The impact of urban groundwater upon surface water - eTheses ...

Details of the model setup and calibration are given in Appendix 24.
6.2.5 UNSAT
n
( k∇h) − Qiδ
( x − xi)
∇ ∑
i=
1
k = hydraulic conductivity [LT -1 ]
h = hydraulic head [L]
Qi = point sink at location xi
+ R =
dh
S
dt
x = location [L]
xi = location of point sink [L]
[L 3 T -1 ]
R = distributed source [T -1 ]
S = specific storativity [L -1 ]
t = time [T]
δ = dirac delta function [L -3 ]
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GROUNDWATER FLOW MODELLING
The computer code UNSAT (Mackay, 2001) is a one-dimensional, box-centred, finite
difference numerical model which solves Richards equation for flow using Van Genuchten’s
(1980) equations for the soil moisture characteristics to simulate the unsaturated zone. Details
of the model setup and calibration are given in Appendix 25.
6.3 Investigation of groundwater flow paths across the river flood plain
The modelling objective was to investigate groundwater flow paths, at the flood plain and
channel scales, and in the vertical and horizontal planes to establish the likely movement of
contaminant plumes from source area to discharge point within the river.