Environmental Engineering Reference
In-Depth Information
Table 13.3
Comparison of the strengths and weaknesses of 1D and 2D surface modelling approaches
1D surface modelling
2D surface modelling
Strengths
Weaknesses
Strengths
Weaknesses
Currently needs external model building
tool
Model build an integral part of current
software
Model build requires additional time for
operation of external tool and import
of data to modelling software
Model build is a rapid process
Uses same numeric outputs as for 1D
subsurface model for a limited number of
nodes and links resulting in simple post-
processing
Relatively low quality graphical output
High-quality graphical outputs show
depths, velocities, levels and
movement of water over the surface
High-quality graphical outputs can
misrepresent low-resolution inputs
Large volumes of numerical output
relating to each modelled surface cell
make post-processing arduous
Simulation times relatively short and with
minimal demand on computer resources
enabling coverage of large areas
Simulation time relatively long, with
considerable demand on computer
resources, limiting the area that can
be simulated, or the resolution of the
surface model (Note 1)
Utilizes all the 1D modelling functionality of
the host software, enabling simulation of
the movement of pollutants over the
surface during an event
Simulation of movement of pollutants
over the surface not possible
The ef
ciency with respect to computer
resources means that this approach can be
used to prioritize areas for more detailed
study and also simulate overland
ows
through areas that are not vulnerable to
ooding
The relatively low quality of the
graphical output means that this
approach is not effective in informing
non-technical stakeholders without
signi
cant post-processing
The quality of the graphical outputs
mean that the outputs can be used to
inform stakeholders of the existing
problems and provide appropriate
outputs for
ood risk assessments
The demands on computer resources
require pre-prioritization to identify
areas where integrated modelling
studies are required
The drainage system data can be quickly
amended to represent new surface
pathways and sinks in each option to be
considered
The need to alter digital elevation
models to represent different options
is time consuming
