## Tidal Characteristic Numbers of Suspended Sediment Transport

### From BAWiki

##### Revision as of 13:41, 5 July 2012 by imported>Spohr Susanne (Transportkenngroessen ergänzt)

graphical representations of the characteristic numbers of salinity

## Contents

- 1 Motivation
- 2 Definitions for the Tidal Characteristic Numbers of Suspended Sediment Transport
- 2.1 Flood Current
- 2.2 Ebb Current
- 2.3 Tidal Cycle
- 2.3.1 Maximum Suspended Sediment Concentration
- 2.3.2 Minimum Suspended Sediment Concentration
- 2.3.3 Mean Suspended Sediment Concentration
- 2.3.4 Tidal Variation of Suspended Sediment Concentration
- 2.3.5 Advective Residual Transport of Suspended Sediment
- 2.3.6 Advective Suspended Sediment Transport, Flood-Ebb-Ratio

- 2.4 Advective Transport of Suspended Load
- 2.5 Mean Advective Suspended Load Transport
- 2.6 Maximum Advective Suspended Load Transport
- 2.7 Minimum Advective Suspended Load Transport

## Motivation

The calculation as well as the graphic visualization of various tidal characteristic numbers of suspended sediment concentration and also for the advective transport of suspended sediment contributes to an improved understanding of tidally dominated transport processes in estuaries. Spatial variations of suspended sediment concentration, advective transport of suspended sediment by means of flood and ebb currents can be highlighted for areas like coastal seas and estuaries as well.

- As the calculations are performed separately for the durations of ebb- and flood-current it can be shown that transport paths can differ significantly for the two tidal phases. From this one can get additional insight with respect to the relevant transport mechanisms dominated by the tidal currents. This can be related to locally varying flood-ebb asymmetries for ebb volume and flood volume. Also the presence of horizontal gradients can contribute to this effect.
- The variation of suspended sediment concentration resulting from the local maximum as well as the local minimum of suspended sediment concentration can be quite large. This is a consequence of the different availability of suspended sediments, e. g. inside or outside of the turbidity maximum. The value for the local suspended sediment concentration variation is mainly the result of the product between the horizontal suspended sediment concentration gradient and the lagrangian drift of a water particle during a complete tidal cycle, but also effected by the strong spatial variation of deposition and erosion of suspended sediments throughout the estuary.

An automatic analysis of all tidal characteristic numbers of suspended sediment transport is carried through by the computer program TDKSF.

## Definitions for the Tidal Characteristic Numbers of Suspended Sediment Transport

### Flood Current

#### Advective Flood Transport of Suspended Sediment

Suspended sediment mass, which is transported by means of flood current through a cross section

Example: not available.

### Ebb Current

#### Advective Ebb Transport of Suspended Sediment

Suspended sediment mass, which is transported by means of ebb current through a cross section

Example: not available.

### Tidal Cycle

#### Maximum Suspended Sediment Concentration

Maximum value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)

Example: not available.

#### Minimum Suspended Sediment Concentration

Minimum value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)

Example: not available.

#### Mean Suspended Sediment Concentration

Average value of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)

Example: not available.

#### Tidal Variation of Suspended Sediment Concentration

Difference between the extreme values of suspended sediment concentration during a complete tidal cycle (period between two subsequent slack water times of ebb current)

Example: not available.

#### Advective Residual Transport of Suspended Sediment

Residual suspended sediment mass which is transported by means of ebb and flood currents through a cross section (the different transport directions are taken into account). If the advective transport by means of flood current is equal but in opposite direction of the ebb current transport this will result in a zero advective residual transport of suspended sediment.

Example: not available.

#### Advective Suspended Sediment Transport, Flood-Ebb-Ratio

Flood to ebb ratio for the suspended sediment volumes which are transported by means of flood and ebb currents

Example: not available.

### Advective Transport of Suspended Load

Volume of suspended sediment, which is transported through a cross section over a period of time.

Example: not available.

### Mean Advective Suspended Load Transport

Mean value of suspended sediment transport within a period of time.

Example: not available.

### Maximum Advective Suspended Load Transport

Highest value of suspended sediment transport within a period of time.

Example: not available.

### Minimum Advective Suspended Load Transport

Lowest value of suspended sediment transport within a period of time.

Example: not available.

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