Resumo (PT):
Abstract (EN):
Cost-effective strategic management of aerial forest fire suppression resources involves decisions about
fleet location, in order to efficiently match supply and demand. In this study, we explore the flexible design
of such a system, pooling the demand of several bases into a “zone”, and analyzing alternative partitions of
the territory into zones. Feasible partitions consider an upper limit on the distance between bases, and require
their adjacency, within the same zone. Then, we classify the feasible partitions according to a set of six criteria
and explore the non-dominated partitions. Finally, we select the preferred partition, with the support of several
experts, by applying the AHP method. The considered criteria evaluate, for each partition, the (c1) mean and
the (c2) value at risk of the number of unattended active fires, the (c3) helicopter idleness, and the (c4-6) Gini
index for each of the previous three criteria.
We apply this strategy to the island of Sardinia, where helicopters play a central role in the suppression
system, and compare the results with the current design, in which each base is autonomous (i.e., each zone
has only one base). Sardinia has eleven helipad operational bases, where the helicopters are allocated at the
beginning of the fire season, with the objective of fighting wildfires located in each base’s coverage area. We
used fire occurrence and helicopter flight data from 2006 to 2010, which revealed spatiotemporal
asymmetries in the forest fire patterns, along the island, and thus the existence of effective opportunities to
benefit from demand pooling. The AHP method was applied with Portuguese experts, and our results point
towards an improvement in the values related to unattended fires, as well as the Gini indexes, if the proposed
strategy of reorganizing the territory in larger zones (with more than one base) is applied.
We explore the results of our approach, and identify efficiency gains, potential fire management
implications, limitations, and opportunities for additional research. In the scope of the latter, as the optimal
value for helicopter idleness is naturally achieved with the current design (partition in zones with one base),
this criterion provides a key trade-off with the other five, that can be used, for instance, to examine a flexible
strategy for helicopter location-allocation along the years, with annual partition redefinitions, considering all
data available up to that point of decision.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
4