Journal articles: 'River system'

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Li, Xiaoning, Chuanhai Wang, Gang Chen, Xing Fang, Pingnan Zhang, and Wenjuan Hua. "Distributed-Framework Basin Modeling System: Ⅲ. Hydraulic Modeling System." Water 13, no. 5 (February 28, 2021): 649. http://dx.doi.org/10.3390/w13050649.

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A distributed-framework basin modeling system (DFBMS) was developed to simulate the runoff generation and movement on a basin scale. This study is part of a series of papers on DFBMS that focuses on the hydraulic calculation methods in runoff concentration on underlying surfaces and flow movement in river networks and lakes. This paper introduces the distributed-framework river modeling system (DF-RMS) that is a professional modeling system for hydraulic modeling. The DF-RMS contains different hydrological feature units (HFUs) to simulate the runoff movement through a system of rivers, storage units, lakes, and hydraulic structures. The river network simulations were categorized into different types, including one-dimensional river branch, dendritic river network, loop river network, and intersecting river network. The DF-RMS was applied to the middle and downstream portions of the Huai River Plain in China using different HFUs for river networks and lakes. The simulation results showed great consistency with the observed data, which proves that DF-RMS is a reliable system to simulate the flow movement in river networks and lakes.

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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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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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Ji, Xiaomin, Youpeng Xu, Longfei Han, and Liu Yang. "Impacts of urbanization on river system structure: a case study on Qinhuai River Basin, Yangtze River Delta." Water Science and Technology 70, no. 4 (June 18, 2014): 671–77. http://dx.doi.org/10.2166/wst.2014.278.

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Stream structure is usually dominated by various human activities over a short term. An analysis of variation in stream structure from 1979 to 2009 in the Qinhuai River Basin, China, was performed based on remote sensing images and topographic maps by using ArcGIS. A series of river parameters derived from river geomorphology are listed to describe the status of river structure in the past and present. Results showed that urbanization caused a huge increase in the impervious area. The number of rivers in the study area has decreased and length of rivers has shortened. Over the 30 years, there was a 41.03% decrease in river length. Complexity and stability of streams have also changed and consequently the storage capacities of river channels in intensively urbanized areas are much lower than in moderately urbanized areas, indicating a greater risk of floods. Therefore, more attention should be paid to the urban disturbance to rivers.

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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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Radulovic, Snezana, P. J. Boon, Dusanka Laketic, P. Simonovic, S. Puzovic, Milica Zivkovic, Tamara Jurca, M. Ovuka, S. Malaguti, and Ivana Teodorovic. "Preliminary checklists for applying SERCON (System for Evaluating Rivers for Conservation) to rivers in Serbia." Archives of Biological Sciences 64, no. 3 (2012): 1037–56. http://dx.doi.org/10.2298/abs1203037r.

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This paper describes the first steps in gathering biological data to assess the conservation value of rivers in Serbia, using SERCON (System for Evaluating Rivers for Conservation). SERCON was developed in the UK to improve consistency in assessments of river ?quality? by using a scoring system to evaluate habitat features and species groups, catchment characteristics, and the potential impacts to which river systems may be subjected. This paper provides checklists for aquatic, semiaquatic and marginal plants, macroinvertebrates, fish and birds associated with rivers in Serbia, collated from a wide range of published and unpublished sources. These lists should be regarded as provisional because few wide-ranging biological surveys have been carried out specifically on Serbian rivers; further revisions are likely as more information becomes available in future. Ultimately, the work will benefit regulators and decision-makers with responsibility for river management under the new Water Law, and contribute to river protection and conservation in Serbia.

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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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Wang, Liu Yan, You Peng Xu, and Ming Jing Yu. "River System Connectivity Analysis of Wuxi’s Central Urban Area Based on Graph Theory." Applied Mechanics and Materials 212-213 (October 2012): 543–48. http://dx.doi.org/10.4028/www.scientific.net/amm.212-213.543.

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Wuxi City is located in the hinterland of Taihu Basin and an important city in Yangtze River Delta Region with a prosperous economy. In the process of urban development, the river system pattern changes a lot. It has an impact on water environment, water ecology and other fields. The central urban area of Wuxi City was selected as the study area. Based on the river system of three periods: 1960s, 1980s and 2009, the rivers were classified into three levels according to the width of channels. The length, acreage and stream structure parameters were calculated. Then from the view of Graph Theory, river system was expressed as network graph, and the vertices, edges and degree of vertices were analyzed. The results show that the changes of rivers of different levels and lakes are not completely the same, but still appear a decreasing trend in general. The river network density and water surface ratio become smaller. Also the complexity and structure stability of river network weaken. The conclusions that the river evolution tends to be trunk and single, the stream structure is simplified and the connectivity of rivers and lakes reduces are verified by the analysis based on Graph Theory as well.

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Ezraneti, Riri, Munawar Khalil, and Marzuki Marzuki. "Study of Water Quality for Aquaculture System in Ujung Pacu River, North Aceh Regency." Omni-Akuatika 16, no. 3 (December 30, 2020): 119. http://dx.doi.org/10.20884/1.oa.2020.16.3.849.

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Ujung Pacu River is one of the rivers found in North Aceh Regency which is often used by surrounding communities such as for industrial, agricultural, residential and aquaculture activities that can affect river water quality. This study aimed to determine the water physical and chemical parameters in the Ujung Pacu River for aquaculture activities. The research method used was a survey method by determining the sampling station based on community activities around the river. The study consisted of 4 stations with 3 sampling points at each station. Data of water physical and chemical parameters were compared with water quality standards and analyzed descriptively with a quantitative approach. The results showed that the range of water quality values were various in each stations. Ujung Pacu River is influenced by daily tide fluctuations. The highest water quality fluctuations occur in salinity, turbidity and depth. The pollution index in the Ujung Pacu river is included to criteria of Lightly polluted rivers with range 1.8545 - 4.4979. The Ujung Pacu River is unsuitable for aquaculture systems using floating net cages system in river bodies. Keywords: Ujung Pacu River, water quality, pollution index

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Dai, Z. X., C. M. Li, P. D. Wu, and Y. Yin. "AN AUTOMATED BOTTOM UP HYDROLOGIC CODING SYSTEM FOR DENDRITIC RIVER SYSTEM." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W16 (October 1, 2019): 169–75. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w16-169-2019.

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Abstract. The hydrologic coding of a dendritic river system can be used to indicate the stream order and spatial-structure features of a river system. However, most conventional hydrologic coding systems use a top down (i.e., from the source to the estuary) approach, which does not accurately reflect the hierarchies of a dendritic river system. Based on Gravelius’ definition of stream order, we have proposed an automated bottom up (i.e., traced from the estuary to the source) coding system for dendritic river systems. Firstly, directed topology trees are constructed to organize the data of a river network, followed by the calculation of stroke connections to construct river entities and identify the main stem. Secondly, the river system is then progressively coded from the estuary up to the source according to the definition of stream order in our system. Finally, actual topographic map data of a river system in some regions of Hubei Province are used to comparatively validate our hydrologic coding system against Horton’s coding system. The experimental results demonstrate that our coding system is very effective in highlighting hierarchies formed by catchment relationships. Our method is also found to be suitable for the selection of streams in topologically shallow dendritic river systems with uniformly distributed tributaries.

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Zhang, Junhong, Luojie Feng, Lu Chen, Dangwei Wang, Minglong Dai, Wensheng Xu, and Tao Yan. "Water Compensation and Its Implication of the Three Gorges Reservoir for the River-Lake System in the Middle Yangtze River, China." Water 10, no. 8 (July 31, 2018): 1011. http://dx.doi.org/10.3390/w10081011.

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Dam construction is an important means to improve water use efficiency and the aquatic environment. However, the flow regulation of the Three Gorges Reservoir (TGR) in the middle Yangtze River has attracted much attention because the severe drought occurred in the river-lake system downstream of the TGR. In this paper, the Dongting Lake was selected as a case study in order to detect the possible relationship between the flow regulation of the TGR and the extreme drought in the river-lake system based on a coupled hydrodynamic model. The results not only confirmed the significant role of the TGR to relieve drought in the river-lake system, but also indicated that the outflow of the TGR and the hydraulic gradient between the Zhicheng to Chenglingji stations were the crucial factors to affect the water exchange between the rivers and the Dongting Lake. The adjustment of hydraulic gradient within a proper range during the water compensation of the TGR will be an effective measure to improve the water exchange and water environment in the river-lake system. These findings present the quantitative influence of these important factors on the water exchange between rivers and lakes and provide a scientific reference for environmental and ecological management of other river-lake systems.

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Niu, Chengzhi, and Yougan Zhu. "Research on River Governance Index System in the Big Data Era." E3S Web of Conferences 275 (2021): 03058. http://dx.doi.org/10.1051/e3sconf/202127503058.

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Realizing the ecological health and sustainable development of rivers has become a worldwide research hotspot. Sustainable development is a large system with multi-system, multi-level and multi-index, In the era of big data, data science methods have made great changes in water resources governance methods. We can obtain more detailed data through big data methods to comprehensively and scientifically measure river governance. Based on the analytic hierarchy process, this paper invites experts in related fields to construct and score the river governance index system, and establish a river governance index system in the era of big data. We hope that the river governance index system will achieve advanced river governance in the era of big data.

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Al-Fradi, Falih Hasan Abdulhussein, Yulia A. Smyatskaya, and Natalia A. Politaeva. "Environmental assessment of Iraq's water system." Butlerov Communications 62, no. 5 (May 31, 2020): 123–29. http://dx.doi.org/10.37952/roi-jbc-01/20-62-5-123.

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The main sources of water supply for the Iraq industries and settlements are water resources of Tigris and Euphrates rivers. The settlements, agriculture and industry facilities, primary located along the banks of the main rivers and their tributaries, together negatively influence the surface waters of the region. The search for sources for water supply is a serious problem due to the high pollution of water in settlements, the growing problem of desertification in the region, the reduction of water volumes in the Tigris and Euphrates rivers due to the construction of dams. A major threat to surface water quality is emergency and unauthorized industrial and domestic discharges, which can be extremely dangerous for water sources. Traditional water treatment technologies are ineffective and do not provide reliable drinking water quality for the population. The water system of the Tigris rivers in Baghdad is characterized by a high content of dissolved substances, sulfates, calcium, some metals (Pb, Cd, Hg), bacteriological indicators. Significant pollution is observed in the Euphrates River, for such parameters as turbidity, suspended and dissolved substances, BOD, sodium, calcium, sodium chloride. Heavy metal pollution is noted in some sections of the river near Hill. The objective of this study was to examine and analyze the geoecological condition of water resources of Iraq as the essential source of water supply for the country. The information was gathered from literature, Internet and own research. The study showed that the water resources of all river systems in Iraq were polluted by some physicochemical parameters which do not satisfy to the Iraq standards.

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Burford, M. A., A. T. Revill, D. W. Palmer, L. Clementson, B. J. Robson, and I. T. Webster. "River regulation alters drivers of primary productivity along a tropical river-estuary system." Marine and Freshwater Research 62, no. 2 (2011): 141. http://dx.doi.org/10.1071/mf10224.

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Worldwide, rivers continue to be dammed to supply water for humans. The resulting regulation of downstream flow impacts on biogeochemical and physical processes, potentially affecting river and estuarine productivity. Our study tested the hypothesis that primary production in the downstream freshwater reaches of a dammed river was less limited by light and nutrients relative to downstream estuarine primary production. In a tropical dryland Australian river estuary, we found that water-column primary productivity was highest at freshwater sites that had lowest light attenuation. Nitrogen may also have limited primary productivity. Below the freshwater zone was a region of macrotidal mixing with high concentrations of suspended soil particles, nutrients and chlorophyll a, and lower but variable primary productivity rates. Light controlled productivity, but the algal cells may also have been osmotically stressed due to increasing salinity. Further downstream in the estuary, primary productivity was lower than the freshwater reaches and light and nutrient availability appear to be a factor. Therefore the reduced magnitude of peak-flow events due to flow regulation, and the resulting decrease in nutrient export, is likely to be negatively impacting estuarine primary production. This has implications for future development of dams where rivers have highly seasonal flow.

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Woo, Ming-ko, and Robin Thorne. "Summer Low Flow Events in the Mackenzie River System." ARCTIC 69, no. 3 (September 2, 2016): 286. http://dx.doi.org/10.14430/arctic4581.

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Most northern rivers experience recurrent low flow conditions in the summer (June to September), and rivers of the Mackenzie Basin are no exception. Low flow affects water supply, poses problems for river traffic, and can adversely affect aquatic ecology. Factors that affect summer low flow, which encompasses flows below specified discharge thresholds of concern, include evapotranspiration that leads to water loss from flow-contributing areas, antecedent high flow in which peak discharge is followed by gradual recession to low flow, rainfall and local glacier melt events that interrupt low discharge, replenishments of flow from upstream drainage networks, and arbitrary termination of summer low flow at the end of September. The storage mechanism of large lakes and the regulation effect of reservoirs can produce low flow regimes that differ from those exhibited by rivers without such storage functions. For most rivers, low flow events of longer duration cause larger deficits, and events with large deficits are accompanied by lower minimum discharge. The deficit-to-demand ratio measures the extent to which river flow fails to satisfy water needs. Applying this index to rivers of the Mackenzie drainage shows the hazard of streamflow drought in the basin. Low flow attributes can be summarized by their probability distributions: Gumbel distribution for minimum discharge of events and generalized exponential distribution for event duration. By fitting theoretical distributions to recorded events, one can estimate the probability of occurrence of low flow events that did not occur in the historical past.

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Sundararajan,, Muniyan, Gaurav Chakrabarty,, and Anand Mohan. "Development of River Quality Management (RQM) Information System for River Stretches Blending with Multi-Industrial Effluents." International Journal of Engineering Research 3, no. 12 (December 1, 2014): 769–73. http://dx.doi.org/10.17950/ijer/v3s12/1214.

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Wang, Zhe, Zhen Kui Jin, and Gui Zai Li. "Sequence Stratigraphic Analysis of Badaowan Formation in Dishuiquan Area, Junggar Basin." Advanced Materials Research 616-618 (December 2012): 56–59. http://dx.doi.org/10.4028/www.scientific.net/amr.616-618.56.

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In the light of the principle and method of sequence stratigraphy, the sequence stratigraphic framework of Badaowan formation in the Dishuiquan area was established. The results show that the sequence of Badaowan formation is one and half, including 5 system tracts. The whole experiences the process of retrogradation, progradation and then retrogradation again. There develop three types of sedimentary facies such as braided river, braided river delta and lakes, five types of sedimentary subfacies and 10 types of sedimentary microfacies. Most of JSQ1 sequence lowstand system tract is braided rivers, the lacustrine transgressive system tract mainly develops shore-shallow lacustrine sediment and most of highstand system tract is braided river delta; lowstand systems tract of JSQ2 sequence mainly develops braided river delta, most of the lacustrine transgressive system tract is shore-shallow lacustrine sediments.

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Степаненко, В. М., А. И. Медведев, И. А. Корпушенков, Н. Л. Фролова, and В. Н. Лыкосов. "A river routing scheme for an Earth system model." Numerical Methods and Programming (Vychislitel'nye Metody i Programmirovanie), no. 4 (September 10, 2019): 396–410. http://dx.doi.org/10.26089/nummet.v20r435.

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Представлена новая версия модели ИВМ РАНМГУ деятельного слоя суши с описанием термогидродинамики речных потоков. Динамика рек представлена уравнениями диффузионной волны, термика одномерным уравнением притока тепла. Объектноориентированная реализация блока речной сети позволяет использовать произвольные решатели одномерных задач речной динамики, например уравнений СенВенана. В описание термодинамики снежного покрова добавлены эффекты просачивания жидкой влаги и ее замерзания. Совокупность усовершенствований модели позволила существенно улучшить расчет годового расхода воды и удовлетворительно воспроизвести термический режим крупной равнинной реки Северная Двина. A new version of the INM RASMSU land surface scheme is presented which includes a module for the thermo and hydrodynamics of rivers. The river dynamics is described by the diffusion wave equations, whereas the river thermodynamics is simulated by the onedimensional heat equation. The objectoriented implementation of the river routing scheme allows one to use arbitrary solvers of onedimensional river dynamics problems, for example, the SaintVenant equations. The snow cover thermodynamics is supplemented by the effects of liquid moisture percolation and freezing. The set of model updates significantly improved simulation of the annual cycle of water discharge and temperature for Severnaya Dvina river.

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Collenn, Callanga, Agustin Alegrado Carl, Hurano Kathleen, Stefani Tenio Gwen, Velarde Paul, and Maristela V. Galon Clare. "River water lever sensor as river flood warning system." International Journal of Physical Sciences 15, no. 4 (October 31, 2020): 138–50. http://dx.doi.org/10.5897/ijps2020.4866.

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Kim, Dong-Su, and Boo-Sik Kang. "Building River Information System using Electromagnetic River Measurement Devices." Journal of the Korea Academia-Industrial cooperation Society 12, no. 1 (January 31, 2011): 507–12. http://dx.doi.org/10.5762/kais.2011.12.1.507.

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Findlay, Merrill. "River stories: Genealogies of a threatened inland river system." Futures 39, no. 2-3 (March 2007): 306–23. http://dx.doi.org/10.1016/j.futures.2006.01.011.

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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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Marcinkowski, Paweł, Adam Kiczko, and Tomasz Okruszko. "Modeling of water flow in multi-channel river system in the Narew National Park." Annals of Warsaw University of Life Sciences – SGGW. Land Reclamation 49, no. 3 (September 1, 2017): 167–77. http://dx.doi.org/10.1515/sggw-2017-0014.

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Abstract Modeling of water flow in multi-channel river system in the Narew National Park. Anastomosing rivers constitute a rare example of multi-channel systems, which used to be very common before the agricultural and industrial development. Presently few of them remain worldwide and the only example in Poland is the Upper River Narew within Narew National Park. Although hydraulic modeling using one-dimensional models is commonly used to describe water flow in rivers, for multi-channel rivers problem is more complicated. For this type of rivers it is expected that the feedback between process of plants growth (expressed by Manning’s coefficient) and distribution of flow in anabranches is high. However, assignment procedure on roughness coefficients in splitting and rejoining channels is laborious and difficult. Therefore, for efficient water flow modeling in multi-channel systems a stand-alone hydraulic model equipped with automatic optimization procedure was developed. Optimization and validation stages, based on field measurements data of discharge and water levels, indicated that the model accurately simulates water flow in multi-channel system.

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Singh, Gurnam, and Naresh Kumar Agarwal. "Fishing methods in upper Ganga River system of Central Himalaya, India." Journal of Fisheries 2, no. 3 (December 6, 2014): 195. http://dx.doi.org/10.17017/jfish.v2i3.2014.43.

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Present study on fishing methods in the upper Ganga River system was conducted during the period 2010-2012. Upper Ganga river system consists of two major rivers basins viz. Alaknanda and Bhagirathi rivers and number of their 1st and 2nd order tributaries which flows through Garhwal region (Central Himalaya). This large network of fluvial water resources harbours rich Ichthyofaunal diversity. The varied potential of fish resources from these water bodies permits the utilization of wide array of fishing methods. Most of the fishing methods of the Garhwal region are primitive, based on indigenous traditional knowledge and well suited to turbulent nature of the streams. In present study eighteen fishing methods and gears have been documented from the upper Ganga River system. Study observed season, habitat and species specificity of the fishing methods. The utilization of crude and unscientific fishing methods is frequent in the streams of remote areas resulting into decline in fish resource. All the fishing methods employed in upper Ganga River system are classified into four types. The classification is based on their utilisation up to the level which will allow the sustainable harvesting and proper management of valuable fish resources.

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Kovalchuk, V. P., P. I. Kovalchuk, M. V. Yatsyuk, R. Yu Kovalenko, O. S. Demchuk, and H. A. Balykhina. "System model of integrated management of the water resources of the Ingulets River by a basin principal." Міжвідомчий тематичний науковий збірник "Меліорація і водне господарство", no. 1 (June 25, 2020): 37–48. http://dx.doi.org/10.31073/mivg202001-219.

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For integrated water management in river basins in Ukraine, there is no toolkit for system modeling and selection of management structure in river basins according to environmental and economic criteria, which corresponds to the creation of water management systems under conditions of sustainable development. Therefore, the urgent task is to develop a system model of integrated water management on the example of the Ingulets River basin. The purpose of the work is to create a system model of integrated water resources management in Ingulets River basin, which provides scenario modeling of technological solutions, their evaluation and optimization of economic criteria for efficient water use under environmental constraints and criteria for achieving a good or excellent ecological status of the river basin. The system model is used as a toolkit, the method of decomposition of the river basin into subsystems, analysis of subsystems and their composition into a holistic model of integrated management by the basin principle. Telecommunication methods are proposed to improve monitoring. A method of scenario analysis is proposed, which performs simulation modeling of prospective management scenarios at the first level of the hierarchy, and at the second level - options are evaluated according to the criteria of cost-effective water use with environmental objectives and regulatory restrictions. For simulation modeling, a system of balance difference equations for the dynamics of water masses, mixing and spreading of pollution in rivers and reservoirs is formalized. A system of combined control for the impulse method of river washing was developed. Multicriteria optimization of variants of the control structure is carried out on the Pareto principle. A system model has been developed for integrated water resources management in the Ingulets River basin that meets the requirements of the EU Water Framework Directive on the establishment of cost-effective water use while ensuring good or excellent ecological status of rivers. The structural and functional diagram of the system model includes the subsystems: the water supply subsystem of the Dnipro-Ingulets canal; a subsystem for flushing the Ingulets River from the Karachunivske reservoir and displacing the saline prism into the Dnipro River; subsystem of environmental safety when discharging pollution into the river Ingulets; subsystem of water supply for irrigation in the Ingulets irrigation system, prevention of soil salinization. A system of technological, economic and environmental criteria for evaluating integrated management by the basin principle has been developed. They include maintaining the water level in reservoirs, displacement of salt water prism and limitation on water quality, ensuring the ecological condition of the river, and the dynamics of water resources consumption. Technological criteria determine the maintenance of water levels in reservoirs. Cost-effective water use is estimated on the basis of the dynamics of water consumption for river washing and irrigation. The formalized integrated management system in the Ingulets River basin includes operational water resources management and structure management. Integrated management is carried out according to subsystems, types of management and a system of criteria. For operational management the balance differential equations of water exchange in reservoirs are formalized. A two-layer model of water masses dynamics, pollutants distribution and mixing when flushing rivers from reservoirs is used. Scenario analysis is offered to select the optimal structure of the management system. Simulation scenarios are being simulated. Scenario optimization is performed on the Pareto principle. An example of evaluating the effectiveness of the proposed system and its comparison with the existing regulations for Ingulets River flushing is given.

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Jordan, Steve, Dennis K. Shiozawa, and J. M. Schmid-Araya. "Benthic invertebrates of a large, sandy river system: The Green and Colorado Rivers of Canyonlands National Park, Utah." Fundamental and Applied Limnology 147, no. 1 (November 29, 1999): 91–127. http://dx.doi.org/10.1127/archiv-hydrobiol/147/1999/91.

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Mykhnovych, Andriy. "STRYVIHOR RIVER SYSTEM STRUCTURE TRANSFORMATION." PROBLEMS OF GEOMORPHOLOGY AND PALEOGEOGRAPHY OF THE UKRANIAN CARPATHIANS AND ADJACENT AREAS 08 (October 2, 2018): 221–31. http://dx.doi.org/10.30970/gpc.2018.08.2028.

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Gurnell, Angela. "Plants as river system engineers." Earth Surface Processes and Landforms 39, no. 1 (April 16, 2013): 4–25. http://dx.doi.org/10.1002/esp.3397.

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Siegel, Herbert, Iris Stottmeister, Jan Reißmann, Monika Gerth, Christin Jose, and Joco Samiaji. "Siak River System — East-Sumatra." Journal of Marine Systems 77, no. 1-2 (April 2009): 148–59. http://dx.doi.org/10.1016/j.jmarsys.2008.12.003.

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Degteva, Marina O., Vyacheslav P. Kozheurov, Evgeniya I. Tolstykh, Marina I. Vorobiova, Lynn R. Anspaugh, Bruce A. Napier, and Alexander N. Kovtun. "THE TECHA RIVER DOSIMETRY SYSTEM." Health Physics 79, no. 1 (July 2000): 24–35. http://dx.doi.org/10.1097/00004032-200007000-00007.

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Bolgovics, Ágnes, Éva Ács, Gábor Várbíró, Keve Tihamér Kiss, Balázs A. Lukács, and Gábor Borics. "Diatom composition of the rheoplankton in a rhithral river system." Acta Botanica Croatica 74, no. 2 (October 1, 2015): 303–16. http://dx.doi.org/10.1515/botcro-2015-0028.

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Abstract Diatom composition of the rheoplankton (phytoplankton) in the Sajó-Hernád river system (Slovakia and Hungary) was studied. Forty two sample sites were designated on the watershed from source to mouth of the two rivers and their tributaries. Samples were taken in July 2012. Altogether, 258 diatom taxa were identified. The microflora was dominated by tychoplanktonic elements. According to the relative abundance of the occurring taxa, four groups could be distinguished. Differentiation of these groups was confirmed by differences in the habitat characteristics, viz. altitude, width of watercourse, macrophyte coverage and river bed material. Diversity of diatom taxa in the phytoplankton was also studied. A positive relationship was found between the macrophyte coverage and the Simpson and the Shannon indices. In contrast, a negative relationship was shown between the macrophyte coverage and Berger-Parker diversity, in which metric the role of the dominant taxa is emphasized. Although the phytoplankton in rhithral rivers is influenced by stochastic events, our results reveal that geographical and hydromorphological characteristics of the rivers and coverage of macrophytes can also play role in shaping the composition and diversity of the phytoplankton.

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Grant, T., and G. McDonald. "Instream Flow Requirements for The Platypus (Ornithorhynchus anatinus): High Flows. Studies of Water Transfers from The Shoalhaven River System to The Hawkesbury-Nepean River System." Australian Mammalogy 20, no. 2 (1998): 304. http://dx.doi.org/10.1071/am98309.

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During periods of low flows into the storages of the Hawkesbury-Nepean River system, Sydney Water pumps water from Lake Yarrunga, a storage at the junction of the Shoalhaven and Kangaroo Rivers. to the Wingecarribee Dam in the southern tablelands of New South Wales. From there it can be released into the upper Nepean River storages and/or the Wingecarribee River, which drains into the Wollondilly River and hence into the stored water behind Warragamba Dam. Prior to the formulation of an operational release strategy for this system, controlled releases of water were made into both the systems. During these releases the effects of flows on bank stability, water birds, benthic organisms and platypus populations and habitat were assessed, and a regime of maximum releases formulated. Potential impact on platypus populations was assessed by determining the height and/or area of bank left available for use by platypuses at the various flows. Subjective assessments were also made of the usable sections of the rivers for foraging at various flows. Broken white water was assumed to be unsuitable for foraging. The various investigations indicated that flows of 400 ML/day during September to March (water bird and platypus breeding and nesting season) and 600 ML/day at other times would have minimal impact on the ecology of the two river systems. Monitoring, studies involving netting and observations of platypuses in the upper Nepean River system indicated that operational releases within the suggested regime between July 1994 and May 1995 may have led to slightly reduced body condition in some animals during the higher flows in the winter of 1994. However the smaller discharges during the latter period of releases did not appear to result in platypuses entering the winter of 1995 in poor condition. Assessment of the usefulness of some sections of the river for foraging indicated that minor adjustments to the higher end of the flow regime may be necessary for future releases and that further monitoring needs to be done. Capture and observational monitoring studies indicated that releases of up to 500 ML/day in the Wingecarribee River between February and June 1995 had no noticeable effect on platypus activity or populations. Further monitoring needs to be done prior to, during and after higher flows and/or for longer periods in the Wingecarribee River.

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Lingote, Dinesh A., Girish S. Katkar, Ritesh Vijay, and R. B. Biniwale. "Responsive Information generation system for Kanhan River, an effective information system for river modeling." International Journal of Computer Sciences and Engineering 6, no. 12 (December 31, 2018): 213–21. http://dx.doi.org/10.26438/ijcse/v6i12.213221.

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Bogan, Arthur E. "Stability of Recent Unionid (Mollusca: Bivalvia) Communities Over the Past 6000 Years." Paleontological Society Special Publications 5 (1990): 112–36. http://dx.doi.org/10.1017/s2475262200005463.

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Historically, the greatest freshwater bivalve species diversity in the world was in the Tennessee, Cumberland and Alabama River systems. The Tennessee River System had 94 and the Cumberland River System had 85 taxa reported (Starnes and Bogan, 1988). Ortmann (1918, 1924, 1925, 1926), Wilson and Clark (1914), Neel and Allen (1964), van der Schalie (1939, 1973) and van der Schalie and van der Schalie (1950) documented this diverse fauna. However, even in the early days of this century these authors noted the decline in the mussel populations and the loss of species from certain rivers (e.g. Ortmann, 1909a, 1918).

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Lauri, Hannu, and Markku Virtanen. "A Decision Support System for management of boreal river catchments." River Systems 13, no. 3-4 (January 1, 2002): 401–8. http://dx.doi.org/10.1127/lr/13/2002/401.

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Jain, Vikrant, and R. Sinha. "Hyperavulsive-anabranching Baghmati river system, north Bihar plains, eastern India." Zeitschrift für Geomorphologie 47, no. 1 (March 19, 2003): 101–16. http://dx.doi.org/10.1127/zfg/47/2003/101.

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Motovilov, Y., V. Danilov-Danilyan, E. Dod, and A. Kalugin. "Flood protection effect of the existing and projected reservoirs in the Amur River basin: evaluation by the hydrological modeling system." Proceedings of the International Association of Hydrological Sciences 370 (June 11, 2015): 63–67. http://dx.doi.org/10.5194/piahs-370-63-2015.

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Abstract. Hydrological modeling system was developed as a tool addressed supporting flood risk management by the existing and projected reservoirs in the Amur River basin. The system includes the physically-based semi-distributed model of runoff generation ECOMAG coupled with a hydrodynamic MIKE-11 model to simulate channel flow in the main river. The case study was carried out for the middle part of the Amur River where large reservoirs are located on the Zeya and Bureya Rivers. The models were calibrated and validated using streamflow measuruments at the different gauges of the main river and its tributaries. Numerical experiments were carried out to assess the effect of the existing Zeya and Bureya reservoirs regulation on 850 km stretch of the middle Amur River stage. It was shown that in the absence of the reservoirs, the water levels downstream of the Zeya and Bureya Rivers would be 0.5–1.5 m higher than the levels measured during the disastrous flood of 2013. Similar experiments were carried out to assess possible flood protection effect of new projected reservoirs on the Zeya and Bureya Rivers.

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Legleiter, Carl, and Brandon Overstreet. "Measuring the Morphology and Dynamics of the Snake River by Remote Sensing." UW National Parks Service Research Station Annual Reports 37 (January 1, 2014): 12–20. http://dx.doi.org/10.13001/uwnpsrc.2014.4035.

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The Snake River is a prominent, central feature of Grand Teton National Park, and this dynamic fluvial system maintains diverse habitats while actively shaping the landscape. Although the riparian corridor is relatively pristine, the Snake River is by no means free from anthropogenic influences: streamflows have been regulated since 1907 by Jackson Lake Dam. Among dam-controlled rivers in the western U.S., the Snake River is unique in that tributaries entering below the dam supply sufficient coarse bed material to produce a braided morphology. As a result of tributary inputs, sediment flux along the Snake River has been relatively unaffected by Jackson Lake Dam, but flow regulation has reduced the magnitude and altered the timing of streamflows. In this study we are coupling an annual image time series with extensive field surveys to document channel changes occurring on the Snake River. Our objective is to quantify how snowmelt runoff events and flow management strategies influence patterns of sediment transfer and storage throughout the river system, with a particular focus on tributary junctions. More specifically, we are using the image sequence to identify areas of erosion and deposition and hence infer the sediment flux associated with the observed changes in channel morphology. This analysis will improve our understanding of the riverâs response to flow management and enable us to generate hypotheses as to how the system might adapt to future anthropogenic and/or climate-driven alterations in streamflow and sediment supply. In addition, our research on the Snake River involves an ongoing assessment of the potential to measure the morphology and dynamics of large, complex rivers via remote sensing. A new aspect of this investigation involves estimating flow velocities from hyperspectral images that capture the texture of the water surface. Extensive field measurements of velocity and water surface roughness are being used to develop this innovative approach and thus increase the amount of river information that can be inferred via remote sensing.

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Chapagain, Binod P., Neelam C. Poudyal, J. M. Bowker, Ashley E. Askew, Donald B. K. English, and Donald G. Hodges. "Demand for and Economic Value of Nonmotorized Boating Access in Rivers at US National Forests." Journal of Forestry 119, no. 3 (May 1, 2021): 275–90. http://dx.doi.org/10.1093/jofore/fvab006.

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Abstract Nonmotorized boating (NMB) is a popular recreation activity in the US National Forest System. Previous studies on NMB were from an individual river or site, which limited aggregating benefit across the system or generalizing to rivers across the country. Further, whether and how site and river characteristics affect the use of rivers for NMB activities are unknown. This study combined trip data collected from visitor surveys across the system with spatially explicit data on river characteristics in a travel cost model, and in the analysis step, characterized the economic benefit of NMB access and evaluated the effect of site and river characteristics. Net economic benefit of NMB access was estimated to be in the range of $56 to $73 per trip, depending on the modeling assumptions used. When aggregated across visits over the country, the total annual economic value of NMB access in National Forest System ranged from $92 million to $120 million. Results further suggest that site and river characteristics including water velocity, ramp availability, and rapid level were significantly related to NMB demand. Results may be useful in highlighting the use and public value of NMB access in rivers and in understanding the importance of site and river characteristics.

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Di, Tang, Tan Long, Wu Xuefeng, and Qi Lijiang. "Development of Tianwan river system and characteristics of river geomorphology." IOP Conference Series: Materials Science and Engineering 794 (May 15, 2020): 012014. http://dx.doi.org/10.1088/1757-899x/794/1/012014.

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Dettmers, John M., Steve Gutreuter, David H. Wahl, and Daniel A. Soluk. "Patterns in abundance of fishes in main channels of the upper Mississippi River system." Canadian Journal of Fisheries and Aquatic Sciences 58, no. 5 (May 1, 2001): 933–42. http://dx.doi.org/10.1139/f01-046.

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Abundance of fishes of the main channels of the upper Mississippi River system and of other large North American rivers is largely unknown because historic sampling methods have been inadequate. We used a bottom trawl to estimate spatial and temporal patterns in abundance in the navigation channels of Pool 26 of the Mississippi River and the lower Illinois River. Total biomass density averaged 21 and 29 kg·ha1 in the navigation channels of Pool 26 and the lower Illinois River, respectively. We identified spatial and temporal patterns in catches of key species using a generalized linear model based on the negative binomial distribution. Some species, including shovelnose sturgeon (Scaphirhynchus platorynchus), are persistent residents of the main channel. Multiple-season residents, including freshwater drum (Aplodinotus grunniens), rely heavily on the main channel during most of the year but leave it briefly, for example to seek thermal refugia in backwaters during winters. We suggest revision of the prevailing notion that main channels of large temperate rivers serve mainly as corridors for movement among other habitat types.

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Sarjiyanto, Sarjiyanto, and Libra Hari Inagurasi. "PERDAGANGAN DI PERTEMUAN SUNGAI KAPUAS DAN TAYAN, SANGGAU, KALIMANTAN BARAT, ABAD KE-19." PURBAWIDYA: Jurnal Penelitian dan Pengembangan Arkeologi 7, no. 1 (August 1, 2018): 71. http://dx.doi.org/10.24164/pw.v7i1.257.

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This paper highlights trading activities at the confluence of the Kapuas River and Tayan River, Sanggau District, West Kalimantan. The meeting of two rivers is a strategic location, the river as a traffic lane, where the growth of settlements and the Malay kingdom. The kingdoms of West Kalimantan are generally located around river encounters, such as Sanggau, Tayan, Landak, Meliau, and Sintang. This paper aims to illustrate trade at the confluence of the Kapuas and Tayan Rivers, for example part of the upstream-downstream trading system between the inland and river mouths or coastal waters that rely on streams in the nineteenth century. The problem to be solved is how to conduct trade around river basin especially around meeting of Kapuas River and Tayan River of the 19th century. The methods used are descriptive, analytical, and historical. Through this research successfully revealed the landscape of trading activities, types of commodities, and trading system.

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Espínola, Luis A., Carolina V. Minte-Vera, Horacio F. Júlio Junior, Luciano N. Santos, and Kirk O. Winemiller. "Evaluation of factors associated with dynamics of Cichla ocellaris invasion of the Upper Paraná River floodplain system, Brazil." Marine and Freshwater Research 66, no. 1 (2015): 33. http://dx.doi.org/10.1071/mf13105.

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Invasion by Cichla ocellaris was studied in the Upper Paraná River floodplain. Generalised linear models and the Akaike Information Criterion (AIC) were applied to standardised gill-net catch data (CPUE), with years, rivers, secchi depth, and their respective interactions. Generalised additive models and AIC were used to evaluate relationships of CPUE for C. ocellaris with standard length, sampling year and secchi depth. C. ocellaris was first recorded in 1992 in the Paraná and Ivinheima Rivers. Nevertheless, the CPUE of individuals was very low in the latter until 2000, and the species was not recorded from the Baía River until 2000. In 2001, CPUE of C. ocellaris greatly increased (from 20 to 140) in all three rivers, and this coincided with changes in hydrology and suspended sediment. Greater secchi depth is thought to benefit foraging by these visually oriented, diurnal piscivores. The estimated annual growth rate for local populations was 21% for the Paraná, 42% for the Ivinheima, and 73% for the Baía Rivers. Consequently, relative to other populations, C. ocellaris of the Baía River and, to a lesser degree, the Ivinheima River, appear to be less influenced by density-dependent factors given their more recent invasions of those areas.

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Kumar, Ashish, and Yogendra Bahadur. "Water Quality of River Kosi and Rajera System at Rampur (India): Impact Assessment." Journal of Chemistry 2013 (2013): 1–4. http://dx.doi.org/10.1155/2013/618612.

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River Kosi, an important tributary of river Ramganga, is one of the important rivers of Uttaranchal and Uttar Pradesh After traveling for about 100 kms in lower Himalayas with higher velocity, it emerges at Ramnagar in Indo-Gangetic plains. Here, the major portion of city sewage is discharged into it. Then, it flows through the famous rice belt area of Kashipur, where a number of polluting industries discharge their highly polluted effluents into it. To determine the extent of pollution in downstream district Rampur, a study was conducted. The aim of this study was to evaluate the effect of dilution caused by the merger of river Rajera with Kosi River. For this samples, were collected from three stations and analyzed for various parameters for the period of one year. The study revealed higher levels of industrial pollution as compared to domestic pollution. It also shows the alleviating effects of dilution caused by the merger of river Rajera.

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Romaidi, Romaidi, Bayu Agung Prahardika, and Muhammad Asmuni Hasyim. "UPAYA PENINGKATAN EKONOMI DAN PENGURANGAN SAMPAH DOMESTIK MASYARAKAT SUMBERSARI MELALUI PEMANFAATAN ALIRAN SUNGAI UNTUK BUDIDAYA IKAN MUJAIR." Journal of Research on Community Engagement 1, no. 2 (March 29, 2020): 54. http://dx.doi.org/10.18860/jrce.v1i2.8839.

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One of the biggest threats from human activities to rivers is the increasing number of residential areas around or even just above the river flow. This condition is certainly very threatening the sustainability of rivers in the region. One of the biggest threats is that the garbage produced by the community will be directly disposed of in the river flow. One way that can be done to reduce waste disposal in the river is by utilizing river flow, so that many rivers are now increasingly being developed as a vehicle for habitat conservation, because the river is considered important for various aquatic plants, migratory and sedentary fishes, and aquaculture ponds, birds and several types of mammals. In this case, the concept of river management must be based on environmental, ecological, economic and social aspects according to the characteristics of the surrounding community. The purpose of this community service is to utilize river flow for tilapia fish farming. The method used in the service is the PAR by way of lectures and direct practice in aquaculture with karamba by utilizing river flow. From the results of community service including partners showed that some respondents know how to fish with karamba, but do not know that river flow can also be used for fish farming with the karamba system. As well as the results of fish farming practices with the karamba system most of the respondents agreed agree (73%) if the fish culture using the karamba system is used as an alternative business idea related to river flow utilization and 60% of respondents agree the use of river flow for fish cultivation can reduce waste disposal in the river.

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Bordoloi, Bobita, and Samujjal Saharia. "Current Status of the Endangered Ganges River Dolphin (Platanista Gangetica), the Aquatic Megafauna in the Brahmaputra River System." Current World Environment 16, no. 2 (August 30, 2021): 600–606. http://dx.doi.org/10.12944/cwe.16.2.24.

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The Ganges River Dolphin (Platanista gangetica) is the most charismatic aquatic species inhabiting rivers of India, Bangladesh, and Nepal. It is an endangered species that occurs both in the Brahmaputra and Barak river systems in Assam (India). In the Brahmaputra river system, the occurence of ‘hihu’ is primarily confirmed in the mainstream Brahmaputra, the Kulsi river of Kamrup district, and the Subansiri river of Lakhimpur district. The dolphins inhabit river confluences or tributary junctions followed by river meanderings with the prevalence of eddy counter-currents and prey-fish abundance. Of late, it has been observed that river dolphin population has declined at an alarming rate due to the potential threats including poaching for dolphin oil, by-catch, overfishing, net entanglements, sand mining, habitat destruction through aquatic pollution, construction of dams, and lack of awareness. The species is left only in certain pockets of the Brahmaputra River. Thus, there is an urgent need for the conservation of this endangered species in its natural habitats. Effective protection of this endangered aquatic megafauna requires elimination and management of the potential threats. This review provides an overview of the distribution and population status, ecology, and management strategies and recommendation to increase awareness for its long-term conservation.

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Vandenberghe, Jef, and Ming-ko Woo. "Modern and ancient periglacial river types." Progress in Physical Geography: Earth and Environment 26, no. 4 (December 2002): 479–506. http://dx.doi.org/10.1191/0309133302pp349ra.

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Climate has been proposed conventionally as the primary factor that determines periglacial river activity (aggradation) and pattern (braided). This concept does not explain the rich diversity in river patterns and morphological processes in both the present and past periglacial environments: besides braided rivers and sandur, meandering, anabranching, transitional and deltaic rivers also occur. A first attempt is made to combine past and present periglacial river types with regard to their morphology, processes and environments. The processes that control river energy and morphology are discussed especially for periglacial conditions. This approach permits an assessment of the responses of periglacial rivers to climatic conditions and the modulation of the responses due to changes in the basin properties. Examples drawn from palaeo- and present-day periglacial rivers and environments demonstrate that there is no unique type of periglacial river but rather an azonal fluvial system with a number of periglacial variants.

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Ortega, J., D. Navarrete, and J. E. Maldonado. "Non–invasive sampling of endangered neotropical river otters reveals high levels of dispersion in the Lacantun River System of Chiapas, Mexico." Animal Biodiversity and Conservation 35, no. 1 (June 2012): 59–69. http://dx.doi.org/10.32800/abc.2012.35.0059.

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Patterns of genetic dispersion, levels of population genetic structure, and movement of the neotropical river otter (Lontra longicaudis) were investigated by screening eight polymorphic microsatellites from DNA extracted from fecal samples, collected in a hydrologic system of the Lacandon rainforest in Chiapas, Mexico. A total of 34 unique genotypes were detected from our surveys along six different rivers, and the effect of landscape genetic structure was studied. We recovered 16 of the 34 individuals in multiple rivers at multiple times. We found high levels of dispersion and low levels of genetic differentiation among otters from the six surveyed rivers (P > 0.05), except for the pairwise comparison among the Lacantún and José rivers (P < 0.05). We recommend that conservation management plans for the species consider the entire Lacantún River System and its tributaries as a single management unit to ensure the maintenance of current levels of population genetic diversity, because the population analyzed seems to follow a source–sink dynamic mainly determined by the existence of the major 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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Morihama, A. C. D., C. Amaro, E. N. S. Tominaga, L. F. O. L. Yazaki, M. C. S. Pereira, M. F. A. Porto, P. Mukai, and R. M. Lucci. "Integrated solutions for urban runoff pollution control in Brazilian metropolitan regions." Water Science and Technology 66, no. 4 (August 1, 2012): 704–11. http://dx.doi.org/10.2166/wst.2012.215.

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One of the most important causes for poor water quality in urban rivers in Brazil is the low collection efficiency of the sewer system due to unforeseen interconnections with the stormwater drainage system. Since the beginning of the 20th century, Brazilian cities have adopted separate systems for sanitary sewers and stormwater runoff. Gradually these two systems became interconnected. A major challenge faced today by water managers in Brazil is to find efficient and low cost solutions to deal with this mixed system. The current situation poses an important threat to the improvement of the water quality in urban rivers and lakes. This article presents an evaluation of the water quality parameters and the diffuse pollution loads during rain events in the Pinheiros River, a tributary of the Tietê River in São Paulo. It also presents different types of integrated solutions for reducing the pollution impact of combined systems, based on the European experience in urban water management. An evaluation of their performance and a comparison with the separate system used in most Brazilian cities is also presented. The study is based on an extensive water quality monitoring program that was developed for a special investigation in the Pinheiros River and lasted 2.5 years. Samples were collected on a daily basis and water quality variables were analyzed on a daily, weekly or monthly basis. Two hundred water quality variables were monitored at 53 sampling points. During rain events, additional monitoring was carried out using an automated sampler. Pinheiros River is one of the most important rivers in the São Paulo Metropolitan Region and it is also a heavily polluted one.

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Journal articles on the topic 'River system'

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