Otimização espacial do microplanejamento da colheita florestal

Abstract

The operational microplanning of forest harvesting, which encompasses the subdivision of forest stands into work strips and the strategic location of wood pile points, is frequently conducted empirically by forest companies, without the support of mathematical optimization models. This gap results in excessive machinery movement, higher operational costs, and avoidable environmental impacts. The incorporation of operational research techniques and grid-based spatial discretization into harvest planning allows this problem to be modeled as a capacitated location-allocation challenge, with the potential to significantly reduce extraction and machinery movement costs. In this context, the present study developed and evaluated a microplanning methodology based on the Capacitated p-Median Problem (CPMP), implemented through the Simulated Annealing (SA) metaheuristic and validated against Integer Linear Programming (PLI) in terms of solution quality and computational efficiency. The study was conducted in three forest stands located in the state of Mato Grosso do Sul, Brazil, with distinct levels of geometric uniformity, characterized by the Patton edge index, from which twelve experimental instances were constructed with different grid granularities. Results demonstrated that SA presented a significant computational advantage across all evaluated instances, with processing time reductions ranging from 50% to 90% compared to PLI. For smaller instances, SA achieved objective function values equivalent to or lower than those of PLI. In more complex instances, PLI tended to provide lower total cost solutions when convergence was reached; however, it failed to generate feasible solutions for three of the twelve instances, whereas SA produced solutions for all evaluated scenarios. It is concluded that SA represents a computationally efficient, scalable, and operationally robust alternative for forest harvest microplanning, being especially recommended for large-scale instances or situations where response time is a critical constraint. The results confirm the viability and competitiveness of metaheuristic approaches at this level of planning, contributing to the consolidation of scientific methodologies applied to the operational management of the Brazilian forest sector.