Infiltration 1

[queque]

If one assumes a pond is full of water and the depth from the top of the water surface to the bottom of the pond is 10 ft. assuming a infiltration/percolation rate of 1 hour per inch, how long would it take for the pond to go dry?

Assuming you use Darcy's law, and you know the permeability of the soil surface, how long would it take for the pond to dry up?
In other words, when do you use Darcy's Law with permeability versus a known percolation rate to determine the time to drain the pond?

What is the difference?

 

[CESSNA1]

QUEQUE: Darcy's law can be used when the percolation rate is not known, and can also be used a check against the known percolation rate. Do not forget that, in general, the soil is rarely uniform. The actual percolation rate can change dramatically with depth under the pond and horizontal location. As the soil becomes saturated the percolation area will expand and the actual rate will probably slow down. The bottom line is that both methods are basically estimates. Do not forget evaporation from the top of the pond and also recharge from rain/runoff.

Regards
Dave

 

[Kwissifar]

Percolation vs Permeability testing.

When introducing a head of water, say 9 feet (8.6 feet cased) to a hole with no ground water present, and 4" of gravel at the bottom and them continued to run a percolation test with everthing that is required, i.e the 4 hours of saturation and timing the rate of drop for every inch.
Would this be considered a percolation or a permeability test?
If in the similar situation you have ground water at 4 feet and you are below that ground water doing this perc test with the head of water, would this be considered a permeability or a percolation test?
How would anyone relate permeability to pecolation? Is there a calculated relationship with regards to the data values and soil types?

I would appreciate it if someone could clarify and perhaps point me to a reference or some expertese.