Geoscience Reference
In-Depth Information
1
0
1
q +
2
0.1
4
10
20
0.01
0
0.1
0.2
0.3
t +
Fig. 10.28 Scaled outflow hydrograph q + = q + ( t + ) from a linearized sloping hydraulic aquifer into an
adjoining open channel as given by Equation (10.147), for the values of the hillslope flow
number Hi = 0 , 1 , 2 , 4 , 10 and 20. Hi = 0 represents the horizontal case (see Example 10.3).
The outflow rate is scaled with the initial outflow rate q = ( I c B x cos α ), so that
q + = q / ( I c B x cos α ); this initial outflow rate results from a steady input I c prior to t + = 0, as
described in Example 10.5. The time is scaled as indicated in Equation (10.137).
[by analogy with (10.130)]
t 2
2 k 0 η 0 P c cos 2
α
z n [1 2 cos( z n )exp(Hi / 2)]
z n + Hi 2
q
= q ( t ) =
0 . 2
/ 4 + Hi / 2
n e B x
n
=
1
,
2
,...
t 1
× exp z n + Hi 2
d τ
/ 4 [ k 0 η 0 cos α ] ( t τ )
n e B x
z n 1 2 cos( z n )exp(Hi / 2)
z n + Hi 2
t 3
/ 4 + Hi / 2
+
0 . 9
n = 1 , 2 ,...
t 2
× exp
d τ
z n + Hi 2
/ 4 [ k 0 η 0 cos α ] ( t τ )
n e B x
(10.148)
This result can be readily integrated to yield (by analogy with Equation (10.131) for the
horizontal case)
z n 1
2)
2 cos( z n )exp(Hi
/
q
=− 2 B x P c cos α
z n + Hi 2
/ 4 z n + Hi 2
/ 4 + Hi / 2
n = 1 , 2 ,..
× 0
2 exp z n +
4 ( t + t + 2 )
exp z n +
4 ( t + t + 1 )
Hi 2
Hi 2
.
/
/
9 exp z n +
4 ( t +
t + 3 )
exp z n +
4 ( t +
t + 2 )
Hi 2
Hi 2
+
0
.
/
/
(10.149)
in which the scaled time variable is defined in Equation (10.137).
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