  Uncontrolled wildfires can lead to loss of life and property and destruction
of natural resources. At the same time, fire plays a vital role in restoring
ecological balance in many ecosystems. Fuel management, or treatment planning
by way of planned burning, is an important tool used in many countries where
fire is a major ecosystem process. In this paper, we propose an approach to
reduce the spatial connectivity of fuel hazards while still considering the
ecological fire requirements of the ecosystem. A mixed integer programming
(MIP) model is formulated in such a way that it breaks the connectivity of
high-risk regions as a means to reduce fuel hazards in the landscape. This
multi-period model tracks the age of each vegetation type and determines the
optimal time and locations to conduct fuel treatments. The minimum and maximum
Tolerable Fire Intervals (TFI), which define the ages at which certain
vegetation type can be treated for ecological reasons, are taken into account
by the model. Previous work has been limited to using single vegetation types
implemented within rectangular grids. In this paper, we significantly extend
previous work by modelling multiple vegetation types implemented within a
polygon-based network. Thereby a more realistic representation of the landscape
is achieved. An analysis of the proposed approach was conducted for a fuel
treatment area comprising 711 treatment units in the Barwon-Otway district of
Victoria, Australia. The solution of the proposed model can be obtained for
20-year fuel treatment planning within a reasonable computation time of eight
hours.
