Calculation of average skidding distance on sloping terrain with GIS tools

Abstract

To determine skidding productivity and costs for skidding operation, it is necessary to estimate real skidding route and to calculate average skidding distance. This study was intended to expose how the real average skidding distance was to be calculated and which operation process was to be followed up for harvesting units/blocks having irregular shapes as three dimensions. Compartments, harvesting stands, were divided into sub-compartment polygons called harvesting blocks with respect to transport borders determined according to road location, stream flow, and topographic structure of mountainous terrain. To calculate average skidding distance based on surface length between the most suitable existing road segments and centroids of the polygons, a selective process was followed. In this study, vector and raster Geographic Information System (GIS) tools were used. To compare with other approaches and evaluate of the calculus algorithm, various skidding distance determination strategy were improved and applied on the same test area. In this study, spatial analyses have been made for 17 compartments selected from Pamucak Forest Planning Unit of Isparta Forest Region, in Southern of Turkey. According to the results the mean difference between real average skidding distance (ASDR) and shortest average skidding distance (ASDS) was found amount 24 meters for the test area. It has been considered that the ASDR amount calculated in this study is too close to real skidding distance used for harvesting operations. Keywords: Average skidding distance, Transport boundary, GIS, ArcHydro tool