A heuristic algorithm for finding the most economical logs landing location (case study: Shiva Dareh district, Kojour watershed)

One of the new approaches in forest road network and skid trail planning is to find suitable terminals in the harvest units and after that planning a road network that optimally connects the terminals. The paper describes a methodology for finding the most economical landing location.
The methodology formulates each harvesting unit as a network problem. Each grid cell that identified as an individual entry node in the network, containing two attributes of the elevation and the timber volume. The exit points of the network are the landing nodes where are candidated based on the terrain slope by the planner. Each entry node were connected to the supposed landing nodes by a direct link. In the present research an economical place for landing location was defined as a point that makes the most volume of stock in access through the shortest distance and slope. The heuristic algorithm, then, calculated two parameters for each landing node: 1) the degree of attractivity as a function of the number of covered nodes, their volume of stock and their distance to the landing, and 2) the average slope of the links. The economical location for landing then was selected. The entire area of the compartment was supposed as the harvesting unit. In addition, the uphill and downhill skidding were included in the program.
The program was implemented for four candidate landing location in the compartment 423 of district 4 (Shiva dareh) in the educational and research forest of Tarbiat Modares University in the northern Iran. The results showed that the point “B” with an attractivity value of 5585.79 and an average slope of 10.41% was designated as the most economical point for landing the timbers.
The present code could be used as an appropriate tool to propose the economical places for landing location where are assumed as desirable terminals in forest road planning within cut blocks.