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1.
Understanding the trade‐offs between water for the environment and water for hydropower in regulated rivers can inform decision making about hydropower system planning, policy and operations, especially with anticipated climate warming–induced changes in runoff. This study used a multireservoir optimisation model to assess the hydropower effects of increasing minimum instream flows (MIFs) and imposing weekly scale down ramp rates (DRRs) in three locations in California's Upper Yuba River (UYR). The UYR is currently used for hydropower generation yet has high potential for freshwater habitat restoration. Trade‐offs between DRRs, MIFs and hydropower generation and revenue are explored with uniform air temperature increases of 0 °C, 2 °C, 4 °C and 6 °C to approximate anticipated regional climate warming. With 6 °C warming, the most ecologically beneficial MIF and DRR reduced hydropower generation by 7.9% and revenue by 5.5% compared with base case management and a historical climate. This has important implications for licensure of the UYR project and other hydropower projects, where multiple benefits under current and potential future conditions must be balanced. This study provides a methodological approach that can be used by water managers, regulators and stakeholders to better understand inherent trade‐offs in allocating water for multiple beneficial uses in a nonstationary hydroclimate. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
2.
Whitewater recreation is an aesthetic ecosystem service potentially affected by climate warming alterations to runoff. In California's Sierra Nevada, climate change is likely to reduce water availability with warmer air temperatures and stationary or decreasing precipitation, which will likely alter whitewater recreation opportunities. In this study, we identified 128 whitewater runs on the west slope of the Sierra Nevada within a 13‐basin study area that ranged from serene float trips to remote, difficult, kayak expeditions. We used a spatially explicit, one‐dimensional rainfall‐runoff model to estimate the unregulated hydrology at specific locations within flow thresholds amenable to whitewater recreation. Climate warming scenarios were simulated by increasing air temperature by 2 °C, 4 °C and 6 °C and assuming no change in precipitation. With mild warming, the average number of boatable weeks per year increases, but more extreme warming decreases the average boatable weeks per year across the Sierra Nevada. Runs in low‐elevation drainages, such as the Cosumnes and the Tule River Basins, are most vulnerable to changes in boatable weeks. Yet, high‐elevation watersheds, such as the Kern River, also have a large reduction in boatable weeks. Watersheds in the central Sierra Nevada show an increase in boatable weeks. Overall, we found elevation and run type to be the best predictors of resiliency for Sierra Nevada whitewater runs. Recreation is important for management of rivers, yet it is difficult to quantify and to plan for. This research provides a sensitivity analysis approach to climate warming for the Sierra Nevada and presents a method that can be applied to other regions and whitewater rivers. The observed reduction in whitewater recreation opportunities in unregulated rivers because of climate warming and continued increases in population will likely increase the importance of whitewater boating on regulated rivers and thus the reliance on operations for meeting multiple demands. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
3.
A. L. Rypel 《河流研究与利用》2011,27(5):580-590
Impoundment of rivers by dams is widespread and one of the most devastating anthropogenic impacts to freshwater environments. Linking theoretical and applied research on river impoundment requires an improved capacity for predicting how varying degrees of impoundment affects a range of species. Here, growth of 14 North American sunfish species resilient to river impoundment was compared in rivers versus impoundments. Growth response to river impoundment varied widely, but consistently among taxa: five species (shadow bass, rock bass, flier, redbreast sunfish and green sunfish) showed significantly higher growth in riverine ecosystems, four species (largemouth bass, smallmouth bass, spotted bass and longear sunfish) showed significantly higher growth in impounded ecosystems, and five species (bluegill, black crappie, white crappie, redear sunfish and warmouth) displayed no difference in growth between rivers and impoundments. Furthermore, significant linear models were developed for predicting growth of two species (largemouth bass, R2 = 0.75 and warmouth, R2 = 0.44) based on a physiographically specific index of reservoir retention time. For another species (white crappie), growth could not be predicted by the retention time index in Central Lowlands rivers (R2 = 0.001), but was strongly predicted by this factor in southeastern Coastal Plain rivers (R2 = 0.76) showing how impacts of impoundment, and prediction of its consequences, can vary across river landscape types. Further analysis of fish growth in response to river impoundment, regulation and fragmentation could greatly enhance conservation biology, restoration ecology and basic land use decisions in riverine landscapes. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
4.
We assessed the climate‐driven changes in ecologically relevant flow regimes expected to occur by the year 2100 in streams across the conterminous United States. We used long‐term daily flow measurements from 601 gauged streams whose watersheds were in relatively natural condition to characterize spatial variation in 16 flow regime variables selected for their ecological importance. Principal component analysis of these 16 variables produced five uncorrelated factors that described patterns of spatial covariation in flow regimes. These five factors were associated with low flow, magnitude, flashiness, timing, and constancy characteristics of the daily flow regime. We applied hierarchical clustering to the five flow factors to classify the 601 streams into three coarses and eight more finely resolved flow regime classes. We then developed a random forest model that used watershed and climate attributes to predict the probabilities that streams belonged to each of the eight finely resolved flow regime classes. The model had a prediction accuracy (per cent correct classification) of 75%. We used the random forest model with downscaled climate (precipitation and temperature) projections to predict site‐specific changes in flow regime classes expected by 2100. Thirty‐three per cent of the 601 sites were predicted to change to a different flow regime class by 2100. Snow‐fed streams in the western USA were predicted to be less likely to change regimes, whereas both small, perennial, rain‐fed streams and intermittent streams in the central and eastern USA were predicted to be most likely to change regime. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
5.
Dams threaten a wide range of aquatic organisms in most rivers and are thus a primary cause of global biodiversity degradation. Although macroinvertebrates play important roles in biogeochemical processes and ecosystem structuring and functioning through food web links, a global overview of research on their responses to dam construction and the subsequent flow alteration is lacking. This study bibliometrically analysed publications with regard to dams and macroinvertebrates over the last 100 years (1920–2018). The results found that macroinvertebrates have been increasingly studied in regard to damming rivers globally during the research period. The United States contributed the most to the total publication output (21.14%). Keyword analysis revealed a clear evolution and distributional pattern of research themes and studied taxa. Studies on a single taxon were more common in early times, and recent studies have shifted to multiple taxa at the community level. Different countries/territories have different research priorities (i.e., themes and taxa). “Dam removal” and “restoration” occurred more frequently in American studies, and “river regulation” was highly researched in Australia and Poland. “Schistosomiasis” was a featured topic in China and Brazil. “Mollusc” was the top taxon of focus for America, China, and Brazil. The results also demonstrated that “functional diversity,” “model,” and “stable isotope” are emerging hotspots in this research area. Possible explanations and implications of the above findings are discussed. This study provides an integral understanding of the research on dams and macroinvertebrates, highlighting the potential conservation imbalance among countries/territories and taxa. 相似文献
6.
The natural flow regime can sustain the ecological integrity of riverine ecosystems. Different reservoir operation polices differ in their effects on the degree of alteration of natural flow regimes. Dynamic programming plays an important role in developing operation policies. When using dynamic programming models to develop operation policies, the discrete number of storage states (DNSS), which is a key factor affecting the reservoirs operation policies, is always been determined based on computational efficiency and economic benefits. Little consideration has been given to the ecological disturbance caused by different DNSS‐based operation policies. To analyze the impact of DNSS, we built a deterministic dynamic programming model to explore the relationship among DNSS, the flow regime alteration (ecological disturbance), and the cumulative annual power generation (economic benefits) by setting a range of DNSS scenarios. We used three reservoirs with different storage coefficients (ratios of usable storage to annual average runoff) as examples and used the range of variability approach to assess the ecological disturbance under these scenarios. We compared the results with those of a stochastic dynamic programming (SDP) model and a Bayesian SDP (BSDP) model. We found that when DNSS is low, increasing DNSS improves economic benefits but causes a more severe ecological disturbance; when DNSS is high, increasing DNSS improves the economic benefits only slightly, without exacerbating the ecological disturbance; for a given DNSS, the BSDP model provides higher economic benefits than the SDP model and a similar disturbance of the riverine ecosystem; and larger reservoirs more often cause more severe disturbance of riverine ecosystems because monthly mean flows and annual extreme flows change more drastically. Our results will help to protect the riverine ecosystems and improve economic benefits if reservoir operation managers consider DNSS using dynamic programming models. 相似文献
7.
针对目前水库生态调度研究重点考虑河道内生态需水量保障单一目标,忽略河道天然径流情势恢复的问题,将水文改变指标(IHA)分为两类,分别量化河道内生态需水与径流情势,定义河道内生态缺水量最小和河道天然径流情势贴合度最大双生态目标,结合河道外社会经济供水目标,构建水库群多目标优化调度模型,对我国南方某水库群开展实例研究。结果表明:基于双生态目标调度模型优选的均衡调度方案可在保障河道外主要用水对象供水保证率不低于95%的同时,使河道内目标生态需水保证率达到91.67%;构建的模型能有效兼顾社会经济和河流生态环境效益,提升河道天然径流情势贴合度,与只考虑河道内生态需水的水库群调度模型相比,更有利于河流生态保护。 相似文献
8.
Benjamin T. Kelly;Lindsey A. Bruckerhoff; 《河流研究与利用》2024,40(7):1273-1285
Intermittent streams exhibit regular patterns of drying and are widespread, but the patterns of drying among streams within geographic proximity are not fully understood. We compared annual patterns of flow and drying among 10 intermittent streams within a single drainage basin and assessed how traditional hydrologic metrics described variation between streams. We installed stream intermittency sensors and evaluated stage height using low-cost methods and evaluated landscape factors as potential drivers of flow patterns. Intermittent streams varied based on both high- and low-flow metrics, driven by a variety of landscape-level factors, especially watershed size. Additionally, we compared the observed flow regimes within our system with predictions generated using an established Soil and Water Assessment Tool, finding that modeled streamflow patterns generally underrepresented observed drying within the system. 相似文献
9.
Natural river flow regimes provide an array of ecological and social functions by sustaining the health of riverine ecosystems. To identify the hydrologic alterations in the lower Yellow River basin caused by natural factors and human activities, we developed multistage hydrologic analysis to investigate the temporal variability of the river's flow regimes. We used a cumulative departure curve and Mann–Whitney–Pettitt nonparametric tests to determine possible change points based on hydrologic data from 1950 to 2006. We then used the range of variability approach to characterize and to quantify the temporal variability of the hydrologic regimes that were associated with perturbations such as dam operation, flow diversions or intensive conversion of land use within the watershed. In the case study, three stages in hydrologic alterations of the flow regime were found: a stage without human impacts, a stage with excessive human impacts and a reservoir‐regulation stage. Our results indicated that (i) after 1997, dam operation efficiently achieved flood control using sediment regulation activities; (ii) although effective in flood control, the Xiaolangdi Reservoir could not handle situations with extremely low flow, such as during droughts; and (iii) under the arid climate of the Yellow River basin, water consumption by agriculture was the main cause of water shortages. The current study shows that multistage hydrologic analysis can greatly assist regional water resources management and the restoration of riparian eco‐environmental systems affected by dam construction under a changing environment. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
10.
水文变化的生态限度框架(ELOHA)是环境流理论最新成果。ELOHA要求对河流按照水文情势特征进行分类,相同类型河流的水文—生态关系具有相似性。ELOHA还要求对开发前后水文情势变化进行分析,计算现状水文条件与基准水文条件的偏离程度。ELOHA提出了水文情势变化预期生态响应的若干假定,总结了一套为建立水文—生态关系采用的生态指标。在建立大型水文和生物数据库的基础上,运用统计学方法拟合水文—生态函数关系。最后,各利益相关者对水文变化引起的生态风险进行评估,认定可以接受的生态风险水平,再依据水文—生态曲线,确定环境流标准。 相似文献
11.
C. L. R. Laizé M. C. Acreman C. Schneider M. J. Dunbar H. A. Houghton‐Carr M. Flörke D. M. Hannah 《河流研究与利用》2014,30(3):299-314
Projection of future changes in river flow regimes and their impact on river ecosystem health is a major research challenge. This paper assesses the implications of projected future shifts in river flows on in‐stream and riparian ecosystems at the pan‐European scale by developing a new methodology to quantify ecological risk due to flow alteration (ERFA). The river network was modelled as 33 668 cells (5′ longitude × 5′ latitude). For each cell, modelled monthly flows were generated for an ensemble of 10 scenarios for the 2050s and for the study baseline (naturalized flows for 1961–1990). These future scenarios consist of combinations of two climate scenarios and four socio‐economic water‐use scenarios (with a main driver of economy, policy, security or sustainability). Environmental flow implications are assessed using the new ERFA methodology, based on a set of monthly flow regime indicators (MFRIs). Differences in MFRIs between scenarios and baseline are calculated to derive ERFA classes (no, low, medium and high risk), which are based on the number of indicators significantly different from the baseline. ERFA classes are presented as colour‐coded pan‐European maps. Results are consistent between scenarios and show that European river ecosystems are under significant threat with about two‐thirds at medium or high risk of change. Four main zones were identified (from highest to lowest risk severity): (i) Mediterranean rim, southwest part of Eastern Europe and Western Asia; (ii) Northern Europe and northeast part of Eastern Europe; (iii) Western and Eastern Europe; and (iv) inland North Africa. Patterns of flow alteration risk are driven by climate‐induced change, with socio‐economics as a secondary factor. These flow alterations could be manifested as changes to species and communities, and loss of current ecosystem functions and services. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
12.
Two‐dimensional hydrodynamic models are being used increasingly as alternatives to traditional one‐dimensional instream flow methodologies for assessing adequacy of flow and associated faunal habitat. Two‐dimensional modelling of habitat has focused primarily on fishes, but fish‐based assessments may not model benthic macroinvertebrate habitat effectively. We extend two‐dimensional techniques to a macroinvertebrate assemblage in a high‐elevation stream in the Sierra Nevada (Dana Fork of the Tuolumne River, Yosemite National Park, CA, USA). This stream frequently flows at less than 0.03 m3 s?1 in late summer and is representative of a common water abstraction scenario: maximum water abstraction coinciding with seasonally low flows. We used two‐dimensional modelling to predict invertebrate responses to reduced flows that might result from increased abstraction. We collected site‐specific field data on the macroinvertebrate assemblage, bed topography and flow conditions and then coupled a two‐dimensional hydrodynamic model with macroinvertebrate indices to evaluate habitat across a range of low flows. Macroinvertebrate indices were calculated for the wetted area at each flow. A surrogate flow record based on an adjacent watershed was used to evaluate frequency and duration of low flow events. Using surrogate historical records, we estimated that flow should fall below 0.071 m3 s?1 at least 1 day in 82 of 95 years and below 0.028 m3 s?1 in 48 of 95 years. Invertebrate metric means indicated minor losses in response to modelled discharge reductions, but wetted area decreased substantially. Responses of invertebrates to water abstraction will likely be a function of changing habitat quantity rather than quality. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
13.
The utility of hydrologic indices for describing various aspects of streamflow regimes has resulted in their increased application in riverine research. Consequently, researchers are now confronted with the task of having to choose among a large number of competing hydrologic indices to reduce computational effort and variable redundancy prior to statistical analyses, while still adequately representing the major facets of the flow regime. The present study addresses this concern by providing a comprehensive review of 171 currently available hydrologic indices (including the commonly used Indicators of Hydrologic Alteration) using long‐term flow records from 420 sites from across the continental USA. We highlight patterns of redundancy among these hydrologic indices and provide a number of statistically and ecologically based recommendations for the selection of a reduced set of indices that can simultaneously (1) explain a dominant proportion of statistical variation in the complete set of hydrologic indices and (2) minimize multicollinearity while still adequately representing recognized, critical attributes of the flow regime. In addition, we examine the transferability of hydrologic indices across ‘stream types’ by identifying indices that consistently explain dominant patterns of variance across streams in varying climatic and geologic environments. Together, our results provide a framework from which researchers can identify hydrologic indices that adequately characterize flow regimes in a non‐redundant manner. In combination with ecological knowledge, this framework can guide researchers in the parsimonious selection of hydrologic indices for future hydroecological studies. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
14.
Flow discharge from the river basin into the sea has severe impacts on the immediate vicinity of river channels, estuaries, and coastal areas. This paper analyzes the features and temporal trends of flow discharge at Pearl River’s three main gauge stations: the Wuzhou, Shijiao, and Boluo gauge stations on the West River, North River, and East River, respectively. The results show no significant trend in annual mean discharge into the sea at the three gauge stations. Changes of monthly mean discharge at the Boluo Gauge Station are evident, and a majority of monthly discharge in the dry season displays significant increasing trends. Furthermore, changes of the extreme discharge are quite evident, with a significant decreasing trend in the annual maximum discharge and a significant increasing trend in the minimum one. The significantly decreasing ratio of the flood discharge to annual discharge at the Boluo Gauge Station indicates that the flow discharge from the East River has increased in the dry season and decreased in the flood season since the construction of dams and reservoirs. At the other two gauge stations, the Wuzhou and Shijiao gauge stations, the seasonal discharge generally does not change perceptibly. Human impacts, especially those pertaining to reservoir and dam construction, appear to be responsible for the seasonal variation of flow discharge. The results indicate that the construction and operation of dams and reservoirs in the East River have a greater influence on flow discharge, which can well explain why the seasonal variation of flow discharge from the East River is more evident. 相似文献
15.
水库运行造成的河道水流条件的改变给下游的水生态系统带来重要影响。耦合水动力过程及生态过程的生态水力学模型可以有效地定量评价这种影响。本研究以广西漓江为实例,建立了全河流一维和局部河段二维水环境模型。其中的一维模型分析全河段水环境变化趋势,二维模型分析关键区间水环境的特点,并为后续的生物栖息地模型奠定基础。模型分析了典型水文年中自然径流和青狮潭水库运行两种模式下下游河道关键水环境因子的变化。模拟结果表明水库运行在平水年的影响大于丰水年和枯水年,局部浅水区的变化大于深水区,年内枯水期(10-12月)的影响大于年均值,而且这些变化沿程逐渐减弱。该研究成果为下一步的生态模型提供了外部因子。 相似文献
16.
Globally, dams fragment river networks, threatening migratory fishes which require access to distinct habitats to complete their life cycles. Efforts to understand how cumulative effects of multiple dams affect migratory fishes across large regions, such as a country or continent, could help to identify locations for connectivity-enhancing actions to conserve migratory fishes. To address this, we evaluated cumulative effects of dams on migratory fishes in rivers across nine ecoregions of the conterminous USA. First, using fish data from thousands of sites (N = 45,989), we summarized ecoregional patterns in assemblages, quantifying the number of migratory species comprising assemblages, showing the prominence of potamodromous species across the large region as well as differences in migratory life history traits among ecoregions. Next, we compared the importance of a set of river network fragmentation metrics that captured influences of multiple dams in networks versus other anthropogenic landscape stressors and natural landscape factors that impact migratory fishes by ecoregion. We found that migratory fishes were more sensitive to cumulative dam effects than other stressors including urbanization and agriculture in the eastern USA. To further identify specific effects of environmental variables on potamodromous fishes, we conducted Boosted Regression Trees analysis in the eastern ecoregions. Our results suggested that the key natural influences on river fishes included catchment area as well as river baseflow and air temperature, suggesting that migratory fishes may be affected by changing climate. Additionally, we found that downstream dams were more influential than other human stressors to potamodromous fishes, underscoring the importance of enhancing connectivity within river networks to conserve migratory fishes. Collectively, our results provide new insights in identifying threats to migratory fish species across the USA, providing information that can aid in conserving this vulnerable but ecologically and socioeconomically important group of fishes. 相似文献
17.
The potential impacts of changing climatic conditions on the operational performance of water resource systems was investigated in this paper. A multi-site streamflow generation model was used to synthesize potential monthly flow sequences reflecting two different sets of climatic conditions. The generated data were subsequently employed as input to a reservoir operation model that was used to determine the reservoir response to the inflow resulting from the implementation of the reservoir operating policy. The performance of an example reservoir system, the Shellmouth Reservoir located in the Canadian province of Manitoba, was evaluated and compared for the two sets of conditions. The operational performance was evaluated in terms of the reliability of the system for meeting the three purposes of the actual reservoir. The reservoir performance was determined to be sensitive to the inflow data. The results indicate that climatic change has potentially important implications for the operation of the example reservoir system. 相似文献
18.
Hydrologic regimes are increasingly altered under the impacts of climate change and human activities. Streamflow data from 1960 to 2014 were analysed to investigate changes in the flow regimes in the Yangtze River using multiple hydrologic metrics and the Budyko framework. The long‐term data were separated into two periods: the preimpact period (1960–2002) and the postimpact period (2003–2014), according to the year the Three Gorges Dam began operation. The results showed that both indicators of hydrologic alteration and ecoflow metrics were clearly altered. The highly changed indicators included flow in February, annual minimum 1‐, 3‐, 7‐, 30‐, and 90‐day flows, base flow index, date of annual minimum flow, and low pulse duration. The integrated degree of hydrologic alteration ranged from 41% to 61%, indicating a moderate alteration of the flow regimes in the Yangtze River. The regulation of the Three Gorges Dam increased low flow and weakened peak flow, which resulted in autumn ecodeficit and winter ecosurplus increasing dramatically since the 2000s. The ecoflow metrics were more sensitive to precipitation than to potential evapotranspiration. The joint effects of human activities and climate change varied among the river reaches in the different decades. The streamflow was mainly affected by human activities in the upper reach during the 1970s–1990s, with a contribution ratio ranging from 63% to 77%. Climate change shifted to a major contributor in the middle and lower reaches since the 1980s as well as in the upper reach in 2000–2014, accounting for 50–82% of the streamflow changes. These different responses were primarily caused by the variations of precipitation and intensive human activities, particularly the rapid growth of reservoirs and other large projects since the 1970s in the upper Yangtze River. These results provide interesting insights into the spatio‐temporal hydrologic alteration across the Yangtze River. 相似文献
19.
Julie K. H. Zimmerman Benjamin H. Letcher Keith H. Nislow Kimberly A. Lutz Francis J. Magilligan 《河流研究与利用》2010,26(10):1246-1260
River regulation can alter the frequency and magnitude of subdaily flow variations causing major impacts on ecological structure and function. We developed an approach to quantify subdaily flow variation for multiple sites across a large watershed to assess the potential impacts of different dam operations (flood control, run‐of‐river hydropower and peaking hydropower) on natural communities. We used hourly flow data over a 9‐year period from 30 stream gages throughout the Connecticut River basin to calculate four metrics of subdaily flow variation and to compare sites downstream of dams with unregulated sites. Our objectives were to (1) determine the temporal scale of data needed to characterize subdaily variability; (2) compare the frequency of days with high subdaily flow variation downstream of dams and unregulated sites; (3) analyse the magnitude of subdaily variation at all sites and (4) identify individual sites that had subdaily variation significantly higher than unregulated locations. We found that estimates of flow variability based on daily mean flow data were not sufficient to characterize subdaily flow patterns. Alteration of subdaily flows was evident in the number of days natural ranges of variability were exceeded, rather than in the magnitude of subdaily variation, suggesting that all rivers may exhibit highly variable subdaily flows, but altered rivers exhibit this variability more frequently. Peaking hydropower facilities had the most highly altered subdaily flows; however, we observed significantly altered ranges of subdaily variability downstream of some flood‐control and run‐of‐river hydropower dams. Our analysis can be used to identify situations where dam operating procedures could be modified to reduce the level of hydrologic alteration. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
20.
J. S. Sanderson N. Rowan T. Wilding B. P. Bledsoe W. J. Miller N. L. Poff 《河流研究与利用》2012,28(9):1369-1377
Growing water demand across the world is increasing the stress on river ecosystems, causing concern for both biodiversity and people. River‐specific environmental flow assessments cannot keep pace with the rate and geographic extent of water development. Society needs methods to assess ecological impacts of flow management at broad scales so that appropriate regional management can be implemented. To meet this need in Colorado, USA, we developed a Watershed Flow Evaluation Tool (WFET) to estimate flow‐related ecological risk at a regional scale. The WFET entails four steps: (i) modelling natural and developed daily streamflows; (ii) analysing the resulting flow time series; (iii) describing relationships between river attributes and flow metrics (flow–ecology relationships); and (iv) mapping of flow‐related risk for trout, native warm‐water species and riparian plant communities. We developed this tool in two watersheds with differing geomorphic settings and data availability. In one of the two watersheds, the WFET was successfully implemented to assess ecological risk across the 3400‐km2 watershed, providing consistent watershed‐wide information on flow‐related risk. In the other watershed, active channel change and limited data precluded a successful application. In Colorado, the WFET will be used to evaluate the risk of impacts on river ecosystems under future climate change and water development scenarios (e.g. for energy development or municipal water supply). As water continues to be developed for people, the WFET and similar methods will provide a cost‐effective means to evaluate and balance ecosystem needs at large scales. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献