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

First tab header

Second tab header

Etc. tab header

Parameter	Description	Unit
First parameter	Description parameter	[Units]

Parameter	Description	Unit
First parameter	Description parameter	[Units]

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

Nomenclature

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)

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)

Gary Parker

References

Key papers

Links

• [Model:DeltaBW]