The BedloadWeb project

BedloadWeb results from a collaboration between Irstea and l'agence France pour la Biodiversité






The english version of this website was funded by the AlpineSpace European project 'HyMoCARES'












Welcome on bedloadWeb

This site makes it easy to visualize data from the literature, and offers assistance in calculating the solid transport associated with a flow section. It aims to be a collaborative platform to encourage exchanges between researchers and practitioners, but also, to be educational for students

The data base

The 'Database' tab is used to select one or more rivers for its physical characteristics (slope, grain size distribution, channel width). The results are displayed graphically and can be downloaded for external use (in text format). The database contains more than 11,000 values collected from more than 120 sites for a wide range of slopes, widths, grain sizes, and from the laboratory and the field. All datasets have been checked for consistency (in particular hydraulics) and include at least the following information: slope, D50, width, flow or depth, solid transport. The 'Select a river' tab allows to find all the information about a particular river (its identity file) and the corresponding data. The 'Multicriteria selection' tab allows selecting data from selection criteria. The data can also be compared with some standard equations. The goal is educational, because it is possible to test the sensitivity of models to the different input parameters

Tool box

It is composed of a series of tools intended to accompany the user in the elaboration of a sediment budget. It has several tabs, each of which represents an essential step for a serious study. The tabs are presented in a logical sequence, each producing useful data to the following ones: (1) the tab 'Granulometry' allows you to define the granulometry of the sediments (2) the tab 'Section' allows to define (topography) and to dress (roughness ..) the flow section (3) the 'hydraulic' tab allows to calculate the main quantities in normal uniform regime (4) the 'solid transport' tab calculates the fluxes for the granulometry, the section and hydraulics previously defined 5) the 'hydrology' tab permts to defien an hydrology and to compute the associated sediment budget

Participative

All information likely to improve the platform are welcome (photos, new data, comments, questions ...). This is especially true during the 'break-in' phase of the site. Any anomalies can be quickly corrected provided they are reported to us


New equations can also be added to the tools already available.

Condition of use

BedloadWeb is free to access. A reference (or web link) to the original publication is always given and must be recalled whenever a dataset is used. The authors would also appreciate the fact that the BedloadWeb platform is cited when it is used.




Download data


Download models

Download figure

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Plot options:
Plot with τ*c=

Percentile i for Di=

Default τ*(D50) , Φ(D50)




Compute with :


Test sensitivity to:


Surface grain size distribution

Download
The model reconstructs a grain size distribution from the D50; it is used when the measured GSD is not available

Note: small differences may exist between the D50 and D84 extracted from the granulometric curves and those provided in the database



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Bedload grain size distribution
The GTM (Generalized Threshold Model) method extends the concept of threshold transport to each fraction of the grain size distribution; it is based on the computation of the bed stress and does not require a preliminary calculation of the solid transport of each fraction, as it is the case for WC and Parker. The model is very flexible because it can simulate almost all situations depending on the setting chosen; its relevance comes up against the limitations of our current knowledge of the physics of the mobility of a sedimentary mixture in a flow (effects of the armor, partial transport or not ...). For more information, see Recking, A. (2016), A Generalized Threshold Model for Computing Bedload Grain Size Distribution, Water Resour. Res., Doi: 10.1002 / 2016WR018735.

β=0.5, γ2=1.5

β defines the percentile of the largest stone transported (for τ*/τ*c<1)
γ2 defines partial transport for each fraction transported
β=2, γ2=20

β defines the percentile of the largest stone transported (for τ*/τ*c<1)
γ2 defines partial transport for each fraction transported
β
γ2
β defines the percentile of the largest stone transported (for τ*/τ*c<1)
γ2 defines partial transport for each fraction transported

Bedload Gain Size Distribution

Download

Note: Parker90 used here with sand fraction of the granulometric curve


                



Slope (m/m):
D50 (mm):
D84 (mm):
Width (m):
q (m3/s/m):
τ*/τ*c



Test Equations:

The results are represented by a percentage ratio qs calculated / qs_measured included in the envelopes [0.1-10] (E10), [0.2-5] (E5) and [0.5-2] (E2)


Result of the selection :

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Plot X with:
Plot Y with:
Download selection




Dowload computation



Download figure


Download saved data
Download the project

IMPORTANT: ENSURE THAT THE ENCODING OPTION IS UFT8 WHILE BACKING UP THE .TXT FILE ON YOUR PC

This function allows you to save your input in your computer, in text format. It does not need to create an account, however the photos and text description of the project are not saved. IMPORTANT NOTES: 1)Data integrity may not be assured in the event of a major program change (new versions), contrarilly to server backup. 2) If you have large hydrographs it is better to save them separately with the proposed option.


Create an account
Email is not mandatory at this stage. But be aware that, for reasons of confidentiality, in the absence of a valid email associated with the account it will no longer be possible to access the account in case of forgotten password.
This code will be asked if you want to exchange folders with another user; it can be defined later from the 'Manage Account' tab

Selected project:

Warning: will only be saved in the project what has already been saved elsewhere in the different tabs
Project management:
By creating an account you can save your projects on the server, including photos and project description

Enter the name of the project:


Available projects:



You have two options to transfer a project to another user: OPTION1 you export the project locally on your PC and you transfer the resulting text file, which can be open by the other user (warning: this option does not take into account the photos and the text 'project description'). OPTION2, you and your contact have a user account and you can use the function below: for this you need to know its identifier (pay attention to lower / upper case), and its share code (different from its password!)


You must re-enter your password to access account changes
Change password:
Change the mail adress:
Files sharing code



This series of tools assists you in a sediment budget study. It consists of several tabs each of which represents an essential step for a serious study. The tabs are presented in a logical sequence, each producing useful data for the following: - the 'Granulometry' tab allows you to define the particle size of the sediments - the 'Section' tab allows you to define (topography) and dress ( roughness ..) the flow section - the 'hydraulic' tab is used to calculate the main hydraulics parameters for the normal uniform regime - the 'solid transport' tab calculates the fluxes for the granulometry, the section and hydraulics previously defined 5) the 'hydrology' tab permts to defien an hydrology and to compute the associated sediment budget

You can save your entry (except photos) in text format on your PC, or create an account (the backup on the server gives access to a project management menu, and allows you to save photos).

Input options:

Use the 'Input' option to enter the points of the curve (wolman count for example), or the 'model' option to reconstruct a curve from its D50. The model reproduces a realistic curve derived from the analysis of over a hundred curves measured in the field. For more details see: Recking, A. (2013), An analysis of non-linearity effects on bedload prediction, Journal of Geophysical Research - Earth Surface, 118, 1-18, doi: 10.1002 / jgrf.20090

Input format








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Name the GSD:
Measurement method
Import an image

Results:




Easy built with trapezes
Use this tool to quickly build a section composed from trapezes

Import a file
Import your distance (X) / altitude (Z) data from text files. The data must be arranged in 2 columns separated by tabs and containing titles (for example X, Z). Describe the section by increasing X from the Left Bank to the Right bank (by convention but it does not really mater as long as the sections are described in the same way). Check the quality of the data, for example by avoiding non-numeric characters or missing values
Manual entry:
Whatever the input mode (keystone, file import) the data is copied into this table from where they can be modified manually










Download

Modelling with trapezes

Enter dimensions (m)
Bottom level (m)

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Name the section:

"Ro: Rock bed, SP: Step-Pool, Pl: Plane bed, Br: Braiding, Wa: Wandering, RP: Riffle-pool, BA: Alternate bars, Sa: Sand bed"

Rock bed:


Step-pool:


Plane bed:


Braiding:


Wandering:


Riffle-pool:


Sand bed:






Import an image
Main channel

The main channel is the part of bed that transfers the current floods, it must be differentiated from the flood plain.
Active bed

The active bed is the part of the bed where solid transport and morphodynamic processes occur during floods. Main channel and active bed are generally the same. It is considered here that there is only one active bed, including in complex beds such as in braiding morphology (it is the active bed that moves in the alluvial mattress).

Bed component


The flood plain is the area solicited during floods, when the main channel is full. From a morphological point of view, it is generally a fairly flat, stable area, devoid of gravel (except in braiding rivers) and large. From a hydraulic point of view, there is generallly a break in the rise of the flood, because when the water stat flowing in the flood plain, each increase in discharge will have a weak impact on the height of water inside the main channel.



Braiding morphologies are the most difficult to treat because the bed is complex. We chose here to limit the active bed to the main channel of the braiding river, even if the morphodynamics seems to be active everywhere: this is based on the observation that, in general, even during large floods, a braiding river has a sedimentary response limited to a single channel that sweeps the braiding plain during the flood. All areas outside this active channel are considered depositional zones.

Define the fix bed left bank if it corresponds to a special roughness (vegetation<85>). This part of the section can correspond to the flood plain.
Define the fix bed right bank if it corresponds to a special roughness (vegetation<85>). This part of the section can correspond to the flood plain.
A secondary channel is a channel which contributes to transfer the flow during a flood, but it is not considered active here in terms of sediment transport.
The roughness zone can be used to attribute a special roughness to a part of the section, via the Strickler coefficient K (vegetation, obstacles<85>)
Flow height in the main channel from which the secondary channel is hydraulically connected

Modify the section


H(m)



Q(m3/s)

Friction law:
It is the friction law which defines the flow height and velocity for given discharge, slope and surface roughness . The calculation method must be defined for each part of the bed: use calculation with the grain size distribution (for example with the Ferguson equation) for the main channel and more generally for all alluvial bed; use the Manning-Strickler equation for more complex areas like vegetation, ice jams ... K values can be set or found in catalogs. Examples of values: flood plain with forest K <10, bed with meadow cover K = 20 to 30. The granulometries must be previously filled in and recorded in the Grain size distribution tab.

The grain size distribution of the active bed is not used in hydraulic calculation but in the calculation of solid transport (number of Shields, Eintein parameter). A priori the granulometry of the active bed is the same as that of the main channel (except special cases, such as the 'traveling bedload'; Piton, G., and A. Recking (2017), The concept of travelling bedload and its consequences for bedload computation of mountain streams, Earth Surface Processes and Landforms, DOI: 10.1002/esp.4105.)
Validation data



R(H) for the main channel:

Download


U(H) for the main channel:

Download


U(Q) for the main channel:

Download


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Critical Shields Tc*
Dcile for T*
Default: T*c=T*c(S) and decile= 50
Calibrate equations
Bagnold: ωc=

Camenen & Larson: τc*=

Lefort: q0=

Meyer-Peter & Muller: τc*=

Parker: τc*=

Parker90: τr*=

Recking: τm*=

Rickenmann: qc=

Schocklitch: qc=

Smart & Jaeggi: τc*=

Van Rijn: uc*=

Wilcock & Crowe: τr*=

Wong & Parker: τc*=

Water density ρ(kg/m3)=

Sediment density ρs(kg/m3)=

Apparent sediment density ρs_app(kg/m3)=

Test sensitivity to:

Bedload grain size distribution:
The GTM (Generalized Threshold Model) method extends the concept of threshold transport to each fraction of the grain size distribution; it is based on the computation of the bed stress and does not require a preliminary calculation of the solid transport of each fraction, as it is the case for WC and Parker. The model is very flexible because it can simulate almost all situations depending on the setting chosen; its relevance comes up against the limitations of our current knowledge of the physics of the mobility of a sedimentary mixture in a flow (effects of the armor, partial transport or not ...). For more information, see Recking, A. (2016), A Generalized Threshold Model for Computing Bedload Grain Size Distribution, Water Resour. Res., Doi: 10.1002 / 2016WR018735.

β=0.5, γ2=1.5

β define percentile of the largest grain transported (when T*/Tc*<1)
γ2 define partial transport for each fraction transported
β=2, γ2=20

β define percentile of the largest grain transported (when T*/Tc*<1)
γ2 define partial transport for each fraction transported
β
γ2
β define percentile of the largest grain transported (when T*/Tc*<1)
γ2 define partial transport for each fraction transported
Calibration data


Bedload grain size distribution validation

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Calibrate the GTM model:
β
γ2
β define percentile of the largest grain transported (when T*/Tc*<1)
γ2 define partial transport for each fraction transported
Data input
Q(m3/s)










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Hydrology input
Build a hydrograph
This tool allows to quickly build a triangular hydrograph compatible with the flow section. Values are given by default, and can be changed

Import a file
Import your time (unit of your choice) / flow (m3 / S) data from text files. The data must be arranged in 2 columns separated by tabs and containing titles (eg T, Q. Avoid special caracters!). Describe the values by increasing T. Check the quality of the data, for example by avoiding non-numeric characters or missing values


The text file should have two columns separated by tabulation
Colomn1 'FND': Frequency of non-exceedance x 100
Colonne2 'Q': associated discharge m3/s
Recall
T=1/FD
FD=1-FND
FD(j/an)=(1-FND)*365
Unites
Management of hydrological data










Download data

Download figure
Management of hydrological data










Download data

Download figure
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Local hydrology
Use this pane to adapt hydrology to the size of the watershed (or sub-basins) using the Myer formula
Referent watershed (km2)
Actual Area (Km2)
Myer coefficient
Walls height
Parameters defined in the tab 'Solid Transport

Sediment budget

Download data
Download figure
This tab only supports sediment balances previously saved. It allows an overview of the calculations made.


Document to download


User manuel.pdf
The equations.pdf
Example.txt
Download the Example file, save it on your PC, open it in the menu: Toolbox> Your project> Local backup> Browse
La granulometrie des cours d eau.pdf
La mesure du charriage.pdf

Version 1.6 - December 2018

Code management Alain Recking

Server management Eric Maldonado

IRSTEA, UGA, UR ETNA, Domaine universitaire 2 rue de la Papeterie, BP 76, 38 402 Saint-Martin-d Heres cedex

Lexique

A: Cross-section area [m2]
d: Flow depth [m]
D: Grain diameter [m]
D50: Mean grain diameter [m]
Dx: Grain diameter (subscript denotes % finer)
Fr: Froude number Fr=U/sqr(gH)
ω: flow power,ω=τU
Φ: Dimensionless transport rate, Φ=qsv/sqrt(g*(s-1)*D^3)
Ψ: Geometric grain size, Ψ=LogD/Log2, D=2^Ψ
Q: Flow discharge [m3/s]
q: Specific discharge (q=Q/W) [m3/s/m]
Qs: Sediment discharge [kg/s]
Qsv: volumetric sediment discharge [m3/s]
Qsapp: apparent solid discharge, Qsapp=ρ/ρapp*Qs
qs: Bedload transport rate per unit width (qs=Qs/W) [kg/s/m]
qsv: Volumetric transport rate per unit width (qs=Qsv/W) [m3/s/m]
R: Hydraulic radius [m]
Re: Reynolds number Re=UR/ν
ρ: water density (kg/m3)
ρs: sediment density (kg/m3)
s: relative density, s=ρs/ρ
S: Slope [m/m]
τ: Bed shear stress (N/m2)
τc: Critical bed shear stress (N/m2)
τ*: Shields number [ ]; τ*=τ/(g(ρs-ρ)D) <=> τ*=RS/((s-1)D)
τc*: Critical Shields number [ ]; τc*=τc/(g(ρs-ρ)D)
U: Mean velocity [m/s]
u*: shear velocity, u*=sqrt(τ/ρ)
z: bed level [m]
W: Channel width [m]