10 Applications of the Inverse Problem of Pollution Propagation
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and offshore activities by means of optimization of the location of potential release
of adverse impacts.
An important application is their use for optimizing fairways in domains (such as
the North Sea or Baltic Sea and especially the narrow and shallow Gulf of Finland)
that host extremely heavy ship traffic in the immediate neighbourhood of valuable
areas or sectors of the coast. In this context, the formulated problem is equivalent
to the task of minimizing the environmental damage for a moving source of danger.
It can be naturally associated with the classical problem of smart ship routing once
the distribution of the underlying quantities is known. For example, an approximate
solution for the environmentally safest sailing line is to route the ships along the
minima of these probabilities (Andrejev et al. 2011).
Alternatively, one can benefit from a choice of the sailing line for a (chemical)
tanker that provides a systematic increase in the time it takes before the adverse impact reaches a vulnerable area (Engqvist and Andrejev 2003; Engqvist et al. 2006).
The use of the maxima for the particle age (Andrejev et al. 2011) for this purpose
is equivalent to buying extra time to combat the leak while the spill travels to the
coast.
For elongated sea areas (such as the Gulf of Finland), it might also rational to
search for the equiprobability line, such that for each of its points it is equally probable that the spill reaches one coastline or the opposite one during a certain time
interval (Soomere et al. 2010). A further challenge (addressed only partially below)
is to minimize the cost of damage so that the additional economic costs would remain manageable.
The goal of this technique is not to produce yet another operational model to
assist rescue and oil combating teams after an accident has happened. Instead the
goal is to identify beforehand the regions where it is statistically safer to travel. The
target is thus the preventive reduction of environmental risks: an optimization of
the location of potentially dangerous activities (e.g., ship traffic) so that the consequences of the resulting unfortunate event (here in terms of the impact of substances
potentially released into the sea and transported by currents) upon high-cost areas
would be minimal once it indeed occurred (cf. Eide et al. 2007).
A precondition for the use of such a way of thinking is the heterogeneity of the
relevant physical or ecological fields (such as the resulting maps of the probabilities
of coastal hit or the particle age). A recent solution of this kind is the relocation of
the fairway entering Boston Harbour (Massachusetts, USA) to minimize the probability of collisions of ship traffic with globally endangered right whales (Stokstad
2009). This action was based on the existence of an area, which was only infrequently visited by whales and thus offered a clear decrease in the probability for a
collision.
10.3 Components of the Technique and Properties of Test Areas
The technology contains four basic steps (Soomere et al. 2011a). The basis is a highresolution three-dimensional (3D) ocean circulation model. As a prerequisite, the
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and offshore activities by means of optimization of the location of potential release
of adverse impacts.
An important application is their use for optimizing fairways in domains (such as
the North Sea or Baltic Sea and especially the narrow and shallow Gulf of Finland)
that host extremely heavy ship traffic in the immediate neighbourhood of valuable
areas or sectors of the coast. In this context, the formulated problem is equivalent
to the task of minimizing the environmental damage for a moving source of danger.
It can be naturally associated with the classical problem of smart ship routing once
the distribution of the underlying quantities is known. For example, an approximate
solution for the environmentally safest sailing line is to route the ships along the
minima of these probabilities (Andrejev et al. 2011).
Alternatively, one can benefit from a choice of the sailing line for a (chemical)
tanker that provides a systematic increase in the time it takes before the adverse impact reaches a vulnerable area (Engqvist and Andrejev 2003; Engqvist et al. 2006).
The use of the maxima for the particle age (Andrejev et al. 2011) for this purpose
is equivalent to buying extra time to combat the leak while the spill travels to the
coast.
For elongated sea areas (such as the Gulf of Finland), it might also rational to
search for the equiprobability line, such that for each of its points it is equally probable that the spill reaches one coastline or the opposite one during a certain time
interval (Soomere et al. 2010). A further challenge (addressed only partially below)
is to minimize the cost of damage so that the additional economic costs would remain manageable.
The goal of this technique is not to produce yet another operational model to
assist rescue and oil combating teams after an accident has happened. Instead the
goal is to identify beforehand the regions where it is statistically safer to travel. The
target is thus the preventive reduction of environmental risks: an optimization of
the location of potentially dangerous activities (e.g., ship traffic) so that the consequences of the resulting unfortunate event (here in terms of the impact of substances
potentially released into the sea and transported by currents) upon high-cost areas
would be minimal once it indeed occurred (cf. Eide et al. 2007).
A precondition for the use of such a way of thinking is the heterogeneity of the
relevant physical or ecological fields (such as the resulting maps of the probabilities
of coastal hit or the particle age). A recent solution of this kind is the relocation of
the fairway entering Boston Harbour (Massachusetts, USA) to minimize the probability of collisions of ship traffic with globally endangered right whales (Stokstad
2009). This action was based on the existence of an area, which was only infrequently visited by whales and thus offered a clear decrease in the probability for a
collision.
10.3 Components of the Technique and Properties of Test Areas
The technology contains four basic steps (Soomere et al. 2011a). The basis is a highresolution three-dimensional (3D) ocean circulation model. As a prerequisite, the