprint | number of steps until a printout is made | - |
| Mprint | number of printouts after the initial one | - |
| Hi | initial depth at top of foreset deposit | m |
| Hcrit | depth for Froude-critical flow | m |
| Ui | initial flow velocity at top of foreset deposit | m / s |
| τsi | initial Shields stress at top of foreset | m / s |
| Hni | normal depth associated with initial slope | m |
| Cf | friction coefficient | - |
| dt | time step | s |
| dxbar | dimensionless spatial step | s |
| τsn | normal Shields stress associated with qw and qtf | |
| Sn | normal slope associated with qw and qtf | |
| Hn | normal depth associated with qw and qtf | m |
| Frn | normal Froude number associated with qw and qtf |
Output
| Symbol | Description | Unit |
|---|---|---|
| qbT | total volume gravel bedload transport rate per unit width summed over all sizes | - |
| v | flow velocity | m / s |
| τsg | shield stress | kg / (m s) |
Notes
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)
Name of the module developer(s)
References
Key papers
Links
Any link, eg. to the model questionnaire, etc.
