| dc.description.abstract | In tactical planning in hierarchical forest management, cut-blocks are selected
for maximizing revenue and road networks are allocated at minimal cost in order to
maximize profit. The selected cut-block set and requisite road-network, connecting the
cut-blocks, therefore have an interdependent relationship. The location of these two
elements in tactical planning must therefore be considered simultaneously in a tactical
harvest-scheduling model. This integration presents a major computational challenge,
especially with regard to the execution time required to find an optimal solution to the
tactical harvest-scheduling model.
The objective of this thesis isto explore the influence of different road location
heuristics, used within the tactical harvest scheduling model, upon the model’s
execution time and solution quality. We nested the three different types of roadlocation heuristics within the harvest-scheduling model in order to evaluate their
effectiveness by three criteria: execution time, road construction cost and objective
function value. In addition, after the tactical model was run, we executed and evaluated
the usefulness of a road network repair algorithm, designed to improve further the
solution of the road-network location generated by the tactical harvest-scheduling
model. The thre heuristics were evaluated on a real-world dataset, representing a
section of the Kenogami forest in Ontario, Canada. Our result show: i) that the Shortest
Path Origin Heuristic (SPOH) achieved the fastest execution time and lowest
construction cost when integrated within the tactical harvest-scheduling model; and ii)
that the road network repair algorithm successfully lowered the road network costs and
thereby increased the objective function value of all solutions generated using the
tactical planning model. These results are significant for two reasons: first, they
show that the choice of the road network heuristic used within a tactical planning
model can have a major influence on the model’s solution quality; and second, that the
use of a road repair algorithm, on the solution generated using a tactical model, is of
major economic value in forest management planning. | en_US |
