2000

1600

H = 0.07

0.06

1200

Q(H,L)

(m3 /hr)

0.05

800

0.04

400

0

2

4

6

8

10

L, Weir Length (m)

the previous calculations:

as a function of weir length:

(4a)

The instantaneous effect of head on flow rates over

the weir is illustrated in Figure 6. This, of course,

1 *V*(*H *)

0 076

is a linear relationship. We can now look at the

*dH *(hours).

(5a)

time-required-to-drain relationship for a given

weir length. The following relationships are used:

Evaluating this integral yields the graph in

Figure 7.

To confirm this analysis, we can look at Hicks'

analysis of the variation in head on a weir with-

out inflow to the reservoir, essentially what we

(4a)

have here. The formula used in Hicks (1972) is

An integral was developed to derive the time

(6)

required to drain based on the flow *(Q)*: volume

where

in head over the fixed weir:

(hour).

(5)

10