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1
Vandenberghe, Jef y Ming-ko Woo. "Modern and ancient periglacial river types". Progress in Physical Geography: Earth and Environment 26, n.º 4 (diciembre de 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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Delina, Aija, Alise Babre, Konrads Popovs, Juris Sennikovs y Baiba Grinberga. "Effects of karst processes on surface water and groundwater hydrology at Skaistkalne Vicinity, Latvia". Hydrology Research 43, n.º 4 (7 de febrero de 2012): 445–59. http://dx.doi.org/10.2166/nh.2012.123.
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The Skaistkalne area in Latvia is one of the places where karst processes in gypsum strata occurs. The Iecava and Memele rivers border the area with extensive surface karst features such as sinkholes and karst lakes. Earlier investigations suggested a hydraulic connection between the Iecava and Memele rivers exists via the karst conduits due to the water level (WL) difference in the rivers. A set of methods was performed to study the possible connection: dye tracer was applied in the Iecava river and its occurrence was visually observed at the karst lakes and Memele river; the current velocity was measured and discharge of rivers calculated at several profiles; surface water and groundwater composition was studied involving in situ measurements of water pH and electrical conductivity, water sampling and chemical analysis of the water samples on the content of sulphates, calcium and magnesium ions. A numerical finite element 3D groundwater flow model was developed to assess the impact of WL changes in rivers to groundwater flow. The study showed that there is direct hydraulic connection between the rivers – water from the Iecava river flows to the Memele river. The groundwater discharge to the Memele river varies seasonally, and more intensive groundwater discharge is observed during the high season.
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Lefebvre, Mario y Fatima Bensalma. "An Application of Filtered Renewal Processes in Hydrology". International Journal of Engineering Mathematics 2014 (5 de mayo de 2014): 1–9. http://dx.doi.org/10.1155/2014/593243.
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Filtered renewal processes are used to forecast daily river flows. For these processes, contrary to filtered Poisson processes, the time between consecutive events is not necessarily exponentially distributed, which is more realistic. The model is applied to obtain one- and two-day-ahead forecasts of the flows of the Delaware and Hudson Rivers, both located in the United States. Better results are obtained than with filtered Poisson processes, which are often used to model river flows.
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Yakhno, Oleg, Ihor Hnativ y Roman Hnativ. "Influence of cavitation processes on river water purification of mountain streams". Mechanics and Advanced Technologies 6, n.º 1 (31 de mayo de 2022): 62–69. http://dx.doi.org/10.20535/2521-1943.2022.6.1.254613.
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Problems: The article considers the study of the influence of cavitation phenomena in hydrodynamically active areas of mountain rivers on the processes of natural self-purification of water. The paper considers the experimental results of determining the change in seasonal indicators of the hydrochemical composition of surface waters in the Stryi river basin.
Objective: to determine the impact of hydrodynamically active areas (HAA) of mountain rivers on the processes of natural self-purification and to develop methods of laboratory modeling of these areas to determine the hydrochemical parameters of river waters.
Methods of implementation: Research of ecological and hydrochemical factors of chemical composition of natural waters of the Stryi river basin combines basin and landscape-geochemical approaches, which allows to integrate various natural and anthropogenic influences, to identify the most important parameters for their detailed analysis. The combination of these approaches made it possible to improve the method of ecological analysis of the area of the Stryi river basin, which allows to spatially differentiate and hydrochemically integrate the factors of formation of the chemical composition of natural waters.
Results: It is stated that microbiological safety of water is a special problem, because even water from underground sources may contain single cells of pathogenic microorganisms, but the main threat is water re-contaminated with microbes in case of leaks in the water supply network.
Conclusions: Analysis of the results of studies of the impact of self-cleaning processes in the river Stryi on the quality of water intake in Stryi showed that there are currently no negative effects of river waters of the river Stryi on groundwater deposits. The quality of river water is satisfactory for its use in domestic and drinking water supply and for recreational purposes.
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Osterkamp, W. R. "Fluvial Processes in River Engineering". Eos, Transactions American Geophysical Union 70, n.º 4 (1989): 51. http://dx.doi.org/10.1029/89eo00033.
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Nafziger, Jennifer, Yuntong She y Faye Hicks. "Dynamic river ice processes in a river delta network". Cold Regions Science and Technology 158 (febrero de 2019): 275–87. http://dx.doi.org/10.1016/j.coldregions.2018.09.005.
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Timuhins, Andrejs, Valērijs Rodinovs y Māris Kļaviņš. "Wavelet analysis of the Baltic region river runoff longh-term trends and fluctuations". Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 64, n.º 5-6 (1 de enero de 2010): 229–35. http://dx.doi.org/10.2478/v10046-011-0009-1.
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Wavelet analysis of the Baltic region river runoff longh-term trends and fluctuations The study of changes in river discharge and flood regime can provide important information on climate change and its impacts. Wavelet analysis offers new possibilities to study changes of river discharge patterns in regard to periodical processes on a background of climate change. In this study wavelet analysis was used to study long-term changes of river discharge in the Baltic region. Periodic oscillations of discharge intensity, and low- and high-water flow years are common for the major rivers in the Eastern Baltic region. Main frequencies of river discharge were estimated to be 14, 28, 37 years for the studied rivers. Wavelet analysis allowed to identify similarities between the river discharge regime, and thus, the factors influencing it. Years of maximal and minimal discharges for major rivers were identified and the impact of large-scale atmospheric circulation processes on the river discharge was studied.
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Wohl, Ellen. "Geomorphic context in rivers". Progress in Physical Geography: Earth and Environment 42, n.º 6 (22 de mayo de 2018): 841–57. http://dx.doi.org/10.1177/0309133318776488.
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Geomorphic context refers to the geomorphic setting of a river reach, which is defined as a length of river with consistent valley and channel geometry. Context includes spatial dimensions of geometry, location within a drainage basin, and location within a global context. Context also includes temporal dimensions of the frequency and duration of specific processes influencing the river reach and the historical sequence of natural and human-induced processes that continue to influence process and form in the river reach. These spatial and temporal characteristics interact to create a geomorphic context that governs the contemporary form of the river corridor, the rates and processes by which diverse materials move through the corridor, and the adjustments of form and process in response to disturbances. Context matters for both basic understanding and effective management of river corridors. Examples of widely used formal articulations of geomorphic context include a bedform-based classification of mountain streams, geomorphic process domains, and river styles. Each has been applied to understanding and predicting longitudinal variations in stream power, sediment budgets, habitat and biotic communities, resilience to disturbance, and other characteristics of rivers. The three Cs of rivers—complexity (or spatial heterogeneity), connectivity, and context—provide a conceptual framework for river research and management.
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Li, Pushuang, Dan Li, Xiaoqing Sun, Zhaosheng Chu, Ting Xia y Binghui Zheng. "Application of Ecological Restoration Technologies for the Improvement of Biodiversity and Ecosystem in the River". Water 14, n.º 9 (27 de abril de 2022): 1402. http://dx.doi.org/10.3390/w14091402.
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With global warming, urbanization, and the intensification of human activities, great pressures on river ecosystems have caused ecosystem degradation, the decline in habitats and biodiversity, and the loss of function. Ecological restoration technologies (ERTs) in rivers are effective measures for improving habitat and biodiversity, which has the advantage of recovering ecosystems and biodiversity and promoting the formation of healthy rivers. Several applications of ERTs, including ecological water transfer, fish passage construction, dam removal/retrofit, channel reconfiguration, river geomorphological restoration, natural shoreline restoration, floodplain reconnection, revegetation, etc., are summarized. The classifications of ERTs are highlighted, aiming to distinguish the difference and relationship between structure and the processes of hydrology, physics, geography, and biology. The pros and cons of these technologies are discussed to identify the applicability and limitations on the river ecosystem. In the dynamic processes in the river, these interact with each other to keep ecosystem balance. ERTs are more helpful in promoting the restoration of the natural function of the river, which contribute to the management of river ecological health. Some proposals on river management are suggested. Establishing a unified river health evaluation system will help promote positive feedback on rivers and the further development of ERTs.
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Zhou, Siping, J. A. McCorquodale y J. Biberhofer. "Modelling of pollutant mixing in the St. Lawrence River". Canadian Journal of Civil Engineering 22, n.º 5 (1 de octubre de 1995): 1041–45. http://dx.doi.org/10.1139/l95-118.
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Many of Canada's large rivers, such as the connecting channels of the Great Lakes, receive contaminant loads from industrial, municipal, and tributary sources. These contaminants experience two general types of mixing, outlet-dominated mixing processes (near field) and river-dominated mixing processes (far field). This note is concerned with the numerical modelling of the far field processes by a fully elliptic form of the two-dimensional depth-averaged river model proposed by Rodi et al. Many of the popular hydrodynamics codes experience numerical diffusion which far exceeds the real turbulent diffusion; a new method known as the semi-implicit skewed upwind method is introduced to minimize the numerical dispersion for rivers with highly nonlinear alignment. The new model is verified by comparison with the field data obtained from a dye study in the St. Lawrence River. Key words: pollutant transport, river mixing, far field model, numerical diffusion.
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Kusuda, Tetsuya, Tohru Futawatari y Kyoko Oishi. "SIMULATION OF NITRIFICATION AND DENITRIFICATION PROCESSES IN A TIDAL RIVER". Water Science and Technology 30, n.º 2 (1 de julio de 1994): 43–52. http://dx.doi.org/10.2166/wst.1994.0027.
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Nitrification and denitrification processes in a well mixed tidal river in Japan are modeled, based on results of long term field observation on water quality and sediments in the river. Laboratory test results and values in references are used for the determination of parameters and coefficients in the model. In modeling of the processes, sediments, suspended solids, and overlying water are taken as elements and in computation a Lagrangian reference frame in terms of accumulated water volume is employed for reduction in numerical dispersion. Simulation results on ammonium and nitrate nitrogen, showing good agreement with long term field observation results, qualitatively explain well the processes in the river. The results indicate some countermeasures to reduce nitrate more such as the increase in the area of sediment surface. The simulation model is available for the estimation of water quality in well mixed tidal rivers and applicable for water quality control.
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DATE, Masanao, Norihiro IZUMI y Hitoshi TANAKA. "DELTAIC PROCESSES AT THE RIVER MOUTH OF THE ABASHIRI RIVER". PROCEEDINGS OF HYDRAULIC ENGINEERING 42 (1998): 1129–34. http://dx.doi.org/10.2208/prohe.42.1129.
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Evans, E. C., G. R. McGregor y G. E. Petts. "River energy budgets with special reference to river bed processes". Hydrological Processes 12, n.º 4 (30 de marzo de 1998): 575–95. http://dx.doi.org/10.1002/(sici)1099-1085(19980330)12:4<575::aid-hyp595>3.0.co;2-y.
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van Griensven, A. y W. Bauwens. "Concepts for river water quality processes for an integrated river basin modelling". Water Science and Technology 48, n.º 3 (1 de agosto de 2003): 1–8. http://dx.doi.org/10.2166/wst.2003.0145.
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Although there are various ways to model the bio-chemical processes in rivers, two main trends can be distinguished: the traditional QUAL2E-type models and the RWQM-type models, developed by extending and adapting the ASM equations. Both approaches have their weak and strong points. This paper focuses on the application of these concepts in an integrated modelling context. To this purpose, the models were adapted to respect the mass balances, to enable linkage to WWTP outputs and to diffuse pollution sources. Both approaches have been included in ESWAT - Extended Soil and Water Assessment Tool - which was developed by the authors to allow for an integral modelling of the water quantity and quality processes in river basins. A comparison and evaluation of both quality models is performed for the river Dender (Belgium). It is shown that both models give a reasonable fit for dissolved oxygen and ammonia. However, the dynamics of the quality processes for the RWQM model are slower, due to the time that bacteria need to adapt to changes of the loads of organic matter.
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Prowse, Terry D. y Joseph M. Culp. "Ice breakup: a neglected factor in river ecology". Canadian Journal of Civil Engineering 30, n.º 1 (1 de febrero de 2003): 128–44. http://dx.doi.org/10.1139/l02-040.
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To minimize environmental impacts that may result from any engineered modifications of stream or river systems, a basic understanding of river ecology is required. Most fundamental theories of river ecology have developed largely from studies of warm-temperate and tropical streams and rivers. As these theories evolved over the last few decades, floods were recognized increasingly as dominant hydrologic events that control numerous abiotic and biotic forms and processes, both within the channel and on the adjacent riparian floodplains. Over approximately the same time frame, river-ice breakup was shown to be a major, if not predominant, source of floods on cold-regions rivers. Despite this, rarely has the role of ice-induced flooding been considered by subsequent modifications to the original theories or in the extensive studies and literature that they spawned. This manuscript reviews the broad, although frequently anecdotal, information about the abiotic and biotic effects of breakup processes and flooding. Based on this, it argues for breakup to be incorporated in future advancements of river ecological theory. The extensive list of cited studies provides a valuable reference source for scientists and engineers assessing development-related impacts on cold-regions streams and rivers, or further researching ecological aspects of river-ice breakup.Key words: river ice, river ecology, freshwater ecology, flooding, breakup, ice jam.
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Shen, Hung Tao, De Sheng Wang y A. M. Wasantha Lal. "Numerical Simulation of River Ice Processes". Journal of Cold Regions Engineering 9, n.º 3 (septiembre de 1995): 107–18. http://dx.doi.org/10.1061/(asce)0887-381x(1995)9:3(107).
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Lal, A. M. Wasantha y Hung Tao Shen. "Mathematical Model for River Ice Processes". Journal of Hydraulic Engineering 117, n.º 7 (julio de 1991): 851–67. http://dx.doi.org/10.1061/(asce)0733-9429(1991)117:7(851).
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Shen, Hung Tao. "Mathematical modeling of river ice processes". Cold Regions Science and Technology 62, n.º 1 (junio de 2010): 3–13. http://dx.doi.org/10.1016/j.coldregions.2010.02.007.
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Timco, Garry. "Mathematical modelling of river ice processes". Cold Regions Science and Technology 62, n.º 1 (junio de 2010): 1–2. http://dx.doi.org/10.1016/j.coldregions.2010.02.009.
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Kędzior, Renata, Małgorzata Kłonowska-Olejnik, Elżbieta Dumnicka, Agnieszka Woś, Maciej Wyrębek, Leszek Książek, Jerzy Grela, Paweł Madej y Tomasz Skalski. "Macroinvertebrate habitat requirements in rivers: overestimation of environmental flow calculations in incised rivers". Hydrology and Earth System Sciences 26, n.º 15 (8 de agosto de 2022): 4109–24. http://dx.doi.org/10.5194/hess-26-4109-2022.
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Abstract. Flow variability determines the conditions of river ecosystems and river ecological functioning. The variability of ecological processes in river ecosystems gradually decreases due to river channelization and incision. Prediction of the environmental flow allows us to keep biological diversity and river health developed as a response to the degradation of aquatic ecosystems overexploited by humans. The goal of the study was to test the influence of river incision on environmental flow estimation based on the Biological Monitoring Working Party (BMWP) macroinvertebrate index. A total of 240 macroinvertebrate assemblages of 12 waterbodies differing in bed substrate and amplitude of discharge were surveyed in southern Poland. Variations in the distribution of 151 466 macroinvertebrates belonging to 92 families were analysed. The similarity of benthic macroinvertebrates reflects the typological division of the rivers into three classes: Tatra mountain streams, mountain flysch rivers, and upland carbonate and silicate rivers. As a response variable reflecting the macroinvertebrate distribution in the river, the BMWP_PL index was chosen. The river incision significantly increased the values of e-flow calculations in relation to redeposited channels. The area of optimal habitat for macroinvertebrates decreased with the bed incision intensity. In highly incised rivers, the environmental flow values are close to the mean annual flow, suggesting that a high volume of water is needed to obtain good macroinvertebrate conditions. As a consequence, river downcutting processes and impoverishment of optimal habitats will proceed.
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Čanjevac, Ivan, Katarina Pavlek y Danijel Orešić. "River lengths in Croatia determined from a topographic map at a scale of 1:25,000". Hrvatski geografski glasnik/Croatian Geographical Bulletin 84, n.º 1 (14 de julio de 2022): 5–30. http://dx.doi.org/10.21861/hgg.2022.84.01.01.
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This study presents methodologically consistent length measurements of rivers with a total length of 40 kilometres or more in the Republic of Croatia. These measurements were performed by vectorising river channels from a topographic map at a scale of 1:25,000. Contemporary orthophoto maps were used as additional cartographic sources for verification. The approaches used to determine the starting and ending points of rivers, i.e. sources and mouths or confluences, have been explained and their spatial coordinates were listed. The results showed that in terms of total river length, the 21 rivers in this study differed from the available official data by less than 5%. Considerable differences were found for rivers where significant river engineering works had been carried out to channelize and divert flow, as well as for rivers in the Adriatic Basin where there have been methodological differences in determining the river mouth, and for large lowland rivers where changes in channel planform are common due to natural dynamics and engineering interventions. Moreover, this research revealed that the longest Croatian river, with its source, confluence, and both river banks situated entirely within the territory of Croatia, is the Karašica River, with a total length of 148 km.
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Kosteniuk, Liudmyla. "RESEARCH OF CHANNEL PROCESSES ON RICHKA RIVER (BLACK CHEREMOSH BASIN)". PROBLEMS OF GEOMORPHOLOGY AND PALEOGEOGRAPHY OF THE UKRANIAN CARPATHIANS AND ADJACENT AREAS 02, n.º 13 (30 de diciembre de 2021): 78–94. http://dx.doi.org/10.30970/gpc.2021.2.3550.
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In the article is devoted to the problem of studying channel processes on small mountain rivers of the Ukrainian Carpathians, where there are no regular observations. It is the lack of a monitoring system on such water bodies that is the main reason for the insufficient level of their study and presentation in literary sources on riverbed science. As is known, channel processes are a phenomenon based on the constant interaction of water flows (rivers) and the land surface. And the lack of real opportunities to assess the hydrological regime of the water body due to lack of information from observations, immediately negates the prospects for the study of channel processes at this site, as the only active component of the flow-channel system. But such preconditions, although a significant obstacle, cannot stop a true specialists in the fluvial processes, and the first step in filling in the gaps in the lack of information on any water body is field research to pre-gather the primary starting information. That is why, in September 2021, the author made an expedition to the river basin, followed by a survey of its course and the channels of its two hydrographic tributaries of the Chorna Richka and Bila Richka, the results of which are presented in this article. Before leaving, a preliminary assessment of the factors of channel formation for the rivers of the studied basin was carried out, which was based on the allocation of HVB (homogeneous areas of the valley bottoms) as the main limiting factor for the channel formation zone. This approach has already been tested by the author for the Upper Prut basin. The results of field research included descriptions, visual observations and measurement work at key points, on the basis of which cross-sections were constructed and channel processes were typified. At one point of the Chorna Richka river, it was possible to determine the particle size distribution of sediments and the average diameter by photogrammetric method. Based on the obtained results, the predominant types of channels according to the morphodynamic classification of R.S. Chalov, in the studied river basin, are: sculptural (to a greater extent) channels and channels with undeveloped alluvial forms. Key words: channel processes; morphodynamic classification; channel types; small mountain rivers; transverse profile.
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Gusarov, A. V. y L. F. Maksyutova. "The main regularities of the ratio between riverbed and basin components of erosion and suspended sediment yield in river basins of the USA". Geomorphology RAS, n.º 1 (4 de abril de 2019): 3–24. http://dx.doi.org/10.31857/s0435-4281201913-24.
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Suspended sediment yield is one of the objective and sufficiently accurate measures of erosion intensity in river basins. In first approximation, it can be divided into the riverbed component –r(rb), the products of vertical and horizontal riverbed deformations), and basin component – r(bas), the products of soil and gully erosion. An attempt was made to distinguish this erosion structure in the USA river basins based on the partition of suspended sediments of 224 rivers (based on the data from the US Geological Service on the average monthly water discharges and suspended sediment yields) according to the method proposed by one of the authors of the paper, as well as an assessment of its factor dependence.
The average r(rb) value for the analyzed rivers of the USA is 7.9±1.1%: for lowland rivers – 10.6±1.7%, for low-mountain (including uplands) rivers – 5.7±1.5%, for mid-mountain rivers – 4.3±1.5%. The geomorphic factor, landscape and climatic conditions within the river basins have a major impact on the suspended sediments flux ratio r(rb)/r(bas). Thus, in the USA plains, the largest average r(rb) portion is in the forest landscapes (taiga, mixed and broadleaf forests of the temperate zone, subtropical forests) – 10–15%. On the contrary, in the arid landscapes (semi-deserts) this value does not exceed 1%. Within these general trends, there are quite strong variations in the r(rb)/r(bas) ratios due to the changes in high river basin areas, agricultural activities and lithologic composition of the riverbed and floodplain sediments. There is an inverse hyperbolic relationship between the actual suspended sediment yield of rivers and the riverbed sediment portion (r(rb)), which is most manifested in the plains and low-mountains of the USA. It is also shown that a composition of the river basin parent (surficial) rocks does not play a significant role in the variability of the r(rb)/r(bas) at this scale of the study. A comparison of the r(rb)/r(bas)-estimates and their factor dependence on the US rivers with the rivers of Northern Eurasia (the territory of the former Soviet Union) makes it possible to reveal good convergence of the results obtained in these parts of the Earth, and to suggest the universal nature of the revealed regularities (in total for 684 river basins) for the whole temperate (partly for subtropical and tropical) zone of the Northern hemisphere of our planet.
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Ma, Xieyao, Tetsuzo Yasunari, Tetsuo Ohata y Yoshihiro Fukushima. "The influence of river ice on spring runoff in the Lena river, Siberia". Annals of Glaciology 40 (2005): 123–27. http://dx.doi.org/10.3189/172756405781813744.
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AbstractThe Lena river is one of the four largest rivers flowing into the Arctic Ocean. It has a complicated hydrological system that is affected not only by the amount of precipitation but also by the timing of ice break-up. To determine the mechanisms of runoff formation, a numerical analysis based on modeling was carried out for the period 1986–2000. The results show that (1) the timing of flood rise and peak can be modeled at Tabaga, which represents the upper and central portions of the Lena river; (2) river-freeze processes delay the spring, snowmelt-dominated flood by about 23 days; and (3) the difference between the break-up dates at Tabaga and Kirensk has ranged from several days to >2 months, and a maximum value of 69 days was recorded in spring 1998.
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A., Mammadova, y Aliyev, S. "Study of the Salt Composition of Some Rivers of the Lerik District". Bulletin of Science and Practice, n.º 1 (15 de enero de 2023): 121–24. http://dx.doi.org/10.33619/2414-2948/86/15.
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The article is devoted to the study of the ionic and salt composition of the rivers of the Lerik District of the southern part of Azerbaijan. The results of analyzes of the river waters selected as the object of the study show that there were no serious processes of mineralization in the rivers. The salinity of the river waters of the Lerik District (the Bilnа River, river waters taken from the villages of Mastail, Lankaranchay, Konjavuchay) varied within the range of 0,440-0.674 g/l. The composition of ions in these water sources varied depending on the rivers.
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Khan, Usman, Hammad Tariq Janjuhah, George Kontakiotis, Adnanul Rehman y Stergios D. Zarkogiannis. "Natural Processes and Anthropogenic Activity in the Indus River Sedimentary Environment in Pakistan: A Critical Review". Journal of Marine Science and Engineering 9, n.º 10 (12 de octubre de 2021): 1109. http://dx.doi.org/10.3390/jmse9101109.
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The Indus River is Asia’s longest river, having its origin in the Tibet Mountain northwest of Pakistan. Routed from northern Gilgit and flowing to the plains, the river passes through several provinces and is connected by numerous small and large tributaries. The river was formed tectonically due to the collusion of the Indian and Eurasian plates, which is referred to as the Indus suture Plains zone (ISPZ). The geological setting of the study area is mainly composed of igneous and metamorphic rocks. The river passed through a variety of climatic zones and areas, although the predominant climate is subtropic arid and sub arid to subequatorial. Locally and globally, anthropogenic activities such as building, dams, and water canals for irrigation purposes, mining exploration, and industries and factories all affected the physical and chemical behaviors of the sediments in various rivers. The main effect of human activities is the reworking of weathered soil smectite, a chemical weathering indicator that rises in the offshore record about 5000 years ago. This material indicates increased transport of stronger chemically weathered material, which may result from agriculture-induced erosion of older soil. However, we also see evidence for the incision of large rivers into the floodplain, which is also driving the reworking of this type of material, so the signal may be a combination of the two. Sediments undergo significant changes in form and size due to clashing with one another in the high-charge river.
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Saleh, A., I. Abustan, Mohd Remy Rozainy M. A. Z. y N. Sabtu. "Sediment Transport and Characteristics in Perak River and Kurau River". International Journal of Engineering & Technology 7, n.º 2.29 (22 de mayo de 2018): 849. http://dx.doi.org/10.14419/ijet.v7i2.29.14270.
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Particle size is the most important parameter to deal in sediment transport processes. This parameter is important to determine the class of sediment transport in river. It is also important for the selection of site for sand mining operation through the determination of the size of sediment, sediment capacity and sediment replenishment rate. Data were obtained through observations made from two rivers namely Sungai Perak and Sungai Kurau in Malaysia. The rivers were categorized as wide river for Sungai Perak and small river for Sungai Kurau. For Sungai Perak, the width of river ranges from 248.18 to 338.53 meter whilst the width of Sungai Kurau ranges from 9 to 11 meter. Data covers flow discharges from 130.988 m3/s to 435.915 m3/s for Sungai Perak and from 2.52 m3/s to 4.723 m3/s for Sungai Kurau. Based on the results, the bed load of two rivers are found to be mostly uniform mixture. The results indicate that these two Malaysian rivers mostly have uniform bed load The bed material for the two rivers are poorly graded mixture and the median size of bed loads mostly ranges from 0.62 to 2.94 mm.
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Kosteniyk, Liudmyla y Natalia Zablotovska. "FEATURES OF LEVEL PROCESSES ON MOUNTAIN RIVERS WITHIN THE BOUNDARIES OF THE VORKHTO-PUTYL LOW MOUNTAINS (CHEREMOSH BASIN)". SCIENTIFIC ISSUES OF TERNOPIL VOLODYMYR HNATIUK NATIONAL PEDAGOGICAL UNIVERSITY. SERIES: GEOGRAPHY 52, n.º 1 (30 de mayo de 2022): 51–59. http://dx.doi.org/10.25128/2519-4577.22.1.7.
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This publication is devoted to the study of the features of channel processes on mountain rivers that cross the Central synclinorium of the Ukrainian Carpathians, namely the region of the Vorokhto-Putilsky low mountains. These are mainly the rivers of the Cheremosh river basin, the hydrographic sources of the Black and White Cheremosh, as well as their small tributaries Iltsa and Richka.
It is within the boundaries of this geological and geomorphological region that atypical hollow expansions of the bottoms of river valleys are observed (Zhabeevskaya, Krivopilskaya, Iltsevskaya, Krivorivnesvkaya and Yablunetskaya).
According to the data of some researchers, the zone of the Vorokhto-Putyl low mountains is part of an older river runoff, the so-called Yasynya-Cheremoshskaya River, which is fragmentarily represented in the modern orography of the Ukrainian Carpathians and is currently not a homogeneous morphological structure. This old river, during the Pliocene period, had an internal flow into the basin of the Siret River, in the direction of its tributary, the Moldova River. It is in this zone that high terrace levels (VIII, IX) are well preserved, the direction of which does not correspond to modern river valleys.
The main feature of the channel processes of the rivers in this particular region is the disproportionate size of the bottoms of their valleys in accordance with the modern dimensions of the channels.
The second feature is the predominantly alluvial type of channels with a clearly expressed thick bottom pavement, as well as alluvial forms with well-rounded sediments.
An important modern element of modern scientific studies of channel processes is the measurement work in the channel to measure the depths of the river channel and the subsequent construction of the transverse profile of the river in certain key areas.
The results of these measurements, as well as the graphs of the transverse profiles themselves, are presented in this paper for the Iltsa, Chorny, and Bely Cheremosh rivers. A brief description of the features of the channel processes in the leveling areas is also given.
The obtained results make it possible to more reasonably and accurately analyze the flood zones of these rivers during the passage of floods and spring floods. And also, based on a comparison of the graphs of transverse profiles for different periods, it will be possible to more accurately assess the vertical deformations in different parts of the channels of the studied rivers.
Thus, for most riverbeds crossing the Vorokhta-Putilsky terraced lowlands, we see atypical hollow expansions of valley bottoms, which indicate local changes in geological and homorphological conditions in these areas, which in turn affects the formation of alluvial type of channels, with quite a large number of deposits of good run-in. This type of channel is more typical of rivers flowing within the foothills and more reminiscent of the free conditions of channel formation. At the same time, when moving to the area of the Skibov Carpathians, the incised type of channel becomes predominant again.
It should also be noted that the development of channel macroforms (incised macro-meanders on the rivers Iltsa, Chorny Cheremosh, Rivers) is observed within this lowland, which indicates a complex hierarchy of channel processes in this geomorphological zone.
Prospects for the use of results. The obtained results give the starting material for further, deeper, study and determination of the peculiarities of channel processes on the studied mountain rivers: due to the cross-sections it is possible to calculate the channel-forming water flow at given speeds and water levels; repeated leveling, after a certain period of time, will allow to estimate the intensity of vertical and planned deformations in the surveyed areas; it became possible to determine the zones of flooding during high floods by mathematical (calculation) methods, even in the absence of regular observations at the object of research and to estimate the coefficient of stability of the riverbed.
Key words: channel processes, mountain rivers, transverse profile, incised channel, vertical deformations
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Palmer, Margaret y Albert Ruhi. "Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration". Science 365, n.º 6459 (19 de septiembre de 2019): eaaw2087. http://dx.doi.org/10.1126/science.aaw2087.
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River ecosystems are highly biodiverse, influence global biogeochemical cycles, and provide valued services. However, humans are increasingly degrading fluvial ecosystems by altering their streamflows. Effective river restoration requires advancing our mechanistic understanding of how flow regimes affect biota and ecosystem processes. Here, we review emerging advances in hydroecology relevant to this goal. Spatiotemporal variation in flow exerts direct and indirect control on the composition, structure, and dynamics of communities at local to regional scales. Streamflows also influence ecosystem processes, such as nutrient uptake and transformation, organic matter processing, and ecosystem metabolism. We are deepening our understanding of how biological processes, not just static patterns, affect and are affected by stream ecosystem processes. However, research on this nexus of flow-biota-ecosystem processes is at an early stage. We illustrate this frontier with evidence from highly altered regulated rivers and urban streams. We also identify research challenges that should be prioritized to advance process-based river restoration.
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Kim, Jonathan P., Keith A. Hunter y Malcolm R. Reid. "Geochemical processes affecting the major ion composition of rivers in the South Island, New Zealand". Marine and Freshwater Research 50, n.º 7 (1999): 699. http://dx.doi.org/10.1071/mf98128.
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The major ion (Na+ , K+ , Mg2+ , Ca2+ , Cl− , SO42− and reactive SiO2 ) compositions of seven rivers in the South Island, New Zealand (Manuherikia, Clutha, Takaka–Cobb, Haast, Grey, Aorere and Rakaia rivers) are reported. All the rivers were pristine in comparison with global average river waters, and the concentrations of most major ions were close to the 1% percentile levels for global river water compositions. A geochemical model that attributes ion compositions to both rain input and to the weathering of various simple mineral types in the catchment was applied to these data, and to data already published. This model, although simplistic, accounts for the main features of major ion composition in the rivers studied. The dominant sources of major ions were the weathering of limestones and feldspars. Atmospheric input was relatively small except for Na+ and Cl− .
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Beltaos, Spyros y Brian C. Burrell. "Climatic change and river ice breakup". Canadian Journal of Civil Engineering 30, n.º 1 (1 de febrero de 2003): 145–55. http://dx.doi.org/10.1139/l02-042.
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The flow hydrograph, thickness of the winter ice cover, and stream morphology are three climate-influenced factors that govern river ice processes in general and ice breakup and jamming in particular. Considerable warming and changes in precipitation patterns, as predicted by general circulation models (GCMs) for various increased greenhouse-gas scenarios, would affect the length and duration of the ice season and the timing and severity of ice breakup. Climate-induced changes to river ice processes and the associated hydrologic regimes can produce physical, biological, and socioeconomic effects. Current knowledge of climatic impacts on the ice breakup regime of rivers and the future effects of a changing climate are discussed.Key words: breakup, climate change, global warming, greenhouse effect, hydrology, ice, ice jam, impacts, prediction, river ice.
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Tsereteli, E., N. Bolashvili, G. Gaprindashvili y M. Gaprindashvili. "Mudflow processes in Georgia". Geography and water resources, n.º 2 (30 de junio de 2022): 28–34. http://dx.doi.org/10.55764/2957-9856/2022-2-28-34.10.
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Natural calamities become more topical in the beginning of XXI century, as the pressure of them on human environment becomes much heavier. The background of global climate change processes immeasurably increases the risk of uncontrollable natural catastrophes. Among the multi-spectral geological processes in Georgia, the most impressive phenomena are landslides and debris/mudflows, washing out of marine coasts and river banks within the limits of settlements. According to special research data, the landslide, mudflow, and river bank erosion out reactivation processes are growing exponentially from year to year.
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Paz-Alberto, Annie Melinda, Melissa Joy M. Sison, Edmark Pablo Bulaong y Marietta A. Pakaigue. "REMOTE SENSING APPLICATION OF THE GEOPHYSICAL CHANGES IN THE COASTLINES AND RIVERS OF ZAMBALES, PHILIPPINES". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (23 de junio de 2016): 379–86. http://dx.doi.org/10.5194/isprs-archives-xli-b8-379-2016.
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Geophysical changes in river outlet, river upstream and coastlines near the rivers of Bucao and Santo Tomas in Zambales, Philippines were analyzed using the Google Earth’s historical satellite imageries from 2004 to 2013. Data in 2015 were gathered from in situ field measurements ground validation. The study aimed to measure and determine changes in the width of river outlet, width of river bank upstream and shifting of coastline. <br><br> Results revealed that there was a decrease and increase in the width size of the Bucao and Santo Tomas river outlets, respectively during the study period. Geophysical changes occurred in the two rivers due to the continuous supply of lahar as an after effect of the Mount Pinatubo eruption in 1991. Coastline positions near the two rivers also changed. The highest rate of erosion along the coastal area was prevalently observed near the river outlet of both rivers. Moreover, accretion was observed in the coastline of Santo Tomas and erosion phenomenon was observed in the North and South coastlines of Bucao River. The shifting was caused by natural processes such as erosion, sedimentation and natural calamities as well as anthropogenic processes such as reclamation/quarrying. Occurrence of erosion and sedimentation played active roles in the changes of coastlines during the study period. <br><br> Furthermore, the upstream of the Bucao river changed physically due to deposits of lahar present in the upstream which are being discharged directly and continuously going down to the river. Generally, the width of the Bucao River upstream decreased its size because of the accumulated sediment in the riverbank. On the other hand, the observed erosion is caused by high velocity of river during heavy rains and typhoons. The width of the Santo Tomas river bank upstream did not change due to the construction of concrete dikes which prevent the lahar-filled river from breaching the embankment and flooding the agricultural, residential and commercial areas near the river.
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Paz-Alberto, Annie Melinda, Melissa Joy M. Sison, Edmark Pablo Bulaong y Marietta A. Pakaigue. "REMOTE SENSING APPLICATION OF THE GEOPHYSICAL CHANGES IN THE COASTLINES AND RIVERS OF ZAMBALES, PHILIPPINES". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B8 (23 de junio de 2016): 379–86. http://dx.doi.org/10.5194/isprsarchives-xli-b8-379-2016.
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Geophysical changes in river outlet, river upstream and coastlines near the rivers of Bucao and Santo Tomas in Zambales, Philippines were analyzed using the Google Earth’s historical satellite imageries from 2004 to 2013. Data in 2015 were gathered from in situ field measurements ground validation. The study aimed to measure and determine changes in the width of river outlet, width of river bank upstream and shifting of coastline. <br><br> Results revealed that there was a decrease and increase in the width size of the Bucao and Santo Tomas river outlets, respectively during the study period. Geophysical changes occurred in the two rivers due to the continuous supply of lahar as an after effect of the Mount Pinatubo eruption in 1991. Coastline positions near the two rivers also changed. The highest rate of erosion along the coastal area was prevalently observed near the river outlet of both rivers. Moreover, accretion was observed in the coastline of Santo Tomas and erosion phenomenon was observed in the North and South coastlines of Bucao River. The shifting was caused by natural processes such as erosion, sedimentation and natural calamities as well as anthropogenic processes such as reclamation/quarrying. Occurrence of erosion and sedimentation played active roles in the changes of coastlines during the study period. <br><br> Furthermore, the upstream of the Bucao river changed physically due to deposits of lahar present in the upstream which are being discharged directly and continuously going down to the river. Generally, the width of the Bucao River upstream decreased its size because of the accumulated sediment in the riverbank. On the other hand, the observed erosion is caused by high velocity of river during heavy rains and typhoons. The width of the Santo Tomas river bank upstream did not change due to the construction of concrete dikes which prevent the lahar-filled river from breaching the embankment and flooding the agricultural, residential and commercial areas near the river.
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VASILEVSKAYA, L. N., I. A. LISINA y D. N. VASILEVSKII. "INFLUENCE OF LARGE-SCALE ATMOSPHERIC PROCESSES ON SEASONAL RUNOFF OF LARGE SIBERIAN RIVERS". Meteorologiya i Gidrologiya, n.º 10 (2021): 36–47. http://dx.doi.org/10.52002/0130-2906-2021-10-36-47.
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Based on daily runoff volumes of four large Siberian rivers (the Ob, Yenisei, Lena, and Kolyma) for 1936-2018, the regime and changes in the total annual and seasonal runoff are analyzed. High synchronous and asynchronous correlations between monthly river runoff and atmospheric circulation indices of hemispheric and regional scales are revealed. In recent decades, the total annual runoff and its variations have increased (the rate of increase is most pronounced for the Kolyma River). A change in water content within a year is heterogeneous: weak positive trends are characteristic of the spring flood runoff and the summer-autumn period, and a significant increase occurred in the winter months. High correlations with a 1-8-month shift made it possible to identify the most informative regions, the atmospheric circulation over which makes a certain contribution to the variance of river runoff.
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Hashimoto, Akihiro, Akira Tai y Toshimitsu Komatsu. "Clarification and Application of Inundation Processes in Basins with Insufficient Observation Devices Installed". Journal of Disaster Research 10, n.º 3 (1 de junio de 2015): 495–502. http://dx.doi.org/10.20965/jdr.2015.p0495.
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Torrential rain possibly due to climate change has begun causing disasters annually, with water and sediment resulting from heavy rainfall in relatively narrow upper basins often arising in short periods. Because most of these basins are traversed by class B rivers administered by local governments, data on disasters are not accumulated comprehensively. Targeting the Sumiyo River basin on Amami Oshima Island, this study involved field surveys and numerical simulations to clarify inundation features in areas short on data based on hearings from investigation results. Calculation results have reproduced water levels, together with hearing results, including the initial inundation process in which rain water flowed directly from mountain slopes and later inundation processes mainly caused by overtopping and dike breach on the Sumiyo River. (Note that river bed fluctuations and dike breach progress are to be addressed in the future.)
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Zhang, Junhong, Luojie Feng, Sujie Chen, Tao Huang, Lu Chen, Dangwei Wang, Minglong Dai y Dongdong Zhang. "Impoundment Impact of the Three Gorge Reservoir on the Hydrological Regime in the Lower Han River, China". Water 10, n.º 11 (16 de noviembre de 2018): 1670. http://dx.doi.org/10.3390/w10111670.
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Reservoir regulation has been playing an increasingly important role in water resources development and its influence on the hydrological processes of downstream tributaries has attracted much attention. The lower Han River is selected as a case study to examine the hydrological and hydraulic influence of the upstream flow regulation of the Three Gorges Reservoir (TGR) in the middle Yangtze River, China. Based on a hydrodynamic model and the observed data, the hydrological processes in the lower Han River were simulated and their changes were analyzed under the impoundment influences of the TGR. The results indicated that there were obviously hydrological changes in the lower Han River after the TGR operation. The decreased stage downstream the TGR during the impounding periods of the TGR resulted in an increase in the stage difference, current speed, hydraulic gradient and the discharge ratio. In addition, the stage difference between the two rivers was decreased during the periods of water compensation from the TGR, which led to the outflow congestion in the lower Han River. The hydrological changes in the lower Han River were the response to the flow regulation of the TGR and the inflow of the two rivers. The variation in the rating curve in the lower Han River mainly resulted from the stage difference between the two rivers during the dispatching periods of the TGR. These results help to explain the hydrological variability under the impounding influence of the TGR for the lower Han River and they can be extended to other river tributaries downstream to the reservoirs.
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Xue, D., P. Boeckx y Z. Wang. "Nitrate sources and dynamics in a salinized river and estuary – a δ<sup>15</sup>N–NO<sub>3</sub><sup>−</sup> and δ<sup>18</sup>O–NO<sub>3</sub><sup>−</sup> isotope approach". Biogeosciences 11, n.º 20 (31 de octubre de 2014): 5957–67. http://dx.doi.org/10.5194/bg-11-5957-2014.
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Abstract. To trace NO3− sources and assess NO3− dynamics in salinized rivers and estuaries, three rivers (Haihe River: HH River, Chaobaixin River: CB River and Jiyun River: JY River) and two estuaries (HH Estuary and CJ Estuary) along the Bohai Bay (China) have been selected to determine dissolved inorganic nitrogen (DIN: NH4+, NO2− and NO3−. Upstream of the HH River, NO3− was removed 30.9 ± 22.1% by denitrification, resulting from effects of the floodgate: limiting water exchange with downstream and prolonging water residence time to remove NO3−. Downstream of the HH River NO3− was removed 2.5 ± 13.3% by NO3− turnover processes. Conversely, NO3− was increased 36.6 ± 25.2% by external N source addition in the CB River and 34.6 ± 35.1% by in-stream nitrification in the JY River. The HH and CY Estuaries behaved mostly conservatively excluding the sewage input in the CJ Estuary. Hydrodynamics in estuaries has been changed by the ongoing reclamation projects, aggravating the loss of the attenuation function of NO3− in the estuary.
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Ahluwalia, Rajeev Saran, S. P. Rai, Sanjay K. Jain, Bhishm Kumar y D. P. Dobhal. "Assessment of snowmelt runoff modelling and isotope analysis: a case study from the western Himalaya, India". Annals of Glaciology 54, n.º 62 (2013): 299–304. http://dx.doi.org/10.3189/2013aog62a133.
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AbstractThe major river systems of India, i.e. the Indus, Ganga and Brahmaputra river systems originating in the Himalayan region, are considered the lifeline of the Indian subcontinent. The main sources maintaining the flow of the Himalayan rivers are snow/glacial melt runoff, rainfall runoff and base flow. The Beas River originates from Beas Kund Glacier in the Himalayan region and flows down to join the Sutlej River, which is a tributary of the Indus River system. In the present study two approaches, namely hydrologic modelling and isotope analysis, have been applied to estimate the contribution of snow and glacier melt. Samples of streamflow, rainfall and snow for isotopic analysis were collected daily from April to September and weekly from October to March during 2010 and 2011. The isotope analysis of samples reveals that the snow/glacier melt contribution to the Beas River at Manali is 50% of the total flow during these 2 years. Snowmelt runoff modelling has been carried out using the SNOWMOD model, and the snow/glacier melt runoff contribution is calculated to be 52% of the total flow during the same period. These findings indicate that the results obtained from the two approaches are similar.
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Chalov, R. S. "CHANNEL PROCESSES MANAGEMENT, HUMAN IMPACTS ON RIVER CHANNELS AND HYDROECOLOGICAL SAFETY PROBLEMS". Bulletin of Udmurt University. Series Biology. Earth Sciences 32, n.º 2 (5 de julio de 2022): 184–91. http://dx.doi.org/10.35634/2412-9518-2022-32-2-184-191.
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Conditions for applying the principles of channel processes management to ensure hydroecological safety in the use of water and other river resources, exploitation of rivers as waterways are considered in the paper. It is shown that management of channel processes to the greatest extent is applied on navigable rivers, on urbanized areas and rivers in economically developed regions. The main management techniques are channel dredging and stabilization, guide dams, and bank protection measures. Development of channel quarries makes such a serious influence on channel processes that it requires the adoption of compensatory measures to prevent adverse environmental consequences. In other cases, it is necessary to take into account the current state of channels and predictive estimates of channel changes in sections where the designed facilities are located. Adverse environmental consequences of any technogenic impacts on rivers are associated with insufficient consideration of channel processes and even their complete disregard.
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Marston, Richard. "Changes in Geomorphic Processes in the Snake River Following Impoundment of Jackson Lake and Potential Changes Due to 1988 Fires in the Watershed". UW National Parks Service Research Station Annual Reports 14 (1 de enero de 1990): 85–90. http://dx.doi.org/10.13001/uwnpsrc.1990.2891.
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Rivers are dynamic features of the landscape whose characteristics vary over time and space with changes in environmental controls. The Snake River in Grand Teton and Yellowstone National Parks has responded to the impoundment of Jackson Lake and subsequent changes in the operation of Jackson Dam. The 1988 fires in the Snake River watershed may also affect channel morphology. Whether a new system equilibrium might be attained and the extent to which the effects of past events might persist in the fluvial landscape, are two critical questions that need to be addressed for the Snake River. The stability of the Snake River, in turn, will affect the quantity and quality of riparian and aquatic habitats judged to be critical to fish and wildlife in the parks. Stream channel dynamics of the Snake River in Grand Teton National Park are also intimately tied to issues of floodplain delineation and management, the aesthetic value of rivers, and the quality of recreational float trips.
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Amissah, Gabriel Jonathan, Tímea Kiss y Károly Fiala. "Active point bar development and river bank erosion in the incising channel of the lower Tisza river, Hungary". Landscape & Environment 13, n.º 1 (20 de diciembre de 2019): 13–28. http://dx.doi.org/10.21120/le/13/1/2.
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The development of point-bars and bank erosion are critical near-bank processes, as they indicatethe sediment and hydraulic regime of a river system, thus, they refer to the equilibrium conditions ofa channel. However, throughout history, rivers have been modified for various benefits which changethe development of point-bars and the rate of bank erosion. In the Lower Tisza River (Hungary), riverregulations influenced the channel and floodplain development, altering the natural fluvial processes.The aim of the research was to determine the rate of near-bank processes and to make trajectory forfuture river evolution to support future engineering works. The bank erosion and point-bar developmentat human-influenced and freely meandering sections of the Tisza River were monitored since 2011.Behind a collapsed revetment, the bank erosion rate was 0.6 m/y, while at a freely meandering section itwas 2.3 m/y. The studied point-bars are located in revetted and freely meandering sections. Their surfaceeroded within the period. These intensive erosional processes refer to an incising meandering channel,which must be considered during future planning of in-channel structures (e.g. revetments, bridges),thus, geomorphic methods must be considered in any river engineering scheme.
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Chapra, S. C. y 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, n.º 2-3 (1 de abril de 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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Sergaliev, N. Kh y K. M. Akhmedenov. "Dynamics of river bed processes of the Ural River in Western Kazakhstan". Water Practice and Technology 9, n.º 4 (1 de diciembre de 2014): 457–63. http://dx.doi.org/10.2166/wpt.2014.050.
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A retrospective analysis of river bed deformation over a 34-year period has been carried out for the first time for the Ural River in West Kazakhstan, in different environmental conditions. Horizontal shifts of the Ural riverbed have been defined according to space shots made in 2012. Erosion risk, as a result of horizontal displacement of the river bed has been determined in West Kazakhstan. A geomorphologic description of the Ural River bed and floodplain, and the dynamics of channel processes in the river within West Kazakhstan are given. The probable pattern of channel realignments for the Ural River has been determined. The paper describes the results of map compilation and related data consolidation with respect to the horizontal river bed shifts in West Kazakhstan, and includes a review of characteristics of the hydrologic and hydrochemical regimes of the river. The main river bed types, which are typical of flat terrain, are also discussed. West Kazakhstan is a region where there is medium-level ecologic stress on the river beds and floodplains.
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Varenov, Aleksandr, Anna Tarbeeva, Dmitriy Botavin, Nadezhda Mikhaylova, Leonid Turykin y Aleksandra Chalova. "Channel processes of a small river heavily modified by human activities". E3S Web of Conferences 163 (2020): 06011. http://dx.doi.org/10.1051/e3sconf/202016306011.
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Widely-spread small rivers are very poorly studied in relation to channel processes. The influence of local factors, high sensitivity to human impact, close connection with basin processes, and relatively low rates of channel changes distinguish them from medium and large ones and make it necessary to form a special approach to studies. Based on collection of long-term maps and local residents’ interviews, we reconstructed the transformation of channels in the Kudma River basin (the Volga Upland) for the last 200 years. Based on the bank erosion monitoring during 2011-2019 the modern rates of channel changes were revealed. We found that significant human impact is associated with the artificial channels cutoffs and draining of ponds which led to channel incision of the Kudma and Ozerka Rivers in the middle reaches and the transformation of floodplain into terrace. Agriculture development caused siltation of the upper reaches of rivers. The rivers of the forested part of the basin experienced the least human changes. From 2011 to 2019 the maximum rates of bank erosion were found to be within range of 0.3 to 2.7 m/year and supposed to be driven by peak water discharge.
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Berkovich, K. M., L. V. Zlotina y L. A. Turykin. "Riverbank erosion: factors, mechanism, human activity". Geomorphology RAS, n.º 2 (26 de abril de 2019): 3–17. http://dx.doi.org/10.31857/s0435-4281201923-17.
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The riverbank erosion produces a great risk for the urban development, structures and communications located on the banks. Bank erosion, as an integral part of the lateral river channel migrations, is a multi-factorial phenomenon. Empirical evidence suggests that the riverbank erosion depends on the size of the river, the morphology of the bends, water flow; however, a big role plays erosion resistance of the banks, due to their structure and vegetation. It varies at changeable riverbank soils wetting in accordance with the hydrological regime of the river. Human activity contributes significantly to the intensification of lateral migrations, especially the construction of reservoirs that change the hydrological regime of rivers and sediment transport. Incision, daily flow regulation, redistribution of annual runoff, reducing the sediment load are the main factors that intensify the riverbank erosion. As an example, the situated downstream of the dam sections of the Volga River and Sheksna River in the Rybinsk City were examined and all these factors were revealed there themselves clearly. Considering these factors allowed predicting the riverbank erosion and provided the basis for bank protection program.
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Kosteniuk, Liudmyla. "Features of the hydrological regime and channel processes on the Iltsya river (Chornyy Cheremosh basin)". Scientific Herald of Chernivtsi University. Geography, n.º 824 (30 de enero de 2020): 37–47. http://dx.doi.org/10.31861/geo.2020.824.37-47.
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This publication analyzes the features of the hydrological regime and channel processes of the Iltsya River, based on regular observations and during the expedition trip in June 2019.The schemes of basin distribution and geomorphological zoning of the studied object, curves of connection of water consumption and levels Q = f (H), graphs of the course of maximum, average and minimum water levels, and also cross sections on key sites are presented in the work. Conditions of channel formation of natural watercourses are a complex and multilateral process which is closely connected with natural features of the territory of their basin.The main factors of the natural channel process are the geological structure of the area, sediment flow and grain size. These factors are key, however, the processes of channel formation are also influenced by additional factors that are temporary or local in nature. At the same time, we should not forget about the influence of the anthropogenic factor, the results of which for the basins of small rivers can sometimes even dominate for some time over the main ones mentioned above. All these factors not only affect the channel process, but also difficult to interact with each other. The geological structure, including the lithology of rocks, as well as the relief of the territory, have a direct impact on the shape of the valley, the longitudinal profile, the composition of channel-forming sediments, and hence the stability of the channel. Water runoff is the main active factor that depends on the hydrological regime of the river and determines its water content and size. The nature of the sediments and their regime is a factor that determines the rate and direction of vertical and horizontal deformations of the channel. The object of our study - is the river Iltsya, a small left tributary of the ChornyyCheremosh, which is characterized by specific geological conditions, and therefore significantly different from other small rivers in the region, including neighboring tributaries of the main river (ChornyyCheremosh). The second feature of the studied river is that the lower part of its basin is located within the Vorokhta-Putilsky ancient terraced lowlands, while the sources are formed within the Pokutsko-Bukovynian Carpathians, which in turn determines a certain specificity in the formation of its channel. This geological and geomorphological feature of the Iltsya river basin distinguishes it among numerous similar small rivers of this region of the Ukrainian Carpathians. Summarizing all the above, we have made some conclusions, the basin of the river Iltsya is currently little studied, both in terms of hydrological regime, channel processes and geomorphological studies, although in fact it is quite interesting and not typical of project, which raises many questions that require more detailed study. The presence of a long series of observations, allows us to identify general tendencies to the gradual incision of the channel in the area of the hydropost, although with little intensity. Visual inspection showed more manifestations of horizontal transformations associated with the movement of alluvial ridges and erosion of the shores. The greatest feature of the Iltsya river basin is the polymorphic formation of its channel system, because within the Vorokhta-Putil lowlands the river Iltsya and VelykyiRosysh occupy a wide valley of the ancient pliocene river, and this nuance has the greatest influence on the nature of riverbeds within its limits.
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Kiraga, Marta. "Hydroelectric Power Plants and River Morphodynamic Processes". Journal of Ecological Engineering 22, n.º 7 (6 de julio de 2021): 163–78. http://dx.doi.org/10.12911/22998993/139068.
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Bengtsson, Lars. "Preface: Hydroclimatological processes in northern river basins". Hydrology Research 44, n.º 1 (1 de febrero de 2013): 1. http://dx.doi.org/10.2166/nh.2012.002.
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Mikhailova, M. V. "Processes of seawater intrusion into river mouths". Water Resources 40, n.º 5 (septiembre de 2013): 483–98. http://dx.doi.org/10.1134/s0097807813050059.
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