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Journal articles on the topic 'River systems'
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1
Anagnostoudi, Th, S. Papadopoulou, D. Ktenas, E. Gkadri, I. Pyliotis, N. Kokkidis, and V. Panagiotopoulos. "THE OLVIOS, RETHIS AND INACHOS DRAINAGE SYSTEM EVOLUTION AND HUMAN ACTIVITIES INFLUNCE OF THEIR FUTURE EVOLUTION." Bulletin of the Geological Society of Greece 43, no. 2 (January 23, 2017): 548. http://dx.doi.org/10.12681/bgsg.11217.
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Olvios, Rethis and Inachos Rivers are multistory drainage systems that occur in Northern Peloponnesus, and at the present day they have and a reversed, North to South, flow element. Dervenios, Skoupeikos and Fonissa Rivers are the misfit streams of Olvios and revealed as juvenile streams and discharge to the Corinth gulf. Agiorgitikos River is the misfit stream of Rethis River and Seliandros River is the juvenile stream. Asopos, Nemeas and Rachiani Rives are the misfit streams of Inachos River and they also discharge to the Corinth gulf. Asopos River characterized as re-established stream. Physical factors such as tectonic regime (active and inactive faults), lithology, erosion and distance from the source influenced the three drainage systems evolution and could be influence them also in the future. The increase of human activities both in their southern parts and in the distal parts close to the coast could be change the physical evolution of the studied drainages, producing a new wind gap in the coastal area and a lake or a lagoon backwards of the coastal area, destroying villages and towns.
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Richardson, Martin, and Mikhail Soloviev. "The Urban River Syndrome: Achieving Sustainability Against a Backdrop of Accelerating Change." International Journal of Environmental Research and Public Health 18, no. 12 (June 13, 2021): 6406. http://dx.doi.org/10.3390/ijerph18126406.
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Human activities have been affecting rivers and other natural systems for millennia. Anthropogenic changes to rivers over the last few centuries led to the accelerating state of decline of coastal and estuarine regions globally. Urban rivers are parts of larger catchment ecosystems, which in turn form parts of wider nested, interconnected systems. Accurate modelling of urban rivers may not be possible because of the complex multisystem interactions operating concurrently and over different spatial and temporal scales. This paper overviews urban river syndrome, the accelerating deterioration of urban river ecology, and outlines growing conservation challenges of river restoration projects. This paper also reviews the river Thames, which is a typical urban river that suffers from growing anthropogenic effects and thus represents all urban rivers of similar type. A particular emphasis is made on ecosystem adaptation, widespread extinctions and the proliferation of non-native species in the urban Thames. This research emphasizes the need for a holistic systems approach to urban river restoration.
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Gensen, Matthijs R. A., Jord J. Warmink, Fredrik Huthoff, and Suzanne J. M. H. Hulscher. "Feedback Mechanism in Bifurcating River Systems: the Effect on Water-Level Sensitivity." Water 12, no. 7 (July 5, 2020): 1915. http://dx.doi.org/10.3390/w12071915.
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Accurate and reliable estimates of water levels are essential to assess flood risk in river systems. In current practice, uncertainties involved and the sensitivity of water levels to these uncertainties are studied in single-branch rivers, while many rivers in deltas consist of multiple distributaries. In a bifurcating river, a feedback mechanism exists between the downstream water levels and the discharge distribution at the bifurcation. This paper aims to quantify the sensitivity of water levels to main channel roughness in a bifurcating river system. Water levels are modelled for various roughness scenarios under a wide range of discharge conditions using a one-dimensional hydraulic model. The results show that the feedback mechanism reduces the sensitivity of water levels to local changes of roughness in comparison to the single-branch river. However, in the smaller branches of the system, water-level variations induced by the changes in discharge distribution can exceed the water-level variations of the single-branch river. Therefore, water levels throughout the entire system are dominated by the conditions in the largest branch. As the feedback mechanism is important, the river system should be considered as one interconnected system in river maintenance of rivers, flood-risk analyses, and future planning of river engineering works.
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Kyryliuk, Serhii. "The assessment algorithm for sustainable development goals in the Hukiv, Dereluy, and Vyzhenka river basin systems of Chernivtsi oblast." Present Environment and Sustainable Development 15, no. 2 (October 3, 2021): 235–44. http://dx.doi.org/10.15551/pesd2021152019.
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The study deals with an integral assessment of hydromorphological and geoecological conditions of the Hukiv (flatland type of river), Dereluy (foothill type of river), and Vyzhenka (mountainous type of river) river basin systems (Figure 1). The indicators characterizing the river basin in the best way as a holistic system, the channel, floodplain, and watershed altogether, in natural reference conditions and in terms of human economic activity are addressed. The assessment hydromorphological test and geoecological monitoring of small rivers (SWOT-analysis) in accordance with the developed universal algorithm for hydromorphological assessment of small river basins for the sustainable development goals are generated and fulfilled. Interpretation maps for the sustainable development of the Hukiv, Dereluy and Vyzhenka rivers are created. The practical importance and relevance concerns the potential application of the proposed monitoring and the algorithm to solve methodological and applied problems related to the functioning of the systems “basin–river–human” and “basin–river–riverbed” in terms of modern human activity and needs; the need to modify consumer-type stereotypes for the use of natural resources, as well as to provide recommendations for enhancing the resource-efficient and sustainable activities in basin systems and small rivers.
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Oka, Hiroaki. "Introduction of River Systems." JAPAN TAPPI JOURNAL 73, no. 12 (2019): 1149–53. http://dx.doi.org/10.2524/jtappij.73.1149.
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Sigdel, Ashok, and Tetsuya Sakai. "Sedimentary facies analysis of the fluvial systems in the Siwalik Group, Karnali River section, Nepal Himalaya, and their significance for understanding the paleoclimate and Himalayan tectonics." Journal of Nepal Geological Society 51 (December 31, 2016): 11–26. http://dx.doi.org/10.3126/jngs.v51i0.24084.
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Fluvial sediments of the Siwalik successions in the Himalayan Foreland Basin are one of the most important continental archives for the history of Himalayan tectonics and climate change during the Miocene Period. This study reanalyzes the fluvial facies of the Siwalik Group along the Karnali River, where the large paleo-Karnali River system is presumed to have flowed. The reinterpreted fluvial system comprises fine-grained meandering river (FA1), flood-flow dominated meandering river with intermittent appearance of braided rivers (FA2), deep and shallow sandy braided rivers (FA3, FA4) to gravelly braided river (FA5) and finally debris-flow dominated braided river (FA6) facies associations, in ascending order. Previous work identified sandy flood-flow dominated meandering and anastomosed systems, but this study reinterprets these systems as a flood-flow dominated meandering river system with intermittent appearance of braided rivers, and a shallow sandy braided system, respectively. The order of the appearance of fluvial depositional systems in the Karnali River section is similar to those of other Siwalik sections, but the timing of the fluvial facies changes differs. The earlier appearance (3-4 Ma) of the flood-flow dominated meandering river system in the Karnali River section at about 13.5 Ma may have been due to early uplift of the larger catchment size of the paleo-Karnali River which may have changed the precipitation pattern i.e. intensification of the Indian Summer Monsoon. The change from a meandering river system to a braided river system is also recorded 1 to 3 Ma earlier than in other Siwalik sections in Nepal. Differential and diachronous activities of the thrust systems could be linked to change in catchment area as well as diachronous uplift and climate, the combination of which are major probable causes of this diachronity.
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Wu, Xue Wen, Ling Li, and Yong Gang Qu. "Modelling and Analysis of River Networks Based on Complex Networks Theory." Advanced Materials Research 756-759 (September 2013): 2728–33. http://dx.doi.org/10.4028/www.scientific.net/amr.756-759.2728.
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River systems are open and self-organizing complex systems. Complex networks theory can well combine rivers' macro properties with their microscopic properties. This paper builds a river network model based on complex networks theory and describes its characteristics. After the analysis of the model used in Haihe River Basin, it shows that Haihe River Basin network has the small-world characteristics. This work provides a new approach to research the properties of river networks, so that to predict and control its behavior.
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Moridi, Ali. "A bankruptcy method for pollution load reallocation in river systems." Journal of Hydroinformatics 21, no. 1 (October 12, 2018): 45–55. http://dx.doi.org/10.2166/hydro.2018.156.
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Abstract This study forms the basis and sets practical guidelines for developing river water quality management strategies for resolving conflicts related to the allocation of pollution discharge permits using bankruptcy methods. This approach was implemented by changing the concepts and considering the river self-purification potential (capacity) as an asset which is to be shared among various beneficiaries. The beneficiaries are the point sources which release their wastewater to the river with minimum treatment costs. Four commonly used bankruptcy methods in the water resources allocation literature are used here to develop new river bankruptcy solution methods for allocating pollution share to the riparian parties of river systems. For this purpose, the Qual2 K river water quality simulation model is integrated with a particle swarm optimization (PSO) model while various pollution loadings discharge policies have been determined based on the bankruptcy method. This method was employed in one of the most polluted rivers of northern Iran, which is the source of eutrophication for Anzali International Wetland. The results show that the application of this method could facilitate the conflict resolution among different beneficiaries in order to improve the conditions of river water quality.
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Parsons, Melissa, Martin C. Thoms, and Joseph E. Flotemersch. "Eight river principles for navigating the science–policy interface." Marine and Freshwater Research 68, no. 3 (2017): 401. http://dx.doi.org/10.1071/mf15336.
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Scientists and policymakers often work together to develop policy about the sustainable use of river ecosystems. River science plays an important role in developing river policy but how can key aspects of river science be conveyed as a heuristic to navigate the interface between river science and river policy? This paper introduces eight principles that encapsulate the key properties of rivers to consider during the development of river policy: (1) rivers are social–ecological systems; (2) river ecosystems provide valuable ecosystem services; (3) tools should support policy development; (4) knowledge of river ecosystems will always be incomplete; (5) social–ecological systems require interdisciplinary perspectives; (6) science is one of many inputs to be considered; (7) heterogeneity and variability are characteristic of river ecosystems; and (8) scale awareness is essential in river ecosystems. Whereas policy challenges are associated with each principle, consideration of principles in the context of the issue at hand may increase the robustness of river policy and enhance the sustainability of river ecosystems. The eight principles are evaluated in relation to the Water Act 2007 and the draft Murray–Darling Basin Plan to demonstrate how the principles can enhance policy development in the area of water allocation.
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Lattaud, Julie, Frédérique Kirkels, Francien Peterse, Chantal V. Freymond, Timothy I. Eglinton, Jens Hefter, Gesine Mollenhauer, et al. "Long-chain diols in rivers: distribution and potential biological sources." Biogeosciences 15, no. 13 (July 9, 2018): 4147–61. http://dx.doi.org/10.5194/bg-15-4147-2018.
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Abstract. Long-chain diols (LCDs) occur widespread in marine environments and also in lakes and rivers. Transport of LCDs from rivers may impact the distribution of LCDs in coastal environments, however relatively little is known about the distribution and biological sources of LCDs in river systems. In this study, we investigated the distribution of LCDs in suspended particulate matter (SPM) of three river systems (Godavari, Danube, and Rhine) in relation with precipitation, temperature, and source catchments. The dominant long-chain diol is the C32 1,15-diol followed by the C30 1,15-diol in all studied river systems. In regions influenced by marine waters, such as delta systems, the fractional abundance of the C30 1,15-diol is substantially higher than in the river itself, suggesting different LCD producers in marine and freshwater environments. A change in the LCD distribution along the downstream transects of the rivers studied was not observed. However, an effect of river flow is observed; i.e., the concentration of the C32 1,15-diol is higher in stagnant waters such as reservoirs and during seasons with river low stands. A seasonal change in the LCD distribution was observed in the Rhine, likely due to a change in the producers. Eukaryotic diversity analysis by 18S rRNA gene sequencing of SPM from the Rhine showed extremely low abundances of sequences (i.e., < 0.32 % of total reads) related to known algal LCD producers. Furthermore, incubation of the river water with 13C-labeled bicarbonate did not result in 13C incorporation into LCDs. This indicates that the LCDs present are mainly of fossil origin in the fast-flowing part of the Rhine. Overall, our results suggest that the LCD producers in rivers predominantly reside in lakes or side ponds that are part of the river system.
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Yang, Xiankun, Xixi Lu, Lishan Ran, and Paolo Tarolli. "Geomorphometric Assessment of the Impacts of Dam Construction on River Disconnectivity and Flow Regulation in the Yangtze Basin." Sustainability 11, no. 12 (June 21, 2019): 3427. http://dx.doi.org/10.3390/su11123427.
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Rivers are under increasing pressure from anthropogenic impacts with incremental dam construction, experiencing global and regional alteration due to river disconnectivity, flow regulation, and sediment reduction. Assessing the cumulative impacts of dams on river disconnectivity in large river basins can help us better understand how humans disintegrate river systems and change the natural flow regimes. Using the Yangtze basin as the study area, this study employed three modified metrics (river connectivity index, RCI; basin disconnectivity index, BDI; and the degree of regulation for each river section, DOR) to evaluate the cumulative impacts on river disconnectivity over the past 50 years. The results indicated that the Yangtze had experienced strong alterations, despite varying degrees and spatial patterns. Among the major tributaries, the greatest impact (lowest RCI value) happened in the Wu tributary basin due to the construction of cascade dams on the main stem of the tributary, while the lowest impact (highest RCI value) happened in the Fu tributary basin, which still has no dams on its main stem. Collectively, rivers in the upper Yangtze reaches experienced more serious disturbances than their counterparts in the middle and lower reaches. The BDI results displayed that a substantial part of the Yangtze River, especially the Wu, Min, Jialing, and Yuan tributaries, only maintain connectivity among one to three representative river systems. No part of the Yangtze connects all the 12 representative river systems. This study also revealed that small dams can also exert significant impacts in flow regulation on regional river systems through their sheer number and density. The study results can help promote more environmentally sustainable river management policies in the Yangtze basin.
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Ouellet Dallaire, Camille, Bernhard Lehner, and Irena Creed. "Multidisciplinary classification of Canadian river reaches to support the sustainable management of freshwater systems." Canadian Journal of Fisheries and Aquatic Sciences 77, no. 2 (February 2020): 326–41. http://dx.doi.org/10.1139/cjfas-2018-0284.
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Climate change is altering the hydrology of Canadian rivers to an unprecedented degree. Consequently, sustainable freshwater management practices need to adapt, which include the development of integrated water resource strategies and environmental flow recommendations. A particular challenge arises for these assessments due to the highly diverse nature of river ecosystems across Canada. This diversity can be addressed by using a classification system to create manageable spatial units. Building upon and adapting the results of a global river reach classification scheme, we present a multidisciplinary K-means clustering approach to categorize all river reaches of Canada into 23 types at fine spatial resolution. The typology is based on classifier variables related to hydrology, mostly derived from modelled long-term means of monthly discharges, physiography, climate, and fluvial geomorphology. Resulting maps provide baseline information for rivers of all size classes, from small headwater streams to very large rivers, across the entire country, including unmonitored regions such as the High Arctic. The classification system also points to some strategic expansion opportunities for the current Canadian monitoring network of river gauging stations.
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Ceola, Serena, Francesco Laio, and Alberto Montanari. "Global-scale human pressure evolution imprints on sustainability of river systems." Hydrology and Earth System Sciences 23, no. 9 (September 25, 2019): 3933–44. http://dx.doi.org/10.5194/hess-23-3933-2019.
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Abstract. Human pressures on river systems pose a major threat to the sustainable development of human societies in the twenty-first century. Previous studies showed that a large part of global river systems was already exposed to relevant anthropogenic pressures at the beginning of this century. A relevant question that has never been explained in the literature so far is whether these pressures are increasing in time, therefore representing a potential future challenge to the sustainability of river systems. This paper proposes an index we call “Differential Human Pressure on Rivers” (DHPR) to quantify the annual evolution of human pressure on river systems. DHPR identifies a per-year percentage increment (or decrement) of normalized human pressures on river systems (i.e., ratio of annual values to long-term average). This index, based on annual nightlights and stationary discharge data, is estimated for 2195 major river basins over a period of 22 years, from 1992 to 2013. The results show that normalized annual human pressure on river systems increased globally, as indicated by an average DHPR value of 1.9 % per year, whereby the greatest increase occurred in the northern tropical and equatorial areas. The evaluation of DHPR over this 22-year period allows the identification of hot-spot areas, therefore offering guidance on where the development and implementation of mitigation strategies and plans are most needed (i.e., where human pressure is strongly increasing).
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Smith, Keith T. "River systems reveal planetary tectonics." Science 356, no. 6339 (May 18, 2017): 712.4–712. http://dx.doi.org/10.1126/science.356.6339.712-d.
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Lindenschmidt, Karl-Erich, and Meghan Carr. "Geospatial Modeling of River Systems." Water 10, no. 3 (March 7, 2018): 282. http://dx.doi.org/10.3390/w10030282.
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Findlay, Sophia Jane, and Mark Patrick Taylor. "Why rehabilitate urban river systems?" Area 38, no. 3 (September 2006): 312–25. http://dx.doi.org/10.1111/j.1475-4762.2006.00696.x.
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Jain, Vikrant, Sonam, Ajit Singh, Rajiv Sinha, and S. K. Tandon. "Evolution of modern river systems: an assessment of ‘landscape memory’ in Indian river systems." Episodes 43, no. 1 (March 1, 2020): 535–51. http://dx.doi.org/10.18814/epiiugs/2020/020035.
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Yu, Junshuang. "Does river restoration result in improved environmental heterogeneity?" E3S Web of Conferences 284 (2021): 01002. http://dx.doi.org/10.1051/e3sconf/202128401002.
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Rivers can shape diverse landscapes, determine the spatial connectivity of river and terrestrial life, and provide a variety of resources and services. Rivers are often over-bound due to the need for flood control and irrigation. Rivers affected by human disturbance often require restoration to improve the ecosystem services they provide. Environmental heterogeneity is generally considered to be the non-uniform variation of environmental elements in space and/or time. The relationship between variability in physical characteristics of restored rivers and biological communities in the river environment is a highly complex feedback, and studying and summarising changes in environmental heterogeneity following river restoration can help refine methodologies for monitoring river restoration outcomes. This study highlights the variability in river geomorphology and river ecology, and demonstrates the feasibility and necessity of incorporating environmental heterogeneity indicators into river restoration outcome evaluation systems at three levels: hydrological, geomorphological and ecological.
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Trifu, M. C., and V. Daradici. "New monitoring technique for rapid investigation of nitrates pollution in aquatic systems." Proceedings of the International Association of Hydrological Sciences 364 (September 16, 2014): 481–85. http://dx.doi.org/10.5194/piahs-364-481-2014.
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Abstract. In situ measurement with a portable multi-parameter sonde was used in the framework of the Cleanwater project – LIFE09 ENV/RO/000612, for a rapid investigation of nitrates pollution in Barlad River basin, in rivers and domestic wells, in addition to laboratory measurements. Water samples were analysed in an accredited laboratory for water monitoring, such as the Vaslui Water Management System from Barlad basin. Sampling campaigns were performed monthly in the period April–November 2011. In order to find the main factors that influence the measurements, the behaviour of equipment was analysed in rivers, for different water sampling points along the river and the cross-sections, taking into account the water level, the turbulence, the vegetation and the obstacles along the river. Results proved the multiparameter sonde as a useful device for rapidly monitoring spatial distributions or temporal trends of nitrates or chlorophyll a, and detecting sudden changes in surface and groundwater quality.
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Sharma, Subodh, and Ram Devi Tachamo Shah. "Major stressors influencing the river ecosystems of Far and Mid Western Development Regions of Nepal." Current World Environment 14, no. 2 (August 16, 2019): 231–38. http://dx.doi.org/10.12944/cwe.14.2.07.
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Maintaining healthy river ecosystem is essential both from aquatic biodiversity conservation perspective as well as for the socio-cultural and economic development of nations all over the world. Many rivers in Nepal have largely been modified with the purpose of supplying drinking water, irrigating agricultural lands, producing hydro-electricity, and operating water mills. During the process, rivers are channelized and the river bed materials are removed. Such activities of river bed excavation have changed both the natural flow regimes and morphological characteristics of rivers. Studies on the impacts caused by such stressors on river ecosystems are lacking in the context of Nepalese river systems. Therefore we have assessed how these stressors might change the faunal composition of benthic macroinvertebrates in headwaters of the Western region of Nepal. The study was conducted in the headwaters of rivers of Mahakali and Karnali rivers. Habitat specific benthic macroinvertebrates were sampled from 33 sites seasonally in the year 2016 and 2017. Physical characteristics of rivers including river bed composition, water abstractions and other local stressors including waste dumping and washing-bathing were noted in the field. The study showed that macroinvertebrates community structures were significantly different in the habitat modified sites compared to reference sites. In general, abstracted sites coupled with river bed removals were found to be colonized by fewer taxa with high dominance of pool preference biota such as genera of Mayflies (Torleya spp., Caenis spp., Choroterpes spp.) and families of true flies (Chironomidae and Ceratopogoniidae). Macroinvertebrates’ abundance was significantly lower in the habitat modified sites. This study envisages that maintaining river’s habitats with minimal flows all round year could preserve ecological integrity of river systems.
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Jackson, Colin R., Justin J. Millar, Jason T. Payne, and Clifford A. Ochs. "Free-Living and Particle-Associated Bacterioplankton in Large Rivers of the Mississippi River Basin Demonstrate Biogeographic Patterns." Applied and Environmental Microbiology 80, no. 23 (September 12, 2014): 7186–95. http://dx.doi.org/10.1128/aem.01844-14.
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ABSTRACTThe different drainage basins of large rivers such as the Mississippi River represent interesting systems in which to study patterns in freshwater microbial biogeography. Spatial variability in bacterioplankton communities in six major rivers (the Upper Mississippi, Missouri, Illinois, Ohio, Tennessee, and Arkansas) of the Mississippi River Basin was characterized using Ion Torrent 16S rRNA amplicon sequencing. When all systems were combined, particle-associated (>3 μm) bacterial assemblages were found to be different from free-living bacterioplankton in terms of overall community structure, partly because of differences in the proportional abundance of sequences affiliated with major bacterial lineages (Alphaproteobacteria,Cyanobacteria, andPlanctomycetes). Both particle-associated and free-living communities ordinated by river system, a pattern that was apparent even after rare sequences or those affiliated withCyanobacteriawere removed from the analyses. Ordination of samples by river system correlated with environmental characteristics of each river, such as nutrient status and turbidity. Communities in the Upper Mississippi and the Missouri and in the Ohio and the Tennessee, pairs of rivers that join each other, contained similar taxa in terms of presence-absence data but differed in the proportional abundance of major lineages. The most common sequence types detected in particle-associated communities were picocyanobacteria in theSynechococcus/Prochlorococcus/Cyanobium(Syn/Pro) clade, while free-living communities also contained a high proportion of LD12 (SAR11/Pelagibacter)-likeAlphaproteobacteria. This research shows that while different tributaries of large river systems such as the Mississippi River harbor distinct bacterioplankton communities, there is also microhabitat variation such as that between free-living and particle-associated assemblages.
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Park, Ji-Hyung, Omme K. Nayna, Most S. Begum, Eliyan Chea, Jens Hartmann, Richard G. Keil, Sanjeev Kumar, et al. "Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems – concepts, emerging trends, and research challenges." Biogeosciences 15, no. 9 (May 17, 2018): 3049–69. http://dx.doi.org/10.5194/bg-15-3049-2018.
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Abstract. Human activities are drastically altering water and material flows in river systems across Asia. These anthropogenic perturbations have rarely been linked to the carbon (C) fluxes of Asian rivers that may account for up to 40–50 % of the global fluxes. This review aims to provide a conceptual framework for assessing the human impacts on Asian river C fluxes, along with an update on anthropogenic alterations of riverine C fluxes. Drawing on case studies conducted in three selected rivers (the Ganges, Mekong, and Yellow River) and other major Asian rivers, the review focuses on the impacts of river impoundment and pollution on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia and Oceania. A critical examination of major conceptual models of riverine processes against observed trends suggests that to better understand altered metabolisms and C fluxes in “anthropogenic land-water-scapes”, or riverine landscapes modified by human activities, the traditional view of the river continuum should be complemented with concepts addressing spatial and temporal discontinuities created by human activities, such as river impoundment and pollution. Recent booms in dam construction on many large Asian rivers pose a host of environmental problems, including increased retention of sediment and associated C. A small number of studies that measured greenhouse gas (GHG) emissions in dammed Asian rivers have reported contrasting impoundment effects: decreased GHG emissions from eutrophic reservoirs with enhanced primary production vs. increased emissions from the flooded vegetation and soils in the early years following dam construction or from the impounded reaches and downstream estuaries during the monsoon period. These contrasting results suggest that the rates of metabolic processes in the impounded and downstream reaches can vary greatly longitudinally over time as a combined result of diel shifts in the balance between autotrophy and heterotrophy, seasonal fluctuations between dry and monsoon periods, and a long-term change from a leaky post-construction phase to a gradual C sink. The rapid pace of urbanization across southern and eastern Asian regions has dramatically increased municipal water withdrawal, generating annually 120 km3 of wastewater in 24 countries, which comprises 39 % of the global municipal wastewater production. Although municipal wastewater constitutes only 1 % of the renewable surface water, it can disproportionately affect the receiving river water, particularly downstream of rapidly expanding metropolitan areas, resulting in eutrophication, increases in the amount and lability of organic C, and pulse emissions of CO2 and other GHGs. In rivers draining highly populated metropolitan areas, lower reaches and tributaries, which are often plagued by frequent algal blooms and pulsatile CO2 emissions from urban tributaries delivering high loads of wastewater, tended to exhibit higher levels of organic C and the partial pressure of CO2 (pCO2) than less impacted upstream reaches and eutrophic impounded reaches. More field measurements of pCO2, together with accurate flux calculations based on river-specific model parameters, are required to provide more accurate estimates of GHG emissions from the Asian rivers that are now underrepresented in the global C budgets. The new conceptual framework incorporating discontinuities created by impoundment and pollution into the river continuum needs to be tested with more field measurements of riverine metabolisms and CO2 dynamics across variously affected reaches to better constrain altered fluxes of organic C and CO2 resulting from changes in the balance between autotrophy and heterotrophy in increasingly human-modified river systems across Asia and other continents.
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Milner, Alexander M., Kieran Khamis, Tom J. Battin, John E. Brittain, Nicholas E. Barrand, Leopold Füreder, Sophie Cauvy-Fraunié, et al. "Glacier shrinkage driving global changes in downstream systems." Proceedings of the National Academy of Sciences 114, no. 37 (September 5, 2017): 9770–78. http://dx.doi.org/10.1073/pnas.1619807114.
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Glaciers cover ∼10% of the Earth’s land surface, but they are shrinking rapidly across most parts of the world, leading to cascading impacts on downstream systems. Glaciers impart unique footprints on river flow at times when other water sources are low. Changes in river hydrology and morphology caused by climate-induced glacier loss are projected to be the greatest of any hydrological system, with major implications for riverine and near-shore marine environments. Here, we synthesize current evidence of how glacier shrinkage will alter hydrological regimes, sediment transport, and biogeochemical and contaminant fluxes from rivers to oceans. This will profoundly influence the natural environment, including many facets of biodiversity, and the ecosystem services that glacier-fed rivers provide to humans, particularly provision of water for agriculture, hydropower, and consumption. We conclude that human society must plan adaptation and mitigation measures for the full breadth of impacts in all affected regions caused by glacier shrinkage.
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Dunne, Kieran B. J., and Douglas J. Jerolmack. "What sets river width?" Science Advances 6, no. 41 (October 2020): eabc1505. http://dx.doi.org/10.1126/sciadv.abc1505.
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One of the simplest questions in riverine science remains unanswered: “What determines the width of rivers?” While myriad environmental and geological factors have been proposed to control alluvial river size, no accepted theory exists to explain this fundamental characteristic of river systems. We combine analysis of a global dataset with a field study to support a simple hypothesis: River geometry adjusts to the threshold fluid entrainment stress of the most resistant material lining the channel. In addition, we demonstrate how changes in bank strength dictate planform morphology by exerting strong control on channel width. Our findings greatly extend the applicability of threshold channel theory, which was originally developed to explain straight gravel-bedded rivers with uniform grain size and stable banks. The parsimonious threshold-limiting channel model describes the average hydraulic state of natural rivers across a wide range of conditions and may find use in river management, stratigraphy, and planetary science.
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Villares Junior, GA, and R. Goitein. "Differences in the feeding of Rhamdia quelen (Siluriformes, Heptapteridae) in four distinct lotic systems." Brazilian Journal of Biology 75, no. 3 (August 25, 2015): 650–54. http://dx.doi.org/10.1590/1519-6984.20313.
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AbstractThe aim of this study was to compare the food composition of Rhamdia quelen in four distinct order rivers. It was performed at a low part at the basin of the Sorocaba river in systems classified as first (Anastácio stream), second (Nego stream), fifth (Tatuí river) and sixth (Sorocaba river) orders. Collections were performed every month between January and December of 2011. The stomach contents were examined by using the alimentary index (IAi) and compared by the non-parametric method non-metric multidimensional scale ranking (NMDS) with the Spearman rank correlation. A diet difference was observed for individuals of the smaller systems (Anastácio and Nego streams) and the larger ones (Tatui and Sorocaba rivers), represented respectively by allochthonous and autochthonous organisms compounding their diets. Marginal vegetation and its interaction with the water conditions may respond to these composition differences.
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Counihan, Timothy D., Kristen L. Bouska, Shannon K. Brewer, Robert B. Jacobson, Andrew F. Casper, Colin G. Chapman, Ian R. Waite, et al. "Identifying monitoring information needs that support the management of fish in large rivers." PLOS ONE 17, no. 4 (April 29, 2022): e0267113. http://dx.doi.org/10.1371/journal.pone.0267113.
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Management actions intended to benefit fish in large rivers can directly or indirectly affect multiple ecosystem components. Without consideration of the effects of management on non-target ecosystem components, unintended consequences may limit management efficacy. Monitoring can help clarify the effects of management actions, including on non-target ecosystem components, but only if data are collected to characterize key ecosystem processes that could affect the outcome. Scientists from across the U.S. convened to develop a conceptual model that would help identify monitoring information needed to better understand how natural and anthropogenic factors affect large river fishes. We applied the conceptual model to case studies in four large U.S. rivers. The application of the conceptual model indicates the model is flexible and relevant to large rivers in different geographic settings and with different management challenges. By visualizing how natural and anthropogenic drivers directly or indirectly affect cascading ecosystem tiers, our model identified critical information gaps and uncertainties that, if resolved, could inform how to best meet management objectives. Despite large differences in the physical and ecological contexts of the river systems, the case studies also demonstrated substantial commonalities in the data needed to better understand how stressors affect fish in these systems. For example, in most systems information on river discharge and water temperature were needed and available. Conversely, information regarding trophic relationships and the habitat requirements of larval fishes were generally lacking. This result suggests that there is a need to better understand a set of common factors across large-river systems. We provide a stepwise procedure to facilitate the application of our conceptual model to other river systems and management goals.
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Zhou, Yuanyuan, and Qiuhong Tang. "Meandering Characteristics of the Yimin River in Hulun Buir Grassland, Inner Mongolia, China." Remote Sensing 14, no. 11 (June 3, 2022): 2696. http://dx.doi.org/10.3390/rs14112696.
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The evolution of meandering rivers continues to attract considerable attention in research and for practical applications, given that it is closely associated with the safety of river systems and riparian zones. There has been much discussion regarding the various channel planform features exhibited by meandering rivers under different river systems and riparian conditions. The Yimin River is a good example and is located southeast of the Hulun Buir Grassland, which is characterised by a fragile ecosystem and little anthropological activity along with active flow during the non-frozen season from May to November each year and relatively low sediment discharge compared with the Yellow River and Mississippi River. Improved analysis of the evolution of the Yimin River from 1975 to 2019 can support increased local species diversity and more effective flood risk and river management. With the combined Google Earth Engine (GEE) platform and the Geographic Information Systems (GIS) technique, remote sensing images, including Landsat images and global surface water data, are used to analyse the channel planform features of the freely meandering river channel in the middle and lower Yimin River. The results show that the percentage of low sinuosity channel bends was higher than that of high-sinuosity bends. Although the bends with an amplitude greater than 0.48 km and sinuosity greater than 2.3 have an evident upstream-skewed trend, the main channel planform features were downstream skewed with 1499 such bends. The river system conditions in the Yimin River, including lower sediment discharge and vegetation cover, are conducive to the development of downstream-skewed bends. The high-sinuosity bends were found to have a relatively larger ratio during 1981–2000, a period with higher mean annual streamflow compared with other time periods.
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Yates, Adam G., Robert B. Brua, Joseph M. Culp, Roger G. Young, and Patricia A. Chambers. "Variation in stream metabolism and benthic invertebrate composition along longitudinal profiles of two contrasting river systems." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 4 (April 2018): 549–59. http://dx.doi.org/10.1139/cjfas-2016-0198.
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Our study aimed to determine drivers of longitudinal variation in stream metabolism and benthic macroinvertebrate (BMI) composition and assess concordance of these ecological measures for two Canadian rivers (Rat River and Tobacco Creek). Gross primary production was associated with longitudinal position in both rivers but also with the percentage of the watershed used for agriculture and hydrogeomorphic zone. However, within- and among-zone differences in stream metabolism indicated that longitudinal variation followed a staircase pattern rather than a clinal pattern. BMI composition was associated with network position in both rivers, but hydrogeomorphic zones were only important in Tobacco Creek. Among-zone differences in BMI communities in Tobacco Creek depended on season. Concordance between stream metabolism and BMI composition was not observed within either river despite metabolism and BMI composition being associated with longitudinal position. For these rivers, segment-scale hydrogeomorphic conditions appear to be important modifiers of longitudinal patterns observed at the whole river scale. The lack of concordance between stream metabolism and BMI composition suggests reach-scale processes are driving ecological differences within sampling sites.
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Basnayaka, Vindhya, Jayanga T. Samarasinghe, Miyuru B. Gunathilake, Nitin Muttil, Dileepa C. Hettiarachchi, Amila Abeynayaka, and Upaka Rathnayake. "Analysis of Meandering River Morphodynamics Using Satellite Remote Sensing Data—An Application in the Lower Deduru Oya (River), Sri Lanka." Land 11, no. 7 (July 16, 2022): 1091. http://dx.doi.org/10.3390/land11071091.
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River meandering and anabranching have become major problems in many large rivers that carry significant amounts of sediment worldwide. The morphodynamics of these rivers are complex due to the temporal variation of flows. However, the availability of remote sensing data and geographic information systems (GISs) provides the opportunity to analyze the morphological changes in river systems both quantitatively and qualitatively. The present study investigated the temporal changes in the river morphology of the Deduru Oya (river) in Sri Lanka, which is a meandering river. The study covered a period of 32 years (1989 to 2021), using Landsat satellite data and the QGIS platform. Cloud-free Landsat 5 and Landsat 8 satellite images were extracted and processed to extract the river mask. The centerline of the river was generated using the extracted river mask, with the support of semi-automated digitizing software (WebPlotDigitizer). Freely available QGIS was used to investigate the temporal variation of river migration. The results of the study demonstrated that, over the past three decades, both the bend curvatures and the river migration rates of the meandering bends have generally increased with time. In addition, it was found that a higher number of meandering bends could be observed in the lower (most downstream) and the middle parts of the selected river segment. The current analysis indicates that the Deduru Oya has undergone considerable changes in its curvature and migration rates.
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Kaushal, Nitin, Suresh Babu, Arjit Mishra, Rajesh Bajpai, Phanish Kumar Sinha, Rama Kant Arya, David Tickner, and Conor Linstead. "Securing Flows in the River Systems through Irrigation Water Use Efficiency—A Case Study from Karula River in the Ganga River System." Water 14, no. 18 (September 16, 2022): 2894. http://dx.doi.org/10.3390/w14182894.
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The pressure on freshwater resources is leading to diminishing flows in some of the critical river systems across the globe. India is no exception, and this is mainly because of water withdrawal for irrigation, which is often to the tune of 70% to 80% of the lean season flows, with some proportion for domestic and industrial use. While graduating from the concept of environmental flows and its assessment methodologies in India, the water-managers, the researchers and the conservationists are now moving towards answering the next question, if the rivers are to be revived, where will the water come from, especially in the case of over-allocated rivers, including the River Ganga. While the logical way is to look at the biggest user of water, i.e., irrigation, it remains to be seen whether the irrigation water savings will actually lead to enhancing flows in a river, complementing the efforts towards maintaining e-flows in rivers, or whether it will lead to more area under agriculture, bring changes in cropping patterns towards more water-intensive crops or result in something else. This is a growing debate across the globe, where India is no exception, and there has been a wide range of opinions in this regard. This paper discusses the process, findings and lessons from a joint initiative involving farmers, the Uttar Pradesh state Irrigation and Water Resources Department, Bijnor District Administration and a conservation organisation, WWF, to enhance flows in a sub-tributary, called the Karula River, which is part of the Ganga River system. Another objective of this paper is to look at the scalability and replicability of similar approaches in other irrigation command areas to benefit nearby river systems in general. Under this initiative, the team attempted to enhance flows in the river Karula by routing the saved water from irrigation supplies in a canal commanded area. This saving of water is being achieved due to supply-side and demand-side measures that are being adopted in the project area. With the objective of ensuring the sustainability of the initiative, efforts are made to form an institutional arrangement, through which this initiative can be sustained beyond the project support.
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Zellman, Kristine L., Piret Plink-Björklund, and Henry C. Fricke. "Testing hypotheses on signatures of precipitation variability in the river and floodplain deposits of the Paleogene San Juan Basin, New Mexico, U.S.A." Journal of Sedimentary Research 90, no. 12 (February 18, 2021): 1770–801. http://dx.doi.org/10.2110/jsr.2020.75.
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ABSTRACTMuch progress has been made in recent years towards a set of recognition criteria for river discharge variability in river channel deposits, and thus sedimentary proxies for precipitation variability. Despite this progress, there is currently no consensus on how different styles of discharge variability are reflected in river sedimentary records, and whether variable-discharge river records from different climate types can be distinguished. Herein, river discharge and precipitation variability in the Paleogene is investigated using associations between river channel and floodplain deposits across the Paleocene–Eocene boundary from the Paleocene upper Nacimiento Formation and the early Eocene San Jose Formation in the San Juan Basin, New Mexico, USA.The succession is identified as deposits of variable-discharge river systems based on shared channel-deposit characteristics with modern and ancient variable-discharge river systems and the proposed facies models, in addition to alternations of poorly drained and well-drained floodplain deposits and/or slickensides indicating alternating wet–dry cycles. A long-term stratigraphic trend toward increasingly well-drained floodplain deposits is also observed and hypothesized to indicate successively more arid conditions from the Paleocene into the early Eocene. Comparisons with modern rivers from various climate zones suggest a long-term shift from a monsoonal climate in the Paleocene, to a fluctuating subhumid climate, ultimately leading to semiarid to arid conditions in the early Eocene. These observations suggest that floodplain deposits may be a better indicator of ambient climate, whereas channel deposits are records for frequency and magnitude of high-intensity precipitation events. Therefore, the existing facies models for variable-discharge rivers that consider only channel facies may not capture critical information needed to make accurate interpretations of paleoclimatic conditions. This study also adds to a growing body of evidence from geologic records of mid-latitude Paleogene river systems suggesting increases in the magnitude or variability of river discharge coinciding with established climate perturbations.
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Willis, Brian J., Anna Kay Behrensmeyer, Thomas M. Bown, Mary Kraus, John S. Bridge, and Imran Khan. "Controls on fluvial systems in the Siwalik Neogene and Wyoming Paleogene." Paleontological Society Special Publications 6 (1992): 315. http://dx.doi.org/10.1017/s2475262200008753.
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The 3-km thick Neogene Siwalik Group (Himalayan foredeep in northern Pakistan) and the 2-km thick Paleogene Fort Union/Willwood Formations (Bighorn Basin, Wyoming) both preserve long records of fluvial deposition adjacent to rising mountain belts. Depositional environments and associated habitats change with spatially varying physiography and deposition by river systems that may differ greatly in size, sediment loads, depositional rates, drainage of adjacent floodplains, and taphonomy of organic remains. At times, some environments may not be preserved; for example, avulsion of channels to low areas removes more deposits of channel-distal environments as avulsions increase relative to net sediment aggradation rates. Recognition of such large-scale biases is important because they represent time scales over which long term paleoecological change is reconstructed, and requires knowledge of how drainage systems changed in time and space within these evolving basins.The Siwalik Group was deposited by large rivers that filled a basin extending at least 1000 km along its axis and 150–250 km away from the mountain front. Despite the scale of these rivers relative to Siwalik exposures, transitions between different fluvial systems have been recognized. For example, a 1-km thick sequence bridging the boundary between Chinji and Nagri formations records displacement of a smaller river system (width < 2 km; depth 5-10 m; discharge 1000-1500 m3/s) by a larger system (width <5 km; depth 15-30 m; discharge at least 5,000-10,000 m3/s), with an associated upsection increase (30 to 70%) in the proportion of channel sandstones, increased mean sediment accumulation rates (150 to 300 m/my), decrease in poorly drained floodplain deposits and well developed paleosols, marked decrease in abundance of faunal remains, and a major change in faunal composition. Stratigraphically higher (Dhok Pathan Fm.), there is a lateral transition between deposits of dissimilar, coeval river systems with corresponding differences in local paleoenvironments and vertebrate taphonomy. Although upsection changes in environments and vertebrate faunas may generally reflect extrabasinal controls such as tectonism and climate change, our studies emphasize the importance of recognizing deposits from different contemporaneous river systems before inferring such large-scale controls on paleoenvironmental change through time.The Bighorn Basin is an intermountain foreland basin extending 200 km along its axis and about 80 km across. A large portion of this basin is exposed, and thus it is possible to reconstruct the distribution of river systems and the spatial paleoenvironments in more detail than in the Siwaliks. The Bighorn Basin was traversed along its axis by an early Eocene, north-south flowing river that was joined by smaller rivers flowing transverse to the axis. The proportion of channel sandstones decreases upsection (50 to 25%) from the Fort Union to the Willwood Fm. The proportion of channel sandstones and the abundance of well developed paleosols decrease with increasing net sediment aggradation rates. Although channel deposits are concentrated along the basin axis in a more complex way in some stratigraphic intervals, it is unclear to what extent these changes reflect deposition by different rivers versus extrinsically controlled changes within individual river systems.
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Amosova, I. Y., and E. A. Ilicheva. "Spatial Distribution of Structural and Hydrographic Characteristics of River Systems in the Lake Baikal Basin." Bulletin of Irkutsk State University. Series Earth Sciences 34 (2020): 21–36. http://dx.doi.org/10.26516/2073-3402.2020.34.21.
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Analysis of structural and hydrographic characteristics of the structure of river systems and their interconnections was carried out for the future use in calculating runoff and the conditions of its formation for unexplored rivers. An annual normal and maximum water discharge observed in the 96 gauging sections of the standard observation network are hydrological basis. The research of river systems was carried out on the basis of topographic maps of scales of 1: 500 000 and 1: 200 000 and radar topographic surveys, which became the basis for constructing static and dynamic models of river systems. The static model is a totality of permanent watercourses and reflects the conditions of continuous flow. The system of impermanent and episodic watercourses is filled in the period of extreme flow. Аt this time, earlier element of the channel network without inflow become elements of a higher order. This model is dynamic. The study was conducted for the river systems of the Russian part of the Baikal basin. All parameters of river systems and their basins are divided into simple, structural and expositional classes, characterizing the conditions for the formation of thalwegs and runoff. The seven areas are identified which combine river systems when studying complex of the calculated parameters. The average structural module is a criterion for the distribution of the study territory into homogeneous area for the calculation of water discharge. The average structural module is determined by the local relation of annual normal water discharge on the total entropy of river systems. This relationship allows runoff calculations for watercourses that are not provided with hydrological information. In connection with this, a new stage of studies of the relationships between the characteristics of the structural class of the water-erosion network and the parameters of the river basin as an indicator of maximum aquifer ability arises.
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Chen, Weitao, Yuefei Li, Xingwei Cai, Denggao Xiang, Shang Gao, Ce Li, Chun Lan, et al. "Genetic Structure of an East Asian Minnow (Toxabramis houdemeri) in Southern China, with Implications for Conservation." Biology 11, no. 11 (November 9, 2022): 1641. http://dx.doi.org/10.3390/biology11111641.
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River dynamics have been hypothesized to substantially influence the genetic structure of freshwater fish taxa. Southern China harbors abundant independent river systems, which have undergone historical rearrangements. This river system is thus an excellent model with which to test the abovementioned hypothesis. In this study, a cyprinid widespread in many independent rivers in southern China, Toxabramis houdemeri, was chosen as an exemplar species with which to explore the effects of river configuration changes on spatial genetic structure using mitochondrial and nuclear markers. The results indicated that the T. houdemeri populations fell into four mitochondrial haplotype groups, each genetically endemic to a single river or two adjacent river systems. The mitochondrial haplotype network recovered a clear genetic boundary between Hainan Island populations and mainland populations. Notable genetic differentiation was observed within populations from distinct river systems in both mitochondrial and nuclear loci. River system separation, mountain barriers, and mobility were the key factors shaping the genetic structure of T. houdemeri populations. Late Pleistocene divergence and historical immigration were identified within the four mitochondrial haplotype groups, indicating that river rearrangements triggered by the Late Pleistocene glacial cycles were important drivers of the complex genetic structure and demographic history of T. houdemeri. Historical demographics suggested that T. houdemeri populations expanded during the Late Pleistocene. The present study has important consequences for the management and conservation of T. houdemeri.
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Mlynowski, Theo J., Marco A. Hernández-Henríquez, and Stephen J. Déry. "An evaluation of hydrometric monitoring across the Canadian pan-Arctic region, 1950–2008." Hydrology Research 42, no. 6 (December 1, 2011): 479–90. http://dx.doi.org/10.2166/nh.2011.105.
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This study evaluates the hydrometric monitoring maintained within the Canadian pan-Arctic and is based on the hydrometric gauges closest to northern seas for 76 river systems throughout 1950–2008. Monitoring is quantified by compiling time series of total gauged area and discharge values from the available hydrometric records. We further evaluate the quality of hydrometric data by examining the availability of hydrometric records, the continuity of individual records, and the influence of water regulation on river systems. The maximum gauged area of the Canadian pan-Arctic was 64% in 1990 before it slowly decreased to 56% in 2008. Larger river systems typically had the most hydrometric data available, though each river system had an average of 46% of their records available. In 1998, a maximum of 22 river systems had more than 30 years of continuous records, which is the maximum attained throughout the study period. For future improvements in hydrometric monitoring, additional gauges on relatively small rivers will need to be deployed. We suggest new gauges should be implemented in the Eastern Hudson Bay, Ungava Bay and Labrador Sea basins in spite of the tremendous need for more in the Arctic Archipelago.
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Turibamwe, Edson, and Rapheal Wangalwa. "A COMPARATIVE STUDY OF TWO BIOLOGICAL MONITORING SYSTEMS IN ASSESSING WATER QUALITY: A CASE OF RIVER BIRIRA, SHEEMA DISTRICT, UGANDA." Water Conservation and Management 4, no. 1 (January 23, 2020): 07–14. http://dx.doi.org/10.26480/wcm.01.2020.07.14.
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River Birira stretches through Kitagata town council and near Kitagata hot springs in southwestern Uganda. These areas receive an inflow of people that utilize the hot springs because of the belief of healing associated with the water. This has led to increased human activities along river Birira, which may negatively impact on the ecological integrity of the river. A number of countries have developed biological monitoring systems to assess the water quality of rivers and streams, however non has been developed specifically for Uganda. This study therefore aimed to assess the water quality of river Birira and determine the compatibility and usability of Biological Monitoring Working Party (BMWP) and Tanzania River Scoring System (TARISS) biological monitoring systems in a Ugandan setting. In this study, four sampling sites were selected basing on human activities taking place along river Birira. The sites were assessed for both physico-chemical and biological parameters using standard methods. In this study 9 physicochemical parameters were used in the computation of water quality index (WQI). Findings of this study indicated that sites in close proximity with the bathing pool of Kitagata hot springs were severely impacted and had undesirable water quality. Results also showed that the water of river Birira is generally unsuitable for human consumption, therefore, needs thorough treatment before consumption and domestic use. This study further revealed that both BMWP and TARISS monitoring systems give similar deductions about the water quality of river Birira. Therefore, any one of the monitoring systems can be adopted in assessing the water quality of the River.
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Chapra, S. C., and P. G. Whitehead. "Modelling impacts of pollution in river systems: a new dispersion model and a case study of mine discharges in the Abrud, Aries and Mures River System in Transylvania, Romania." Hydrology Research 40, no. 2-3 (April 1, 2009): 306–22. http://dx.doi.org/10.2166/nh.2009.075.
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A new model of dispersion has been developed to simulate the impact of pollutant discharges on river systems. The model accounts for the main dispersion processes operating in rivers as well as the dilution from incoming tributaries and first-order kinetic decay processes. The model is dynamic and simulates the hourly behaviour of river flow and pollutants along river systems. The model has been applied to the Aries and Mures River System in Romania and has been used to assess the impacts of potential dam releases from the Roşia Montană Mine in Transylvania, Romania. The question of mine water release is investigated under a range of scenarios. The impacts on pollution levels downstream at key sites and at the border with Hungary are investigated.
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Kuriata-Potasznik, Angela, Sławomir Szymczyk, and Andrzej Skwierawski. "Influence of Cascading River–Lake Systems on the Dynamics of Nutrient Circulation in Catchment Areas." Water 12, no. 4 (April 17, 2020): 1144. http://dx.doi.org/10.3390/w12041144.
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Matter circulates in nature constantly, between terrestrial and aquatic ecosystems, exchanging elements between the biotope and biocenosis. Each aquatic ecosystem is resistant to a specific load, above which its degradation occurs. It seems that the resistance of cascade reservoirs is higher than that of drainless reservoirs. Changes taking place in one part of the river–lake system cause disturbances in the dynamics of nutrient circulation in another. Rivers supplying water to lakes in a river–lake system have a significant impact on their water quality and on the spatial distribution of pollutants in their bottom sediments and in macrophytes located along their route. The assimilation capabilities of cascading river–lake systems result from their reaction to environmental stressors in the form of anthropogenic factors. They act as natural biogeochemical barriers, limiting the transport of pollutants outside ecosystems. In-depth knowledge of the processes taking place in the river–lake systems enables analyses aimed at forecasting the directions and intensity of these changes and predicting the response of the river–lake systems to the loads from the catchment areas. The collected information makes it possible to create simulations of processes occurring in river–lake systems, which allows for effective action to be taken to protect surface waters. This article provides an overview of available literature, presenting significant research results which enable an understanding of these processes.
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Jenkins, W. O., and P. W. Jowitt. "Expert systems in river basin management." Civil Engineering Systems 4, no. 1 (March 1987): 31–38. http://dx.doi.org/10.1080/02630258708970455.
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Habersack, Helmut, Daniel Haspel, and Ian Campbell. "Integrated management of large river systems." International Journal of River Basin Management 11, no. 2 (June 2013): 137. http://dx.doi.org/10.1080/15715124.2013.824148.
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Palmer, Richard N., and Julia L. Cohan. "Complexity in Columbia River Systems Modeling." Journal of Water Resources Planning and Management 112, no. 4 (October 1986): 453–68. http://dx.doi.org/10.1061/(asce)0733-9496(1986)112:4(453).
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Perkins, Sid. "Science visualized: Evolution of river systems." Science News 185, no. 7 (March 25, 2014): 32. http://dx.doi.org/10.1002/scin.5591850722.
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Grabowski, R. C., and A. M. Gurnell. "Hydrogeomorphology-Ecology Interactions in River Systems." River Research and Applications 32, no. 2 (February 2016): 139–41. http://dx.doi.org/10.1002/rra.2974.
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Lawrence, Susan, James Grove, Peter Davies, Jodi Turnbull, Ian Rutherfurd, and Mark Macklin. "Historical dredge mining as a significant anthropomorphic agent in river systems: A case study from south-eastern Australia." Holocene 31, no. 7 (March 25, 2021): 1158–74. http://dx.doi.org/10.1177/09596836211003272.
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Bucket dredging to mine and extract gold and tin from rivers is a global industry that has had a range of negative effects on physical environments. These include the destruction of riparian soil profiles and structures, artificial channel straightening and loss of in-stream biodiversity. In this paper we evaluate the immediate effects and long-term consequences of bucket dredging on rivers in Victoria and New South Wales during the period 1900–1950. High quality historical sources on dredge mining are integrated with geospatial datasets, aerial imagery and geomorphological data to analyse the scale of the dredging industry, evidence for disturbance to river channels and floodplains and current land use in dredged areas. The study demonstrates that the environmental impact of dredging was altered but not reduced by anti-pollution regulations intended to control dredging. An assessment of river condition 70–100 years after dredge mining ceased indicates that floodplains and river channels continue to show the effects of dredging, including bank erosion, sediment slugs, compromised habitat and reduced agricultural productivity. These findings have significant implications for river and floodplain management.
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Han, Peng-Fei, Xu-Sheng Wang, Li Wan, Xiao-Wei Jiang, and Fu-Sheng Hu. "The Exact Groundwater Divide on Water Table between Two Rivers: A Fundamental Model Investigation." Water 11, no. 4 (April 2, 2019): 685. http://dx.doi.org/10.3390/w11040685.
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The groundwater divide within a plane has long been delineated as a water table ridge composed of the local top points of a water table. This definition has not been examined well for river basins. We developed a fundamental model of a two-dimensional unsaturated–saturated flow in a profile between two rivers. The exact groundwater divide can be identified from the boundary between two local flow systems and compared with the top of a water table. It is closer to the river of a higher water level than the top of a water table. The catchment area would be overestimated (up to ~50%) for a high river and underestimated (up to ~15%) for a low river by using the top of the water table. Furthermore, a pass-through flow from one river to another would be developed below two local flow systems when the groundwater divide is significantly close to a high river.
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Shaazizov, Farrukh. "The flow Confluence of river systems of the Pskem and Koksu river basins." E3S Web of Conferences 264 (2021): 03041. http://dx.doi.org/10.1051/e3sconf/202126403041.
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In the Bostanlyk district of the Tashkent region, there are high-mountain breakthrough lakes located in the Pskem and Koksu rivers basin, which pose a particular danger to the downstream territories. The river system of the basins of the Pskem and Koksu rivers located in the Tashkent region is characterized by the presence of many nodes of a confluence of tributaries that form the hydrographic network of the basins of the high-mountain rivers under consideration. In the event of man-made and natural emergencies, a breakthrough wave can form on high-mountain outburst-hazardous lakes. The main purpose of these studies is to develop a method for the hydraulic calculation to determine the depths of flows in the confluence nodes. Based on the use of the law of conservation of momentum, a model and method for calculating the junction of open water streams have been developed. To determine the depth h2 in the main channel after the confluence point, we recommend using the well-known hydraulic methods for determining the depth of water in open channels. Determination of the depths h1 and h0 of the main flow and inflow, respectively, can be analytically obtained based on the obtained dependences (9) and (10).
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Wils, C., A. Schneiders, L. Bervoets, A. Nagels, L. Weiss, and R. F. Verheyen. "Assessment of the ecological value of rivers in flanders (Belgium)." Water Science and Technology 30, no. 10 (November 1, 1994): 37–47. http://dx.doi.org/10.2166/wst.1994.0509.
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Assessment of the ecological value of streams and rivers is important to determine which watercourses should be preserved for the future. Throughout the world, a large number of evaluation systems have been developed either to assess complete river systems or merely to evaluate the water quality. However, in a region such as Flanders, where rivers are generally very polluted, it is not only important to evaluate the current ecological value, but also to recognize those watercourses which still have a high potential value. For this purpose a system was developed in Flanders to assess the present as well as the potential ecological value of streams and rivers. The evaluation is based on a number of morphological characteristics, on the water quality and on the aquatic communities. The result is a global ecological evaluation map of each river basin. This map is made available to policy makers in order to assist in the elaboration of purification programmes and river restoration and conservation projects.
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Meybeck, Michel. "Global analysis of river systems: from Earth system controls to Anthropocene syndromes." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 358, no. 1440 (November 25, 2003): 1935–55. http://dx.doi.org/10.1098/rstb.2003.1379.
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Continental aquatic systems from rivers to the coastal zone are considered within two perspectives: (i) as a major link between the atmosphere, pedosphere, biosphere and oceans within the Earth system with its Holocene dynamics, and (ii) as water and aquatic biota resources progressively used and transformed by humans. Human pressures have now reached a state where the continental aquatic systems can no longer be considered as being controlled by only Earth system processes, thus defining a new era, the Anthropocene. Riverine changes, now observed at the global scale, are described through a first set of syndromes (flood regulation, fragmentation, sediment imbalance, neo–arheism, salinization, chemical contamination, acidification, eutrophication and microbial contamination) with their related causes and symptoms. These syndromes have direct influences on water uses, either positive or negative. They also modify some Earth system key functions such as sediment, water, nutrient and carbon balances, greenhouse gas emissions and aquatic biodiversity. Evolution of river syndromes over the past 2000 years is complex: it depends upon the stages of regional human development and on natural conditions, as illustrated here for the chemical contamination syndrome. River damming, eutrophication and generalized decrease of river flow due to irrigation are some of the other global features of river changes. Future management of river systems should also consider these long–term impacts on the Earth system.
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Barclay, Leah, Toby Gifford, and Simon Linke. "River Listening: Acoustic Ecology and Aquatic Bioacoustics in Global River Systems." Leonardo 51, no. 3 (June 2018): 298–99. http://dx.doi.org/10.1162/leon_a_01516.
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River Listening is an interdisciplinary research project exploring the cultural and biological diversity of global river systems through sound. The project examines the creative possibilities of accessible and noninvasive recording technologies to monitor river health and engage local communities in the conservation of global river systems. River Listening combines emerging fields of science with acoustic ecology, creativity and digital technology to further the understanding of aquatic biodiversity and inspire action at a time when the conservation and management of freshwater ecosystems is a critical priority.
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Beechie, Timothy J., Martin Liermann, Michael M. Pollock, Sarah Baker, and Jeremy Davies. "Channel pattern and river-floodplain dynamics in forested mountain river systems." Geomorphology 78, no. 1-2 (August 2006): 124–41. http://dx.doi.org/10.1016/j.geomorph.2006.01.030.
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