Articles de revues : « Impaired river »

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Sajina, Aliyamintakath Muhammadali, Deepa Sudheesan, Srikanta Samanta, Samir Kumar Paul, Sanjay Bhowmick, Subir Kumar Nag, Vikas Kumar et Basanta Kumar Das. « Development and validation of a fish-based index of biotic integrity for assessing the ecological health of Indian Rivers Mahanadi and Kathajodi-Devi ». Aquatic Ecosystem Health & ; Management 25, n^o 2 (1 avril 2022) : 25–35. http://dx.doi.org/10.14321/aehm.025.02.25.

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Abstract India has a vast network of 14 major rivers and their tributaries, covering 83% of the drainage basin and accounting for 85% of the surface flow. Anthropogenic activities like damming, channel modification, water abstraction, sewage and effluent disposal, sand mining, unthoughtful exploitation of biotic resources, etc. are the major threats faced by the rivers in the country. Monitoring protocol of Indian rivers lacks an integrated approach based on judicious use of both abiotic and biotic components as well as a total lack of consideration for ecological health. Index of Biotic Integrity is a flexible multimetric index that can be modified and adapted to the various zoogeographic regions of the world. A fish-based multi-metric IBI was developed by modifying and incorporating metrics that are sensitive to the various ecological stressors faced by Indian rivers, fishes being excellent indicators of river health. The adapted IBI was validated and used to assess ecological health of two rivers—Mahanadi, and its distributary Kathajodi-Devi—flowing through central-eastern India. The study indicated that in River Mahanadi, around 25% of the freshwater river stretch was slightly impaired and the remaining 75% stretch was moderately impaired. In Kathajodi-Devi, most of the river stretches were in a moderately impaired condition, except at Italnga stretch where the river was severely impaired. The Index of Biotic Integrity scores estimated could reflect the ecological health of the rivers. The study shows that use of Index of Biotic Integrity is a useful and reliable approach to assess the health conditions of Indian aquatic resources warranting initiatives to be taken to implement and incorporate it into the country's water resource management.

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Kasahara, Tamao, Thibault Datry, Michael Mutz et Andrew J. Boulton. « Treating causes not symptoms : restoration of surface - groundwater interactions in rivers ». Marine and Freshwater Research 60, n^o 9 (2009) : 976. http://dx.doi.org/10.1071/mf09047.

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Many river restoration projects seek to address issues associated with impaired hydrological and ecological connectivity in longitudinal (e.g. effects of dams, weirs) or lateral (e.g. alienated floodplain) dimensions. Efforts to restore the vertical dimension of impaired stream–groundwater exchange are rare, hampered by limited understanding of the factors controlling this linkage in natural alluvial rivers. We propose a simplified two-axis model of the ‘primary drivers’ (sediment structure and vertical hydraulic gradient) of stream–groundwater exchange that acknowledges their interaction and provides a practical template to help researchers and river managers pose hypothesis-driven solutions to restoration of damaged or lost vertical connectivity. Many human activities impact on one or both of these drivers, and we review some of the tools available for treating the causes (rather than symptoms) in impacted stream reaches. For example, creating riffle-pool sequences along stream reaches will enhance vertical hydraulic gradient, whereas flushing flows can remove clogging layers and sustain sediment permeability. Our model is a first step to specifying mechanisms for recovery of lost vertical connectivity. Assessing results of river restoration using this approach at reach to catchment scales will provide scientific insights into the interplay of hydrology, fluvial geomorphology and river ecosystem function at appropriately broad scales.

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Hinds, L., et D. Goldney. « A Comparison of Plasma Testosterone and Progesterone Levels in The Thredbo and Duckmaloi River Platypuses Over a Twelve Month Cycle. » Australian Mammalogy 20, n^o 2 (1998) : 305. http://dx.doi.org/10.1071/am98311.

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A 1-2 ml blood sample was removed from the bill sinus of 208 captured platypuses from the Duckmaloi and Thredbo Rivers over the period January 1991-March 1993. Platypuses from the Duckmaloi were sampled monthly during 1992 and in February, August and December from the Thredbo River in the same year. The numbers and sex of platypuses sampled are recorded in the following Table. Samples were stored on ice and plasma separated from blood cells within 24 hours of sampling by centrifugation for I0 minutes and the supernatant stored at -20°C. The changes in plasma testosterone and progesterone for platypuses from both rivers were compared over a 12 month cycle. The levels of these two hormones were considerably less in the breeding season in the Thredbo River platypuses than in those from the Duckmaloi River. Peak plasma progesterone levels of the order of 90 ng/ml were measured in the Duckmaloi River females compared to levels of <5 ng/ml in Thredbo River females. Male plasma testosterone levels in animals from the Duckmaloi River peaked around 15 ng/ml, whereas Thredbo River males had levels of around 6 ng/mI. These data suggest that over the period of the two year study, platypus breeding potential in the Thredbo River was significantly impaired.

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Nayamatullah, M. M. M., S. Bin-Shafique et H. O. Sharif. « A study to estimate the fate and transport of bacteria in river water from birds nesting under a bridge ». Water Science and Technology 68, n^o 12 (24 octobre 2013) : 2568–75. http://dx.doi.org/10.2166/wst.2013.521.

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To investigate the effect of input parameters, such as the number of bridge-dwelling birds, decay rate of the bacteria, flow at the river, water temperature, and settling velocity, a parametric study was conducted using a water quality model developed with QUAL2Kw. The reach of the bacterial-impaired section from the direct droppings of bridge-nesting birds at the Guadalupe River near Kerrville, Texas was estimated using the model. The concentration of Escherichia coli bacteria were measured upstream, below the bridge, and downstream of the river for one-and-a-half years. The decay rate of the indicator bacteria in the river water was estimated from the model using measured data, and was found to be 6.5/day. The study suggests that the number of bridge-dwelling birds, the decay rate, and flow at the river have the highest impact on the fate and transport of bacteria. The water temperature moderately affects the fate and transport of bacteria, whereas, the settling velocity of bacteria did not show any significant effect. Once the decay rates are estimated, the reach of the impaired section was predicted from the model using the average flow of the channel. Since the decay rate does not vary significantly in the ambient environment at this location, the length of the impaired section primarily depends on flow.

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Farag, Aïda M., Mark A. Stansbury, Harold L. Bergman, Christer Hogstrand et Elizabeth MacConnell. « The physiological impairment of free-ranging brown trout exposed to metals in the Clark Fork River, Montana ». Canadian Journal of Fisheries and Aquatic Sciences 52, n^o 9 (1 septembre 1995) : 2038–50. http://dx.doi.org/10.1139/f95-795.

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Tissue metal accumulation and physiological responses were measured in brown trout (Salmo trutta) collected from two sites on the Clark Fork River, Montana, and two reference sites to determine the health status of the resident fish population. Concentrations of metals in tissues, products of lipid peroxidation, and microscopic Cu inclusions were significantly higher in fish collected from the upper Clark Fork River site than in fish from reference sites. Metallothionein concentrations were higher in the livers of fish from the upper Clark Fork River than in those of fish from reference sites. The health of the fish population in the upper Clark Fork River is probably impaired because of previously reported elevated concentrations of metals including As, Cd, Cu, Pb, and Zn in the surface water and aquatic invertebrates in the upper Clark Fork River. The high concentrations of metals in the surface waters and sediments of the Clark Fork River are typical of rivers in the intermountain western United States where discharges from mining activities have occurred since the late 1800s. Thus, our findings can be used as a guide for researchers throughout the intermountain western United States who may investigate similar field conditions.

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Meng, Han, Yuanyuan Lin, Wenjun Zhong, Zheng Zhao, Liang Shen, Zhen Ling, Kaisong Zhao et Shan Xu. « Fish Biomonitoring and Ecological Assessment in the Dianchi Lake Basin Based on Environmental DNA ». Water 15, n^o 3 (18 janvier 2023) : 399. http://dx.doi.org/10.3390/w15030399.

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Fish are among the main target groups when conducting biomonitoring and ecological assessment of aquatic environments. Environmental DNA (eDNA) metabarcoding provides a unique opportunity to enhance biomonitoring throughput, precision, and standardization. However, few fish monitoring studies based on eDNA metabarcoding have been conducted at the basin scale. Taking Dianchi Lake and the three inflowing rivers (Panlong River, Baoxiang River, and Chai River) as research objects, this study monitored fish diversity via eDNA metabarcoding, and the Fish Index of Biological Integrity (F-IBI) was constructed and applied for the ecological assessment of the aquatic environment. Here, we detected 41 species belonging to 9 orders, 15 families, and 35 genera in the sampling areas, including 17 native fish species such as Hemiculter leucisculus, Cyprinus carpio, and Silurus soldatovi. Distinct diversity patterns were observed among Dianchi Lake and the three inflowing rivers. Particularly, the fish diversity of Panlong River was richer than that of Dianchi Lake, Baoxiang River, and Chai River. Water temperature (WT), chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) significantly influenced the distribution of fish communities in most sampling sites of the Dianchi Lake basin (p < 0.05). Moreover, according to the F-IBI assessment system, 25% of the sampling sites were defined as ‘fine’ or above, and 75% were ‘impaired’ or below. This study provided insights into the ecological restoration and precise management of the aquatic environment of the Dianchi Lake basin.

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Vidal, Tânia, Joana I. Santos, Catarina R. Marques, Joana L. Pereira, Maria Teresa Claro, Ruth Pereira, Bruno B. Castro, Amadeu Soares et Fernando Gonçalves. « Resilience of the macroinvertebrate community of a small mountain river (Mau River, Portugal) subject to multiple stresses ». Marine and Freshwater Research 65, n^o 7 (2014) : 633. http://dx.doi.org/10.1071/mf13207.

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Freshwaters commonly face human pressure, which produces multiple stressor scenarios that may threaten their ecological status. Biotic community assessments are useful tools to monitor such changes, and the European Water Framework Directive (WFD) has brought this into the legislative framework. The present study focused on a small mountain river facing multiple stresses, with the purpose of (1) evaluating the sensitivity of the macroinvertebrate community to the stresses, (2) assessing whether the ecological status was impaired in different years and (3) comparing the WFD approach with more refined community analyses. The river was generally in a very good ecological state. Despite seasonal and inter-annual fluctuations, no evident stressor-related effects were detected. We hypothesise that the observed resilience was the result of (1) the current dormant state of the abandoned mining areas (the most relevant potential source of contamination) and (2) the naturalness and strong current of the river, which buffered the impacts of contamination. Such a pattern may be generally valid for small mountain rivers, making them therefore more resilient to stresses. Nevertheless, small changes in community structure in the lowest reach of the river – undetected by the WFD assessment scheme – suggest that some disturbance was present, signalling the need for intervention by managers.

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Pradilla, Gonzalo, Georg Lamberty et Johannes Hamhaber. « Hydromorphological and socio-cultural assessment of urban rivers to promote nature-based solutions in Jarabacoa, Dominican Republic ». Ambio 50, n^o 8 (1 juin 2021) : 1414–30. http://dx.doi.org/10.1007/s13280-021-01565-3.

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AbstractIn Latin America and the Caribbean, river restoration projects are increasing, but many lack strategic planning and monitoring. We tested the applicability of a rapid visual social–ecological stream assessment method for restoration planning, complemented by a citizen survey on perceptions and uses of blue and green infrastructure. We applied the method at three urban streams in Jarabacoa (Dominican Republic) to identify and prioritize preferred areas for nature-based solutions. The method provides spatially explicit information for strategic river restoration planning, and its efficiency makes it suitable for use in data-poor contexts. It identifies well-preserved, moderately altered, and critically impaired areas regarding their hydromorphological and socio-cultural conditions, as well as demands on green and blue infrastructure. The transferability of the method can be improved by defining reference states for assessing the hydromorphology of tropical rivers, refining socio-cultural parameters to better address river services and widespread urban challenges, and balancing trade-offs between ecological and social restoration goals.

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Garcier, R. J. « Rivers we can't bring ourselves to clean – historical insights into the pollution of the Moselle River (France), 1850–2000 ». Hydrology and Earth System Sciences Discussions 4, n^o 3 (15 juin 2007) : 1697–727. http://dx.doi.org/10.5194/hessd-4-1697-2007.

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Abstract. As products of both natural and social systems, rivers are highly complex historical objects. We show in this paper that historical analysis works on two different levels: one level, which we call "structural", shows the materiality of the riverine environment as the spatial-temporal product of natural factors and human impacts (bed and course alterations, pollution, etc.). On a second level – "semiotic" – we show that river systems are also social constructs and the subjects of ancient and diverse management practices. The quality of a river will be a function of the dialectical interaction between both levels. Historical analysis can uncover the inherited constraints that bear upon current management practices. To help substantiate this analytical framework, we analyse the case of the Moselle river in eastern France by using archival sources and statistical data. Severely impaired by industrial discharges from iron, coal and salt industries between the 1875s and the early 1980s, the waters of the Moselle became the subject of a social consensus between stakeholders that prevented the implementation of efficient pollution management policies until the 1990s. The example urges caution on the pervasiveness of participatory approaches to river management: social consensus does not necessarily benefit the environment.

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Garcier, R. J. « Rivers we can't bring ourselves to clean – historical insights into the pollution of the Moselle River (France), 1850–2000 ». Hydrology and Earth System Sciences 11, n^o 6 (6 novembre 2007) : 1731–45. http://dx.doi.org/10.5194/hess-11-1731-2007.

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Abstract. As products of both natural and social systems, rivers are highly complex historical objects. We show in this paper that historical analysis works on two different levels: one level, which we call "structural", shows the materiality of the riverine environment as the spatial-temporal product of natural factors and human impacts (bed and course alterations, pollution, etc.). On a second level –"semiotic" – we show that river systems are also social constructs and the subjects of ancient and diverse management practices. The quality of a river will be a function of the dialectical interaction between both levels. Historical analysis can uncover the inherited constraints that bear upon current management practices. To help substantiate this analytical framework, we analyse the case of the Moselle river in eastern France by using archival sources and statistical data. Severely impaired by industrial discharges from iron, coal and salt industries between the 1875s and the early 1980s, the waters of the Moselle became the subject of a social consensus between stakeholders that prevented the implementation of efficient pollution management policies until the 1990s. The example urges caution on the pervasiveness of participatory approaches to river management: social consensus does not necessarily benefit the environment.

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Cox, Timothy J., Daniel F. Turner, Greg J. Pelletier et Alfred Navato. « Stochastic Water Quality Modeling of an Impaired River Impacted by Climate Change ». Journal of Environmental Engineering 141, n^o 11 (novembre 2015) : 04015035. http://dx.doi.org/10.1061/(asce)ee.1943-7870.0000971.

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Pander, Joachim, et Juergen Geist. « The Contribution of Different Restored Habitats to Fish Diversity and Population Development in a Highly Modified River : A Case Study from the River Günz ». Water 10, n^o 9 (6 septembre 2018) : 1202. http://dx.doi.org/10.3390/w10091202.

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Despite of structural deficits, highly modified water bodies (HMWB) contain remnant populations of endangered fish that have high conservation value. Restoration in HMWBs underlies different principles when compared to natural rivers because of impaired river dynamic processes. The objective herein was to assess the contribution of restored habitats of the River Günz, Germany to fish diversity and restoration success of target species. All habitat restoration types, including bank habitats, fast flowing habitats with gravel, structured shallow water zones, nature like fish passes, and a former river course below a spillway were assessed. None of them comprised the full set of 27 fish species or size classes, indicating that the diversity and interlinkage of the restored habitats is most crucial to sustainable fish populations and high biodiversity. When considering the rheophilic target species Chondrostoma nasus and Barbus barbus, only fish passes and the former river course with their high flow current contributed much to their population development, particularly to young specimens <20 cm. The results of this study indicate that measures inside the main channel are unlikely to mitigate deficiencies in HMWBs concerning specialized riverine fish. Instead, interlinkage of a diversity of restoration measures and investment of resources for restoration in HMWBs into nature-like fish passes or former river courses below spillways with dynamically managed discharges seem most useful.

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Brooks, Andrew J., Matthew Russell, Robyn Bevitt et Matthew Dasey. « Constraints on the recovery of invertebrate assemblages in a regulated snowmelt river during a tributary-sourced environmental flow regime ». Marine and Freshwater Research 62, n^o 12 (2011) : 1407. http://dx.doi.org/10.1071/mf11128.

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The impacts of river regulation on aquatic biota have been extensively studied, but long-term assessments of the restoration of biota by environmental flows and the principal mechanisms of recovery have rarely occurred. We assessed whether the provision of an environmental flow regime (EFR) via the decommissioning of an aqueduct on a tributary stream altered downstream macroinvertebrate assemblages in the highly regulated Snowy River, Australia. Macroinvertebrate assemblages of the Snowy River, reference and control sites remained distinct despite the provision of environmental flows. Invertebrate assemblages detrimentally affected by regulation probably remained impaired due to either constraints on colonisation from the tributary stream (dispersal constraints) or unsuitable local environmental conditions in the Snowy River caused by flow regulation (e.g. high levels of fine sediments, elevated temperature regime) suppressing new colonists or recovery of extant populations. Our study showed that restoration may be ineffective if EFRs are too small to ameliorate local environmental factors constraining the recovery of affected biota. Other barriers to recovery, such as dispersal constraints, also need to be overcome. Successful restoration of regulated rivers using environmental flows requires an understanding of the mechanisms and pathways of recovery, together with identification and amelioration of any potential barriers to recovery.

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Money, Eric, Gail P. Carter et Marc L. Serre. « Using river distances in the space/time estimation of dissolved oxygen along two impaired river networks in New Jersey ». Water Research 43, n^o 7 (avril 2009) : 1948–58. http://dx.doi.org/10.1016/j.watres.2009.01.034.

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Odume, Oghenekaro Nelson, Blessing Nonye Onyima, Chika Felicitas Nnadozie, Gift Ochonogor Omovoh, Thandi Mmachaka, Blessing Odafe Omovoh, Jude Edafe Uku, Frank Chukwuzuoke Akamagwuna et Francis Ofurum Arimoro. « Governance and Institutional Drivers of Ecological Degradation in Urban River Ecosystems : Insights from Case Studies in African Cities ». Sustainability 14, n^o 21 (29 octobre 2022) : 14147. http://dx.doi.org/10.3390/su142114147.

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The degradation of rivers in urban landscapes is alarming and impaired their ecological functions and the services they provide to society. In African cities, urban rivers are among the most degraded ecosystems, yet ecologically sustainable utilisation of river resources can contribute to and support sustainable urban development. In this paper, we identify and analyse key governance and institutional drivers of ecological change in urban river systems in the Swartkops catchment in South Africa and the Federal Capital Territory (FCT) in Nigeria. Our results indicate that poor ecological conditions of rivers in the two urban landscapes can be attributed to: (1) a lack of system view of the water value chain and associated infrastructure, (2) ambiguity in roles, responsibilities, and poor accountability, (3) prioritizing short-term social–economic–political agenda over long-term environmental sustainability goals, (4) institutional silos and failure of cooperative governance, and (5) over-centralised, top-down, state-centric governance processes. Strengthening the interactions between actors in the science, policy and practice domains, mainstreaming planning with rivers in integrated urban development plans, and strengthening cooperative and polycentric governance across administrative scales are key governance and institutional processes needed to address the trajectory of urban ecological degradation. Our paper sheds light on the fundamental role of strengthening governance and institutional processes for steering urban rivers toward sustainable paths for city resilience.

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Huang, Jingshui, Hailong Yin, Seifeddine Jomaa, Michael Rode et Qi Zhou. « Limited nitrogen retention in an urban river receiving raw sewage and wastewater treatment plant effluent ». Environmental Science : Processes & ; Impacts 21, n^o 9 (2019) : 1477–88. http://dx.doi.org/10.1039/c9em00201d.

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Stevens, Tim, Cindy Gilder et Donna Walsh. « Category 4b Demonstration for Petroleum Hydrocarbon Impaired Waters in the Kenai River, Alaska ». Proceedings of the Water Environment Federation 2009, n^o 6 (1 janvier 2009) : 811–20. http://dx.doi.org/10.2175/193864709793958219.

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Ismail, Niveen S., Jake P. Tommerdahl, Alexandria B. Boehm et Richard G. Luthy. « Escherichia coliReduction by Bivalves in an Impaired River Impacted by Agricultural Land Use ». Environmental Science & ; Technology 50, n^o 20 (28 septembre 2016) : 11025–33. http://dx.doi.org/10.1021/acs.est.6b03043.

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González-Paz, Lorena, María Comesaña, Isabel Pardo, José Barquín, Alejandra Goldenberg-Vilar et Cristina Delgado. « Variability of diatom community composition and structure in mountain streams ». Hydrobiologia 849, n^o 5 (16 décembre 2021) : 1177–94. http://dx.doi.org/10.1007/s10750-021-04779-4.

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AbstractSmall rivers support high levels of biodiversity, being especially sensitive to the effects of global change. Temporal records of community composition in minimally impaired streams can be used to explore trends in biodiversity in response to climate change and natural temporal variation. We approached the comparison of two time periods (2003–2008 and 2016–2020) to study whether the composition of diatom assemblages changed over time in twenty-three streams of the mountain range of Picos de Europa (Northern Spain). The stream’s water chemistry indicated significant decreases in N_NO3− and P_PO43− content over time. In these minimally disturbed streams, the specific diatom community was dominated by Achnanthidium pyrenaicum, Achnanthidium minutissimum and Cocconeis euglypta. PERMANOVA analyses did not identify significant changes in diatom assemblage composition between periods or river types. Diatom indices (e.g. IPS, NORTIdiat) indicated high or good ecological status and relatively high alpha diversity values were found in these mountain rivers during the studied years. Although diversity and evenness showed a significant decrease over time, the temporal stability of the river-type diatom reference community between the two periods should be considered as an indicator of biodiversity persistence of high importance when monitoring the ecological status following the reference condition approach.

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Nam, Beom Sik, Ha Sun Hwang et Moo Hwan Cho. « A Study on River Representation for Water Impaired Analysis of Measurement Data at TPLMs ». Journal of Korean Society of Environmental Engineers 42, n^o 4 (30 avril 2020) : 197–209. http://dx.doi.org/10.4491/ksee.2020.42.4.197.

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Objectives:This study assessed the applicability of the total pollutant load management (TPLM) data on the analysis of impaired waterbody and pollutant source characterization. To achieve the study objective, the TPLM data collected in the downstream of Yeongcheon-Dam within the Geumho A unit-basin, Nakdong River basin for 6 years (2013-2018) were used to analyze the accountability for precipitation conditions, seasons, and flow rates. Methods:The study area is the downstram of Yeongcheon Dam within the Geumho A unit-basin, Nakdong River basin. The TPLM data used in this study were obtained from the two monitoring stations in the mainstream of Geumho River (i.e., Jahocheon and Geumho A station) and the three tributary streams (i.e., Gochoncheon, Sillyeongcheon, and Bugancheon). Precipitation conditions were classified into rainy (>10 mm/day) and non-rainy days (≤10 mm/day) to assess the TPLM data accountability for the two precipitation conditions. Seasonal accountabilities of the TPLM data were assessed for spring (March-May), summer (June-August), autumn (September-November), and winter (December-February). The TPLM data accountability for stream flow rates was assessed using the standardized daily flow rates which were estimated by % of maximum flow rate. The daily flow rates were simulated using the Hydrologic Simulation Program-Fortran (HSPF).Results and Discussion:During the study period (2013-2018), TPLM data were collected 35-41 times throughout a year in the two Geumho River mainstream stations (i.e., Jahocheon, and Geumho A), while the tributary streams (i.e., Gochoncheon, Sillyeongcheon, and Bugancheon) were monitored 36 times per year excluding every January, February, and December. The tributary streams shown the missing data months because those stations were monitored through the implementation assessment for total maximum daily load (TMDL) management. But, the mainstream data were continuously collected by the Water Environment Research Institute. The accountability assessment results shown that 28%, 25%, 28%, and 19% of TPLM data for the two mainstream stations represents spring, summer, autumn, and winter seasons. The three TPLM station data in the tributary streams could not account for winter season with the seasonal data ratios of 29% for spring, 32% for summer, 34% for autumn, and 4% for winter. Secondly, 37.9% and 23.1% of TPLM data for the two mainstream stations and the three tributary streams, respectively, were collected during rainy days. Comparing to 22% of rainy days throughout the study period, the two mainstream stations were monitored more frequently during rainy days than the tributary stations. Lastly, accountability for stream flow rates shown that the annual TPLM data cannot account for mainstream flow conditions. For the tributary stream flow rates, six years composite TPLM data could not represent the flow conditions. Therefore, the TPLM data need to be carefully reviewed before assessing impaired waterbody and pollutant source characterization. Conclusions:TPLM data was widely used in TMDL implementation and research activities. Thus, detailed TPLM monitoring plans should be developed to improve accountability for various stream characteristics including precipitation, season, and flow rate, etc. In addition, further research is needed to represent wide ranges of flow rate which are hard to be predicted due to the large uncertainties induced by precipitation, precipitation intensity, precedent rain days, and other factors (e.g., dams, wastewater treatment plants, etc.).

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Flynn, Trevor, Tom Stiles, Bruce Perkins et Eric Monschein. « Category 4b Demonstration for Atrazine Impaired Waters in the Little Arkansas River Subbasin, Kansas ». Proceedings of the Water Environment Federation 2009, n^o 6 (1 janvier 2009) : 830–44. http://dx.doi.org/10.2175/193864709793958048.

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Alam, Khorshed. « Public attitudes toward restoration of impaired river ecosystems : Does residents’ attachment to place matter ? » Urban Ecosystems 14, n^o 4 (16 avril 2011) : 635–53. http://dx.doi.org/10.1007/s11252-011-0176-5.

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O'Briain, Rossa, Samuel Shephard et Brian Coghlan. « River reaches with impaired riparian tree cover and channel morphology have reduced thermal resilience ». Ecohydrology 10, n^o 8 (10 août 2017) : e1890. http://dx.doi.org/10.1002/eco.1890.

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Kilbum, Kaye H., et Raphael H. Warshaw. « Effects on Neurobehavioral Performance of Chronic Exposure to Chemically Contaminated Well Water ». Toxicology and Industrial Health 9, n^o 3 (mai 1993) : 391–404. http://dx.doi.org/10.1177/074823379300900301.

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Occupational exposure lo trichloroethylene (TCE) and other solvents impairs neurobehavioral performance. Use of well water contaminated with TCE and solvents has been associated with excessive symptoms, cancers, birth defects and impaired blink reflex. We extended these observations by measuring the neurophysiological (NPH) and neuropsychological (NPS) status of subjects who used water contaminated with 6 to 500 ppb of TCE for 1 to 25 years. The 170 well-water exposed subjects who resided in southwest Tucson, Arizona overlying the Santa Cruz River aquifer, were compared to 68 referent subjects for NPH and NPS tests. Also, 113 histology technicians (HT) were referents for blink reflex latency only. Affective status was assayed by a Profile of Mood States (POMS). Exposed subjects were statistically significantly impaired when compared to referents for NPH tests. These impairments included sway speed with eyes open and closed, blink reflex latency (R-1), eye closure speed, and two choice visual reaction time. NPS status was statistically significant impaired for Culture Fair (intelligence) scores, recall of stories, visual recall, digit span, block design, recognition of fingertip numbers, grooved pegboard and Trail making A and B. POMS scores were elevated. Prolonged residential exposure to well-water containing TCE at lower levels than occupational exposures, but without time away from exposure for metabolism and excretion of toxins, was associated with neurobehavioral impairment.

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Li, Heying, Demin Zhou, Shanshan Hu, Jianchen Zhang, Yuemei Jiang et Yue Zhang. « Barrier-based Longitudinal Connectivity Index for Managing Urban Rivers ». Water 10, n^o 11 (21 novembre 2018) : 1701. http://dx.doi.org/10.3390/w10111701.

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A large variety of barriers can affect longitudinal connectivity, which leads to shipping blocking and even flood hazard. However, few existing methods can quantify physically the river channel connectivity from the barrier’s details perspective in a watershed. This paper establishes a new model of the River Channel Connectivity Index (RCCI) to quantify the unobstructed degree of river flow in river channels within geographic information system (GIS ) platforms based on the modified concept of time accessibility. A comprehensive classification system of barriers is setup before these barriers are identified by the remote sensing technology. The model is applied to Dashi Watershed in suburban Beijing, China. Results show that submersible bridges and sediment siltation are the main barriers in the watershed. RCCI values in the mountainous areas are generally higher than that of the plains. The assessment results verified by two historical flood events show that the RCCI can reveal where the river channel connectivity is impaired, how serious it is, and what the reason is for managers. Through scenarios’ results, the best restoration measure for each tributary is obtained from the perspective of reducing flood hazards. The new RCCI method not only has methodological significance, but also helps policymakers to enhance river flooding reduction and determine restoration priorities of the river channel.

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Dunagan, Heidi H., Jacqueline Michel et Jonathon Burr. « Assessment and Restoration Scaling of Stream Services Impaired by the Obed River 2002 Oil Spill ». International Oil Spill Conference Proceedings 2011, n^o 1 (mars 2011) : abs39. http://dx.doi.org/10.7901/2169-3358-2011-1-39.

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Lee, Jong-Won, Sang-Woo Lee, Soon-Jin Hwang, Min-Ho Jang, Doo-Hee Won, Kyung-Jin An, Hye-Jin Park et Junga Lee. « Establishing Diagnosis Systems for Impaired Stream Ecosystem using Stream/River Ecosystem Survey and Health Assessment. » Korean Journal of Ecology and Environment 53, n^o 1 (31 mars 2020) : 1–10. http://dx.doi.org/10.11614/ksl.2020.53.1.001.

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Macfarlane, William W., Christopher M. McGinty, Brian G. Laub et Suzanne J. Gifford. « High-resolution riparian vegetation mapping to prioritize conservation and restoration in an impaired desert river ». Restoration Ecology 25, n^o 3 (1 septembre 2016) : 333–41. http://dx.doi.org/10.1111/rec.12425.

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Zhang, Junhong, Tao Huang, Lu Chen, Xiaofang Liu, Lingling Zhu, Luojie Feng et Yunping Yang. « Water-Exchange Response of Downstream River–Lake System to the Flow Regulation of the Three Gorges Reservoir, China ». Water 11, n^o 11 (15 novembre 2019) : 2394. http://dx.doi.org/10.3390/w11112394.

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Hydrological regime changes in the river–lake system and their influences on the ecological environment downstream dams have attracted increasingly more attention all over the world. The Dongting lake downstream of the Three Gorges Dam (TGD) in the Yangtze River has been experiencing a series of hydraulic and hydrological changes over the last decade. The hydrological and ecological influences of the TGD flow regulation on the Dongting river–lake system and its functional mechanism during the impounding periods remain extremely unclear. This study examines the hydrological changes in the Dongting river–lake system based on a 1D/2D coupled hydrodynamic model. In particular, the inflow boundary of the model with and without the TGD was applied with the outflow and inflow of the TGD, respectively, during the same regulation periods. The results show that the diverted flow from the Yangtze River into the Dongting lake and outflow from the lake back to the river drastically decreased during the impounding periods, especially in October. The decreased water exchange between the Yangtze River and the Dongting lake impaired the water residence capacity to some extent in the lake. Stage decrease in the lake area resulted in a significant reduction in the water volume of the Dongting lake with the same time percentage. In addition, the obvious drainage effect in Dongting lake due to the increased stage difference and current speed after the TGD operation was the essential cause of hydrological changes in the lake area. These results provide an improvement in the understanding of impoundment influences on the large river–lake system and give some practical information for ecological environment management in similar river–lake systems.

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Kaiser, Klaus L. E., Ken R. Lum et Virginia S. Palabrica. « Review of Field Applications of the Microtox Test in Great Lakes and St. Lawrence River Waters ». Water Quality Research Journal 23, n^o 2 (1 mai 1988) : 270–78. http://dx.doi.org/10.2166/wqrj.1988.018.

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Abstract The Microtox™ toxicity test, a bioassay employing the luminescent marine bacterium Photobacterium phosphoreum as the test organism, has previously been used in field and laboratory research for the assessment of water contamination in the Detroit River and in Lake St. Clair. The test results indicated locations and zones of impaired water quality and were found to be useful in connection with other studies of the same areas. This review presents new Microtox toxicity data on the St. Lawrence River and discusses the results in conjunction with other biological, chemical and physical data collected at the same time. It assesses the advantages and limitations of this bioassay for exploratory work on water contamination in the Great Lakes and in other aquatic organisms.

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Ikpi, Eyong, Emmanuel, Arikpo, Ikpi Abam et Inyango, Martina Ongbonya. « INFLUENCE OF BILINGUALISM ON THE ACADEMIC PERFORMANCE OF HEARING IMPAIRED STUDENTS IN CROSS RIVER STATE, NIGERIA ». International Journal of Scientific & ; Engineering Research 5, n^o 7 (25 juillet 2014) : 1467. http://dx.doi.org/10.14299/ijser.2014.07.005.

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Zupanc, Vesna, Gerhard Kammerer, Helena Grčman, Igor Šantavec, Rozalija Cvejić et Marina Pintar. « Recultivation of Agricultural Land Impaired by Construction of a Hydropower Plant on the Sava River, Slovenia ». Land Degradation & ; Development 27, n^o 2 (2 décembre 2015) : 406–15. http://dx.doi.org/10.1002/ldr.2463.

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Rivers, Ray. « Socio-Economics of Remediating Contaminated Sediment for the St. Clair River Area of Concern ». Water Quality Research Journal 36, n^o 3 (1 août 2001) : 377–94. http://dx.doi.org/10.2166/wqrj.2001.023.

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Abstract Of the total amount of contaminated sediment in the upper stretch of the St. Clair River, there are approximately 4500 cubic meters of sediment contaminated by mercury and organic chemicals that represent five of the remaining seven impaired uses in the St. Clair River Area of Concern. This material is the result of industrial pollution over a number of years in the Sarnia, Ontario, “Chemical Valley” and has most likely entered the St. Clair River via a surface drain passing through an industrial landfill. Scientific studies indicate that the contaminated material is constantly migrating downstream and has a potential for significant releases from large vessel traffic propeller wash or ice action. This paper examines two remediation options in the light of the potential benefits from a cleanup of the contaminated sediments. While not a typical benefit-cost analysis, this study explores the relationship between remediation and the social and economic benefits associated with “delisting” of the St. Clair River as an Area of Concern. The study has implications for other Areas of Concern that have sediment-related problems and require remedial action to meet the goals of the Great Lakes Water Quality Agreement.

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I.A., Usmanov. « The improvement of ecological monitoring for water bodies of the middle course of Syrdarya river ». Ekologiya i stroitelstvo 1 (2017) : 10–14. http://dx.doi.org/10.35688/2413-8452-2017-01-002.

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The article is devoted to research of the ecological state of water bodies used by the population for drinking water usage. It is established that in areas of discharges of insufficiently treated industrial waste waters located in the river basin enterprises water quality does not meet the requirements on the studied parameters. To improve environmental monitoring and development of measures on protection of water objects in the basin of the middle course of the Syrdarya river carried out medium-term forecast of influence of the enterprise's waste water on water quality of the river Chirchik. The results of the forecast showed that by 2020, the standards of water quality in Chirchik river may be impaired for ammonia, nitrites, nitrates, petroleum products, and sanitary-indicative microorganisms. The magnitude of ammonia will exceed the installed regulations 2.9; nitrite and 9.3; nitrate and 3.2 and petroleum products – by 3.4 times, respectively. For the settlement period of the forecast should also expect increased levels of bacterial pollution of water by index lactosonegative Escherichia coli, Escherichia coli and enterococci. Based on the research developed the methodical recommendations on monitoring of water objects in the basin of the middle course of the Syrdarya river, to the Ministry of Health of the Republic of Uzbekistan, the practical application of which will prevent further pollution of water bodies used for potable and cultural-domestic water use of the population.

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Allsing, Nicholas, Scott T. Kelley, Alexandra N. Fox et Karilyn E. Sant. « Metagenomic Analysis of Microbial Contamination in the U.S. Portion of the Tijuana River Watershed ». International Journal of Environmental Research and Public Health 20, n^o 1 (29 décembre 2022) : 600. http://dx.doi.org/10.3390/ijerph20010600.

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The Tijuana River watershed is binational, flowing from Tijuana, Mexico into San Diego and Imperial Beach, USA. Aging sewage and stormwater infrastructure in Tijuana has not kept pace with population growth, causing overflows into this watershed during major rainfall or equipment failures. The public health consequences of this impaired watershed on the surrounding communities remain unknown. Here, we performed untargeted metagenomic sequencing to better characterize the sewage contamination in the Tijuana River, identifying potential pathogens and molecular indicators of antibiotic resistance in surface waters. In 2019–2020, water samples were collected within 48 h of major rainfall events at five transborder flow sites and at the mouth of the river in the US portion of the Tijuana River and estuary. After filtration, DNA was extracted and sequenced, and sequences were run through the Kaiju taxonomic classification program. A pathogen profile of the most abundant disease-causing microbes and viruses present in each of the samples was constructed, and specific markers of fecal contamination were identified and linked to each site. Results from diversity analysis between the sites showed clear distinction as well as similarities between sites and dates, and antibiotic-resistant genes were found at each site. This serves as a baseline characterization of microbial exposures to these local communities.

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Zelnik, Igor, et Tjaša Sušin. « Epilithic Diatom Community Shows a Higher Vulnerability of the River Sava to Pollution during the Winter ». Diversity 12, n^o 12 (5 décembre 2020) : 465. http://dx.doi.org/10.3390/d12120465.

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The aim of the research was to investigate the influence of environmental factors on the structure of epilithic diatom communities in the Sava River from the source to the state border 220 km downstream. The river had numerous human influences along its course, such as municipal and industrial wastewater, agriculture, hydroelectric power plants, etc. The main objective of the research was to find out the influence of human pressure on the structure of the epilithic diatom community under winter and summer conditions. Winter and summer samples were taken at nine sites. At each sampling site, a set of abiotic factors was measured and another set of environmental parameters was evaluated. The analyses showed that nitrogen and phosphorus concentrations increased downstream. We identified 118 different species of diatoms. The most common taxa were Achnanthidium minutissimum and A. pyrenaicum. Planktonic species Cyclotella meneghiniana was only found in the samples of the lower part of the Sava, which is unusual for the epilithic community. The composition of the epilithic diatom community was significantly influenced by conductivity and water temperature, pH and distance from the source. The similarity between diatom communities closer to the source of the river was higher than between communities from the lower part of the Sava River. The values of the trophic and saprobic indices increased downstream and showed that the pollution of the river with nutrients and organic matter increases with the distance from the source. Both indices were significantly higher in winter and showed a more impaired river ecosystem during the winter.

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Stringfellow, William, Joel Herr, Gary Litton, Mark Brunell, Sharon Borglin, Jeremy Hanlon, Carl Chen et al. « Investigation of river eutrophication as part of a low dissolved oxygen total maximum daily load implementation ». Water Science and Technology 59, n^o 1 (1 janvier 2009) : 9–14. http://dx.doi.org/10.2166/wst.2009.739.

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In the United States, environmentally impaired rivers are subject to regulation under total maximum daily load (TMDL) regulations that specify watershed wide water quality standards. In California, the setting of TMDL standards is accompanied by the development of scientific and management plans directed at achieving specific water quality objectives. The San Joaquin River (SJR) in the Central Valley of California now has a TMDL for dissolved oxygen (DO). Low DO conditions in the SJR are caused in part by excessive phytoplankton growth (eutrophication) in the shallow, upstream portion of the river that create oxygen demand in the deeper estuary. This paper reports on scientific studies that were conducted to develop a mass balance on nutrients and phytoplankton in the SJR. A mass balance model was developed using WARMF, a model specifically designed for use in TMDL management applications. It was demonstrated that phytoplankton biomass accumulates rapidly in a 88 km reach where plankton from small, slow moving tributaries are diluted and combined with fresh nutrient inputs in faster moving water. The SJR-WARMF model was demonstrated to accurately predict phytoplankton growth in the SJR. Model results suggest that modest reductions in nutrients alone will not limit algal biomass accumulation, but that combined strategies of nutrient reduction and algal control in tributaries may have benefit. The SJR-WARMF model provides stakeholders a practical, scientific tool for setting remediation priorities on a watershed scale.

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Feio, Maria João, Robert M. Hughes, Marcos Callisto, Susan J. Nichols, Oghenekaro N. Odume, Bernardo R. Quintella, Mathias Kuemmerlen et al. « The Biological Assessment and Rehabilitation of the World’s Rivers : An Overview ». Water 13, n^o 3 (31 janvier 2021) : 371. http://dx.doi.org/10.3390/w13030371.

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The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2–3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.

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STEWART-KOSTER, B., S. E. BUNN, S. J. MACKAY, N. L. POFF, R. J. NAIMAN et P. S. LAKE. « The use of Bayesian networks to guide investments in flow and catchment restoration for impaired river ecosystems ». Freshwater Biology 55, n^o 1 (janvier 2010) : 243–60. http://dx.doi.org/10.1111/j.1365-2427.2009.02219.x.

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Wang, Junna, Zhonglong Zhang et Billy Johnson. « Low flows and downstream decline in phytoplankton contribute to impaired water quality in the lower Minnesota River ». Water Research 161 (septembre 2019) : 262–73. http://dx.doi.org/10.1016/j.watres.2019.05.090.

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Tagert, Mary Love, Joseph H. Massey, David R. Shaw et Jeffery A. Ballweber. « SURFACE WATER SAMPLING AND ANALYSIS TO PRIORITIZE POTENTIALLY PESTICIDE “IMPAIRED” WATERBODIES IN MISSISSIPPI'S UPPER PEARL RIVER BASIN ». Proceedings of the Water Environment Federation 2004, n^o 4 (1 janvier 2004) : 94–104. http://dx.doi.org/10.2175/193864704790896658.

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Epstein, Dave M., Julia E. Kelso et Michelle A. Baker. « Beyond the urban stream syndrome : organic matter budget for diagnostics and restoration of an impaired urban river ». Urban Ecosystems 19, n^o 4 (20 avril 2016) : 1623–43. http://dx.doi.org/10.1007/s11252-016-0556-y.

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Epstein, Dave M., Julia E. Kelso et Michelle A. Baker. « Beyond the urban stream syndrome : organic matter budget for diagnostics and restoration of an impaired urban river ». Urban Ecosystems 19, n^o 3 (7 mai 2016) : 1041–61. http://dx.doi.org/10.1007/s11252-016-0557-x.

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Bailey, Ryan T., Saman Tavakoli-Kivi et Xiaolu Wei. « A salinity module for SWAT to simulate salt ion fate and transport at the watershed scale ». Hydrology and Earth System Sciences 23, n^o 7 (31 juillet 2019) : 3155–74. http://dx.doi.org/10.5194/hess-23-3155-2019.

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Abstract. Salinity is one of the most common water quality threats in river basins and irrigated regions worldwide. However, no available numerical models simulate all major processes affecting salt ion fate and transport at the watershed scale. This study presents a new salinity module for the SWAT model that simulates the fate and transport of eight major salt ions (SO42-, Ca2+, Mg2+, Na+, K+, Cl−, CO32-, HCO3-) in a watershed system. The module accounts for salt transport in surface runoff, soil percolation, lateral flow, groundwater, and streams, and equilibrium chemistry reactions in soil layers and the aquifer. The module consists of several new subroutines that are imbedded within the SWAT modelling code and one input file containing soil salinity and aquifer salinity data for the watershed. The model is applied to a 732 km2 salinity-impaired irrigated region within the Arkansas River Valley in southeastern Colorado and tested against root zone soil salinity, groundwater salt ion concentration, groundwater salt loadings to the river network, and in-stream salt ion concentration. The model can be a useful tool in simulating baseline salinity transport and investigating salinity best management practices in watersheds of varying spatial scales.

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Johnson, Bruce R., et Glen T. Daigger. « Integrated nutrient removal design for very low phosphorus levels ». Water Science and Technology 60, n^o 9 (1 novembre 2009) : 2455–62. http://dx.doi.org/10.2166/wst.2009.618.

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The State of Washington has found that the Spokane River is DO impaired, and is requiring dischargers to reduce phosphorus inputs to the river. Spokane County elected to build a new water recovery facility with a target effluent total phosphorus level of 50 μg/L on a seasonal average basis. Spokane County elected to use a private company to design/build and operate their facility. The very low nutrient requirements, and lack of historical operating information, necessitated an integrated approach to the nutrient removal design while considering the risks and benefits of the various treatment options. The process selection evaluated membrane bioreactors and tertiary membranes for the primary liquids process in combination with chemical and/or biological phosphorus removal. The final process selection included chemically enhanced primary treatment, membrane bioreactor with metal salts, and dewatering liquor treatment with an innovative post aerobic digestion step.

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Selego, Stephen M., Charneé L. Rose, George T. Merovich, Stuart A. Welsh et James T. Anderson. « Community-Level Response of Fishes and Aquatic Macroinvertebrates to Stream Restoration in a Third-Order Tributary of the Potomac River, USA ». International Journal of Ecology 2012 (2012) : 1–9. http://dx.doi.org/10.1155/2012/753634.

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Natural stream channel design principles and riparian restoration practices were applied during spring 2010 to an agriculturally impaired reach of the Cacapon River, a tributary of the Potomac River which flows into the Chesapeake Bay. Aquatic macroinvertebrates and fishes were sampled from the restoration reach, two degraded control, and two natural reference reaches prior to, concurrently with, and following restoration (2009 through 2010). Collector filterers and scrapers replaced collector gatherers as the dominant macroinvertebrate functional feeding groups in the restoration reach. Before restoration, based on indices of biotic integrity (IBI), the restoration reach fish and macroinvertebrate communities closely resembled those sampled from the control reaches, and after restoration more closely resembled those from the reference reaches. Although the macroinvertebrate community responded more favorably than the fish community, both communities recovered quickly from the temporary impairment caused by the disturbance of restoration procedures and suggest rapid improvement in local ecological conditions.

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Hamner, Steve, Bonnie Brown, Nur Hasan, Michael Franklin, John Doyle, Margaret Eggers, Rita Colwell et Timothy Ford. « Metagenomic Profiling of Microbial Pathogens in the Little Bighorn River, Montana ». International Journal of Environmental Research and Public Health 16, n^o 7 (27 mars 2019) : 1097. http://dx.doi.org/10.3390/ijerph16071097.

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The Little Bighorn River is the primary source of water for water treatment plants serving the local Crow Agency population, and has special significance in the spiritual and ceremonial life of the Crow tribe. Unfortunately, the watershed suffers from impaired water quality, with high counts of fecal coliform bacteria routinely measured during run-off events. A metagenomic analysis was carried out to identify potential pathogens in the river water. The Oxford Nanopore MinION platform was used to sequence DNA in near real time to identify both uncultured and a coliform-enriched culture of microbes collected from a popular summer swimming area of the Little Bighorn River. Sequences were analyzed using CosmosID bioinformatics and, in agreement with previous studies, enterohemorrhagic and enteropathogenic Escherichia coli and other E. coli pathotypes were identified. Noteworthy was detection and identification of enteroaggregative E. coli O104:H4 and Vibrio cholerae serotype O1 El Tor, however, cholera toxin genes were not identified. Other pathogenic microbes, as well as virulence genes and antimicrobial resistance markers, were also identified and characterized by metagenomic analyses. It is concluded that metagenomics provides a useful and potentially routine tool for identifying in an in-depth manner microbial contamination of waterways and, thereby, protecting public health.

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Walrath, John D., Daniel C. Dauwalter et Drew Reinke. « Influence of Stream Condition on Habitat Diversity and Fish Assemblages in an Impaired Upper Snake River Basin Watershed ». Transactions of the American Fisheries Society 145, n^o 4 (22 juin 2016) : 821–34. http://dx.doi.org/10.1080/00028487.2016.1159613.

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Scholl, E. A., H. M. Rantala, M. R. Whiles et G. V. Wilkerson. « Influence of Flow on Community Structure and Production of Snag-Dwelling Macroinvertebrates in an Impaired Low-Gradient River ». River Research and Applications 32, n^o 4 (25 mars 2015) : 677–88. http://dx.doi.org/10.1002/rra.2882.

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Prairie, R., K. Schiefer, L. J. Moulins et V. Chapados. « Impact of an Acid Spill on the Resident Fauna of the York River and its Recovery ». Water Quality Research Journal 24, n^o 4 (1 novembre 1989) : 569–82. http://dx.doi.org/10.2166/wqrj.1989.035.

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Abstract As a result of a sulphuric acid spill in June 1982 at the Mines Gaspé operation in Murdochville, Québec, water quality of effluents being discharged into the headwaters of the York River was temporarily impaired. It rapidly became apparent that the aquatic fauna of this important Atlantic salmon river had been affected in some areas. This paper provides an overview of the results obtained in biological studies (Atlantic salmon population and benthic communities) carried out by Beak Consultants Ltd. and Noranda Technology Centre, annually, from 1982 to 1985. The biological and water chemistry surveys carried out during this four-year period indicated a short duration event of high dissolved metal levels, primarily copper, shortly after the spill, followed by a rapid improvement in water quality. Both the aquatic macroinvertebrate benthos and fish life in the river were negatively impacted. The nature and degree of this impact as well as the subsequent recolonization of aquatic habitats by both groups were observed and documented. The most affected aquatic groups in 1982 were the youngest salmon age classes (0+ and 1+) along with the intermediate and sensitive benthic communities. This impact was mainly observed in the upper and middle river section. Maintenance of suitable water quality during the following years has permitted excellent survival rates for juvenile salmon and recolonization of benthic habitats by sensitive species. This has contributed to the gradual re-establishment of a natural aquatic fauna in the York River. More recent surveys carried out since 1985 confirm that the quality of the York River ecosystem has been maintained and suggest that the survival rates observed for juvenile salmon are higher than the theoretical values usually used in salmon production models.

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