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Assessing biomass-fired gas turbine power plants: a techno-economic and environmental perspectiveIhiabe, Daniel 07 1900 (has links)
Fossil fuels continue to deplete with use as they are irreplaceable. In addition,
the environmental impact with the continuous use of these conventional fuels
has generated global concern due to the production of harmful emission gases.
An alternative source of energy has become inevitable. Technological
advancements in the area of biomass use for both aviation and power
generation are at different levels of development.
There is however the need for an integrated approach to assess gas turbine
engine behaviour in terms of performance, emission and economics when they
are running on biofuels. The current research work is concerned with finding
alternative fuel resources for use on stationary gas turbine engines for power
generation with the necessary identification of suitable biofuels using a multidisciplinary
approach.
A techno-economic, environmental and risk assessment (TERA) model
comprising the performance, emissions, economics and risk modules has been
developed. There had been several simulations of two gas turbine engines
(GTEs) to ascertain the effects of both ambient and operating conditions and
the effect of fuel types on the engines. These simulations were done with the
use of an in-house code-the Turbomatch and a code developed for the steam
cycle which is employed for the combined cycle simulation. Cont/d.
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Risk analysis of performance measure forecasts in road safety engineeringMilligan, Craig Alexander January 2014 (has links)
This research contributes to improved risk analysis of performance measure forecasts in road safety engineering by designing and applying a method to characterize uncertainty associated with forecast input data in cases where input uncertainty is not known. The research applies this method to quantify uncertainty in three categories of inputs used in risk analysis of performance measure forecasts in road safety engineering: (1) estimates of pedestrian exposure to collision risk; (2) estimates of vehicular exposure to collision risk; and (3) estimates of engineering economics parameters that assign valuations to mortality risk reductions based on individual willingness to pay. The common methods used in each of these categories are repeated comparisons of input ground truth to input estimations, the use of simulation approaches (e.g. the simulation of short-term counts by sampling permanent count data), and the use of non-parametric techniques to characterize input uncertainty. Some highlights of quantified input uncertainty levels include: (1) when obtaining pedestrian risk exposure estimates at a site in Winnipeg, MB by expanding two-hour short-term counts using the National Bicycle and Pedestrian Documentation Project method, 90% of errors are between 62% and 170%; (2) when obtaining estimates of vehicle exposure to collision risk by expanding two 48-hour counts using the individual permanent counter method for Manitoba highways, 92 % of errors are between 9.5% and 10.8%; and (3) when applying an income-disaggregated transfer function to estimate value of a statistical life for road safety in developing countries, 90% of errors are between 53% and 54%. The results provide further detail on the structure of these input uncertainties. Analytic and computational capabilities in forecasting and risk analysis have advanced beyond our understanding of corresponding input uncertainty levels; this research closes some of this gap and enables better risk analysis of performance measure forecasts in road safety engineering.
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Att systematiskt hantera kunskap vid planering av ny infrastruktur : En fallstudie om skyfallsskador på riksväg 90 i Kramfors kommunThom, Nina January 2014 (has links)
Natural disasters are becoming more common due to climate change and it is important to adapt the society and its infrastructure to withstand events such as extreme rainfall. Precipitation is an important climatic factor affecting the transport and annually generates the cost of millions in damages, over the past 40 years heavy rain has increased and will continue to increase in the future. The extreme rainfall that occurred in Kramfors municipality in September 2013 led to flooding and destroyed several roads, including highway 90, which recently both had been rebuilt and given a new stretch of road. Extreme rainfall had also occurred in the municipality earlier. The aim of the thesis was to examine how the Swedish Transport Administration handles new knowledge gained after natural disasters and how this is used in the planning of new roads. From the aim of the study a case study was used as a method. Information was sought from reports, official documents and government investigations in order to see how the Swedish Transport Administration’s work looks like and to find studies about the incident on highway 90. There were also conducted interviews with informants within the Swedish Transport Administration to find out how the planning and investigation of roads looks like, and to get information about the work of national highway 90. Within the Swedish Transport Administration lessons are learned from natural disasters and events in the past, but learning is mainly individual - based and internally. There is no system in the Swedish Transport Administration to manage new information or collect past experiences. New knowledge and new conditions are used in the investigation and planning of roads, but depends on which people work with those. The planning of highway 90 follows the regulations and plans to be followed, but with additional information on past events and climate adaptation in those, the damages caused by the extreme rain on highway 90 could perhaps have been avoided. / Naturolyckor blir allt vanligare i samband med klimatförändringar och det är viktigt att anpassa samhället och dess infrastruktur för att motstå händelser som exempelvis skyfall. Nederbörd är en viktig klimatfaktor som påverkar transportsystemet och som årligen genererar i miljonbelopp i form av skador. Under de senaste 40 åren har andelen skyfall ökat och det kommer att öka mer i framtiden. Skyfallet som drabbade Kramfors kommun i september 2013 medförde översvämningar och flera förstörda vägar. Bland annat skadades riksväg 90 som nyligen både byggts om och fått en ny vägsträcka. Skyfall har också tidigare inträffat i kommunen. Syftet med examensarbetet var att undersöka hur man på Trafikverket hanterar ny kunskap som man fått efter att naturolyckor inträffat och hur man använder denna vid planering av nya vägar. Utifrån syftet valdes fallstudien som metod. Information söktes från rapporter, myndighetsdokument och statliga utredningar för att kunna se hur Trafikverkets arbete ser ut och för att hitta utredningar runt händelsen på riksväg 90. Vidare utfördes intervjuer med informanter inom Trafikverket för att ta reda på hur arbetet med planering och utredning av vägar ser ut, samt för att få information runt arbetet med riksväg 90. Inom Trafikverket dras lärdom av naturolyckor och tidigare händelser, men lärandet är främst personbaserat och internt. Det finns inget system inom Trafikverket för att hantera ny kunskap eller samla in tidigare erfarenheter. Ny kunskap och nya förutsättningar används vid utredning och planering av vägar, men det påverkas av vilka personer som genomför dessa. Planeringen av riksväg 90 gjordes i enighet med de regelverk och planer som ska följas, men med ytterligare information om tidigare händelser och klimatanpassning i dessa hade kanske de skadorna som uppkom vid skyfallet på riksväg 90 kunnat undvikas.
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Estimation Of Expected Monetary Values Of Selected Turkish Oil Fields Using Two Different Risk Assessment MethodsKaya, Egemen Tangut 01 January 2004 (has links) (PDF)
Most investments in the oil and gas industry involve considerable risk with a wide range of potential outcomes for a particular project. However, many economic evaluations are based on the &ldquo / most likely&rdquo / results of variables that could be expected without sufficient consideration given to other possible outcomes and it is well known that initial estimates of all these variables have uncertainty. The data is usually obtained during drilling of the initial oil well and the sources are geophysical (seismic surveys) for formation depths and areal extent of the reservoir trap, well logs for formation tops and bottoms, formation porosity, water saturation and possible permeable strata, core analysis for porosity and saturation data and DST (Drill-Stem Test) for possible oil production rates and samples for PVT (Pressure Volume Temperature) analysis to obtain FVF (Formation Volume Factor) and others. The question is how certain are the values of these variables and what is the probability of these values to occur in the reservoir to evaluate the possible risks. One of the most highly appreciable applications of the risk assessment is the estimation of volumetric reserves of hydrocarbon reservoirs. Monte Carlo and moment technique consider entire ranges of the variables of Original Oil in Place (OOIP) formula rather than deterministic figures. In the present work, predictions were made about how statistical distribution and descriptive statistics of porosity, thickness, area, water saturation, recovery factor, and oil formation volume factor affect the simulated OOIP values. The current work presents the case of two different oil fields in Turkey. It was found that both techniques produce similar results for 95%. The difference between estimated values increases as the percentages decrease from 50% and 5% probability.
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Assessment Of Low Temperature Geothermal ResourcesArkan, Serkan 01 January 2003 (has links) (PDF)
One of the most applicable methods of low-temperature geothermal resource
assessment is volumetric method. While applying volumetric method, the values
of uncertain parameters should be determined. An add-in software program to
Microsoft EXCEL, @RISK, is used as a tool to define the uncertainties of the
parameters in volumetric equation. In this study, Monte Carlo simulation
technique is used as the probabilistic approach for the assessment of lowtemperature
Balç / ova-Narlidere geothermal field.
Although Balç / ova-Narlidere geothermal field is being utilized for several direct
heat applications, there exists limited data for resource assessment calculations.
Assessment studies using triangular and uniform distribution type functions for
each parameter gave the mean values of recoverable heat energy of the field as
25.1 MWt and 27.6 MWt, respectively. As optimistic values (90%), those values
were found as 43.6 MWt and 54.3 MWt. While calculating these numbers, a
project life of 25 years with a load factor of 50% is used.
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Using risk analysis to prioritise road-based intelligent transport systems (ITS) in QueenslandJohnston, Katherine Amelia January 2006 (has links)
With perpetual strains on resources, road agencies need to develop network-level decision-making frameworks to ensure optimum resource allocation. This is especially true for incident management services and in particular variable message signs (VMS), which are relatively immature disciplines compared to traditional road engineering. The objective of incident management and VMS is to minimise the safety, efficiency, reliability and environmental impacts of incidents on the operations of the transport system. This may be achieved by informing travellers of the incidents so they can adapt their behaviour in a manner that reduces community impacts, such as lateness and the associated vehicle emissions, unreliability of travel times, as well as secondary accidents due to incidents.
Generally, road authorities do carry out needs assessments, but qualitatively in many cases. Therefore, this masters research presents a framework that is systematic, quantitative and relatively easy to implement. In order to prioritise VMS infrastructure deployment, a risk management approach was taken that focuses on minimising the impacts on, and costs to the community. In the framework and case study conducted, safety, efficiency and reliability, and environmental impacts are quantified using an economic risk management approach to determine an overall risk score. This score can be used to rank road sections within the network, indicating the roads with the highest risk of incident network impacts and therefore the roads with the highest need for intervention. A cost-effectiveness based risk-reduction ranking can then be determined for each incident management treatment type, comparing the net risk with treatment to that without treatment, and dividing by the net present value of deployment. The two types of ranking, pure risk and cost-effectiveness based risk reduction, will help to minimise the network impacts on the community and optimise resource allocation.
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Incorporating interdependence in risk likelihood analysis to enhance diagnostics in condition monitoringWiliem, Leonard January 2008 (has links)
This research is aimed at addressing problems in the field of asset management relating to risk analysis and decision making based on data from a Supervisory Control and Data Acquisition (SCADA) system. It is apparent that determining risk likelihood in risk analysis is difficult, especially when historical information is unreliable. This relates to a problem in SCADA data analysis because of nested data. A further problem is in providing beneficial information from a SCADA system to a managerial level information system (e.g. Enterprise Resource Planning/ERP). A Hierarchical Model is developed to address the problems. The model is composed of three different Analyses: Hierarchical Analysis, Failure Mode and Effect Analysis, and Interdependence Analysis. The significant contributions from the model include: (a) a new risk analysis model, namely an Interdependence Risk Analysis Model which does not rely on the existence of historical information because it utilises Interdependence Relationships to determine the risk likelihood, (b) improvement of the SCADA data analysis problem by addressing the nested data problem through the Hierarchical Analysis, and (c) presentation of a framework to provide beneficial information from SCADA systems to ERP systems. The case study of a Water Treatment Plant is utilised for model validation.
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APPLICATION AND APPRAISAL OF A MULTI-OBJECTIVE DECISION SUPPORT SYSTEM FOR THE EVALUATION OF FARM FORESTRY VIABILITYDavid Ian Jeffreys Unknown Date (has links)
Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.
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APPLICATION AND APPRAISAL OF A MULTI-OBJECTIVE DECISION SUPPORT SYSTEM FOR THE EVALUATION OF FARM FORESTRY VIABILITYDavid Ian Jeffreys Unknown Date (has links)
Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.
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APPLICATION AND APPRAISAL OF A MULTI-OBJECTIVE DECISION SUPPORT SYSTEM FOR THE EVALUATION OF FARM FORESTRY VIABILITYDavid Ian Jeffreys Unknown Date (has links)
Abstract This thesis presents innovative applications of Multi-Objective Decision Support Systems (MODSS) to forestry decision support. New MODSS methodologies were developed to assess and evaluate forestry practices and finance regimes. The assessment of forestry investments draw on case studies conducted in the Hodgson Creek catchment on the Darling Downs in south Queensland and on the Atherton Tablelands in north Queensland, Australia. MODSS are systems that aid decision-making, in which a set of alternative management options are evaluated against a set of decision criteria. The criteria, that represent the stakeholders’ goals and objectives, are weighted to reflect stakeholder preferences regarding their relative importance. The weighted criteria scores are then aggregated to create an overall measure of option performance. In the first case study, MODSS procedures identified from the literature as being most suitable to forestry and the MODSS software package DEFINITE was used. After a critical review of the first study, a new MODSS was developed to address the particular needs of forestry evaluations and the weaknesses of current MODSS for addressing these needs. Limitations of the Hodgson Creek MODSS included lack of stakeholder engagement in the MODSS development process, inefficient use of the stakeholder time and an excessive work load on the experts in the scoring process. The new MODSS development process included the combined use of weighted sum and Electré aggregation methods, these being compensatory and non-compensatory aggregation methods. This combination of aggregation methods provided a measure of overall option performance and identified the presence of fatal flaws in the options. Various criteria weighting methods were trialled – including rank order methods, the analytical hierarchy process and direct assessments – to assess their utility for defining weights that reflected stakeholder priorities. A new hybrid weighting technique was developed using a combination of rank order methods and direct assessments. A new and innovative process for scoring options and criteria was developed, using an adaption of the Nominal Group Technique (NGT) in conjunction with a new computer-based Group Decision Support System (GDSS). This iterative process involved repeated rounds of individual scoring and group discussions. In the workshop conducted to elicit scores from experts, the GDSS was used to identify criteria where the elicited scores differed and discussions were focused on these criteria. After the discussions the options were rescored against the criteria and discussed further. This analysis was innovative in that uncertainty around the individual option scores was addressed for the first time using MODSS. This new application was developed in a spreadsheet using the risk analysis package @RISK. Evaluations of forestry options were undertaken at various time scales to address the long delay between incurring costs of tree planting and receiving returns from harvest. The various time scales identify the periods in which environmental and social benefits occurred as the trees grow and the economic benefits occurred at clearfell (or selective) harvest. This thesis specifically focuses on situations where measured and modelled data is not available, and seeks to increase the scientific rigour of the use of expert and stakeholder opinion in MODSS. The MODSS analyses revealed that forestry in the case study areas had the potential to offer considerable economic, environmental and social benefits to both landholders and the wider community. However, these benefits (and the associated costs) were not viewed as equally important. The MODSS developed in this study addressed these concerns. The benefits and costs of an option were reflected in its performance against the criteria. The degree of importance of the individual criteria varied from minor to high and overriding all other considerations. Criteria against which an option performed highly (the option’s strengths) were identified, as were criteria against which an option performed poorly (the option’s weaknesses). When these weaknesses occurred in highly important criteria, these were identified as fatal flaws in the option. The first case study in the Hodgson Creek catchment considered eight forestry options against 17 economic criteria, 12 environmental criteria and 12 social criteria. The second case study on the Atherton Tablelands considered 16 forestry options against eight economic criteria, six environmental criteria and five social criteria. The MODSS analysis identified the most preferred forestry options and the strengths and weaknesses of the options. In both case studies the most preferred options were large or medium-sized plantations with monoculture plantings with an element of non-landholder funding, in the form of government funding, joint ventures or land leasing agreements. These options had the highest performance against the economic criteria at all time scales and satisfactory environmental and social performance. Other forestry options that performed well included plantings focused on under-utilised land areas and salinity prevention areas, agroforestry, and selective harvesting of private native forest. These options generally had a higher level of performance against the social and environmental criteria, but lower levels of performance against economic criteria. These plantings would be undertaken for environmental and social reasons and not for financial returns. The application of MODSS developed in this thesis presents a significant scientific contribution to MODSS methodology. This thesis includes: the use of multiple time-periods to address the temporal differences in the delivery of benefits and costs, the use of NGT and a GDSS to provide a process for rapidly eliciting expert opinion, and the use of the combination of Electré and weighted sum aggregation methods to provide an overall measure of option performance and to identify fatal flaws in the options.
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