Development and evaluation of a novel 3D simulation software for modelling wood stacks.

Felipe De Miguel-Díez,Tim Pettenkofer,Thomas Purfürst,Eduardo Tolosana-Esteban,Philippe Guigue,Tobias Cremer,Frank H Koch

doi:10.1371/journal.pone.0264414

Abstract

Assessing the solid wood content is crucial when acquiring stacked roundwood. A frequently used method for this is to multiply determined conversion factors by the measured gross volume. However, the conversion factors are influenced by several log and stack parameters. Although these parameters have been identified and studied, their individual influence has not yet been analyzed using a broad statistical basis. This is due to the considerable financial resources that the data collection entails. To overcome this shortcoming, a 3D-simulation model was developed. It generates virtual wood stacks of randomized composition based on one individual data set of logs, which may be real or defined by the user. In this study, the development and evaluation of the simulation model are presented. The model was evaluated by conducting a sensitivity and a quantitative analysis of the simulation outcomes based on real measurements of 405 logs of Norway spruce and 20 stacks constituted with these. The results of the simulation outcomes revealed a small overestimation of the net volume of real stacks: by 1.2% for net volume over bark and by 3.2% for net volume under bark. Furthermore, according to the calculated mean bias error (MBE), the model underestimates the gross volume by 0.02%. In addition, the results of the sensitivity analysis confirmed the capability of the model to adequately consider variations in the input parameters and to provide reliable outcomes.

Highlights

IntroductionIndustrial wood is generally commercialized in stacks. Concerning this process there are three important reference values: gross volume of the wood stack, solid wood content (or net volume) and the conversion factors that relate to each other.To determine the gross volume of the stack, several methods have been developed over time
The second objective of this study was to evaluate the developed simulation model by means of 1) a quantitative analysis of the model results comparing these with real measurements of wood stacks and 2) a sensitivity analysis conducted by modifying the lengths of the logs and comparing the resulting conversion factors with others gleaned from the literature
The approach of using a simulation model makes it possible to obtain large databases that allow the investigation of the current research issues in this research field on a sufficient statistical basis

Summary

Introduction

Industrial wood is generally commercialized in stacks. Concerning this process there are three important reference values: gross volume of the wood stack, solid wood content (or net volume) and the conversion factors that relate to each other.To determine the gross volume of the stack, several methods have been developed over time. Industrial wood is generally commercialized in stacks. Concerning this process there are three important reference values: gross volume of the wood stack, solid wood content (or net volume) and the conversion factors that relate to each other. To determine the gross volume of the stack, several methods have been developed over time. The most common of these is the sectional volumetric measurement method.

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