A model was formulated to estimate tree component weight by geometrically describing the tree with basic tree parameters such as diameter, height, crown width, and crown length and the shape equations that relate them. The stem is divided into three sections with shape equations to describe the wood and bark in each section. The crown is divided into three sections with three equations. The main branch stems are described in three sections by six equations as in the stem. The shapes and their defining parameters provide a volume estimate for the tree components. The density of the wood and bark in each section of the stem and branches is estimated as a random variable. The density of the crown is defined by estimates of interwhorl distances and numbers of branches per whorl, both of which are random variables. The length of the branches also Influences the density of the crown because the weight of the needles and branchlets is a function of branch length. The density and volume of the components combine to give estimates of the weight of the components. In addition to this indirect calculation of tree component weight, the model calculates-the weight of individual tree components with equations having specific tree parameters as independent variables. The estimates of weight are used to calculate the quantity of slash per tree and the center of mass of each major tree component. The weights of the stump and the unmerchantable top are also calculated in conjunction with the slash calculations. The weights and centers of mass are produced in tabular form. The accuracy of the model is limited by the accuracy of the input data. The model was verified for Douglas-fir, western hemlock, and western redcedar. The verification procedure included manual calculations and comparison with other estimates of weight. The model in its present form can aid in understanding the quantitative effects on the tree of variation in the parameters which describe the tree. Because the weight and volume of the tree components influence their combustibility, the model can aid in describing the tree component of the forest fuel complex. New data and further analyses would be needed to determine the full potential and practical utility of the model described herein. / Forestry, Faculty of / Graduate

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Forest Park, a 5,000 acre heavily-forested park within the city limits of Portland, Oregon was selected as the study area for performing a fire simulation analysis. A well-documented fire swept over a large area of the park in 1951, and provides both direct inputs, including the ignition point, and context for the present day fire simulations. The goal of the research was two fold. First, determine the difference between small area simulations using standard and custom surface fuel models. Second, determine if fire simulation can be an effective tool in assessing fire danger and behavior in a wildland-urban interface environment like Forest Park.

Radio propagation in the presence of fire is known to be problematic to communications. In this thesis we use both experimental and theoretical approaches to examine and understand radio propagation in fire environments. Propagation is examined for three small scale fires with broadband equipment operating from 50MHz to 1GHz. Results for line of sight propagation show a strong interaction of fire with electromagnetic propagation. The next section develops electromagnetic modelling of the fire environment. A model of the combustion induced plasma is developed, as well as a refractive index model of the surrounding atmosphere of a fire. Simple propagation calculations are undertaken, using the developed fire models, to provide an intial understanding of propagation in fire environments. The next portion of the thesis considers propagation using a more rigorous electromagnetic simulation technique. A modified Finite Difference Time Domain method is presented and is utilised to examine three dimensional propagation in the small scale fire experiments. The outcome is a more solid understanding of propagation and the contributing factors. The last portion of the thesis is the application of the above electromagnetic modelling and simulation methods to bushfire scenarios. Various scenarios that are problematic to radio communication are examined. Discussion and recommendations are made concerning radio communication frequency selection and considerations for propagation in fire environments. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1457560 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2009

Radio propagation in the presence of fire is known to be problematic to communications. In this thesis we use both experimental and theoretical approaches to examine and understand radio propagation in fire environments. Propagation is examined for three small scale fires with broadband equipment operating from 50MHz to 1GHz. Results for line of sight propagation show a strong interaction of fire with electromagnetic propagation. The next section develops electromagnetic modelling of the fire environment. A model of the combustion induced plasma is developed, as well as a refractive index model of the surrounding atmosphere of a fire. Simple propagation calculations are undertaken, using the developed fire models, to provide an intial understanding of propagation in fire environments. The next portion of the thesis considers propagation using a more rigorous electromagnetic simulation technique. A modified Finite Difference Time Domain method is presented and is utilised to examine three dimensional propagation in the small scale fire experiments. The outcome is a more solid understanding of propagation and the contributing factors. The last portion of the thesis is the application of the above electromagnetic modelling and simulation methods to bushfire scenarios. Various scenarios that are problematic to radio communication are examined. Discussion and recommendations are made concerning radio communication frequency selection and considerations for propagation in fire environments. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1457560 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2009

The purpose of this study has been to test public perceptions of both scenic quality and recreational acceptability of southwestern ponderosa pine forests exibiting one-to-five years of recovery from both light and severe fire. Public fire-effects information documents were also constructed and tested. Appropriate ponderosa forest areas in Arizona were selected and randomly photographed. Population samples, drawn from Tucson, Arizona, first read fire-ecology or "control" information brochures and then rated forest scenes on 1-to-10 scales for scenic quality and for acceptability for selected forms of outdoor recreation. Respondents finally answered a short fire-knowledge, fire-attitude questionnaire. Ratings were subjected to SBE analysis (Daniel and Boster, 1976), and analysis of variance was applied to both ratings and questionnaire results. The clearest distinction drawn, for both scenic quality and recreational acceptability, is between light-fire and severe-fire effects. Light fire improves scenic quality for a 3-to-4 year period, while severe fire seriously detracts from scenic quality for an unknown length of time exceeding the 5-year period tested. Recreational acceptability is differentiated according to the recreational activity selected: camping is nearly twice as sensitive to severe fire effects as scenic quality, and is somewhat disrupted by light fire effects; picnicking is second-most impacted by severe fire effects; hiking or backpacking is affected by severe fire to about the same degree as scenic quality; nature study is least affected. Picnicking, hiking and nature study are not significantly affected by light fire. Provision of fire-effects information does not significantly affect scenic or recreational evaluation of forest burn areas. The fire-effects information brochures produced general "halo" effects on both fire knowledge and fire attitude in the groups sampled. Fire knowledge shifted toward the expert position that fire effects are less severe than generally believed. Fire attitude shifted toward the expert position of greater tolerance for fire in ponderosa ecosystems. Results show prescribed burning as generally acceptable. The results of this study demonstrate distinctions between affect (perceptual evaluations) and cognition (questionnaire response). Scenic and recreational evaluations emerge as clearly distinct entities.

Fire is a major disturbance force that affects global ecosystems and associated biomes and plays a pivotal role in the determination of ecosystem structure, functionality and dynamics. Anthropogenic environmental disturbances have resulted in shifts in fire regimes and the biogeochemical processes of these ecosystems are thus unable to function as they have done in the past, impacting both floral and faunal species. Therefore there is a need for anthropogenic management. Prescribed burning is one of the few beneficial fire management options available to decrease the severity of wildfires, decrease the associated costs in suppressing these fires and restore fire-dominated ecosystems. The uKhahlamba Drakensberg Park World Heritage Site (UDP-WHS) is predominantly managed for water resource and nature conservation, and fire hazard reduction. It is divided into management compartments in which prescribed management burns are conducted, (i.e. manager’s burn by compartment). These compartments are subdivided by three altitudinal belts (alpine, sub-alpine and montane). Each of these belts contains different vegetation communities and therefore requires different fire regimes. However these compartments do not coincide with the natural contours and consequently, the altitudinal belts of the Park. This is problematic for management as a certain percentage per altitudinal belt is required to be burnt annually. When burning a compartment that falls within two or more belts, the total area of that compartment needs to be sub-divided into its respective altitudinal belts as a whole compartment can be prescribed to burn not a sub-division thereof. A fire management environmental decision support system (EDSS) was developed to achieve prescribed burning objectives in the UDP-WHS. The system is based on ecologically ideal fire regimes and fire management objectives of the heritage site, using GIS and associated graphs to visually display the required fire regimes. The EDSS data preparation, statistical analysis and modelling was completed using ESRI ArcGIS suite (ArcMap, Scene and Catalog). Its main components are two models, an excel spreadsheet and an ArcMap document. The spreadsheet contains the historical burning data of the management compartments based on the compartment codes, with each compartment being not burnt or having a burning treatment. Years Since Last Burnt (YSLB) was calculated from these data and joined to the management compartments in the ArcMap document. The Intermediate output model was developed to create numerous temporary outputs allowing decision makers to decide which compartments to treat with prescribed burning by re-running the model with required alterations. The second model (Final Output model) is then run to export the selected burning treatment in table format to update the original historical data, and consequently YSLB, in the excel and ArcMap document. The ArcMap document contains the user interface housing the graphs for each altitudinal belt showing the percentage area selected to be burnt per YSLB compared to the minimal, maximum and ideal fire regimes. The fire management EDSS for the UDP-WHS consists of an ArcMap document, geodatabase, excel document and folders, which are all housed in one single folder. The use of GIS and EDSSs in environmental management improves the efficiency and accuracy of the decision making process and provides the ability to validate outputs. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Motivados pela urgente necessidade de apoiar os estudos de estratégias, controle e combate a incêndios, principalmente em reservas florestais, desenvolvemos uma ferramenta computacional para auxiliar nessa tarefa. O nosso principal objetivo nesse trabalho foi elaborar um software, e realizar um primeiro estudo de caso, de simulação de incêndios na REBIO do Lago Piratuba AP. O trabalho foi desenvolvido em três etapas: primeiro, criamos um modelo lógico e matemático baseado na dinâmica de reações e na termodinâmica da combustão de uma árvore; segundo, implementamos um programa computacional em linguagem utilizada pelos profissionais da área de computação para torná-lo mais acessível ou portável; terceiro, realizamos um teste com imagens reais de satélite obtidas da REBIO do Lago Piratuba. Obtivemos imagens de incêndios simulados em florestas virtuais que demonstraram um alto grau de realismo ou semelhança com o que é observado em imagens reais. Também aplicamos o software em imagens reais da REBIO obtidas de satélite. Realizamos testes de propagação de incêndios nessas imagens sob a introdução de obstáculos naturais e artificiais para o fogo. Os resultados das imagens dinâmicas demonstram o efeito qualitativo esperado, mas a delimitação geométrica das áreas atingidas fica mais evidente com a observação precisa em escala no mapa, da extensão do fogo, e suas conseqüências, permitindo que parâmetros espaciais e temporais, úteis ao serviço de combate a incêndios, sejam medidos na simulação. / Motivated by urgent necessity to support the studies of strategies, controlling and combat to big fires, mainly in forest reserves, we develop a computational tool for assistance in this task. Our main goal in this work was to elaborate software, and to develop a first case study, that is fire simulation in the REBIO of the Lake Piratuba AP. We reached this goal in three stages: first, we created a logical and mathematical model about tree combustion dynamics of reactions and the thermodynamics; second, we implement a computational program in a professional language for becomes it accessible or portable; third, we carry through a test with actual images of satellite of the REBIO of the Piratuba Lake. We got fire images simulated in virtual forests that demonstrated a high degree of realism or similarity that it is observed in real images. We also applied this software in satellite images of REBIO. The results of the dynamic images demonstrate the expected qualitative effect, but the geometric delimitation of the reached areas is more evident with the precise fire extension visualization, in the map scale, and its consequences, allowing that space and time, useful parameters to the fireman service, are measured in the simulation.

Made available in DSpace on 2017-06-01T18:20:25Z (GMT). No. of bitstreams: 1 Dinaldo Silva Jr_ diss.pdf: 2263144 bytes, checksum: 4d00c56f72c32488fe5f7002dd8d8335 (MD5) Previous issue date: 2007-07-27 / Motivated by urgent necessity to support the studies of strategies, controlling and combat to big fires, mainly in forest reserves, we develop a computational tool for assistance in this task. Our main goal in this work was to elaborate software, and to develop a first case study, that is fire simulation in the REBIO of the Lake Piratuba AP. We reached this goal in three stages: first, we created a logical and mathematical model about tree combustion dynamics of reactions and the thermodynamics; second, we implement a computational program in a professional language for becomes it accessible or portable; third, we carry through a test with actual images of satellite of the REBIO of the Piratuba Lake. We got fire images simulated in virtual forests that demonstrated a high degree of realism or similarity that it is observed in real images. We also applied this software in satellite images of REBIO. The results of the dynamic images demonstrate the expected qualitative effect, but the geometric delimitation of the reached areas is more evident with the precise fire extension visualization, in the map scale, and its consequences, allowing that space and time, useful parameters to the fireman service, are measured in the simulation. / Motivados pela urgente necessidade de apoiar os estudos de estratégias, controle e combate a incêndios, principalmente em reservas florestais, desenvolvemos uma ferramenta computacional para auxiliar nessa tarefa. O nosso principal objetivo nesse trabalho foi elaborar um software, e realizar um primeiro estudo de caso, de simulação de incêndios na REBIO do Lago Piratuba AP. O trabalho foi desenvolvido em três etapas: primeiro, criamos um modelo lógico e matemático baseado na dinâmica de reações e na termodinâmica da combustão de uma árvore; segundo, implementamos um programa computacional em linguagem utilizada pelos profissionais da área de computação para torná-lo mais acessível ou portável; terceiro, realizamos um teste com imagens reais de satélite obtidas da REBIO do Lago Piratuba. Obtivemos imagens de incêndios simulados em florestas virtuais que demonstraram um alto grau de realismo ou semelhança com o que é observado em imagens reais. Também aplicamos o software em imagens reais da REBIO obtidas de satélite. Realizamos testes de propagação de incêndios nessas imagens sob a introdução de obstáculos naturais e artificiais para o fogo. Os resultados das imagens dinâmicas demonstram o efeito qualitativo esperado, mas a delimitação geométrica das áreas atingidas fica mais evidente com a observação precisa em escala no mapa, da extensão do fogo, e suas conseqüências, permitindo que parâmetros espaciais e temporais, úteis ao serviço de combate a incêndios, sejam medidos na simulação.