The energy consumption and greenhouse gas (GHG) emissions associated with urban water systems have come under scrutiny in recent times, as a result of increasing interest in climate change, to which urban water systems are particularly vulnerable. The approach most commonly taken previously to modelling these results has been to consider various urban water system components in great detail, but in isolation from the rest of the system. This piecewise approach is suboptimal, since it systematically fails to reveal the relative importance of the energy consumption and GHG emissions associated with each system component in the context of the entire urban water system. Hence, it was determined that a new approach to modelling the energy consumption and GHG emissions associated with urban water systems was necessary. It was further determined that the value derived from such a model would be greatly enhanced if it could also model the water consumption and wastewater generation associated with each system component, such that integrated policies could be developed, aimed at minimising water consumption, wastewater generation, energy consumption and GHG emissions concurrently. Hence, the following research question was posed: How should the relationships between the water consumption, wastewater generation, energy consumption and GHG emissions associated with the operation of urban water systems be modelled such that the impact of various changes to the system configuration made at different spatial scales can be determined within the context of the entire system? In this research project, life cycle assessment ideas were employed to develop such a new modelling methodology. Initially, the approach was developed at the building-scale, such that the end uses of water present in a selected building and any associated appliances could be modelled, along with the fraction of the citywide water supply and wastewater systems directly associated with providing services to that building. This vast breadth of scope was delivered by considering only the operational life cycle stage of each urban water system component, excluding both the pre- and post-operational life cycle stages of the associated infrastructure. The value of this pilot model was illustrated by several case studies, focused on residential buildings connected to the centralised water supply and wastewater systems in Melbourne, Australia. Later, the approach was extended to the city-scale by using probabilistic distributions of each input parameter, such that all of the end uses of water present in a city, and all of the associated building-scale appliances could be modelled, along with the associated complete water supply and wastewater systems. The value of this city-scale model was illustrated by applying it to model a hypothetical case study city, resembling Melbourne, Australia in many ways. Due to a lack of data, this application was limited to the residential sector of the case study city, along with the fraction of the citywide water supply and wastewater systems directly associated with providing services to that sector. The results generated by the pilot and city-scale models showed that the new modelling methodology could be employed at a wide range of scales to assess the relative importance of each modelled urban water system component in terms of the specified results. Importantly, the high resolution of those results enabled the identification of the underlying causes of the relative importance of each urban water system component, such that efficient and effective approaches to reducing each result for each system component could be developed. Interestingly, for the specific case studies investigated, it was revealed that some commonly neglected system components were actually extremely important, such as domestic hot water services, a trend found to be largely driven by hot water consumption in showers.

This thesis presents the results of a computational study on salt transport and accumulation in crop root zone. The main objective of this study is to examine the impacts of past land use on the environment and to examine the effect of irrigation water on the rising of groundwater level and the subsequent salinity problem in rice growing area under given climatic conditions. A special focus has been such impacts in the Wakool irrigation area, NSW, Australia. To this end, a computational model for the assessment and prediction of salinisation in agricultural areas has been developed. This modelling system consists of a land surface scheme (ALSIS) for simulating unsaturated soil moisture and moisture flux, a groundwater flow model (MODFLOW) for estimating the spatial and temporal variations of groundwatertable, a surface flow model (DAFLOW) for calculating water flow in river networks, a module for calculating solute transport at unsaturated zone and a 3-D model (MOC3D) for simulating solute transport in groundwater as well as a module for calculating the spatial and temporal distributions of overland flow depth during wet seasons. The modelling system uses a finite difference linked technique to form a quasi three dimensional model. The land surface scheme is coupled with the groundwater flow model to account for the interactions between the saturated and unsaturated zones. On the land surface, the modelling system incorporates a surface runoff model and detailed treatments of surface energy balance, which is important in es-timating the evapotranspiration, a crucial quantity in calculating the moisture and moisture fluxes in the root zone. Vertical heterogeneity of soil hydraulic properties in the soil profile has been considered. The modelling system has the flexibility of using either Clapp and Hornberger (1978), Broadbridge and White (1988), van Genuchten (1980) or Brooks and Corey (1966) soil water retention models. Deep in the soil, the impact of groundwater table fluctuation on soil moisture and salinity in the unsaturated soil is also included. The calibration and validation for the system have been partially performed with observed groundwater levels in the Wakool irrigation area. The applications of the model to theWakool region are made in two steps. Firstly, a one-dimensional simulation to a selected site in the Wakool irrigation area is carried out to study the possible impact of ponded irrigation on salinisation and the general features of salt movement. Secondly, a more realistic three-dimensional simulation for the entire Wakool region is performed to study the spatial and temporal variations of root zone soil salinity under the influence of past land use from 1975 to 1994. To allow the assessment and prediction of the effects of ponded rice irrigation water (which contains salt) on soil salinity in the area, several hypothetical scenarios using different qualities of water for rice irrigation are tested. To facilitate comparative analysis of different scenarios, a base case is defined, for which irrigation water is assumed to be free of salt. The simulated results show that irrigation increases overall recharge to groundwater in the Wakool irrigation area. The use of ponded irrigation for rice growing has a substantial effect on salt accumulation in the root zone and the rising of groundwater level, indicating that irrigation at rice bay is a major budget item for controlling soil salinity problem in the local area.

Following concerns expressed by canegrowers in the Burdekin River Irrigation Area (BRIA) of Northern Queensland regarding rising groundwater and salinity the Department of Primary Industries instigated action to investigate and develop Best-On-Farm Water Management Practices. The purposes of this project were to improve landholder awareness of water use to maximise cane production while minimising the likelihood of salinity and changes in the groundwater balance, and to facilitate the development of soil and water management practices on a range of soils in the BRIA. The project lasted for 12 months, and this short duration affected research methodologies and techniques selected. Groups of farmers were organised, participation was good and useful outcomes resulted. These included: improved landholder awareness of the relationships between salinity, water use and groundwater; identification of a range of best practices; identification of social theories about water management practices; development of an extension model based on the value of indigenous knowledge; equality between government and farmers; examination of underlying assumptions in relation to water management by both government and farmers; identification of issues for future research and extension. / Master of Science (Hons)

Excessive water formation inside the polymer electrolyte membrane (PEM) fuel cell’s structures leads to the flooding of the cathode gas diffusion layer (GDL) and cathode gas flow channels. This results in a negative impact on water management and the overall cell performance. Liquid water generated in the cathode catalyst layer and the water moved from anode to cathode side due to electro-osmotic drag transport through the GDL to reach the gas flow field channels, where it is removed by air cathode gas stream. Due to high and uniform capillary force distribution effect of the pores through the GDL plane and surface tension between the water droplets and gas flow field channels surfaces, liquid water tends to block/fill the pores of the GDL and stick to the surface of the GDL and gas flow channels. Therefore, it is difficult to remove the trapped water in GDL structure which can lead to flood of the PEM fuel cell. The GDL surfaces are commonly treated uniformly with a hydrophobic material in order to overcome the flooding phenomena inside PEM fuel cell. Despite the importance impact of the surface wettability of both channel and GDL surface characteristics especially for the cathode side on the water management, few experimental studies have been conducted to investigate the effect of the two-phase flow in cathode gas flow channel and their crucial role. The work presented in this thesis covers contributions that provide insight, not only into the investigation of the effects of hydrophobic cathode GDL and cathode gas flow channels, on water removal, two phase flow inside the channel, and on PEM fuel cell performance, but also the superhydrophobic and superhydrophilic GDLs and gas flow channels effects. Further, the effects of a novel GDL designs with sandwich and gradient wettability with driving capillary force through GDL plane have been investigated. Two-phase flow especially in the cathode gas flow field channels of PEM fuel cell has a crucial role on water removal. Hence, in this research, ex-situ investigations of the effects of channels with different surface wettability; superhydrophobic, hydrophobic, slightly hydrophobic, and superhydrophilic on the two-phase flow characteristics have been tested and visualized at room temperature. Pressure drop measurements and two-phase flow visualization have been carried out using high speed camera. The effect of the various coating materials on graphite and GDL surface morphology, roughness, static contact angle (θ), and sliding contact angle (α) have been investigated using scanning electron microscopy (SEM), Profilometry, and sessile drop technique, respectively. It has been observed that the two-phase flow resistance is considerably affected by surface wettability of the channels. Further, the overall cell performance can be improved by superhydrophobic gas flow channels mainly at high current density over slightly hydrophobic and superhydrophilic cases tested. In addition, sandwich wettability GDL has been coated with a silica particle/ Polydimethylsiloxane (PDMS) composite. The porometric characteristics have been studied using, method of standard porosimetry (MSP). It has been found that sandwich wettability GDL has superhydrophobic surfaces with (θ = 162±2°), (α = 5±1°), and the internal pores are hydrophilic, while the mean pore radius is 7.1μm. This shows a low resistance to gas transport. On the other hand, performance testing indicates that (PEM) fuel cell equipped with sandwich wettability GDL results in the best performance compared to those with raw (non-coated) (slightly hydrophobic), PTFE coated (commercial with micro-porous layer (MPL)) (superhydrophobic), and silica coated (superhydrophilic) GDL. The wettability gradient has been introduced through plane of the one side hydrophobic GDL by coating one side of non-coated GDL with 15 wt. % of PTFE solution; however, the other side remains uncoated. The effects of wettability gradient on the water removal rate, droplet dynamics, and PEM fuel cell performance have been covered in this thesis. Water removal rate is determined using a 20 ml syringe barrel, wherein a 13 mm diameter GDL token is fixed on the barrel opening. The droplets penetrating through the GDL are visualized via a high speed camera to study the droplets’ dynamic characteristics. The GDL wettability gradient has a significant impact on water removal rate, droplets’ dynamic characteristics, and consequently enhances the overall PEM fuel cell performance.

Ideas about water use and ethics have been linked for many thousands of years. In this millennium, water resources remain a primary area of concern throughout the world, including such issues as shortages, supply, flooding, quality, restoration, allocation and regulation. Today, electronic environmental news and specialty websites contain a breadth of information on current water resources conflicts and issues throughout the world. In many parts of the world, water quantity is decreasing and water quality is worsening, lack of access to improved water supplies is decreasing, as is access to basic sanitation. Water challenges relating to water quantity and water quality are increasingly common in Canada and the United States due to water resources being under increasing pressure from population growth, economic activity and intensifying competition for the water among users. Faced with these challenges, humans are confronted with momentous decisions. Before making more decisions that will have an influence over water resources, and in response to repeated calls for a water ethic, this research takes the perspective that it is necessary to explore the ethical intentions of decision-makers with respect to water resources legislation and policy in Canada. The ultimate goal is to define a set of principles for a proposed water ethic that could and should be implemented at the municipal level of government in Canada. A review of academic and professional literature and a mixed methods research approach comparing two case study areas was used to gain a baseline understanding of the potential influences of underlying ethical frameworks on policy makers in Calgary, Alberta and Guelph, Ontario. A proposed water ethic, containing a set of principles compiled from ethical considerations for water use in academic and professional literature, was also developed and presented to case study participants. Participants provided feedback on their strength of agreement with each principle, thoughts on modifications, improvements and/or deletions of any principle, and implementation considerations of the proposed water ethic at the municipal level of government. The results indicate that case study participants in both areas apply a variety of ethical frameworks when making professional decisions about water resources management, and when preparing water legislation and policy. A review of relevant legislation, policies, documents and strategies in the case study areas supports this conclusion. In particular, components of the Consequentialist ethical framework (a perspective that can be associated with sustainable development and sustainability) are most often acknowledged in the statements of intent of the participants and water resource legislation and policies. Respondents also indicated that value positions associated with the Intrinsic Value ethical framework influenced policy preparation and decision-making; however, the ethical considerations associated with this framework are not as obvious in the language and intent of relevant legislation, plans, documents, and strategies. The case study participants in both areas supported all six proposed principles of the proposed water ethic and offered only minor modifications to the presented wording and intent. The endorsed principles of the proposed water ethic are: (1) allocate sufficient water to maintain and enhance ecosystem integrity; (2) establish conservation and efficiency measures as a priority over new supply initiatives in water resources planning; (3) meet basic human needs and enhance equity; (4)establish open and participative decision-making processes; (5) identify and seek to obtain multiple sustainability benefits from water-centered initiatives; and, (6) explicitly acknowledge system complexity and emphasize precaution. The feedback from the participants about the proposed water ethic, in association with the results of the ethical frameworks, informed the eight implementation recommendations, including: (1) entrench a water ethic vision in Provincial and municipal legislation; (2) work from within existing governance structures and institutional arrangements; (3) use an incremental model of decision-making; (4) provide specific policy examples for each principle within a water ethic; (5) include realistic and measurable targets within the policies; (6) accept that all six water ethic principles are unlikely to be accepted at once; (7) ensure the overall vision of the water ethic, principles, associated examples, and measureable targets, are defensible; and, (8)acknowledge the importance of strategy. The recommendations acknowledge that while the proposed water ethic is presented as a package and each principle is valuable, conflict and trade-offs may occur during the implementation process. The recommendations are therefore pragmatic and take into account the current governance structures and institutional arrangements. There is a growing recognition that understanding the underlying ethical perspectives that influence decision-makers may contribute to more effective water resources management legislation and policy. This research adds to this body of knowledge by showing that it is possible to identify ethical frameworks, extract the defining characteristics associated with each framework, and use case studies to suggest which ethical frameworks assert varying degrees of influence. This link between theory and practice may help organizations recognize what ethical considerations influence decision-making and identify the strengths and limitations of these ethical approaches to managing water resources. In addition, prior to this study, research had only been conducted into the identification of principles for the ethical use of water and not into the potential for implementation of a realistic and desirable water ethic that reflects sustainability and lasting well-being at the municipal level of government in Canada. Several opportunities exist to build on this research. They include (1) investigate if the ethical intent of legislation and policy related to water resources management is put into practice, (2) identify other ethical frameworks that may apply to decision-making, (3) focus on political decision-makers and their claims and intentions about water use, (4) test the implementation of the water ethic proposed in this study, and (5) investigate how to integrate ethical considerations about water into checklists and protocols related to land use development, professional codes of conduct and standards, institutional and organizational training programs, performance measures for official plans, and as standard components for municipal council reports and ministerial presentations. This exploratory research concludes that policy makers are willing to become more aware of their underlying ethical underpinnings and to learn how ethical considerations embedded in legislation and policy have the potential to exert significant influence over the behaviour of current and future water users.

This research deals with urban water reuse planning and management modeling in the context of sustainable development. Rapid urbanization and population growth have presented a great challenge to urban water resources management. As water reuse may alleviate pollution loads and enhance water supply sources, water reuse is being recognized as a sustainable urban water management strategy and is becoming increasingly attractive in urban water resources management. An efficient water reuse planning and management model is of significance in promoting water reuse practices. This thesis introduces an urban water reuse management and planning model using optimization methods with an emphasis on modeling uncertainty issues associated with water demand and water quality. The model is developed in conjunction with the overall urban water system with considerations over water supply, water demand, water distribution, water quality, and wastewater treatment and discharge. The objective of the model is to minimize the overall cost of the system subject to technological, societal and environmental constraints. Uncertainty issues associated with water demand and treatment quality are modeled by introducing stochastic programming methods, namely, two-stage stochastic recourse programming and chance-constraint programming. The model is capable of identifying and evaluating water reuse in urban water systems to optimize the allocation of urban water resources with regard to uncertainties. It thus provides essential information in planning and managing urban water reuse systems towards a more sustainable urban water resources management. An application was presented in order to demonstrate the modeling process and to analyze the impact of uncertainties.

Freshwater availability, allocation and quality are increasingly becoming a concern in Canada. Canada’s apparent availability of abundant freshwater is not what it was thought to be. With increasing competition for water sources and inadequate management systems water use and management approaches are being re-examined. While urban and municipal water uses are highly studied, Canadian industrial water use is not. Despite that industrial water use is understudied, the Canadian pulp and paper industry is a major user of water and contributes to quality water issues where mills are located. This thesis is divided into two equally important parts. First, this research seeks to understand the influences and prevailing conditions on the decision-making framework of pulp and paper mills. Second, it seeks to understand how the prevailing conditions affect the applicability of the water soft-path concept in the pulp and paper industry. It will contribute to the literature of Canadian industrial water management. This research specifically examines the applicability of the water soft-path concept under the stresses and realities of the systems of influence identified as market forces, policy and regulation, and technology faced by the Canadian pulp and paper industry. Corporate culture was an implicitly common thread that ran through these systems of influence. A variety of methods were used in this study including, a literature review conducted by themes, surveys, interviews, analysis of archival data and backcasting were used as the methodological approaches. The literature review was conducted by themes of water management, technology, market forces, regulation and corporate culture. Surveys were conducted to gain water use data from specific mills but a low response rate required a widening of the research boundaries. Interviews were conducted with government officials, industry representatives, and environmental non-governmental organizations. The interviews contributed to the boundary setting and understanding of the influences that impact decision-making for industry. The analysis of archival data was to better understand how water use in pulp and paper mills has changed through the years. Understandably the systems of influence (market forces, policy and regulation, and technology) work independently and together to create a complex environment in which decisions on water use in pulp and paper mills are made. The complexity of the decision-making framework is great and the barriers to water soft-path application difficult. Market forces are less capable of addressing environmental externalities such as water. Regulation and policy has yet to address water use in industry. Technology does provide an important opportunity for efficient water use and application of the pulp and paper industry. Ultimately, the Canadian pulp and paper industry is in a redefining moment where opportunity exists to create a new direction and approach to water use in the Canadian pulp and paper industry.

This research deals with urban water reuse planning and management modeling in the context of sustainable development. Rapid urbanization and population growth have presented a great challenge to urban water resources management. As water reuse may alleviate pollution loads and enhance water supply sources, water reuse is being recognized as a sustainable urban water management strategy and is becoming increasingly attractive in urban water resources management. An efficient water reuse planning and management model is of significance in promoting water reuse practices. This thesis introduces an urban water reuse management and planning model using optimization methods with an emphasis on modeling uncertainty issues associated with water demand and water quality. The model is developed in conjunction with the overall urban water system with considerations over water supply, water demand, water distribution, water quality, and wastewater treatment and discharge. The objective of the model is to minimize the overall cost of the system subject to technological, societal and environmental constraints. Uncertainty issues associated with water demand and treatment quality are modeled by introducing stochastic programming methods, namely, two-stage stochastic recourse programming and chance-constraint programming. The model is capable of identifying and evaluating water reuse in urban water systems to optimize the allocation of urban water resources with regard to uncertainties. It thus provides essential information in planning and managing urban water reuse systems towards a more sustainable urban water resources management. An application was presented in order to demonstrate the modeling process and to analyze the impact of uncertainties.

Freshwater availability, allocation and quality are increasingly becoming a concern in Canada. Canada’s apparent availability of abundant freshwater is not what it was thought to be. With increasing competition for water sources and inadequate management systems water use and management approaches are being re-examined. While urban and municipal water uses are highly studied, Canadian industrial water use is not. Despite that industrial water use is understudied, the Canadian pulp and paper industry is a major user of water and contributes to quality water issues where mills are located. This thesis is divided into two equally important parts. First, this research seeks to understand the influences and prevailing conditions on the decision-making framework of pulp and paper mills. Second, it seeks to understand how the prevailing conditions affect the applicability of the water soft-path concept in the pulp and paper industry. It will contribute to the literature of Canadian industrial water management. This research specifically examines the applicability of the water soft-path concept under the stresses and realities of the systems of influence identified as market forces, policy and regulation, and technology faced by the Canadian pulp and paper industry. Corporate culture was an implicitly common thread that ran through these systems of influence. A variety of methods were used in this study including, a literature review conducted by themes, surveys, interviews, analysis of archival data and backcasting were used as the methodological approaches. The literature review was conducted by themes of water management, technology, market forces, regulation and corporate culture. Surveys were conducted to gain water use data from specific mills but a low response rate required a widening of the research boundaries. Interviews were conducted with government officials, industry representatives, and environmental non-governmental organizations. The interviews contributed to the boundary setting and understanding of the influences that impact decision-making for industry. The analysis of archival data was to better understand how water use in pulp and paper mills has changed through the years. Understandably the systems of influence (market forces, policy and regulation, and technology) work independently and together to create a complex environment in which decisions on water use in pulp and paper mills are made. The complexity of the decision-making framework is great and the barriers to water soft-path application difficult. Market forces are less capable of addressing environmental externalities such as water. Regulation and policy has yet to address water use in industry. Technology does provide an important opportunity for efficient water use and application of the pulp and paper industry. Ultimately, the Canadian pulp and paper industry is in a redefining moment where opportunity exists to create a new direction and approach to water use in the Canadian pulp and paper industry.

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