Environmental Engineering Reference
In-Depth Information
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
100% 'Fair' Condition
50% 'Fair', 50% 'Poor'
25% 'Fair', 75% 'Poor'
0.2
0.1
0.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Asset Length (m)
Fig. 15.10
The influence of asset length with the simplified Risk Assessment Field-based Tool (RAFT).
.
How would an intervention change the risk?
.
Howmuchwould a particular intervention cost?
.
Is it better to intervene physically or should
more data be collected/analysis undertaken?What
level of confidence do I have in this decision?
.
Which intervention strategy is best, given the
future uncertainties?
.
Which are the most important uncertainties in
terms of their contribution to the doubt as to what
to do for the best?
The foregoing sections outline the underlying
risk analysis tools that can be used to explore the
majority of these questions. More recently a num-
ber of projects have started to enact thesemethods
within flexible decision support tools (Surendran
et al. 2008; McGahey and Sayers 2008; Woodward
et al. 2010). These decision support tools focus on
providing the evidence to support the selection of a
preferred investment action/strategy. Various
considerations are essential to this process beyond
the analysis of flood risk, including:
.
Robustness: are the proposed actions robust? -
i.e. will the strategy performwell in the context of
a wide range of possible futures (resources, cli-
mate, socioeconomic, etc.)?
.
Flexibility: are the proposed actions flexible? -
i.e. are future choices compromised, or can alter-
native actions be taken at a future date with
limited additional cost?
.
Adaptability: can the strategy be adapted to
account for future change? - i.e. as the reality of
the future unfolds can the asset designs be
adapted (heightened/widened, etc.) with minimal
cost?
.
Uncertainty: is the strategy robust to the uncer-
tainty within the data, methods and model struc-
tures, aswell as to the gross uncertainty associated
with future change?
