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Flow Through-Discharge - example 3 (THESIS - Figure 10.23)

Problem Description

Non-dimensional Ratios:

2a /B 8 Ratio of lake length to aquifer depth.
2a /LR 0.09 Ratio of lake length to regional length of aquifer.
LL /LR 0.2 Position of the lake within the regional setting, normalised by the regional length.
Aquifer Properties
KH /KV 1 Hydraulic conductivity anisotropy.
SoB 1.0E-05 Aquifer elastic storage coefficient.
Sy 0.3 Aquifer specific yield.
Boundary Fluxes
RLs /Rs -1.74 Ratio of average lake recharge to average aquifer recharge.
RLaSy /Ra 0 Ratio relating theamplitude of fluctuation in lake recharge to the amplitude of aquifer recharge.
q /P 0 The phase difference between the lake and aquifer recharges, normalised by the period.
System Response
LR2Sy /KHBP 0.44 Non-dimensional response time describing the ability of the lake-aquifer system to propagate periodic forcing applied at the boundaries.
RsLR2 /KHB2 0.79 A non-dimensional measure of the mean height of the regional groundwater mound above the groundwater level at the regional discharge boundary.
RaP /SyB 0.18 Ratio describing the size of potential fluctuation in advective flowpaths relative to the aquifer depth.

Near-Field Animation


Animated gif: 24 frames per period

See description below...

All groundwater from up-gradient in the aquifer is captured by the lake in this example; the lake capture zone is said to fully penetrate the aquifer. On the down-gradeint side of the lake there is some capture of shallow groundwater (contributed as down-gradient groundwater recharge) and there is release and partial recapture of lake water within the aquifer. In the long-term, a lake release zone develops down-gradeint in the aquifer that is composed of many smaller remnant release zones formed during each period of fluctuation. Note that the lake release zone lies at the base of the aquifer, including the former lake water released from beneath the lake shoreline.


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