Modelling forest road trafficability with satellite-based soil moisture variables

Recent decades have seen increased temperatures and precipitation in the Nordic countries with long-term projections for reduced frost duration and depth. The consequence of these trends has been a gradual shift of delivery volumes to the frost-free season, requiring more agile management to exploit suitable weather conditions. Bearing capacity and trafficability are dependent on soil moisture state and in this context two satellite missions offer potenially useful information on soil moisture levels; NASA's SMAP (Soil Moisture Active Passive) and ESA's Sentinel-1. The goal of this pilot study was to quantify the performance of such satellite-based soil moisture variables for modeling forest road bearing capacity (e-module) during the frost-free season. The study was based on post-transport registrations of 103 forest road segments on the coastal and interior side of the Scandinavian mountain range. The analysis focused on roads of three types of surface deposits. Weekly SMAP soil moisture values better explained the variation in road e-module than soil water index (SWI) derived from Sentinel-1. Soil Water Index (SWI), however, reflected the weather conditions typical for operations on the respective surface deposit types. Regression analysis using (i) SMAP-based soil dryness index and (ii) its interaction with surface deposit types, together with (iii) the ratio between a combined SMAP_SWI dryness index and segment-specific depth to water (DTW) explained over 70% of the variation in road e-module. The results indicate a future potential to monitor road trafficability over large supply areas on a weekly level, given further refinement of study methods and variables for improved prediction

International benchmarking of electricity distribution utilities.

Benchmarking by means of applying the DEA model is appearing as an interesting alternative for regulators under the new regimes for electricity distributors. A sample of large electricity distribution utilities from Denmark, Finland, Norway, Sweden and the Netherlands for the year 1997 is studied by assuming a common production frontier for all countries. The peers supporting the benchmark frontier are from all countries. New indexes describing cross country connections between peers and their inefficient units are developed, as well as productivity measurements between units from different countries.Electricity utility; benchmarking; efficiency; DEA; Malmquist productivity index

The Transport Game - A Tool for Teaching the Basics of Transport Decision Proficiency

This paper presents the transport game; a pedagogical tool developed to provide a competition-driven introduction to important issues in transport planning. The competitive element of the game concerns minimizing transportaton. The game is played between three two-player teams. Each team has wood supply responsibility for a pulp mill and a saw mill. Given a varying weekly demand for each mill, the teams procure round wood from the 64 supply nodes in the region. The planning decisions in the game are aimed at minimizing the total transport distance (loaded + unloaded) for the weekly demand. Planning decisions have the following priority: 1) filling the mill demand, 2) minimizing the loaded transport distance by purchasing wood close to the mill 3) minimizing the unloaded transport distance by identifying backhauls flows. The game forces the players to manually handle a high number of decision alternatives without any form of decision support. It is used to give the students a practical understanding of basic issues to accompany their theoretical lessons. It can also be used as an experimental laboratory to examine the effect of different restrictions on proficiency. The paper presents results from student exercises where development of player proficiency is examined

Far out or alone in the crowd: Classification of selfevaluators in DEA

The units found strongly efficient in DEA studies on efficiency can be divided into self-evaluators and active peers, depending on whether the peers are referencing any inefficient units or not. The contribution of the paper starts with subdividing the selfevaluators into interior and exterior ones. The exterior self-evaluators are efficient “by default”; there is no firm evidence from observations for the classification. These units should therefore not been regarded as efficient, and be removed from the observations on efficiency scores when performing a two-stage analysis of explaining the distribution of the scores. A method for classifying self-evaluators based on the additive DEA model is developed. The application to municipal nursing- and home care services of Norway shows significant effects of removing exterior self-evaluators from the data when doing a two-stage analysis.Self-evaluator; interior and exterior self-evaluator; DEA; efficiency; referencing zone; nursing homes

Simulating Effects of Supply Chain Configuration on Industrial Dynamics in the Forest Sector

Two wood games are developed based on the structure and dynamics of the Beer Game. By introducing divergent and convergent flows in the supply chain, the relevance to the forest sector is increased. Using eight players in each run, the game is, in essence, a simulation tool that includes the human aspect in decision-making. The wood game is used to simulate the challenges that may be met when introducing a greater degree of customer orientation in the forest sector. Performance is measured using total system costs, amplification of demand variation and basic statistics of order rates. Results from pilot experiments indicate that performance and predictability of the system are negatively affected by increasing the complexity of the supply chain. The level of demand distortion varies considerably between different games. Distorted demand signals may complicate the planning and execution of upstream operations

Service Divergence In Swedish Round Wood Transport

Structural changes in the Swedish forest products sector have resulted in increased round wood consumption per mill. Increased consumption volumes result in increased round wood transport distances and transport output (m³·km). At the same time, the coordination of transport services is being taken over by transport organizations of increasing size. New technological developments combined with organizational innovations have made linking between transport service providers easier. This has lead to the opportunity to offer different services through networking and diversify service levels for different customers (service divergence). This study examines the service divergence potential of round wood transport in Sweden. The goal of the study is to develop a better understanding of customer demands and service complexity. This study is based on the interview results of 20 transport service providers and buyers in the Swedish forest sector. The results presented concern three main themes: transport service goals, decisions and decision support processes. The study reports the rankings of responses as well as their correlations in order to group them into a goal-decision-decision support hierarchy. The rankings and correlations are used to suggest a customer service matrix for round wood transport. The interview also included a fourth theme describing current problems with planning and control. The responses of this final theme are related to the different parts of the hierarchy in order to identify impediments to service divergence

Spatial Patterns of Round Wood Transport Associated with Mobile Data Systems in Sweden

The use of mobile data systems (MDS) in round wood transport is increasing. The most common functions for MDS include: distribution of transport plans and orders, navigation to the forest site (GPS, GIS) and reporting of transport volumes. This paper examines the transport patterns for trucks with and without the support of MDS in central Sweden. The variables are based on data from 13 trucks with MDS and 13 without MDS. All trucks were operating within the same planning organization however the selection of trucks to be equipped with MDS support was done independent of this study. Data was collected using a random sample of 5 days per month over one year of operations. While the number of operating days per month was similar for the two groups, other differences were observed. The daily number of separate forest destinations was 4.13 for trucks with MDS and 3.70 for those without. The daily number of separate mill destinations visited was 2.66 for trucks with MDS and 2.17 for those without. The size of the total annual operating area was 29,050 km2 for those with MDS and 18,656 km2 for those without. The main operating area constituted 35.3 % and 28.2 % of the total annual operating areas for trucks with and without MDS, respectively

The Economic Potential For Optimal Destination of Roundwood in North Sweden - Effects of Planning Horizon and Delivery Precision

This study quantifies the economic effect of optimizing roundwood destinations in North Sweden. The effect of planning horizon and delivery precision on costs and revenues are also quantified. The results show that the effect of optimizing roundwood destination varies with the specific application. When minimizing transport costs for a forest company, the transport output (t-km) was reduced by 8-9%. The reductions of transport costs in this case were often in the range of 4-5% (two-week planning horizons). Longer planning periods gave slightly greater cost reductions. Increased net revenues of roundwood sales by an independent forest owner organization were in the area of 1-4% (two-week planning horizons). In this case, however, transport output was often increased by the optimization. Reduced demands to delivery precision made it possible to achieve greater increases in net revenue. Shorter planning horizons had fewer active supply nodes. This situation requires greater spatial variation in procurement areas in order to fill the demand restrictions per period. Only 15-20% of the annual procurement volume per sawmill came from supply nodes where the mill acted as monopsonist

The economic potential of semi-automated tele-extraction of roundwood in Sweden

The mechanization of roundwood harvesting in Sweden has historically cut costs rapidly. However, machinery and work methods have conceptually stayed the same since the introduction of the single-grip harvester. Current trends indicate that the next major wave of development will be based on automation, and that teleoperation is a step in this direction. This study aims to evaluate the economic potential of semi-automated tele-extraction compared to standard forwarding within the Nordic CTL two-machine harvesting system. The initial scenario examined autonomous terrain transportation with teleoperation during loading and unloading. A Discrete Event Simulation was implemented in the AnyLogic software. Input data included 1100 Swedish harvest sites, with in total 1.6 million m(3) and extraction distances from 20 to 1500 m. Scenarios with different numbers of teleoperators for a fleet of ten forwarders were tested. The optimum number of operators was seven per ten forwarders, resulting in a potential extraction cost reduction of 7% compared to standard forwarding. Extraction distances further than 500 m enabled use of five or six teleoperators, resulting in potential cost reductions of up to 15%. The highest potential cost reductions were linked to increased time used for autonomous driving, increasing the teleoperator availability for other machines. The simulation model provides a framework for further evaluation of new scenarios of automation and teleoperation of forwarders

The online wood supply game

This paper describes the Wood Supply Game (WSG), a prize-winning e-learning tool that is freely available for players all over the world. The game effectively helps students and managers realize the challenges in managing demand and supply in wood supply chains, and gain insight into the types of measures required to make these divergent chains effective. The WSG is an adaptation of the Beer game, a popular didactic tool used to empirically demonstrate demand amplification in a simple and generic context. The supply chain modeled by the Beer game does not involve co-products, and thus is very different from the wood supply chain, which is divergent by nature. The WSG presented in this paper models a supply network with one point of divergence and demand for two products. This preserves the simplicity of the game but enables it to offer a base for supply network simulation in a large number of industrial sectors with divergent processes. We describe an online version of the WSG, discuss our experiences playing it with students and managers, and provide hints to the instructor