Environmental Flow Research Papers - Academia.edu (original) (raw)

The flow regimes of temperate large lowland rivers are manipulated to provide various services for society. Most water policy decisions are based on economic considerations, with little or no consideration toward fish conservation and fisheries. The prerequisite for a stronger implementation of these interests in water policy decisions is the development of appropriate tools for assessing the adequate flow needed to protect fish diversity and fisheries resources.

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- Environmental Engineering, Ecology, River, Environmental Flow
- by Seleshi Awulachew
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- Energy Economics, Land management, Behavioral Economics, Institutions

The conclusions of numerous stream restoration assessments all around the world are extremely clear and convergent: there has been insufficient appropriate monitoring to improve general knowledge and expertise. In the specialized field of instream flow alterations, we consider that there are several opportunities comparable to full-size experiments. Hundreds of water management decisions related to instream flow releases have been made by government agencies, native peoples, and non-governmental organizations around the world. These decisions are based on different methods and assumptions and many flow regimes have been adopted by formal or informal rules and regulations. Although, there have been significant advances in analytical capabilities, there has been very little validation monitoring of actual outcomes or research related to the response of aquatic dependent species to new flow regimes. In order to be able to detect these kinds of responses and to better guide decision, a general design template is proposed. The main steps of this template are described and discussed, in terms of objectives, hypotheses, variables, time scale, data management, and information, in the spirit of adaptive management. The adoption of such a framework is not always easy, due to differing interests of actors for the results, regarding the duration of monitoring, nature of funding and differential timetables between facilities managers and technicians. Nevertheless, implementation of such a framework could help researchers and practitioners to coordinate and federate their efforts to improve the general knowledge of the links between the habitat dynamics and biological aquatic responses.

- by C. Sabaton and +1
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- Environmental Engineering, Facility Management, Ecology, River

The demand for sustainable water management has promoted the development of methodologies for estimating environmental flows (EF). In this paper, the EF in an Andean river (Pance, Colombia) for conservation and a Mediterranean river (Wadi-Zomar, Palestine) for restoration purposes is made. Different methodologies are applied given the objectives for each river. The authors used hydrological indices proposed for watersheds with different water regimes and adaptations and validations were made to the local context. These methods allow for estimating the EF at various points in the river and the assessment of disruption scenarios for decision-making. In the Wadi Zomar River, three sampling points were selected. The water samples were then examined for the presence of pathogens. No one indicator or simple hydrological parameter is entirely suitable for all environmental systems and pathogens. In the base flow conditions, the amount of pollutant load varied temporally according to the am...

- by Wilson Noe Garces Aguilar
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- Decision Making, Water quality, Water Management, Case Study

Knowledge of wetland hydrology and quantification of water inputs and outputs are Prerequisites to understanding wetland environments and determining their vulnerability to change. To get a better understanding of the dynamics of wetland change in the Usangu Plains, a study was conducted to: a) investigate the effects of human interventions on the wetlands, and b) determine the amount of dry season inflow required to maintain environmental flows downstream of the wetlands. The study integrated hydrologic data, remote sensing and GIS techniques to study the dynamics and spatial response of the wetlands. A monthly water balance model was developed for the wetlands to determine the major components of the water budget. The results of the analyses indicate that the wetlands have changed appreciably in size over recent years and the inflow volumes have decreased with time as a result of increased human interventions. The dry season vegetated swamp cover, a major component of the swamp, d...

- by Japhet Kashaigili
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- Remote Sensing, Environmental Management, Water balance, Hydrological modelling

In this paper, the effects of environmental stresses on the properties of polymer optical waveguides were studied. Optical multimode waveguides were fabricated on printed circuit boards using commercial polymers. The stability of the optical properties of the guide systems was investigated in damp heat-high humidity, high temperature storage, thermal shock and in environmental flowing multigas tests. Aging at high temperature and temperature cycling reduced the refractive index to largest extent. The optical build-up (o-BU) structure in which the optical layer was fabricated on the board surface was observed to be vulnerable under temperature shock when compared with the structure where the optical layer was laminated inside the FR4/Cu boards. The buffer layer beneath the optical build-up was found to improve the stability of the optical waveguides significantly.

- by marika immonen
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- Printed Circuit Board, Optical Waveguide, Refractive Index, Optical Properties

A reservoir operation simulation study is carried out to analyze the impact of alternative scenarios of a hydropower system operation on energy production and natural flow regime in the La Nga river basin in Vietnam. The current operation policy causes severe hydrologic alteration in the natural flow regime represented by 32 parameters of the Range of Variability Approach (RVA). In the cases of the hydropower system operating at its full generation capacity and under a specified RVA target range at a downstream location, the power production can be increased by eight and four percent while reducing the overall degree of hydrologic alterations by 24 and 27 percent respectively compared to the existing rule-curve based operation. Results indicate that the system operation can be improved with increased power production while maintaining the environmental flow requirements for downstream ecosystems. Ó

- by Umamahesh Nanduri
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- Engineering, Earth Sciences, Vietnam, Hydropower

In regulated rivers, the relationship between wetted perimeter and discharge is sometimes used as an expedient technique for determining the minimum flow allowable for environmental purposes. The critical minimum discharge is supposed to correspond to the point where there is a break in the shape of the curve (usually a logarithmic or power function). Below this discharge, wetted perimeter declines rapidly. This critical point on the curve is almost universally, but incorrectly, termed an 'inflection' point, and is usually determined subjectively by eye from a graph. The appearance of a break in the shape of the curve is strongly dependent on the relative scaling of the axes of the graph. This subjectivity can be overcome by defining the break in shape using mathematical techniques. The important break in the shape of the curve can be systematically defined by the point where the slope equals 1, or where the curvature is maximized. The technique can be applied to other habitat -discharge relationships, provided the habitat variable increases with discharge. These techniques were applied to two regulated headwater streams located in the Melbourne catchment area. Channel survey data were used to model the relationship between discharge and wetted perimeter, flowing water perimeter and blackfish habitat area. A logarithmic function could be fitted to the wetted perimeter data for Starvation Creek, but the relationship for Armstrong Creek was linear. Both streams showed logarithmic relationships between discharge and flowing water perimeter. For these streams, the wetted perimeter relationships did not suggest an optimum environmental flow, nor did they suggest a flow level that would maintain the macroinvertebrate community in its unregulated state if it was applied for a long period of time. Fish habitat area does not necessarily increase with discharge, so the method of curve analysis suggested here for wetted perimeter may not be applicable to some fish habitat area data. Flowing water perimeter is preferable over wetted perimeter as a variable to define habitat suitable for macroinvertebrates.

- by Niladri Dasgupta
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- Environmental Engineering, Ecology, Habitat Suitability, Transect

A group of river managers, stakeholders, and scientists met during summer 2005 to design a more naturalized flow regime for the Lower Missouri River (LMOR). The objective was to comply with requirements under the U.S. Endangered Species Act to support reproduction and survival of threatened and endangered species, with emphasis on the endangered pallid sturgeon (Scaphirhynchus albus), while minimizing negative effects to existing social and economic benefits of prevailing river management. Specific hydrograph requirements for pallid sturgeon reproduction are unknown, hence much of the design process was based on features of the natural flow regime. Environmental flow components (EFCs) extracted from the reference natural flow regime were used to design and assess performance of alternative flow regimes.

- by Robert Jacobson
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- Decision Making, Ecohydrology, Endangered Species, Biological Sciences

We attempted to estimate the economic value of environmental services provided by restored instream flows in the water-scarce Yaqui River Delta in Mexico. The Yaqui River begins near the U.S.-Mexico border and continues for 400 km before reaching the Oviachic dam, but has not reached the nearby Gulf of California for decades due to diversions for irrigation. These diversions have degraded the riparian ecosystem, coastal wetlands, and estuaries. Environmental services provided by restored flows in the Yaqui River would include healthy riverside vegetation, wetlands and estuaries, fish and wildlife habitats, nonuse values, and recreation. A contingent valuation survey in 40 neighborhoods in the most populated Delta city, Ciudad Obregon, was administered to estimate non-market values of instream uses. Respondents were given a current and hypothetical Delta scenario (the latter assumed restored water flows in the River) and asked a willingness-to-pay (WTP) question regarding purchasing water for environmental flows through higher water bills. Results from 148 in-person interviews indicated that households would pay an average of 73 pesos monthly. WTP was found related to key variables suggested by economic theory and contingent valuation studies elsewhere: income, educational level, number of children in the household, and initial bid amount. These results will allow decision makers to compare the benefits generated by different water uses, including environmental services, and to manage scarce water resources under a long-term sustainable approach.

- by Barry D Solomon
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- Ecological Economics, Economic Theory, Applied Economics, Contingent valuation

The South African Water Act of 1998 stipulates that future water resource developments should be environmentally sustainable and that a component of the natural flow of rivers should be reserved to ensure some level of ecological functioning. Detailed methods for quantifying the environmental instream flow requirements of rivers have been available internationally and in South Africa for some time, but the implementation of the new act introduced a degree of urgency and pointed towards the need for rapid, low-confidence assessments that could be used for initial planning. The desktop reserve model was developed to fulfil this requirement, but since its development in 1999 there have been many more detailed IFR determinations. During 2001 the model underwent a complete review based on the results from 97 detailed IFR determinations involving groups of specialists applying the building block methodology (BBM). The paper explains the conceptual links between the BBM and the model, describes the algorithms that constitute the model and discusses some of the problems associated with developing a model of this type from limited data and limited scientific understanding of the underlying principles. Most of the problems are related to the lack of a consistent understanding of the relationships between hydrological variations and ecological functioning of rivers across a range of river types within a large geographic region (South Africa, for example). The paper indicates that despite these problems the model has found a niche in the water resource management industry within South Africa and has the potential to be improved as our scientific understanding of eco-hydrology improves. q

- by Denis Hughes
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- Hydrology, Environmental Sustainability, Multidisciplinary, South Africa

Diatom blooms in the middle reaches of the shallow, freshwater, Hunter River, Australia, are a frequent nuisance to river users. During a 4-year study, blooms of Cyclotella meneghiniana and Nitzschia spp. coincided with water temperatures above 23°C and flows below 400 Ml d À1 that lasted for more than 12 days. Redundancy analysis showed that water temperature was positively related, and antecedent flow was negatively related, to the abundance of both taxa. Addition experiments indicated that nutrients are seldom limiting to growth. It is suggested that a combination of faster growth rates at higher temperatures and longer retention times at low flows allows bloom populations to develop. Simulation modelling showed that flow regulation and water extraction have decreased flows in the river during summer, and consequently have probably increased the number of diatom blooms. Environmental flows have been provided to the river, but are not sufficient to prevent blooms. Discharges required for bloom suppression are described.

- by Simon Mitrovic and +1
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- Earth Sciences, Biological Sciences, Environmental Sciences, Water Temperature

This paper is concerned with the major issues considered to be important for successful application of computational #uid dynamics to environmental #ows. Among the issues of primary concern in the present paper are meshing and turbulence modeling. As regards meshing, we propose an approach that employs unstructured meshes in conjunction with solution-adaptive mesh re"nement. Examples are presented to illustrate the e$cacy of the unstructured mesh-based approach. The issue of turbulence modeling is discussed at length, inasmuch as turbulence modeling determines the "delity of computational results for environmental applications. Emphasis is laid upon the capability of engineering turbulence models to capture the salient features of environmental #ows such as atmospheric boundary layer over a smooth terrain and #ows around blu! bodies.

If strategies in natural resource management are to 'work with nature', reliable biophysical baseline data on ecosystem structure and function are required. The River Styles framework provides a geomorphic template upon which spatial and temporal linkages of biophysical processes are assessed within a catchment context. River Styles record river character and behaviour. As the capacity for a river reach to adjust varies for each style, so too do management issues and associated rehabilitation programmes. The framework also provides a basis for assessing geomorphic river condition and recovery potential, framed in terms of the evolutionary pathways of differing River Styles in the period since the European settlement of Australia. Within a catchment context, the River Styles framework provides a unified baseline upon which an array of additional information can be applied, thereby providing a consistent framework for management decision-making. The framework was developed as a research tool by geomorphologists working in collaboration with the New South Wales Department of Land and Water Conservation, which has used it for a range of river management applications. Target conditions for rehabilitation programmes are framed within a catchment vision that integrates understanding of the character, behaviour, condition and recovery potential of each reach. A prioritization procedure determines the most cost-effective and efficient strategies that should be implemented to work towards the catchment vision. In addition, the River Styles framework is being used to identify rare or unusual geomorphic features that should be pre- * Corresponding author.

- by David Outhet and +1
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- Human Geography, Decision Making, Water quality, Natural Resource Management

In the last decade there has been an increasing awareness of the importance of channel morphology in the healthy functioning of Australian rivers. However, the relationship between channel morphology and the flow and sediment regime of a river is often poorly understood. As a result, within-channel features such as bars, banks and benches are often considered static. Benches are an actively accreting fine-grained bankattached feature within the river channel which contribute a significant store of suspended-grained sediment and have been identified as ecologically important. As managers design and release environmental flows, they need to know how much these flows will modify benches. Benches are a characteristic feature of Australian rivers, and this paper describes initial findings of a field study of the relationship between flow, sediment transport, and bench morphology in the mostly unregulated Ovens River, and highly regulated River Murray, southeastern Australia. We discuss t...

- by Michael Stewardson
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- Environmental flows, Sediment transport, Field Study, Flow Regime
- by Aster Denekew
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- Energy Economics, Land management, Behavioral Economics, Institutions

ISBN 0 7347 5191 5 Integrated monitoring of environmental flows: design report Department of Land and Water Conservation 3 Contents Preface____________________________________________________________________5 1. Background____________________________________________________________7 2. Environmental flows monitoring ___________________________________________9 3. Context, scope and limitations ____________________________________________10 4. Approach to project design and implementation______________________________13 5. Intended environmental outcomes of RFOs _________________________________15 6. Likely flow changes under current flow rules ________________________________19 7. Sensitive ecosystem components and attributes ______________________________22 8. Development of hypotheses ______________________________________________34 9. Prioritisation of hypotheses ______________________________________________37 10. Study design and statistical analysis _______________________________________39 11. Review _______________________________________________________________45 12. References ____________________________________________________________46 Appendix 1: Flow rules for 1999-2000 _________________________________________64

- by Kerrie Tomkins
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- Aquatic Ecology, River Engineering, Australia, Environmental Sustainability
- by Angela Arthington
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- Environmental Engineering, History, Hydrology, Ecology
- by Luyla Netto
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- Environmental Flow
- by Angela Arthington
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- Earth Sciences, Biological Sciences, High Frequency, Aquatic Ecosystem
- by Niladri Dasgupta
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- Water Purification, Multidisciplinary, Water Management, Habitat complexity
- by Angela Arthington
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- Environmental Flow

Current understanding of tropical cyclone (TC) structure and intensity changes has been reviewed in this article. Recent studies in this area tend to focus on two issues: (1) what factors determine the maximum potential intensity (MPI) that a TC can achieve given the thermodynamic state of the atmosphere and the ocean? and (2) what factors prevent the TCs from reaching their MPIs? Although the MPI theories appear mature, recent studies of the so-called superintensity pose a potential challenge. It is notable that the maximum intensities reached by real TCs in all ocean basins are generally lower than those inferred from the theoretical MPI, indicating that internal dynamics and external forcing from environmental flow prohibit the TC intensification most and limit the TC intensity. It remains to be seen whether such factors can be included in improved MPI approaches.

- by Yuqing Wang
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- Thermodynamics, Atmospheric sciences, Inner Core, Environmental Conditions
- by Robin Welcomme
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- Environmental Engineering, Geomorphology, Ecology, Biodiversity

This paper investigates water availability and use in the Komati catchment. The Komati catchment is shared by Swaziland and South Africa and forms part of the Incomati basin, with Mozambique as the third riparian country. In 2002 the three countries reached agreement about how the scarce water should be allocated, based on the principle of equitable and sustainable utilization, as stipulated by the SADC Protocol. The Komati catchment has five main water uses: afforestation, irrigation, the environment, urban/industrial/mining (UIM), and interbasin water transfers (for industrial use). In addition, South Africa and Swaziland have committed themselves to satisfy a certain cross border flow to downstream Mozambique.

- by Sakhiwe Nkomo
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- Geology, Geochemistry, Geophysics, Water Availability

1. Relationships between river flow characteristics and fish community/population dynamics (i.e.
flow–ecology relationships) underpin methods to determine and monitor environmental water allocations.
Quantifying these relationships can be difficult, and consequently, most environmental flow
strategies for fish conservation in Australian rivers are based on general flow–ecology relationships
as opposed to statistical predictions.
2. Of those studies that have investigated relationships between flow and fish, most have not
accounted for incomplete and variable detection of fish by the sampling methods, thus making the
implicit assumption that sampling efficiency is invariant. This important assumption is rarely met,
leading to inconsistent research findings and spurious results, and a reliance on generic flow–ecology
principles for defining flow management strategies.
3. We illustrate how and when detection probability varies when sampling freshwater fish and the
consequences to scientific inference about fish–flow relationships. Methods for accounting for imperfect
detection of fish are identified and tools to increase the efficiency of experimental designs while
reducing sampling cost are discussed. These tools include methods for borrowing information among
experimental components and simulation techniques to optimise sampling designs.
4. We argue that, due to the very nature of sampling designs to quantify flow–ecology relationships
(e.g. sampling at different flow magnitudes/regimes), the challenge of imperfect detectability is particularly
relevant to environmental flow science. We encourage the broader adoption of methods that
account for imperfect detection to improve inference about fish–flow relationships and increase the
successful application of environmental flows for managing fish communities.

- by Daniel C Gwinn and +3
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- River Ecology, Fish Ecology, Fish management and conservation, Environmental flows

1. In an effort to develop quantitative relationships between various kinds of flow alteration and ecological responses, we reviewed 165 papers published over the last four decades, with a focus on more recent papers. Our aim was to determine if general relationships could be drawn from disparate case studies in the literature that might inform environmental flows science and management. 2. For all 165 papers we characterised flow alteration in terms of magnitude, frequency, duration, timing and rate of change as reported by the individual studies. Ecological responses were characterised according to taxonomic identity (macroinvertebrates, fish, riparian vegetation) and type of response (abundance, diversity, demographic parameters). A 'qualitative' or narrative summary of the reported results strongly corroborated previous, less comprehensive, reviews by documenting strong and variable ecological responses to all types of flow alteration. Of the 165 papers, 152 (92%) reported decreased values for recorded ecological metrics in response to a variety of types of flow alteration, whereas 21 papers (13%) reported increased values. 3. Fifty-five papers had information suitable for quantitative analysis of ecological response to flow alteration. Seventy per cent of these papers reported on alteration in flow magnitude, yielding a total of 65 data points suitable for analysis. The quantitative analysis provided some insight into the relative sensitivities of different ecological groups to alteration in flow magnitudes, but robust statistical relationships were not supported. Macroinvertebrates showed mixed responses to changes in flow magnitude, with abundance and diversity both increasing and decreasing in response to elevated flows and to reduced flows. Fish abundance, diversity and demographic rates consistently declined in response to both elevated and reduced flow magnitude. Riparian vegetation metrics both increased and decreased in response to reduced peak flows, with increases reflecting mostly enhanced non-woody vegetative cover or encroachment into the stream channel. 4. Our analyses do not support the use of the existing global literature to develop general, transferable quantitative relationships between flow alteration and ecological response; however, they do support the inference that flow alteration is associated with ecological change and that the risk of ecological change increases with increasing magnitude of flow alteration. 5. New sampling programs and analyses that target sites across well-defined gradients of flow alteration are needed to quantify ecological response and develop robust and

1. Methods to assess the physical habitat available to aquatic organisms provide important tools for many aspects of river management, including river health monitoring, determination of river restoration/rehabilitation strategies,... more

- by Kirsty Robson
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- Geomorphology, Ecology, Biological Sciences, Environmental Sciences

The EU water framework directive (WFD) provides a template for sustainable water management across Europe. The WFD requires the development of procedures to ensure appropriate mitigation of anthropogenic impacts on river ecosystems resulting from water abstraction and impoundments. It is widely acknowledged that alterations to flow regime impact on riverine ecosystems. As a result, hydromorphology, which includes the hydrological regime, is embedded within the WFD as a supporting element to achieve good ecological status (GES). Environmental flow releases from impoundments such as reservoir dams will need to be implemented to mitigate impacts from their construction and operation. This paper outlines the process involved in the analysis of available scientific information and the development of guidance criteria for the setting of environmental flow release regimes for UK rivers. The paper describes two methods-developed by round-table expert knowledge and discussions and supported by available data-for implementation of the WFD for rivers subject to impoundments. The first is a method for preliminary assessment of a water body to determine if it is likely to fail to achieve GES because of changes to the flow regime (indexed by simple flow regime statistics) in systems where appropriate biological assessment methods are limited or currently unavailable. The second is a method for defining an environmental flow regime release based on the requirements of riverine ecological communities and indicator organisms for basic elements (building blocks) of the natural flow regime.

Environmental flow requirements for the Rusape River, a tributary of the Save River, in Zimbabwe, were estimated using a rapid results approach. Thirty years of hydrological data with daily time steps from gauging stations upstream and downstream of the Rusape Dam were analysed using DRIFT Software. The dam appeared to have caused an increase in intra-annual and inter-annual flood events downstream compared to upstream, including significant dry season releases, while inter-annual floods were larger. The water releases from the dam differ from the natural flow in both volume and frequency, especially in the dry season and may have had a negative impact on the local ecosystem and subsistence farmers.The building block method (BMM) was applied, using the hydrological analyses performed, in order to estimate environmental flow requirements, which are presented in mean monthly flows. The flow regime that is recommended for the Rusape River should reduce or reverse these impacts, whilst ensuring sufficient water resources are released for economic needs. The EFR proposed can be achieved within mean monthly flows observed. However, it should be stressed that the EFR proposed have been developed from a rapid method, and are only a first estimate of the EFR for the Rusape River. This study represents a step in developing a management plan for the Save Basin, shared between Zimbabwe and Mozambique.

- by evans kaseke
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- Geology, Geochemistry, Geophysics, Environmental flows

This paper employs an economic-engineering optimization model to explore water supply options for environmental restoration of the Colorado River Delta, Mexico. Potential water sources include reductions in local agricultural and urban water use through water markets, wastewater reuse, and additional Colorado River flows from the United States. For these alternatives, the optimization model estimates operating and water scarcity costs, water scarcity volumes, and marginal economic costs of environmental flows and values of additional Colorado River flows from the United States over a range of required delta environmental flows. Economic values for agricultural and urban water uses were estimated by two ancillary models. The results provide insights into economically promising water supplies for restoration activities. Quantifying the trade-off between agricultural and urban economic valuation and environmental flows provides a framework for decision makers to quantify their valuation of environmental flows. The model also provides a framework for integrating additional knowledge of the system as information becomes available.

- by Angela Arthington
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- Environmental Engineering, Ecology, River, Environmental Flow

To assess global water availability and use at a subannual timescale, an integrated global water resources model was developed consisting of six modules: land surface hydrology, river routing, crop growth, reservoir operation, environmental flow requirement estimation, and anthropogenic water withdrawal. The model simulates both natural and anthropogenic water flow globally (excluding Antarctica) on a daily basis at a spatial resolution of 1 • ×1 • (longitude and latitude). This first part of the two-feature report describes the six modules and the input meteorological forcing. The input meteorological forcing was provided by the second Global Soil Wetness Project (GSWP2), an international land surface modeling project. Several reported shortcomings of the forcing component were improved. The land surface hydrology module was developed based on a bucket type model that simulates energy and water balance on land surfaces. The crop growth module is a relatively simple model based on concepts of heat unit theory, potential biomass, and a harvest index. In the reservoir operation module, 452 major reservoirs with >1 km 3 each of storage capacity store and release water according to their own rules of operation. Operating rules were determined for each reservoir by an algorithm that used currently available global data such as reservoir storage capacity, intended purposes, simulated inflow, and water demand in the lower reaches. The environmental flow requirement module was newly developed based on case studies from around the world. Simulated

- by Kooiti Masuda
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- Environmental Engineering, Civil Engineering, Climate Change, Hydrology

River scientists are increasingly asked to provide recommendations about the amount and timing of water flows needed to support ecosystem health. The need for scientifically credible environmental flow assessments and the limited availability of resources to conduct in-depth studies place a premium on methods that can be readily applied at low cost. The Indicators of Hydrologic Alteration (IHA) software program was originally developed by The Nature Conservancy in the 1990s to quickly process daily hydrologic records to enable characterization of natural water conditions and facilitate evaluations of human-induced changes to flow regimes. The evolution of the IHA software is discussed, including recent revisions and additions to the IHA that have improved its utility in environmental flow-setting processes. Drawing from holistic methodologies developed around the world, the ability to calculate characteristics of five components of flow important to river ecosystem health -extreme low flows, low flows, high-flow pulses, small floods and large floods -has been added to the IHA. A practical advantage of these environmental flow components is that an environmental flow prescription based upon them can be readily implemented in most water management settings. Frequently used as a one-time generator of flow statistics, the value of the IHA increases when used interactively with ecological models. A process for linking IHA output to an ecological model to explore flow-ecology relationships within an adaptive management context is presented and demonstrated through its application on the Green River, Washington. The IHA used in conjunction with ecological models facilitates the creation and testing of flow-ecology hypotheses, formulation of water and land protection or restoration goals, and development of a focused research and monitoring program, all important components of environmental flow-setting processes.

IWMI receives its principal funding from 58 governments, private foundations and international and regional organizations known as the Consultative Group on International Agricultural Research (CGIAR). Support is also given by the... more

- by Kamal eldin Bashar
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- Geography, Energy Economics, Land management, Behavioral Economics

- by Michael Stewardson
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- Environmental Engineering, Ecology, Habitat Suitability, Transect

The River Murray is a "working river" in the sense that its regulation and management delivers significant economic wealth and social benefits to local communities and wider Australia. Recognition of ongoing deterioration of the riverine environment has prompted several environmental flow initiatives, including establishment in 1999 of the "Environmental Flows and Water Quality Objectives for the River Murray Project" (the Project). This paper reports progress on the main aspects of the Project to date.

- by T. Jacobs and +1
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- Water quality, Australia, Environmental Monitoring, Multidisciplinary

IWMI's mission is to improve water and land resources management for food, livelihoods and nature. In serving this mission, IWMI concentrates on the integration of policies, technologies and management systems to achieve workable solutions to real problems-practical, relevant results in the field of irrigation and water and land resources.

- by Hans Bressers
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- Civil Engineering, Geology, Geochemistry, Geophysics

The establishment of environmental flows and the management of flood releases from existing dams is a complicated process involving numerous stakeholders. Whilst the benefits of environmental flows have been demonstrated in many parts of the world, there is much less experience with managed flood releases from reservoirs. In this paper, we will present the experience of a WWF sponsored project

- by Jamie Pittock
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- Food Security, Hydrological modelling, River Basin, Flow Regime

The populist view of economic development and the environment is that advances in one will necessarily result in a decline in the other. Evidence in the Australian context is that the dual goals can be achieved simultaneously. As economic development progresses, the increasing levels of income stimulate greater demand for environmental improvements. The population engages in more environmentally focused consumption and calls for its governments to introduce more policies designed to rehabilitate and protect environmental assets. Concurrently, the increasing levels of wealth allow for increasing expenditure on research and development into production processes that generate greater productivity and less environmental damage. The Australian agricultural sector provides numerous examples of concurrent improvements in productivity and environmental condition. Zero tillage broad acre grain cultivation practices have led to lower rates of soil erosion and have enriched soil biota while de...

- by Jeff Bennett
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- Economics, Financial Economics, Energy Economics, Political Economy

This paper presents results of a large-scale economic-engineering optimization model of California's water supply system. The results of this 4-year effort illustrate the value of optimization modeling for providing integrated information needed to manage a complex multipurpose water system. This information includes economic benefits of flexible operations, economic valuation of capacity expansion opportunities, estimating user willingness to pay for additional water, economic opportunity costs of environmental flows, and identification of promising conjunctive use and water transfer opportunities. The limitations of such modeling also are discussed. Overall, the results suggest improvements to system operation and water allocations with a statewide expected value potentially as high as $1.3 billion/year. Significant improvements in performance appear possible through water transfers and exchanges, conjunctive use, and various operational changes to increase flexibility. These changes also greatly reduce costs to agricultural and urban users of accommodating environmental requirements. Model results also suggest benefits for expanding selected conveyance and storage facilities.

- by guilherme marques
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- Environmental Engineering, Civil Engineering, Water, Optimization

Rivers provide a special suite of goods and services valued highly by the public that are inextricably linked to their flow dynamics and the interaction of flow with the landscape. Yet most rivers are within watersheds that are stressed to some extent by human activities including development, dams, or extractive uses. Climate change will add to and magnify risks that are already present through its potential to alter rainfall, temperature, runoff patterns, and to disrupt biological communities and sever ecological linkages. We provide an overview of the predicted impacts based on published studies to date, discuss both reactive and proactive management responses, and outline six categories of management actions that will contribute substantially to the protection of valuable river assets. To be effective, management must be place-based focusing on local watershed scales that are most relevant to management scales. The first priority should be enhancing environmental monitoring of changes and river responses coupled with the development of local scenario-building exercises that take land use and water use into account. Protection of a greater number of rivers and riparian corridors is essential, as is conjunctive groundwater/surface water management. This will require collaborations among multiple partners in the respective river basins and wise land use planning to minimize additional development in watersheds with valued rivers. Ensuring environmental flows by purchasing or leasing water rights and/or altering reservoir release patterns will be needed for many rivers. Implementing restoration projects proactively can be used to protect existing resources so that expensive reactive restoration to repair damage associated with a changing climate is minimized. Special attention should be given to diversifying and replicating habitats of special importance and to monitoring populations at high risk or of special value so that management interventions can occur if the risks to habitats or species increase significantly over time. Keywords River Á Climate change Á Management options Á Land use change Á Floods Á Droughts

- by Brian Richter
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- Climate Change, Environmental Management, Forecasting, Environmental Monitoring

With increasing demand being placed on water resources the efficient use of water is inevitable to increase rice productivity. The availability of water through a catchment can vary significantly with some water being used in upstream irrigation activities, for environmental flows, groundwater and infiltration movements, all resulting in challenges and costs for irrigators accessing water for their production systems. The use of tubewells, dams and groundwater extraction to access available water requires substantial capital investments.

- by Jerry Maroulis
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- Water Reuse, Capital Investment, Surface Water, Water scarcity

Australia’s largest river system, the Murray-Darling Basin, is the focus of scientific and political attention, due mainly to the competing issues of economic productivity versus environmental flows. Central to this dialogue is the need to know about the Basin’s natural condition and the degree to which the system has deviated from this pre-disturbance, baseline status. This study examines the patterns of ecological change in Lake Cullulleraine, a permanently connected artificial wetland adjacent to Lock Nine on the Murray River, south-east Australia. A 43-cm sediment core was collected in January 1998 and diatoms were analysed at 1-cm intervals for use as aquatic ecological indicators. The sediment core was dated using 210Pb. Changes in the diatom community have occurred since the time of lake formation in 1926, particularly shifts between Aulacoseira subborealis, Staurosira construens var. venter, Aulacoseira granulata, Staurosirella pinnata and Pseudostaurosira brevistriata. An electrical conductivity (EC) transfer function was applied to the fossil diatom assemblages and inferred EC values were compared to long-term, historical EC data from the River. Despite the presence of good analogues between fossil and modern diatom assemblages, inferred EC did not reflect measured EC accurately. In recent decades, patterns in the two data sets were reversed. Despite clear changes in the fossil record, quantitative palaeo-environmental interpretation was limited because the dominant taxa occupy broad ecological niches. Despite these limitations, changes in the Lake Cullulleraine record, particularly in the planktonic taxa, can be interpreted in terms of landscape change. Furthermore, because of the good chronology from the site, the record may be useful for dating changes observed in sites with poor chronological control.

- by John Tibby
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- Geology, Ecological Niche Modeling, Paleolimnology, Ecological Indicator

Management of scarce water resources through the use of environmental flows, particularly in developing countries in data-poor arid areas, raises many scientific challenges. These include transforming hydrological data into an ecologically relevant format, providing quantified predictions of river responses to flow change, describing the impacts of river change on common-property users of the rivers, providing the information in a format

- by Cate Brown
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- Common Property, Decision support system, Aquatic Ecosystem, South Africa