Geology Reference
In-Depth Information
14.3 SHETRAN
erties, inputs and responses are represented on a
three-dimensional, finite-difference mesh, and
the channel system is represented along the
boundaries of the mesh grid squares as viewed in
plan (Fig. 14.1). Table 14.1 summarizes the main
processes modelled and the equations used to
describe them.
Detailed descriptions of the SHE/SHETRAN
system can be found in Abbott
et al
. (1986b),
Bathurst
et al
. (1995), Ewen (1995), Birkinshaw
and Ewen (2000) and Ewen
et al
. (2000). In addi-
tion, a website (http://www.ceg.ncl.ac.uk/shetran/)
provides details of the system, access to the soft-
ware, and a user guide with test datasets. As com-
putational power has increased, the hardware
required for running the system has evolved from
mainframe computer to Unix-based workstation,
to desktop computer and laptops.
SHETRAN is a descendant of the original SHE
(Système Hydrologique Européen) hydrological
modelling system, which was built in a collabora-
tive programme in the late 1970s and early 1980s
by the then UK Institute of Hydrology (now the
Centre for Ecology and Hydrology, Wallingford),
the then Danish Hydraulic Institute (now DHI)
and the French consultancy SOGREAH (Abbott
et al
., 1986a,b). SHETRAN was created at
Newcastle University after the transfer there of
the UK SHE programme in the late 1980s, and its
development paralleled that of MIKE SHE
(Refsgaard & Storm, 1995), the Danish SHE
descendant. SHETRAN is now a general, physi-
cally-based, spatially-distributed modelling sys-
tem that can be used to construct and run models
of all or any part of the land phase of the hydro-
logical cycle, including sediment and contami-
nant transport (Ewen
et al
., 2000). It is physically
based in the sense that the various flow and trans-
port processes are modelled either by finite differ-
ence representations of the partial differential
equations of mass, momentum and energy con-
servation, or by empirical equations derived from
experimental research. The model parameters
have a physical meaning and can be evaluated by
measurement. Spatial distributions of basin prop-
14.3.1
SHETRAN hydrological component
Subcomponents account for evapotranspiration
and interception, overland and channel flow, sub-
surface flow, snowmelt and channel/surface aqui-
fer exchange (Fig. 14.1 and Table 14.1). SHETRAN
is continually evolving as new process descrip-
tions and solution schemes are introduced. The
current most advanced version is Version 5,
although this does not yet support some of the
Elevation (m)
SHETRAN V4
Evapotranspiration
877 -1053
1054 -1229
1230 -1405
1406 -1582
1583 -1758
1759 -1934
1935 -2111
Landslides,
erosion &
sediment
transport
Snowmelt
Canopy
interception
Overland &
channel
flow
Root zone
3D
Variably
saturated
subsurface
flow model
Resolution 500 m
Stream - aquifer interactions
Fig. 14.1
SHETRAN schematic and example of a model grid network, channel system (in solid black lines)
and elevation distribution. The schematic has evolved through time; this particular version was created by
Dr Isabella Bovolo.
