Figure 5-4 shows the relationship of the terms used in the following formula for available yield

from an artesian well:

Figure 5-4. Diagram of well in artesian aquifer.

c. Determination of Values. The well driller's log provides the dimensions of H, h, and b.

The value of R usually lies between 100 and 10,000 feet. It may be determined from

observation wells or estimated. K may be determined from laboratory tests or field tests. A

pumping test and observation wells may provide the values for all of these equations. Figure

5-3 shows the values for calculating K in water table aquifer:

1055 Q log (r2/r1)

K

=

__________________

(h22 -h12)

(eq. 5-3)

5-8

Integrated Publishing, Inc. |