Surface infiltration formula (Water Overlay): Difference between revisions

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First, the infiltration capacities are calculated:
First, the infiltration capacities are calculated:


<math> \bar{I_top} =   
<math> \bar{I}_{top} =   
\begin{cases}
\begin{cases}
\bar{I_{con}}, & \text{if constructions are present on top of the surface} \\
\bar{I}_{con}, & \text{if constructions are present on top of the surface} \\
\bar{I_{terrain}}, & \text{otherwise}\\
\bar{I}_{terrain}, & \text{otherwise}\\
\end{cases}
\end{cases}
</math>
</math>


<math> I_{surface} = min(\bar{I_{ground}}, \bar{I_{top}}})
<math> \bar{I}_{surface} = min(\bar{I}_{ground}, \bar{I}_{top})</math>


Then the actual infiltration:
Then the actual infiltration:


<math>\Delta w = min( h, \Delta t \cdot I_{surface})</math>  
<math>\Delta w = min( h, \Delta t \cdot \bar{I}_{surface})</math>  


Where:
Where:


: <math>\bar{I_{con}}</math> = The average infiltration speed based on constructions on top of the surface, based on [[Function ground infiltration md (Water Overlay)|GROUND_INFILTRATION_MD]].
: <math>\bar{I}_{con}</math> = The average infiltration speed based on constructions on top of the surface, based on [[Function ground infiltration md (Water Overlay)|GROUND_INFILTRATION_MD]].
: <math>\bar{I_{terrain}}</math> = The average infiltration speed based on the surface terrain, defined by [[Terrain ground infiltration md (Water Overlay)|GROUND_INFILTRATION_MD]]. This value should be interpreted as the vertical conductivity (Kv) of the sub-soil.
: <math>\bar{I}_{terrain}</math> = The average infiltration speed based on the surface terrain, defined by [[Terrain ground infiltration md (Water Overlay)|GROUND_INFILTRATION_MD]]. This value should be interpreted as the vertical conductivity (Kv) of the sub-soil.


: <math>\bar{I_top}</math> = The average infiltration speed on top of the surface.
: <math>\bar{I}_{top}</math> = The average infiltration speed on top of the surface.
: <math>\bar{I_ground}</math> = The average infiltration speed below the surface.
: <math>\bar{I}_{ground}</math> = The average infiltration speed below the surface.
: <math> I_{surface}</math> = The (limited) infiltration speed from surface to the unsaturated zone.
: <math>\bar{I}_{surface}</math> = The (limited) infiltration speed from surface to the unsaturated zone.


: <math>h</math> = The amount of water on the surface. Also known as the water column.
: <math>h</math> = The amount of water on the surface. Also known as the water column.
: <math>\Delta w</math> = The surface infiltration which takes place.
: <math>\Delta w</math> = The surface infiltration which takes place.
: <math>\Delta t</math> = Computational timestep.
: <math>\Delta t</math> = Computational timestep.
==Related==
==Related==
The following topics are related to this formula.
The following topics are related to this formula.

Revision as of 13:26, 3 June 2021

Surface infiltration is calculated per cell.

First, the infiltration capacities are calculated:

Then the actual infiltration:

Where:

= The average infiltration speed based on constructions on top of the surface, based on GROUND_INFILTRATION_MD.
= The average infiltration speed based on the surface terrain, defined by GROUND_INFILTRATION_MD. This value should be interpreted as the vertical conductivity (Kv) of the sub-soil.
= The average infiltration speed on top of the surface.
= The average infiltration speed below the surface.
= The (limited) infiltration speed from surface to the unsaturated zone.
= The amount of water on the surface. Also known as the water column.
= The surface infiltration which takes place.
= Computational timestep.

Related

The following topics are related to this formula.

Formulas
Surface water level formula
Groundwater level formula
Underground infiltration formula
Models
Surface model
Underground model
Infiltration model
Tracer flow model