| 1. |
- Arthington, Angela H, et al.
(author)
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Preserving the biodiversity and ecological services of rivers : new challenges and research opportunities
- 2010
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In: Freshwater Biology. - : Wiley. - 0046-5070 .- 1365-2427. ; 55:1, s. 1-16
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Journal article (peer-reviewed)abstract
- Natural biogeochemical processes and diverse communities of aquatic biota regulate freshwater quantity and quality in ways that are not sufficiently acknowledged nor appreciated by the water resources management community. The establishment and enforcement of environmental flow requirements offer promising means to improve and care for these critical environmental services. This Special Issue provides new insights and novel techniques to determine, protect and restore ecologically and socially sustainable flow regimes, and thereby help achieve the water-related goals of the Millennium Ecosystem Assessment.Whilst alteration of flow, sediment, organic matter and thermal regimes interact to reduce biological diversity and the ecological integrity of freshwater ecosystems - and thereby degrade the properties and ecological services most valued by humans - ‘environmental flows' left in rivers, or restored to developed rivers, will sustain many ecological and societal values. The success of river protection and rehabilitation ⁄ restoration depends upon understanding and accurately modelling relationships between hydrological patterns, fluvial disturbance and ecological responses in rivers and floodplains.This Special Issue presents new analytical and modelling approaches to support the development of hydro-ecological models and environmental flow standards at multiple spatial scales - applicable to all rivers in any economic and societal setting. Examples include the new framework Ecological Limits of Hydrologic Alteration (ELOHA) founded on hydrological classification and gradient analysis; ecological trait analysis; Bayesian hierarchical modelling; Bayesian Decision Networks; and Integrated Basin Flow Assessment (IBFA).Advances in the allocation of flood flows along the River Murray in Australia, an Ecosystems Function Model (HEC-EFM) for the Bill Williams River restoration programme in Arizona (U.S.A), the European Water Framework Directive, and improved management of hydroelectric dams demonstrate the potential for significant ecological recovery following partial restoration of natural river flow regimes.Based on contributions to this Special Issue, the action agenda of the 2007 Brisbane Declaration on environmental flows and the wider literature, we propose an invigorated global research programme to construct and calibrate hydro-ecological models and to quantify the ecological goods and services provided by rivers in contrasting hydro-climatic settings across the globe. A major challenge will be to find acceptable ways to manage rivers for multiple uses. Climate change intensifies the urgency. Environmental flows help to preserve the innate resilience of aquatic ecosystems, and thereby offer the promise of improved sustainability and wellbeing for people as well as for ecosystems.
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| 2. |
- Pahl-Wostl, Claudia, et al.
(author)
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Environmental flows and water governance : managing sustainable water uses
- 2013
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In: Current Opinion in Environmental Sustainability. - : Elsevier BV. - 1877-3435 .- 1877-3443. ; 5:3-4, s. 341-351
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Research review (peer-reviewed)abstract
- Human water security is often achieved with little consideration of environmental consequences and, even when these are acknowledged, the trade-offs between human and environmental water needs are increasing in frequency and amplitude on the increase. The environmental flows concept has continued to evolve in response to these challenges. However, the field is characterized by a limited transferability of insights, due to the prevalence of specific case-study analyses and a lack of research on the governance of environmental flows. Building on recent advances in environmental flow science, water governance and management, we identify a clear need for a more systematic approach to the determination of environmental flow requirements (EFRs) on both the natural and social science fronts and, in particular, on the interaction between social/political and environmental systems. We suggest a framework that details as to how these advances and interactions can be achieved. The framework supports scientific analysis and practical implementation of EFRs involving systematic compilation, sharing and evaluation of experiences from different riverine ecosystems and governance systems around the globe. The concept of ecosystem services is introduced into the framework to raise awareness for the importance of ecosystem functions for the resilience of social-ecological systems, to support negotiation of trade-offs and development of strategies for adaptive implementation. Experience in implementation of environmental flow policies reveals the need for an engaged, transdisciplinary research approach where research is closely linked to implementation initiatives on the ground. We advocate that this is more effective at building the foundations for sustainable water management.
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| 3. |
- Reidy Liermann, Catherine, 1972-
(author)
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Ecohydrologic impacts of dams : A global assessment
- 2007
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Doctoral thesis (other academic/artistic)abstract
- This dissertation aims to improve our understanding of how dams and reservoirs impact freshwater systems worldwide. The following questions were addressed specifically: 1) what are the spatial patterns and magnitudes of flow regulation and channel fragmentation by dams globally; 2) how are dam impacts distributed biogeographically, and which are the biogeographic regions and taxa most threatened by dam impacts; and 3) how can climate change and dams be expected to interact in basins, and what management actions would mitigate adverse interactions? Results show that the majority of the world’s large river systems are fragmented and have their flow altered by dams. Exceptions to this tend to lie in regions inhospitable to hydropower development, such as northern tundra, or in the least economically active regions. The biogeographic distribution of dam impact is widespread, both at terrestrial and freshwater scales, representing significant threat to global biodiversity. Relatively species-poor tundra is the world’s only terrestrial ecoregion which remains predominantly unaffected by dams. Nearly half of the world’s freshwater ecoregions are internally fragmented by dams, and ecoregional distinctions may be artifically imposed by dams in many cases. Freshwater ecoregions with the highest counts of total and endemic species remain relatively unobstructed, representing significant conservation potential. Diadromy is one of the few fish traits indicative of vulnerability to dams for which data are sufficient for global scale analysis. Lampreys (Lampetra spp.), Eels (Anguilla spp.) and Shad (Alosa spp.) are examples of genera particularly vulnerable to dams because their distributions coincide with the most heavily fragmented freshwater ecoregions, and a large proportion of the coincident species for each genera are diadromous. Due to changes in discharge and water stress, the area of large river basins in need of management interventions to protect ecosystems or people will be much greater for basins impacted by dams than for basins with free-flowing rivers. Proactive measures that restore the natural capacity of rivers to buffer climate-change impacts are more desirable than reactive actions since they may also lead to environmental benefits such as higher water quality and restored fish populations – benefits which may later be unattainable.
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