Model help:DeltaNorm

The CSDMS Help System

DeltaNorm

This is a calculator for evolution of long profile of a river ending in a 1D migrating delta, using the normal flow approximation.

Model introduction

This program calculates the bed surface evolution for a narrowly channelized 1D fan-delta prograding into standing water, as well as calculating the initial and final amounts of sediment in the system.

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
ηd	water surface elevation of the lake	m
ηbl	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
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	-
x	downstream coordinate	m
η	bed surface elevation	m
Sl	bed slope	-
qb	volume bedload transport per unit width	m2 / s
H	water depth	m
τ	shear stress	N / m2
sU	location of the upstream coordinate	m
sbb	reach of the alluvium bottom	m
sss	reach of the alluvium top	m
etaup	upstream bed surface elevation	m
etatop	bed surface elevation of the top of the forest	m
etabot	bed surface elevation of the bottom of the forest	m
q	flood discharge	m2 / s
I	flood intermittency	-
Q	upstream bed material sediment feed rate during floods	m2 / s
D	grain diameter	mm
C	coefficient in the Chezy rlation, Cf	-
n	exponent in the load relation	-
T	critical shields stress in load relation	-
E	elevation of the top of the forest	m
e	initial elevation of the bottom of the forest	m
f	initial fluvial bedslope	-
b	subaqueous basement slope	-
s	initial length of the fluvial zone	m
S	slope of the forest face, Sa	-
R	submerged specific gravity	-
L	bed porosity	-
k	coefficient in the Manning-Strickler relation	-
a	coefficient in the total bed material load relation	-
r	coefficient in the Manning-Strickler relation	-
M	number of fluvial nodes	-
t	time step	days
p	number of prints	-
i	number of iterations per print	-

Notes

This model is used to calculate 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 fan builds outward by forming a prograding delta front with an assigned foreset slope. The code employs the normal flow approximation rather than a full backwater calculation.

• Note on model running

This model assumes a uniform grain size.

The fan builds outward by forming a prograding delta front with an assigned foreset slope.

The water depth is calculated using a Chézy formulation, when only the Chézy coefficient is present in the inputted text file, and with the Manning-Strickler formulation, when only the roughness height, kc, value is present. When both are present the program will ask the user which formulation they would like to use.

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:DeltaNorm]