Ground bottom flow formula (Water Overlay): Difference between revisions

Revision as of 09:59, 10 July 2020

Underground seepage (from (or to) outside the project area) is calculated per cell.

The seepage is calculated using the following formula:

\Delta s={\frac {h_{d}(t)-h_{x,y}}{c}}\cdot {\frac {\Delta t}{24\cdot 60\cdot 60}}

The external seepage head is variable over time by the introduction of h_v,t

h_{d}(t)=h_{c}+h_{v,t}(t)

Finally, calculate the actual amount of water infiltrating.

\Delta w={\frac {\Delta s}{ws}}

Where:

$\Delta s$ = The underground seepage which takes place, in meters.
$\Delta t$ = Computational timestep in seconds.
$h_{d,t}$ = ground water level (or head) of the external zone causing the seepage at time t, in meters
$h_{c}$ = constant ground water level (or head) of the external zone causing the seepage, in meters
$h_{v,t}$ = additional variation of seepage head over time
$c$ = resistance of the separating layer in days
$ws$ = water storage fraction of the soil

@@ Line 11: / Line 11: @@
 Where:
-* Δs = The underground seepage which takes place, in meters.
+* <math>\Delta s</math> = The underground seepage which takes place, in meters.
-* Δt = Computational timestep in seconds.
+* <math>\Delta t</math> = Computational timestep in seconds.
-* h<sub>d</sub> = ground water level (or head) of the external zone causing the seepage, in meters
+* <math>h_{d,t}</math> = ground water level (or head) of the external zone causing the seepage at time t, in meters
-* h<sub>v> = additional variation in head of h<sub>d</sub> over time
+* <math>h_{c}</math> = constant ground water level (or head) of the external zone causing the seepage, in meters
-* c = resistance of the separating layer in days
+* <math>h_{v,t}</math> = additional variation of seepage head over time
-* ws = soil water storage fraction
+* <math>c</math> = resistance of the separating layer in days
+* <math>ws</math> = water storage fraction of the soil
-* H<sub>unsat</sub> = The height of the unsaturated zone.
-* S = Ratio of water to height in the unsaturated zone.
-* C<sub>inf</sub> = The height in the unsaturated zone which can be subject to infiltration to the saturated zone.
-* 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 formula (Water Overlay)|groundwater level]], relative to {{datum}}.
-* H<sub>surface</sub> = The [[Terrain height (Water Overlay)|terrain height]] in the cell, relative to {{datum}}.
-* I<sub>und</sub> = The [[Terrain ground infiltration md (Water Overlay)|GROUND_INFILTRATION_MD]] of the underground terrain type.
 ==Related==
@@ Line 36: / Line 27: @@
 : [[Underground model (Water Overlay)|Underground model]]
 : [[Infiltration model (Water Overlay)|Infiltration model]]
-: [[Substance flow model (Water Overlay)|Substance flow model]]
 {{Template:WaterOverlay_nav}}

Ground bottom flow formula (Water Overlay): Difference between revisions

Revision as of 09:59, 10 July 2020

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