| Product(s): | PondPack | ||
| Version(s): | Varies | ||
| Environment: | N\A | ||
| Area: | Calculations |
When a pond's infiltration method is set to "Infiltration Head / Depth", two fields need to be entered. The Infiltration per unit of Head and the K Exponent.
For the example discussed in this article, the following values will be used:
Infiltration per unit of Head = 2 (in/hr)/(ft^K)
K Exponent = 0.5
The infiltration rate and K exponent are typically derived from physical infiltration tests performed for a pond site.
To view a table of pond infiltration calculations:
- Compute the scenario(s).
- Open the Report menu and select Report Builder.
- Select the scenario(s) that you would like included in the report and click OK.
- Click on the subsection Pond Infiltration Calculations to highlight the row.
- Click the Generate Preview icon.
|
Elevation (Water Surface) (ft) |
Elevation (Low) (ft) |
Head (ft) |
Area (Total) (ft²) |
Area (Edge) (ft²) |
Infiltration (ft³/s) |
Flow (Total) (ft³/s) |
|
0.0 |
0.0 |
0.0 |
100.0 |
100.0 |
0.000000 |
0.000000 |
|
0.5 |
0.0 |
0.5 |
100.0 |
100.0 |
0.003274 |
0.003274 |
|
0.5 |
0.0 |
0.5 |
108.5 |
8.5 |
0.000277 |
0.003550 |
|
1.0 |
0.0 |
1.0 |
100.0 |
100.0 |
0.004630 |
0.008180 |
|
1.0 |
0.0 |
1.0 |
108.5 |
8.5 |
0.000391 |
0.008572 |
|
1.0 |
0.5 |
0.5 |
117.3 |
8.8 |
0.000288 |
0.008860 |
|
1.5 |
0.0 |
1.5 |
100.0 |
100.0 |
0.005670 |
0.014530 |
|
1.5 |
0.0 |
1.5 |
108.5 |
8.5 |
0.000479 |
0.015009 |
|
1.5 |
0.5 |
1.0 |
117.3 |
8.8 |
0.000407 |
0.015417 |
|
1.5 |
1.0 |
0.5 |
126.4 |
9.1 |
0.000299 |
0.015716 |
|
2.0 |
0.0 |
2.0 |
100.0 |
100.0 |
0.006547 |
0.022263 |
|
2.0 |
0.0 |
2.0 |
108.5 |
8.5 |
0.000554 |
0.022817 |
|
2.0 |
0.5 |
1.5 |
117.3 |
8.8 |
0.000499 |
0.023316 |
|
2.0 |
1.0 |
1.0 |
126.4 |
9.1 |
0.000423 |
0.023739 |
|
2.0 |
1.5 |
0.5 |
135.9 |
9.5 |
0.000311 |
0.024049 |
The infiltration values are calculated using the equation:
Infiltration = (I/(H^K))*(H^K) *(A)*((1/12)*(1/60)*(1/60))
(I/(H^K)) is Infiltration per unit of Head and is entered in units (in/hr)/(ft^K)
H is the Head of over "Area (Edge)"
K is the head exponent.
A is the area of the segment and is labeled "Area (Edge)" in the table.
((1ft/12in)*(1hr/60min)*(1min/60sec)) is used to convert units (in/hr)/ft to (ft/s)/ft
The infiltration is calculated at each incremental segment and then summed to account for different head values.
When the water surface elevation is 0.5ft the total flow is:
0.003274cfs+0.000277cfs = 0.003550cfs
See Also
How to vary pond infiltration rate with water surface elevation
Reporting total cumulative infiltration volume
| Original Author: | Craig Calvin |