Additional parameters for breach flow (HMBreach) has to be specified
Input screen for the 4 sets of additional HMBreach parameters.
The greyed input fields are fixed on a default value
Initial conditions of upper layer
Name in English | Name in Dutch | Description | Symbol | Unit | Default decimals + (range) |
|---|---|---|---|---|---|
Froude number | Froude getal |
|
| – | 2 Fixed value |
Concentration | Concentratie |
|
| % | 12 Fixed value |
Minimal initialization height | Minimale initiele hoogte |
|
| m | 0.1 (0.1-5.0) |
Maximal initialization height | Maximale initiele hoogte |
|
| m | 2.5 (0.1-5.0) |
Interval | Interval |
|
| m | 0.01 (0.1-1.0) |
Layer discretization
Name in English | Name in Dutch | Description | Symbol | Unit | Default decimals + (range) |
|---|---|---|---|---|---|
Maximum thickness highest layer | Maximale dikte bovenste laag | For the calculation, the soil profile is divided into sub-layers. This is the maximum thickness of the highest layer of the soil profile. |
| m | 0.05 (0.01-1) |
Maximum thickness lowest layer | Maximale dikte onderste lag | For the calculation, the soil profile is divided into sub-layers. This is the maximum thickness of the lowest layer of the soil profile. |
| m | 0.5 (0.01-1)
|
Approval criterion
Name in English | Name in Dutch | Description | Symbol | Unit | Default + decimals + (range) |
|---|---|---|---|---|---|
Ratio sand transport | Verhouding Zandtransport | Ratio between the sand transport at the toe and the sand transport at the top of a sand cluster, indicating if the considered initialization height is sufficient to produce a breach flow slide, characterized by a strongly increasing sand transport rate along the slope. The minimal initialization height for which this is the case is defined as the critical height. | RatioZV | - | 10 (2-100) |
| Allowable critical height | Toelaatbare kritische beginhoogte | If the critical initialization height is higher than the allowable critical height, the slope is safe. If not, it means that the probability that a breach flow slide will occur is high. | hallowable | m | 1.0 |
Physical constants
Symbol | Description | Unit | Default + decimals + (range) |
|---|---|---|---|
a_1_n0 | Constant erosion formula | – | 1.0 Fixed value |
Aeros | Constant erosion formula | – | 0.012 Fixed value |
Beros | Constant in erosion formula | – | 1.3 Fixed value |
dn | Porosity increase during dilatancy. | – | 0.04 Fixed value |
f0 | Darcy-Weisbach bed friction coefficient. | – | 0.1 Fixed value |
fki | Ratio of bed to internal friction. | – | 0.333 Fixed value |
i | Hydraulic gradient. Default is 0. | – | 0 Fixed value |
rk3 | Constant in entrainment model. | – | 0.0015 Fixed value |
temp | Water temperature. Defines viscosity, fall velocity and permeability | ºC | 15.0 (0.0-30.0) |
Only the temperature can be changed, other values cannot be adjusted.
