Curve Number 2

[Gunns]

Has anyone model runoff from a coal pile?
What did you use for a curve number?

 

[RWF7437]

This must be a very big coal pile to warrant modeling using the NRCS Curve Number method. I would use something like 98 since virtually all rainfall would runoff quickly and almost completely.

Good Luck

 

[Gunns]

Do you really think it would be that high, won't the coal absorb some rain water

 

[RWF7437]

Can you test it and calculate it ? Then you won't have to guess.

 

[psmart]

If the coal absorbs a significant amount of water, you may be able to estimate a CN value based on the potential storage. For details see

http://www.hydrocad.net/curvenumber.htm

 

[Gunns]

Don't have the money to test, I am already making a lot of assumptions since there is little available data. But I would like to have a better assumptions for the coal pile curve number since it makes up a majority of the site.

 

[psmart]

Take a dry piece of coal and put it in a cup of water. Measure the immediate displacement, and then the amount absorbed over a couple of hours. This should let you estimate the potential storage for the entire coal layer. Use the previous link to estimate the CN.