Flood risk management is increasingly seeking to involve local stakeholders in decision-making, both to harness and benefit from their tacit knowledge and to devolve responsibility for delivering local-scale, individual and community responses. Current techniques used in flood risk management centre on a techno-scientific approach, which is well-suited to appraising and modelling hazard, but often inaccessible to those without specialist, technical expertise. This leads to participation that is often limited to infrequent consultation periods, keeping local stakeholders at the periphery of the decision-making process. Their absence from the more technical elements of the process can leave local stakeholders struggling to understand how different options have been identified, appraised and/or prioritised. This can in turn lead to dissatisfaction with process outcomes, lack of support for selected options, and foster distrust in expert practitioners. This thesis explores how participatory modelling techniques could complement current approaches, facilitating the co-production of models with local stakeholders that explore social constructions of risk, and the vulnerability of different receptors. It identifies the qualities that are sought from participation, including the need to remain highly accessible, yet sufficiently robust to capture the complexities encountered when working at the interface of social and physical systems. Reporting on two UK case studies, it exemplifies the benefits that two popular techniques, Bayesian networks and system dynamics, can deliver at different stages in the flood risk decision-making process. In each case, the effectiveness of the participatory approach is assessed using an evaluative framework that advances current approaches by including an early assessment of context, as well as a detailed exploration of substantive (user-defined goals), and social change outcomes. The holistic nature of the evaluation framework, and its population with practical criteria bespoke to flood risk management, enhance its transferability between different contexts. The thesis finds that participatory modelling techniques support the collating of diffuse tacit knowledge, building of consensus, strengthening of social networks, and the empowerment of local citizens to become volunteer risk managers; provided that process managers are willing to simplify the techniques to maintain accessibility, and be open to different metrics of success.

The redevelopment of existing riverine barriers with modern hydropower turbines is becoming increasingly prevalent on main stem rivers with valuable stocks of migratory salmonids. This is a concern because these fish rely on longitudinal connectivity to complete their lifecycles, and modifications for hydropower could jeopardize that connectivity by obstructing or injuring migrating fish. In order to exploit very low head hydropower potential, novel turbine types are emerging. The Archimedean screw hydropower turbine is one such technology which is becoming increasingly popular for low-head applications. However the impact of these turbines on fish movements remains largely untested. This thesis aims to provide much needed evidence on the effects that these turbines and schemes may have on migrating salmonids. Fixed radio and passive integrated transponder receivers were used to track the downstream movements of wild migrating juvenile salmonids through a low-head Archimedean screw hydropower scheme. Atlantic salmon smolts were found to pass through the alternative routes of the turbine and main river channel in proportion to flow through these channels. Passage times were generally fast through both routes (median = 17.6, range = 5.1-905.6 minutes over the 350m scheme extent, for radio tagged fish), and longer passage times were associated with daytime presence in both routes. The majority of PIT tagged Atlantic salmon and sea trout smolts that passed through the 100 m long turbine channel, did so in under 27 minutes (median = 6.8 minutes), whilst a few fish had much longer passage times, associated with daytime presence. There were no differences in onward survival (measured as distance survived downstream) between turbine passed and non-turbine passed migrants. Atlantic salmon smolts were passed through an Archimedean screw turbine to test for harmful effects from the turbine, with comparison to equivalently handled non-turbine passed smolts. There was no evidence of visible damage aside from low to moderate scale loss, which was not significantly associated with turbine passage. Blood chemistry parameters were used to test for subtle turbine-induced damage. This novel application of these techniques did not yield conclusive results, but serves as a useful precedent for future studies. Radio and PIT telemetry equipment were used to investigate the movements of upstream migrating adult salmonids at three separate low-head hydropower schemes which may act as obstacles to migration. These schemes each had distinct configurations and flow management regimes. Movements within, and progression beyond these schemes varied substantially between sites, and in some cases were related to flow management parameters. Whilst not conclusive, the results suggest that scheme configuration and the management of flows influence the time that fish spend at such schemes, and the proportion of fish that ascend beyond them. With the global shift towards renewable energy generation, the exploitation of running water for hydropower is likely to become increasingly pervasive. The results of these studies provide valuable information for the informed and ecologically sustainable development of low-head hydropower schemes.

Ballast water has been identified as a major vector for the translocation of Non- Indigenous Invasive Species (NIS) and pathogens across zoogeographical regions and subsequent discharged into recipient port states/regions. This is bound to increase given factors like the globalization of trade and the economy of scale of the ship size. Established NIS has posed significant threat to the human health, economy, finances and marine bio-diversity of recipient regions and port states. The risks associated with the discharged NIS are uncertain and difficult to assess due to the stochastic nature of species assemblages and dispersal mechanism. The safest control measure advocated by the IMO is the conduct of ballast water exchange at sea while appropriate and effective proto-type treatment technologies are being developed and approved for future application. This study has been conducted while recognizing the inability of probabilistic approaches applied in ballast water risk management to addressing uncertainty and inadequacy of data. A qualitative approach using powerful multi-criteria decision making techniques and the safety principles of the Formal Safety Assessment framework have been utilized in this research to develop three generic models for ballast water hazard estimation, risk evaluation and decision-making analysis respectively. The models are capable of being modified and utilized in the industry to address the problems of uncertainty and inadequacy of data in ballast water management. This is particularly useful as an interim measure for port states in developing economies (with insufficient data and technology) to developed robust ballast water management plans. While recognising the huge impact of ballast water pollution in recipient regions this study recommends that ballast water management programmes be given due recognition as an important element of sustainable development programmes at national and international levels. The non-availability of a benchmark based on previous research on which to fully validate the research outcome was identified as a major limitation of this research study. The models developed will therefore be subject to modifications as new data become available.

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This research has first reviewed the current status and future aspects of marine and offshore safety assessment. The major problems identified in marine and offshore safety assessment in this research are associated with inappropriate treatment of uncertainty in data and human error issues during the modelling process. Following the identification of the research needs, this thesis has developed several analytical models for the safety assessment of marine and offshore systems/units. Such models can be effectively integrated into a risk-based framework using the marine formal safety assessment and offshore safety case concepts. Bayesian network (BN) and fuzzy logic (FL) approaches applicable to marine and offshore safety assessment have been proposed for systematically and effectively addressing uncertainty due to randomness and vagueness in data respectively. BN test cases for both a ship evacuation process and a collision scenario between the shuttle tanker and Floating, Production, Storage and Offloading unit (FPSO) have been produced within a cause-effect domain in which Bayes' theorem is the focal mechanism of inference processing. The proposed FL model incorporating fuzzy set theory and an evidential reasoning synthesis has been demonstrated on the FPSO-shuttle tanker collision scenario. The FL and BN models have been combined via mass assignment theory into a fuzzy-Bayesian network (FBN) in which the advantages of both are incorporated. This FBN model has then been demonstrated by addressing human error issues in a ship evacuation study using performance-shaping factors. It is concluded that the developed FL, BN and FBN models provide a flexible and transparent way of improving safety knowledge, assessments and practices in the marine and offshore applications. The outcomes have the potential to facilitate the decision-making process in a risk-based framework. Finally, the results of the research are summarised and areas where further research is required to improve the developed methodologies are outlined.

This research has reviewed the current status of offshore and marine safety. The major problems identified in the research are associated with risk modelling under circumstances where the lack of data or high level of uncertainty exists. This PhD research adopts an object-oriented approach, a natural and straightforward mechanism of organising information of the real world systems, to represent the Offshore Gas Supply Systems (OGSSs) at both the component and system levels. Then based on the object-oriented approach, frameworks of aggregative risk assessment and fault tree analysis are developed. Aggregative risk assessment is to evaluate the risk levels of components, subsystems, and the overall OGSS. Fault trees are then used to represent the cause-effect relationships for a specific risk in the system. Use of these two assessment frameworks can help decision makers to obtain comprehensive view of risks in the OGSS. In order to quantitatively evaluate the framework of aggregative risk, this thesis uses a fuzzy aggregative risk assessment method to determine the risk levels associated with components, subsystems, and the overall OGSS. The fuzzy aggregative risk assessment method is tailored to quantify the risk levels of components, subsystems, and the OGSS. The proposed method is able to identify the most critical subsystem in the OGSS. As soon as, the most critical subsystem is identified, Fuzzy Fault Tree Analysis (FFTA) is employed to quantitatively evaluate the cause-effect relationships for specific undesired event. These results can help risk analysts to select Risk Control Options (RCOs) for mitigating risks in an OGSS. It is not financially possible to employ all the selected RCOs. Therefore, it is necessary to rank and select the best RCO. A decision making method using the Fuzzy TOPSIS (FTOPSIS) is proposed to demonstrate the selection of the best RCOs to control the existing risks in the system. The developed models and frameworks can be integrated to formulate a platform which enables to facilitate risk assessment and safety management of OGSSs without jeopardising the efficiency of OGSSs operations in various situations where traditional risk assessment and safety management techniques cannot be effectively applied.

This research is carried out to improve Human Reliability Analysis (HRA) in oil tanker operations in general, to extend and enhance in specific Cognitive Reliability and Error Analysis Method (CREAM), with the aim of reducing human error and thus subsequently preventing oil tanker spills. It is concentrated on oil tanker operations to address the limitation of availability of human reliability data in the maritime domain. The continual occurrence of oil tanker spills, which was substantiated with analysis of historical data of oil tanker incidents/accidents from 1970 to 2008, provides a judicious reason to conduct this research. The critical review of Formal Safety Assessment (FSA) and HRA results in the development of a conceptual framework of HRA facilitating FSA and incorporating Human Organisational Factors (HOF), which addresses the shortcomings of the generic HRA and FSA methodologies that exist independently in the management of oil tankers to prevent oil spills. The CREAM is reviewed due to its prominent use in identifying the root causes of human error. However, its inability of providing solutions to an incident/accident investigation and robust quantification of human reliability features stimulates the development of an advanced CREAM and a human reliability quantification model using a combined Analytic Hierarchical Process (AHP) and fuzzy logic approach in this research. In addition to facilitating identification of the root causes of human error, the advanced CREAM also provides the solutions to a quantification model, which enables the development of HRA data in the maritime domain. Furthermore, lack of CREAM studies on relationships among Common Performance Conditions (CPCs) is addressed by proposing a Decision Making Trial and Evaluation Laboratory (DEMATEL) model, which allows for a comprehensive understanding of relationships and interdependencies among the CPCs. The model could also be used toappreciate and assimilate the relationships and interdependencies among human factor variables involved in other transportation systems and industrial fields. Finally, the research is concluded with an integrated AHP and fuzzy Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) model for determining the selection of an appropriate risk control option (RCO) while performing an incident/accident investigation by taking subjective judgments of decision makers into consideration. This research as a pioneer work in developing and applying advanced techniques to improve the generic CREAM in oil tanker operations establishes a foundation for future effort to improve the use of CREAM in other industries. The techniques developed can also be tailored to investigate and deal with an incident/accident effectively, resulting in the reduction of human error within the system management of any organisation.

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M.Ing. (Mechanical Engineering) / The development of crashworthy seats for helicopters during the past three decades is discussed. The primary design criteria is mentioned and the disadvantages of crashworthy seats that are currently in use are highlighted. An hydraulic energy absorber which automatically compensates for the mass of the seat occupant was designed and a simulation model was developed. The concept for the control valve used was obtained from WARRICK [25]. Results of the simulations correlated well with those of WARRICK. A prototype of a mechanical/hydraulic accelerometer was designed, manufactured and tested. The results obtained from the experiments compared favourably with simulation values. The simulated and experimental results indicate that the concept of using an hydraulic energy absorber, in a crashworthy seat, is very satisfactory. Future crashworthy seat designs could be enhanced by incorporating this promising device.