Environmental Engineering Reference
In-Depth Information
Short Exercise 8: Calculation of Groundwater Flow Using the
Segmented-Darcy Method
The segmented-Darcy approach shown in Fig.
3.21
provides values for
Q
In
and
Q
Out
that are based on data from monitoring wells and wetland stage. The figure
below (Fig.
3.36
) is identical to Fig.
3.21
but heads for three of the wells are
changed slightly. Use the data shown in Fig.
3.36
, along with the assumptions that
K
is 30 m/day and
b
is 20 m, to fill out the data in Table
3.9
. Sum the positive values to
determine
Q
In
and sum the negative values to determine
Q
Out
. Then answer the
following questions.
1. Where is the greatest rate of exchange (
Q
/
A
) between groundwater and the
wetland? Why?
2. A hinge line is a point along a shoreline that separates a shoreline reach where
groundwater discharges to the wetland from a shoreline reach where wetland
water flows to the groundwater system. What are the approximate locations of
the hingelines?
3. If there is no surface-water exchange with the wetland, and overland flow is
negligible, what does this analysis tell you about the other terms of the water
budget?
Fig. 3.36 The same wetland setting shown in Fig.
3.21
but with several different head values.
Figure legend is shown in Fig.
3.21
