Harvesting and transport accounts for up to 70% of the total production cost of roundwood in South Africa. This invokes an interest to improve harvesting systems through the introduction of improved equipment, road networks and more refined operating techniques. A literature review was conducted which investigated the various harvesting systems and equipment with a focus on ground based extraction, as it accounts for 96% of the timber being extracted annually in South Africa. A review of forest roads in South Africa was also conducted and it was concluded that at present there has been little focus on the upgrading and maintenance of forest road networks. It was concluded that the most significant reduction in transport costs would be achieved by reducing the distances travelled by expensive extended pnmary transport (R5.83 t-1.km-1) and by allowing less expensive secondary terminal transport (R0.4 t-1.km-1) to move further into the plantations. This could only be achieved by investing large amounts of capital into the upgrading of forest roads to a standard suitable to service secondary transport vehicles. A model was developed which was able to determine the tonnage of timber needed to flow over a particular road that will warrant the upgrading cost. The model was applied to two study areas, the first study yielded no results due to the already dense network of B- class roads, possibly excessive. The second study area identified three possible road upgrades to improve the existing transport system. A full costing of the existing and modified transport system was completed and a significant cost saving was shown, not accounting for the road upgrading cost. Capital budgets were used to account for more complex parameters, such as tax and discount rates, previously excluded from the simple model. These were used to determine the economic viability of the upgrades and to evaluate the suitability of the model. The model proved to be successful and confirmed that forest roads can be optimised accompanied by significant cost savings. The model is generic and simple allowing for easy application to a variety of situations and is also flexible to modifications. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.

River stage or flow rates are required for the design and evaluation of hydraulic structures. Most river reaches are ungauged and a methodology is needed to estimate the stages, or rates of flow, at specific locations in streams where no measurements are available. Flood routing techniques are utilised to estimate the stages, or rates of flow, in order to predict flood wave propagation along river reaches. Models can be developed for gauged catchments and their parameters related to physical characteristics such as slope, reach width, reach length so that the approach can be applied to ungauged catchments in the region. The objective of this study is to assess Muskingum-based methods for flow routing ill ungauged river reaches, both with and without lateral inflows. Using observed data, the model parameters were calibrated to assess performance of the Muskingum flood routing procedures and the Muskingum-Cunge method was then assessed using catchment derived parameters for use in ungauged river reaches. The Muskingum parameters were derived from empirically estimated variables and variables estimated from assumed river cross-sections within the selected river reaches used. Three sub-catchments in the Thukela catchment in KwaZulu-Natal, South Africa were selected for analyses, with river lengths of 4, 21 and 54 km. The slopes of the river reaches and reach lengths were derived from a digital elevation model. Manning roughness coefficients were estimated from field observations. Flow variables such as velocity, hydraulic radius, wetted perimeters, flow depth and top flow width were determined from empirical equations and cross-sections of the selected rivers. Lateral inflows to long river reaches were estimated from the Saint-Venant equation. Observed events were extracted for each sub-catchment to assess the Muskingum-Cunge parameter estimation method and Three-parameter Muskingum method. The extracted events were further analysed using empirically estimated flow variables. The performances of the methods were evaluated by comparing both graphically and statistically the simulated and observed hydrographs. Sensitivity analyses were undertaken using three selected events and a 50% variation in selected input variables was used to identify sensitive variablesThe performance of the calibrated Muskingum-Cunge flood routing method using observed hydrographs displayed acceptable results. Therefore, the Muskingum-Cunge flood routing method was applied in ungauged catchments, with variables estimated empirically. The results obtained shows that the computed outflow hydrographs generated using the Muskingum-Cunge method, with the empirically estimated variables and variables estimated from cross-sections of the selected rivers resulted in reasonably accurate computed outflow hydrographs with respect to peak discharge, timing of peak flow and volume. From this study, it is concluded that the Muskingum-Cunge method can be applied to route floods in ungauged catchments in the Thukela catchment and it is postulated that the method can be used to route floods in other ungauged rivers in South Africa. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.

Thesis (M.S.)--California Polytechnic State University, 2010. / Title from PDF title page; viewed on April 22, 2010. Major professor: Brian C. Ditterick, Ph.D., P.H. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Forestry Sciences." "March 2010." Includes bibliographical references (p. 101-109).

Made available in DSpace on 2014-06-11T19:31:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-11Bitstream added on 2014-06-13T20:02:30Z : No. of bitstreams: 1 marcelino_fa_dr_botfca.pdf: 1108555 bytes, checksum: 954f5bc6b7506cad69a496a783189e2d (MD5) / A rede viária é fundamental para o desenvolvimento das atividades florestais. As estradas florestais são importantes vias de acesso às florestas, servindo para viabilizar o tráfego de mão-de-obra e dos meios de produção necessários para implantação, proteção, colheita e transporte dos produtos florestais. A construção inapropriada e a manutenção inadequada das estradas são as principais causas da erosão, logo, os sedimentos das estradas florestais carreados para os cursos d’água representam impactos ambientais negativos aos recursos naturais. Desta forma, o objetivo desse trabalho foi avaliar diferentes sistemas de redes viárias florestais em função dos custos e do risco de erosão. Para a identificação das redes viárias e quantidade de camalhões no sistema de drenagem, utilizou-se o programa computacional SIG-GRASS. O camalhão pode ser um recurso de controle de erosão em estradas florestais, por isso foi estudado uma classificação de distância entre camalhões para manter o fator topográfico LS igual a 1. A aplicação do modelo teórico de distância entre camalhões desenvolvido neste trabalho possibilita dimensionar corretamente o número de camalhões necessários para controlar o risco de erosão em estradas florestais não pavimentadas. Foram estimados os custos anuais de estradas para diferentes sistemas de redes viárias florestais (Ortogonal 1, Ortogonal 2, Readequada 1, Readequada 2 e Nível). Os custos anuais de estradas são compostos pela depreciação, custos de manutenção, custos de oportunidade do capital e custos de oportunidade da terra. O principal custo de estrada da rede viária Ortogonal 1 e 2 foi a manutenção. Entretanto, nas redes viárias Readequada 1 e 2, e Nível o principal custo de estrada foi o custo de oportunidade de capital. Conseqüentemente, com um planejamento adequado da rede viária florestal,... / A roadway system is essential for forest activities development. Road forests are important access ways to the forest areas, being a useful tool to facilitate workers and vehicles traffic to implementation, protection, harvesting and transport of forest products. Roads inappropriate building and maintenance are the main causes of erosion; therefore, road forest sediments carried by water courses represent negative environmental impact to natural resources. Therefore, this study aimed to evaluate different roadway forest systems in function of costs and erosion risk. The software SIG-GRASS was used for road system identification and cross drains quantification in drainage system. Cross drains could be a resource used to control erosion in forest roads network. Thus, it was studied a classification of distances between cross drains to maintain a LS topographic factor equal 1. Theoretical model application for distance between cross drains may help correctly measurement of cross drain numbers necessary to control erosion risk in unpaved forest roads. Annual costs of roads in different roadway forest networks were estimated (Orthogonal 1, Orthogonal 2, Readequacy 1, Readequacy 2 and Level). Annual costs of roads are composed by depreciation, maintenance costs, capital opportunity costs and land opportunity costs. The main cost of Orthogonal roadway system 1 and 2 was the maintenance. Otherwise, in Readequacy 1 and 2, and Level roadway system the main road cost was with capital opportunity. Consequently, with an adequate forest roadway network planning the costs with maintenance could be reduced, roads life span could be increased and reduce negative impacts caused by roads, mainly erosion and sediments accumulation in rivers.

Resumo: A rede viária é fundamental para o desenvolvimento das atividades florestais. As estradas florestais são importantes vias de acesso às florestas, servindo para viabilizar o tráfego de mão-de-obra e dos meios de produção necessários para implantação, proteção, colheita e transporte dos produtos florestais. A construção inapropriada e a manutenção inadequada das estradas são as principais causas da erosão, logo, os sedimentos das estradas florestais carreados para os cursos d'água representam impactos ambientais negativos aos recursos naturais. Desta forma, o objetivo desse trabalho foi avaliar diferentes sistemas de redes viárias florestais em função dos custos e do risco de erosão. Para a identificação das redes viárias e quantidade de camalhões no sistema de drenagem, utilizou-se o programa computacional SIG-GRASS. O camalhão pode ser um recurso de controle de erosão em estradas florestais, por isso foi estudado uma classificação de distância entre camalhões para manter o fator topográfico LS igual a 1. A aplicação do modelo teórico de distância entre camalhões desenvolvido neste trabalho possibilita dimensionar corretamente o número de camalhões necessários para controlar o risco de erosão em estradas florestais não pavimentadas. Foram estimados os custos anuais de estradas para diferentes sistemas de redes viárias florestais (Ortogonal 1, Ortogonal 2, Readequada 1, Readequada 2 e Nível). Os custos anuais de estradas são compostos pela depreciação, custos de manutenção, custos de oportunidade do capital e custos de oportunidade da terra. O principal custo de estrada da rede viária Ortogonal 1 e 2 foi a manutenção. Entretanto, nas redes viárias Readequada 1 e 2, e Nível o principal custo de estrada foi o custo de oportunidade de capital. Conseqüentemente, com um planejamento adequado da rede viária florestal,...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: A roadway system is essential for forest activities development. Road forests are important access ways to the forest areas, being a useful tool to facilitate workers and vehicles traffic to implementation, protection, harvesting and transport of forest products. Roads inappropriate building and maintenance are the main causes of erosion; therefore, road forest sediments carried by water courses represent negative environmental impact to natural resources. Therefore, this study aimed to evaluate different roadway forest systems in function of costs and erosion risk. The software SIG-GRASS was used for road system identification and cross drains quantification in drainage system. Cross drains could be a resource used to control erosion in forest roads network. Thus, it was studied a classification of distances between cross drains to maintain a LS topographic factor equal 1. Theoretical model application for distance between cross drains may help correctly measurement of cross drain numbers necessary to control erosion risk in unpaved forest roads. Annual costs of roads in different roadway forest networks were estimated (Orthogonal 1, Orthogonal 2, Readequacy 1, Readequacy 2 and Level). Annual costs of roads are composed by depreciation, maintenance costs, capital opportunity costs and land opportunity costs. The main cost of Orthogonal roadway system 1 and 2 was the maintenance. Otherwise, in Readequacy 1 and 2, and Level roadway system the main road cost was with capital opportunity. Consequently, with an adequate forest roadway network planning the costs with maintenance could be reduced, roads life span could be increased and reduce negative impacts caused by roads, mainly erosion and sediments accumulation in rivers. / Orientador: Paulo Torres Fenner / Coorientador: Helmer Schack-Kirchner / Coorientador: Maura Seiko Tsutsui Esperancini / Banca: Carlos Cardoso Machado / Banca: Elias José Simon / Banca: Alessandro Antonangelo / Banca: Jair Rosas da Silva / Doutor

The diploma thesis is focused on evaluation and realization of the complex land amendments in south bohemia district. The theoretical part provides general information about the land amendments from the history to their goals following with description of the forest paths mainly their categories and requests on path network propositions. In the practical part there is described realization of the forest paths mainly their costs and how many kilometers had been carried out in the particular districts. The next part describes Tabor district. There are evaluated mainly technical parameters of the roads, start and finish of the build and if it had been new build or restoration. Finally there is financial comparison put into graphs.

Habitat fragmentation and destruction caused by development of infrastructure such as roads threaten biodiversity. Roads act as barriers by impeding animal movements and restricting space use. Understanding factors that influence barrier effects is important to discern the impacts of habitat fragmentation and to develop appropriate mitigations. We combined telemetry and demographic data in 2008 to 2012 with remote sensing imagery to investigate barrier effects of forest roads and assess effects of traffic, road edges, and canopy gaps on space use of an endangered, endemic forest obligate, the Mt. Graham red squirrel (Tamiasciurus hudsonicus grahamensis). We mapped low to high traffic roads, road edges, canopy gaps, and random lines in forests to serve as references. We determined if red squirrels included these linear features in their total and core home ranges, and used this metric as an indicator of crossing and preference for habitat adjacent to the linear features. Forest roads acted as barriers regardless of traffic volume and had long-term impacts on animal space use. Animals did not avoid entering roadside areas, and probability of crossing linear features in the forest was not affected by distance to roads. In contrast, greater canopy cover increased probability of crossing, and gaps in canopy impeded animal movements. Higher likelihood of road crossing was associated with more variable tree height and mating activity. We demonstrated that narrow forest roads with low traffic volume were barriers for forest dependent species, and suggest that gap avoidance inhibits road crossings. (C) 2016 Published by Elsevier Ltd.

Forest roads and stream crossings have the potential to be sources of sediment from forest operations. Recent litigation has renewed interest in furthering research related to forest road Best Management Practices (BMPs). Three legacy (100 year old) forest road stream crossings were monitored for suspended sediment for nine months before and six months after upgrading three unimproved ford crossings with one bridge, one culvert, and one improved ford. During construction, rainfall simulation was utilized to estimate the sediment contribution of each crossing with minimal BMPs (BMP-), BMPs equal to state recommendations (BMP), and BMPs beyond state recommendations (BMP+). Construction costs were recorded to quantify the change in cost with a change in BMP level. Three levels of rainfall simulation were used on each BMP treatment for each crossing resulting in 27 rainfall simulations. Water samples collected by an automatic sampler downstream of the crossings were analyzed for suspended sediment. Pre - and post- construction time periods were compared to assess how the improved crossings altered total suspended sediment concentrations downstream of the crossings. The number of stream crossings constructed per year in Virginia was also estimated using satellite imagery on 400 harvest tracts. Site visits were conducted on 240 harvest tracts where data were collected on the presence of crossings, the types of crossings, and the level of BMP implementation. Rainfall simulation experiments showed decreased sediment with increased BMP level and daily total suspended sediment concentrations measured over 15 months showed a decrease in mean daily sediment concentration after construction of the bridge and culvert crossings. There was no decrease in sediment concentration for the ford crossing. Statewide crossing construction and BMP implementation rates were estimated. Approximately 67% of the audited stream crossings were characterized as having BMPs that were equal to or beyond state recommendations. Increased BMPs and upgrading of stream crossings resulted in decreased total suspended sediment. However, increased BMP implementation also increased stream crossing construction costs. Effectiveness of increased levels of BMPs and the pre and post construction analysis suggests the improvement of a legacy stream crossing may reduce total suspended sediment concentrations. / Ph. D.

Forestry best management practices (BMPs) programs were developed by individual states in response to the Clean Water Act in order to protect water quality during and after timber harvests. Our research goals are to compare BMP implementation at stream crossings by region and road type in Virginia and to quantify effectiveness of BMPs by developing hypothetical upgrades and determining upgrade costs. Stream crossings (75 truck, 79 skidder) sampled for BMP implementation were on operational harvests conducted in 2016, from the Mountains, Piedmont, and Coastal Plain of Virginia. Erosion rates of stream crossing approaches were modeled using the Universal Soil Loss Equation modified for forest lands (USLE-Forest) and Water Erosion Prediction Project (WEPP) methodologies. Implementation ratings (BMP-, BMP-standard, BMP+) were developed to characterize crossings with respect to state implementation standards. Costs for upgrading crossings to a higher BMP category were estimated by adjusting cover percentages and approach lengths. Sixty-three percent of stream crossings were classified as BMP-standard, with an average erosion rate of 7.6 Mg/ha/yr; 25% of crossings were classified as BMP+, with an average erosion rate of 1.7 Mg/ha/yr; and 12% of crossings were classified as BMP-, with an average erosion rate of 26.2 Mg/ha/yr. Potential erosion rates decreased with increasing BMP implementation (p <0.0001). Average BMP implementation audit scores for stream crossings were 88% on skid trails and 82% on truck roads. To upgrade from a BMP- to BMP-standard, the cost-benefit ratio of dollars to tons of sediment prevented averaged $166.62/Mg for skid trails and $2274.22/Mg for truck roads. Enhancement to the BMP+ level is not economically efficient and BMP implementation at stream crossings reaches maximum efficiency at the BMP-standard level. / M. S.

Lastbilstransport är den vanligast förekommande transportmetoden för den svenskaskogssektorn. År 2015 transporterades drygt 60 miljoner skogsråvara med hjälp avlastbil. För att tillgängliga skogsråvaran ute i skogen krävs de så kalladeskogsbilvägarna. För att veta vilka skogsbilvägar som är körbara är navigations- ochtransportledningssystem innehållande geografisk information i form av vägdata enförutsättning. Syftet med denna studie var att undersöka vilka brister ochförbättringsmöjligheter virkestransportörerna såg med systemen.Studien genomfördes som en enkätundersökning med en kompletterandetelefonintervju. Studien innehöll 58 respondenter inklusive telefonintervjun och enmajoritet såg brister och förbättringsmöjligheter främst avseendehöjdvariationsinformation, vändmöjligheter och vägdatans trovärdighet.Slutsatserna var att det finns förbättringsmöjligheter i navigations- ochtransportledningssystemens effektivitet och trovärdighet. Trovärdigheten kanpotentiellt förbättras med hjälp av fjärranalys och således erhålla en mer löpandeuppdatering av vägdatan. En systemeffektivisering får i sin tur konsekvensen attskogssektorn besparar tid, förbättrar arbetsmiljön och sänker koldioxidutsläppen frånvirkestransporterna.