Surface infiltration formula (Water Overlay)

Surface infiltration is the amount of water that infiltrates from the surface to the unsaturated zone below the surface.

Surface infiltration is calculated per grid cell. First, the infiltration capacities are calculated:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{I}_{top} = \begin{cases} \bar{I}_{con}, & \text{if constructions are present on top of the surface} \\ \bar{I}_{terrain}, & \text{otherwise}\\ \end{cases} }

${\bar {I}}_{surface}=min({\bar {I}}_{ground},{\bar {I}}_{top})$

Then the actual infiltration:

$\Delta w_{t}=min(h_{t},{\bar {I}}_{surface}\cdot \Delta t\cdot f_{i,t})$

Where:

${\bar {I}}_{con}$ = The average infiltration capacity based on constructions on top of the surface, based on GROUND_INFILTRATION_MD defined in either the building or function.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{I}_{terrain}} = The average infiltration capacity based on the surface terrain, defined by GROUND_INFILTRATION_MD. This value should be interpreted as the vertical conductivity (Kv) of the sub-soil.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{I}_{top}} = The average infiltration capacity on top of the surface.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{I}_{ground}} = The average infiltration capacity below the surface.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \bar{I}_{surface}} = The infiltration capacity from surface to the unsaturated zone.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \Delta w_t} = The surface infiltration which takes place at time Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle t} .

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle h_t} = The amount of water on the surface at time Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle t} . Also known as the water column.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \Delta t} = Computational timestep.

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle f_{i,t}} = The interpolated infiltration factor at time Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle t} . Configured using INFILTRATION_FACTOR_S.

Related

The following topics are related to this formula.

Formulas

Surface water level formula (Water Overlay)

Groundwater level formula (Water Overlay)

Ground infiltration formula (Water Overlay)

Models

Surface model (Water Overlay)

Ground model (Water Overlay)

Infiltration model (Water Overlay)

Tracer flow model

Notes

• When Surface infiltration Only is active, the maximum amount of water that can infiltrate into the unsaturated zone can be configured. See Infiltration Model: Surface infiltration Only for more details.

How-to's

• How to configure a dynamic infiltration factor for a Water Overlay

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