| Summary: The transportation of raw wood materials in forestry is carried out in two steps including wood extraction from stump to landings and main transportation from landings to main depots. During these operations average unit cost of transportation can be very high, but there are ways to reduce the cost involved and, of these, the optimization is the most efficient. In this study, a model was developed to provide a solution for the problem of transporting raw wood material on forest roads. This model aimed to minimize the cost of transportation of raw wood materials of various standards from the landings to the main depots in forest sections where production is done on a large scale. The model also aimed to include the designs of transportation networks. For this purpose, a modeling strategy that is compatible with technical, topographic and economic criteria was developed. During the optimization process, a spatial database was established by means of Geographical Information Systems (GIS). Simulated Annealing (SA) Algorithm and Network Analysis, which are among the meta-heuristic techniques and were used for the solution of the model. The database includes topography of the forest section, stand characteristics, sale price at the depot, labor costs, transportation cost and loading costs. By using these data, the models searches for the optimum route that will minimizes the transportation costs by considering the raw wood materials in various standards, number of landings and depots, and then finds the route with the highest net income by considering transportation costs and the sale price of the raw wood material at the depot. To present the capabilities of the model, an experimental design and analysis were made in the study. Multiple variance analysis were used in order to understand whether the factors at work during the experimental design were effective on the SA algorithm performance and Duncan multiple test was used in order to understand whether there is a significant difference among the levels taken of these factors. It was concluded that with the use of transportation model in the research area, 14,45 % of the total transportation cost can be saved. Through the use of GIS, Network Analysis, SA and Statistical methods during the transportation plans, a considerable amount of labor force, time, and cost were saved.
Key Words: Forest Roads, Wood Raw Material Transportation, Geographical Information Systems, Network Analysis, Simulated Annealing, Optimization |
