Ground infiltration formula (Water Overlay): Difference between revisions

Revision as of 12:14, 4 April 2019

Underground infiltration (from the unsaturated zone to the saturated zone) is calculated per cell.

First the height of the unsaturated zone is calculated.

H_unsat = H_surface - WL_underground

Then the ratio of water amount to unsaturated height is calculated.

S = W_unsat/H_unsat

Then calculate the distance of the unsaturated zone which can infiltrate.

C_inf = min( H_unsat , Δt * I_und )

Finally, calculate the amount of actual amount of water infiltrating.

Δw = C_inf * S

Where:

H_unsat = The height of the unsaturated zone.
S = Ratio of water to height in the unsaturated zone.
C_inf = The height in the unsaturated zone which can be subject to infiltration to the saturated zone.

W_unset = The amount of water in the unsaturated zone. The height of the water column if the equivalent amount of water was placed on the surface.
WL_underground = The groundwater level, relative to datum.
H_surface = The terrain height in the cell, relative to datum.
I_und = The GROUND_INFILTRATION_MD of the underground terrain type.

@@ Line 22: / Line 22: @@
 * W<sub>unset</sub> = The amount of water in the unsaturated zone. The height of the water column if the equivalent amount of water was placed on the surface.
-* WL<sub>underground</sub> = The groundwater level, relative to {{datum}}.
+* WL<sub>underground</sub> = The groundwater level, relative to [[Datum|datum]].
-* H<sub>surface</sub> = The terrain height in the cell, relative to {{datum}}.
+* H<sub>surface</sub> = The terrain height in the cell, relative to datum.
-* I<sub>und</sub> = The {{inlink|GROUND_INFILTRATION_MD_underground|GROUND_INFILTRATION_MD}} of the underground terrain type.
+* I<sub>und</sub> = The [[Ground infiltration md (Terrain) (Water Overlay)|GROUND_INFILTRATION_MD]] of the underground terrain type.
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