4,200 research outputs found

    Governance of a complex system: water

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    This paper sets out a complex adaptive systems view of water governance. Overview Fresh water is a life - enabling resource as well as the source of spiritual, social and economic wellbeing and development. It is continuously renewed by the Earth’s natural recycling systems using heat from the sun to evaporate and purify, and then rain to replenish supplies. For thousands of years people have benefited from these systems with little concern for their ability to keep up with human population and economic development. Rapid increases in population and economic activity have brought concern for how these systems interact with human social and economic systems to centre stage this century in the guise of a focus on water governance. What do we mean by governance and how might we better understand our water governance systems to ensure their ongoing sustainability? This paper sets out a complex adaptive systems view of water governance. It draws on the academic literature on effective governance of complex systems and effective water governance to identify some principles for use in water governance in New Zealand. It illustrates aspects of emerging water governance practice with some examples from New Zealand which have employed a multi-actor, collaborative governance approach. The paper concludes with some implications for the future evolution of effective water governance in New Zealand. Collaborative governance processes are relatively unfamiliar to New Zealand citizens, politicians and other policy actors which makes it more important that we study and learn from early examples of the use of this mode of governance

    Potential for ecological nonlinearities and thresholds to inform Pacific salmon management

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    AbstractEcology is often governed by nonlinear dynamics. Nonlinear ecological relationships can include thresholds—incremental changes in drivers that provoke disproportionately large ecological responses. Among the species that experience nonlinear and threshold dynamics are Pacific salmon (Oncorhynchus spp.). These culturally, ecologically, and economically significant fishes are in many places declining and management focal points. Often, managers can influence or react to ecological conditions that salmon experience, suggesting that nonlinearities, especially thresholds, may provide opportunities to inform decisions. However, nonlinear dynamics are not always invoked in management decisions involving salmon. Here, we review reported nonlinearities and thresholds in salmon ecology, describe potential applications that scientists and managers could develop to leverage nonlinear dynamics, and offer a path toward decisions that account for ecological nonlinearities and thresholds to improve salmon outcomes. It appears that nonlinear dynamics are not uncommon in salmon ecology and that many management arenas may potentially leverage them to enable more effective or efficient decisions. Indeed, decisions guided by nonlinearities and thresholds may be particularly desirable considering salmon management arenas are often characterized by limited resources and mounting ecological stressors, practical constraints, and conservation challenges. More broadly, many salmon systems are data‐rich and there are an extensive range of ecological contexts in which salmon are sensitive to anthropogenic decisions. Approaches developed to leverage nonlinearities in salmon ecology may serve as examples that may inform analogous approaches in other systems and taxa

    Classifying resilience approaches for protecting smart grids against cyber threats

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    Smart grids (SG) draw the attention of cyber attackers due to their vulnerabilities, which are caused by the usage of heterogeneous communication technologies and their distributed nature. While preventing or detecting cyber attacks is a well-studied field of research, making SG more resilient against such threats is a challenging task. This paper provides a classification of the proposed cyber resilience methods against cyber attacks for SG. This classification includes a set of studies that propose cyber-resilient approaches to protect SG and related cyber-physical systems against unforeseen anomalies or deliberate attacks. Each study is briefly analyzed and is associated with the proper cyber resilience technique which is given by the National Institute of Standards and Technology in the Special Publication 800-160. These techniques are also linked to the different states of the typical resilience curve. Consequently, this paper highlights the most critical challenges for achieving cyber resilience, reveals significant cyber resilience aspects that have not been sufficiently considered yet and, finally, proposes scientific areas that should be further researched in order to enhance the cyber resilience of SG.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Funding for open access charge: Universidad de Málaga / CBUA

    Administering the Clean Water Act: Do Regulators Have Bigger Fish to Fry When it Comes to Addressing the Practice of Chumming on the Chesapeake Bay?

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    The Chesapeake Bay is one of the country\u27s most productive estuaries. However, for decades the health of the Bay has been declining due in large part to nutrification. Excessive nutrients encourage algal blooms, which lower dissolved oxygen and increase turbidity in the Bay\u27s waters. More than 40% of the Bay\u27s main stern is now dead largely as a result of this problem. The practice of chumming, the discarding of baitfish, usually menhaden, over the sides of fishing boats to attract game fish like striped bass, is contributing to the Bay\u27s nutrification problem because the decomposing chum raises the waters biological oxygen demand which lowers dissolved oxygen and increases water turbidity causing bay grasses to die and setting in motion destructive positive feedback loops. Chum may also be a source of disease in game fish, and the demand for chum is contributing to the decline of menhaden, an important food and filter fish, on the Atlantic Coast. Despite these problems, the practice of chumming is not regulated by either the federal government or the state of Maryland. This article explores whether citizens can compel regulation by either jurisdiction and concludes that such initiatives would likely fail because of the absence of a duty to regulate. The article examines why regulators decline to regulate and finds that the most likely reasons are an over dependence on economic approaches to environmental regulation, which drives regulators to choose the largest targets of opportunity, and a failure to understand how small disturbances in complex systems like estuaries can set off a cascade of potentially catastrophic and irreversible consequences--here, the loss of the Bay\u27s biodiversity. The article concludes by suggesting that the Precautionary Principle offers a much better approach to identifying regulatory targets in estuarine systems where much is scientifically uncertain; and exhorts citizens to spend time educating regulators of these facts rather than in fruitless and time-consuming litigation

    Holistic Resilience Quantification Framework of Rural Communities

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    Communities need to prepare for anticipated hazards, adapt to varying conditions, and resist and recover rapidly from disturbances. Protecting the built environment from natural and man-made hazards and understanding the impact of these hazards helps allocate resources efficiently. Recently, an indicator-based and time-dependent approach was developed for defining and measuring the functionality and disaster resilience continuously at the community level. This computational method uses seven dimensions that find qualitative characteristics and transforms them into quantitative measures. The proposed framework is used to study the resilience of rural communities’ subject to severe flooding events. Harlan County in the Appalachian region is chosen as a case study to evaluate the proposed resilience quantification framework subject to severe flooding. The results show the validity of the proposed approach as a decision-support mechanism to assess and enhance the resilience of rural communities

    Resilience-oriented control and communication framework for cyber-physical microgrids

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    Climate change drives the energy supply transition from traditional fossil fuel-based power generation to renewable energy resources. This transition has been widely recognised as one of the most significant developing pathways promoting the decarbonisation process toward a zero-carbon and sustainable society. Rapidly developing renewables gradually dominate energy systems and promote the current energy supply system towards decentralisation and digitisation. The manifestation of decentralisation is at massive dispatchable energy resources, while the digitisation features strong cohesion and coherence between electrical power technologies and information and communication technologies (ICT). Massive dispatchable physical devices and cyber components are interdependent and coupled tightly as a cyber-physical energy supply system, while this cyber-physical energy supply system currently faces an increase of extreme weather (e.g., earthquake, flooding) and cyber-contingencies (e.g., cyberattacks) in the frequency, intensity, and duration. Hence, one major challenge is to find an appropriate cyber-physical solution to accommodate increasing renewables while enhancing power supply resilience. The main focus of this thesis is to blend centralised and decentralised frameworks to propose a collaboratively centralised-and-decentralised resilient control framework for energy systems i.e., networked microgrids (MGs) that can operate optimally in the normal condition while can mitigate simultaneous cyber-physical contingencies in the extreme condition. To achieve this, we investigate the concept of "cyber-physical resilience" including four phases, namely prevention/upgrade, resistance, adaption/mitigation, and recovery. Throughout these stages, we tackle different cyber-physical challenges under the concept of microgrid ranging from a centralised-to-decentralised transitional control framework coping with cyber-physical out of service, a cyber-resilient distributed control methodology for networked MGs, a UAV assisted post-contingency cyber-physical service restoration, to a fast-convergent distributed dynamic state estimation algorithm for a class of interconnected systems.Open Acces
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