Articoli di riviste sul tema "Rivers"
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1
Guo, Si Zhe, Qing Ping Wang e Ming Ming Hou. "A Discussion on the Construction of Information Integration Based on the Integrated Development and Management of International River". Advanced Materials Research 989-994 (luglio 2014): 5267–72. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.5267.
Testo completoAbstract (sommario):
Integrated development and management of international rivers requires objectively international river’s information integration.Based on the analysis of the connotation and requirement of integrated development and management of international rivers, the article point out that the information integration is the basis and means of the of integrated development and management of international rivers. And then analyze how to utilize modern information technology to build information management system of international river to achieve international river’s information sharing and scientific decision-making. Finally, analyze the factors affecting international river information integration.
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Anwari, Muhammad Rizqan, e J. C. Heldiansyah. "MUSEUM SUNGAI DI BANJARMASIN". JURNAL TUGAS AKHIR MAHASISWA LANTING 10, n. 2 (31 agosto 2021): 240–52. http://dx.doi.org/10.20527/jtamlanting.v10i2.871.
Testo completoAbstract (sommario):
The river museum in Banjarmasin is a place to capture the existence of rivers in Banjarmasin. The existence of rivers decrease in function and existence until it turns into a dead river. The river's existence is influenced by river culture. River culture is formed by people whose lives depend on rivers. Therefore, to preserve the information related to this matter, efforts are made by preserve and communicate it to the public by create a river museum.To create a river museum, the point of view concept is used which tells the museum narrative based on time, place, and actor. This concept is supported by the application of the sense of place method. Thus, river museums can make visitors educated and empathize with rivers in Banjarmasin.
3
Rocha da Silva, Maria do Socorro, Eduardo Antonio Ríos-Villamizar, Hillândia Brandão da Cunha, Sebastião Átila Fonseca Miranda, Sávio José Filgueiras Ferreira, Sergio R. Bulcão Bringel, Núbia Abrantes Gomes, Domitila Pascoaloto e Luana Monteiro Silva. "A CONTRIBUTION TO THE HYDROCHEMISTRY AND WATER TYPOLOGY OF THE AMAZON RIVER AND ITS TRIBUTARIES". Caminhos de Geografia 20, n. 72 (23 dicembre 2019): 360–74. http://dx.doi.org/10.14393/rcg207246295.
Testo completoAbstract (sommario):
The geological diversity of the Amazon Basin, as well as the pluvial regime, influences the characteristics of the waters. To know the water types of the rivers of the Amazon basin, 288 superficial water samples were collected, 94 of them along the Amazon River and 194 in their tributaries, from March 2009 to September 2012. The physical, chemical, and physicochemical properties were analyzed. Rivers with pH between 6.5 and 7.6 and electrical conductivity (40.00 - 80.00 μS cm-1) are water bodies that are influenced by the Andean region (e.g., the Amazon River and some of its right bank tributaries). On the other hand, the rivers with pH in the range of 3.5 to 5.5 and conductivity <30.00 μS cm-1, which are Amazon River’s left bank tributaries, reflect the characteristics of the Guiana Shield. The rivers with pH (6.0 to 7.0), low ionic charge, and conductivity <40.0 μS cm-1, such as the lower Amazon River’s right bank tributaries (Tapajos and Xingu) which are influenced by the Central Brazilian Shield, and also the middle/upper Amazon River’s right bank tributaries (Tefé, Coari and Jutaí).
4
Kuparinen, Anna, e Juha Merilä. "Variation in the timing of river entry of Atlantic salmon (Salmo salar L.) in the Baltic". Current Zoology 55, n. 5 (1 ottobre 2009): 342–49. http://dx.doi.org/10.1093/czoolo/55.5.342.
Testo completoAbstract (sommario):
Abstract The timing of river entry in the Atlantic salmon is known to depend on genetic, demographic and environmental factors, but little is known about the relative magnitude of among population and among year variation and covariation in this respect in natural state Atlantic salmon rives. To investigate this, variability in the timing of river entry in three historical Finnish Atlantic salmon populations were analyzed using salmon trap data collected during 1870 - 1902. The analyses reveled that 1) the timing of river entry differed substantially and consistently among the rivers, and that 2) variation among the rivers was much larger than variation among years. Annual variations were not explained by regional environmental conditions, whereas in one river the timing of the local flood peak was a significant predictor of the timing of river entry. Differences in the timing of salmon entry to geographically closely situated rivers suggests that a regionally fixed opening date for coastal fisheries might not be the best management strategy as it may lead to uneven exploitation of salmon populations from different rivers
5
Sharma, Subodh, e Ram Devi Tachamo Shah. "Major stressors influencing the river ecosystems of Far and Mid Western Development Regions of Nepal". Current World Environment 14, n. 2 (16 agosto 2019): 231–38. http://dx.doi.org/10.12944/cwe.14.2.07.
Testo completoAbstract (sommario):
Maintaining healthy river ecosystem is essential both from aquatic biodiversity conservation perspective as well as for the socio-cultural and economic development of nations all over the world. Many rivers in Nepal have largely been modified with the purpose of supplying drinking water, irrigating agricultural lands, producing hydro-electricity, and operating water mills. During the process, rivers are channelized and the river bed materials are removed. Such activities of river bed excavation have changed both the natural flow regimes and morphological characteristics of rivers. Studies on the impacts caused by such stressors on river ecosystems are lacking in the context of Nepalese river systems. Therefore we have assessed how these stressors might change the faunal composition of benthic macroinvertebrates in headwaters of the Western region of Nepal. The study was conducted in the headwaters of rivers of Mahakali and Karnali rivers. Habitat specific benthic macroinvertebrates were sampled from 33 sites seasonally in the year 2016 and 2017. Physical characteristics of rivers including river bed composition, water abstractions and other local stressors including waste dumping and washing-bathing were noted in the field. The study showed that macroinvertebrates community structures were significantly different in the habitat modified sites compared to reference sites. In general, abstracted sites coupled with river bed removals were found to be colonized by fewer taxa with high dominance of pool preference biota such as genera of Mayflies (Torleya spp., Caenis spp., Choroterpes spp.) and families of true flies (Chironomidae and Ceratopogoniidae). Macroinvertebrates’ abundance was significantly lower in the habitat modified sites. This study envisages that maintaining river’s habitats with minimal flows all round year could preserve ecological integrity of river systems.
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Akers, Mary Anne Alabanza. "Rivers Lost, Rivers Regained: Rethinking City–River Relations". Journal of Urban Technology 25, n. 2 (3 aprile 2018): 163–65. http://dx.doi.org/10.1080/10630732.2018.1472436.
Testo completo
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Brett-Crowther, Michael. "Rivers lost, rivers regained: rethinking city-river relations". International Journal of Environmental Studies 75, n. 2 (14 settembre 2017): 380–84. http://dx.doi.org/10.1080/00207233.2017.1376861.
Testo completo
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Kim, Dongkyun, Tae-Sun Park, Jeryang Park e Seung-Oh Lee. "A river environment index for Korean national rivers: rationale, methods and application". Water Policy 16, n. 3 (30 gennaio 2014): 481–500. http://dx.doi.org/10.2166/wp.2014.108.
Testo completoAbstract (sommario):
A methodology for indexing river environmental condition was developed and applied to 269 subsections of national rivers located in the Republic of Korea, based on a river management perspective. The resulting index has been called the River Environment Index (REI). To develop the methodology, a total of 32 factors related to a river's environment were initially investigated, from which 16 were chosen based on their measurability, predictability, measurement regularity and obtainability. Then, using the analytical hierarchy process (AHP) and based on a survey of 62 river management experts in Korea, the weighting coefficient for each of the 16 factors was determined. Finally, the REI values were estimated by linearly combining the 16 measured factors for the 269 river subsections and mapped using a geospatial information system platform. We expect that the REI will be used to increase the efficient allocation of national budgets for environmentally-friendly river restoration projects of the country's national rivers. Through this new index, prioritization of these rivers will be made using an holistic river management perspective.
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Surjono, Sugeng S., Erlangga Wijaya, Andreas Yufianto e Arfian Firmansyah. "THE POTENTIAL OF LAHARIC FLOWS DISASTER ALONG GENDOL AND OPAK RIVERS, YOGYAKARTA, INDONESIA". ASEAN Engineering Journal 4, n. 3 (1 dicembre 2015): 16–26. http://dx.doi.org/10.11113/aej.v4.15541.
Testo completoAbstract (sommario):
Gendol River flows from the south slope of Merapi Volcano meets Opak River to form a wider river, namely Opak River. In the upper stream of Opak and Gendol Rivers area, volcanic material accumulated from the 2010 Merapi Volcano eruption that ready to flow downstream through both rivers. The total amount of volcanic material in the Merapi’s peak area is predicted as much as 140 million cubic meters, part of it is distributed in the upper stream of both rivers. In the downstream area, the Opak River flows nearby the great Prambanan Temple and across the main road of Yogyakarta-Surakarta capital cities.To know the laharic flow disaster potential of both rivers, collecting of primary data along the river flows is needed in order to understand the characteristic and mechanism of laharic flows. DEM analysis combined with ArcGIS 9.3 tools are applied to know the additional volume of volcanic material after 2010 Merapi Volcano eruption. The triggering factor of laharic flows in the study area including the runoff, soil water saturation rate, rainfall and soil water saturation time are mathematically calculated based on data analysis on soil mechanics.Based on the calculation of thickness and distribution in the Merapi Peak area, the mass volcanic material that is ready to be transported as the laharic flows through Gendol and Opak Rivers is around 14,745,496 m3. The volcanic material can transform into laharic flows by initial runoff if the soil water saturation column reach at least 5.96 m. With the rainfall average in the southern part of Merapi Volcano is 17.32 mm/day, that saturation value can be reached by 21.8 hours in the upper stream area and 17.67 hours in the lower part area. If the laharic flows occurred, the damage would happen in villages along the rivers, Prambanan Temple, and Opak River’s Bridge connecting Yogyakarta-Surakarta main road.
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Hashim, Sarfraz, Xie Yuebo, Muhammad Saifullah, Ramila Nabi Jan e Adila Muhetaer. "Integrated Evaluation of Urban Water Bodies for Pollution Abatement Based on Fuzzy Multicriteria Decision Approach". BioMed Research International 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/327280.
Testo completoAbstract (sommario):
Today’s ecology is erected with miscellaneous framework. However, numerous sources deteriorate it, such as urban rivers that directly cause the environmental pollution. For chemical pollution abatement from urban water bodies, many techniques were introduced to rehabilitate the water quality of these water bodies. In this research, Bacterial Technology (BT) was applied to urban rivers escalating the necessity to control the water pollution in different places (Xuxi River (XXU); Gankeng River (GKS); Xia Zhang River (XZY); Fenghu and Song Yang Rivers (FSR); Jiu Haogang River (JHH)) in China. For data analysis, the physiochemical parameters such as temperature, chemical oxygen demand (COD), dissolved oxygen (DO), total phosphorus (TP), and ammonia nitrogen (NH3N) were determined before and after the treatment. Multicriteria Decision Making (MCDM) method was used for relative significance of different water quality on each station, based on fuzzy analytical hierarchy process (FAHP). The overall results revealed that the pollution is exceeding at “JHH” due to the limit of “COD” as critical water quality parameter and after treatment, an abrupt recovery of the rivers compared with the average improved efficiency of nutrients was 79%, 74%, 68%, and 70% of COD, DO, TP, and NH3N, respectively. The color of the river’s water changed to its original form and aquatic living organism appeared with clear effluents from them.
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Boymurodov, Kh, e S. Suyarov. "Bivalve mollusk fauna and ecological groups of Unionidae and Corbiculidae families in natural and artificial reservoirs of Uzbekistan". E3S Web of Conferences 265 (2021): 01014. http://dx.doi.org/10.1051/e3sconf/202126501014.
Testo completoAbstract (sommario):
The length of the rivers in Uzbekistan and the presence of all the biotopes in the mollusks have made they a favourable reservoir for the mollusks. However, it should be noted that all species in the rivers differ in their density. Rivers and fishery farms play a great role in formation of bivalve mollusks fauna in the canals. It was studied the fishery farms of the Syrdarya River and its surroundings have a major effect on the fauna of the Mirzachul and South Mirzachul canals; the Zarafshan River’s effect on spreading of bivalve mollusks in the Dargom and Eskiankhor canals; the Amudarya River and its surrounding areas influence of fishery farms on the fauna of the Amu-Bukhara, Kizketgan and Karshi main canals. Colletopterum family breeds in the water studied, do not show any superiority in natural or artificial reservoirs compared to other breeds. Three species of these family are included in the Red Book of the Republic of Uzbekistan (C.baсtrianum, C. cyreum sogdianum, C. kokandicum). C. Bactrianum can be found only in rivers in the middle Zarafshan and Amudarya, in the Syrdarya river (Syrdarya Region only), in the reservoir and in the fishery farms only in Chelak, and the canals only in the Tuyatortar and Mirzachul canals.
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Peng, Jing, Shaoming Li e Lan Qi. "Study on river regulation measures of dried-up rivers of Haihe River basin, China". Water Science and Technology 67, n. 6 (1 marzo 2013): 1224–29. http://dx.doi.org/10.2166/wst.2013.680.
Testo completoAbstract (sommario):
In recent years, the ecological environment of plain rivers within Haihe River basin is questionable because of severe water shortages. Most of the rivers dry up regularly and it is therefore necessary to take measures to improve the river ecological environment. Meanwhile, flood control is the principal function for most of the dried-up rivers, so river regulation works for flood control also should be undertaken. In this paper, some measures of river regulation were selected applied to the Haihe River basin, taking these measures not only ensure the river security but also realize its ecological benefit. Examples of the application of selected measures for the representative rivers, Yongding River and Hutuo River, both located within the Haihe River basin, are also assessed. These measures provide practical solutions to ecological and flood control problems of dried-up rivers, are generic in nature, and could therefore be applied to other same type rivers.
13
Pears, B., A. G. Brown, J. Carroll, P. Toms, J. Wood e R. Jones. "Early Medieval Place-Names and Riverine Flood Histories: A New Approach and New Chronostratigraphic Records for Three English Rivers". European Journal of Archaeology 23, n. 3 (20 marzo 2020): 381–405. http://dx.doi.org/10.1017/eaa.2019.72.
Testo completoAbstract (sommario):
Environmental information from place-names has largely been overlooked by geoarchaeologists and fluvial geomorphologists in analyses of the depositional histories of rivers and floodplains. Here, new flood chronologies for the rivers Teme, Severn, and Wye are presented, modelled from stable river sections excavated at Broadwas, Buildwas, and Rotherwas. These are connected by the Old English term *wæsse, interpreted as ‘land by a meandering river which floods and drains quickly’. The results reveal that, in all three places, flooding during the early medieval period occurred more frequently between AD 350–700 than between AD 700–1100, but that over time each river's flooding regime became more complex including high magnitude single events. In the sampled locations, the fluvial dynamics of localized flood events had much in common, and almost certainly differed in nature from other sections of their rivers, refining our understanding of the precise nature of flooding which their names sought to communicate. This study shows how the toponymic record can be helpful in the long-term reconstruction of historic river activity and for our understanding of past human perceptions of riverine environments.
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Oliveira, Paula Caroline dos Reis, Marcos Gomes Nogueira e Luciana Pinto Sartori. "Differential environmental impacts on small and medium size rivers from center of São Paulo State, Brazil, and regional management perspectives". Acta Limnologica Brasiliensia 26, n. 4 (dicembre 2014): 404–19. http://dx.doi.org/10.1590/s2179-975x2014000400008.
Testo completoAbstract (sommario):
AIM: This study aimed to evaluate, comparatively, the influence of distinct environmental impacts in the watershed on the rivers Capivara, Lavapés, Araquá and Pardo and the transference of effects downstream. METHODS: The limnological/water quality study was carried out in rainy (March/2007) and dry (September/2007) seasons, considering 17 sampling stations. RESULTS: Variables such as channel width and depth, water velocity and temperature increased towards the river's mouth; water transparency, velocity and dissolved oxygen were higher in the upstream regions. Light penetration was total at most sampling stations and pH was predominantly acid. The sampling stations impacted by pollution sources, Lavapés and Araquá Rivers, exhibited higher values of electric conductivity, suspended solids, total nitrogen, nitrate, nitrite, ammonium, total dissolved phosphorus, BOD, and thermotolerant coliforms. Higher values of electric conductivity, turbidity and suspended solids were observed in the rainy season, whereas higher chlorophyll concentrations occurred in the dry season. The Lavapés River exhibits the worst environmental condition, while Capivara River is under better state of conservation. This study shows that it is urgent the implementation of measures for preservation and restoration of these regional aquatic ecosystems. All studied rivers were influenced by seasonal variation, sewage discharges and by watershed use and occupation. The TSI is a good analysis tool. The studied rivers export organic matter and TN, TP and SS loads to Tietê and Paranapanema rivers. CONCLUSIONS: This study show the importance of river management and that the accelerated degradation of the river systems indicates the little progress of the Brazilian legislation in terms of preservation and good management practices and that the interface between science, law, management and conservation need to be improved.
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Obodovskyi, О., K. Danko e O. Pochaievets. "THE TOTAL HYDROPOWER POTENTIAL OF THE UKRAINIAN CARPATHIANS RIVERS". Bulletin of Taras Shevchenko National University of Kyiv. Geography, n. 66-67 (2017): 15–29. http://dx.doi.org/10.17721/1728-2721.2017.66.2.
Testo completoAbstract (sommario):
The results of calculating the total hydropower potential of Ukrainian Carpathians rivers were presented in the article. The total hydropower potential of specific sections of the rivers was calculated. The boundaries of the sections were identified by the changing characteristics of hydraulic channels.Calculation of the total hydropower potential of the rivers of the Carpathian region for Tisa, Siret, Prut and Dniester river basins, which have a length over 10 km were executed. There 334 rivers in the region were examined, 1,247 sections were identified. Total hydropower potential of Ukrainian Carpathians rivers are 2340531 kW or 2340,5 MW. The volume potential annual capacity consists 20.5 billion KWh / year. The largest hydroelectric capacity is typical for the Tisza river basin (within Ukraine). Their total hydropower potential amounts 1092,4 MW, provides 46.4% all hydropower capacity of all Carpathian rivers of Ukraine. Hydroelectric power of Dniester river basin is 34,9% (321 MW) of the total general hydropower potential of the rivers of the Carpathian region of Ukraine. Part of the hydropower potential of the rivers of Prut river basin amounts 17,2% (404 MW) and of the Siret river basin amounts 1,01% (24 MW). Total hydropower potential of the rivers of Ukrainian Carpathians proportionate to production capacity Dnipro hydropower cascade. In addition, total hydropower potential of rivers Ukrainian Carpathians exceeds economically effective hydropower potential of rivers in Ukraine to 3 bln. kWh / year, which is 17.5 billion. kWh / year.
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Dombrovskiy, K. O., e A. F. Rylsky. "Micro- and macrofauna of benthic invertebrates of the estuary section of the Mokra Moskovka, a small river in the City of Zaporizhzhia". Ukrainian hydrometeorological journal, n. 29 (21 luglio 2022): 85–94. http://dx.doi.org/10.31481/uhmj.29.2022.07.
Testo completoAbstract (sommario):
Nowadays, in the period of scientific and technological progress, the anthropogenic impact on the environment keeps increasing. At the same time, its forms and its degree are very diverse. The study of aquatic ecosystems, including ecosystems of small rivers, is one of the applied environmental researches. Small rivers form water resources, hydrochemical composition and water quality of medium and large rivers. They form natural landscapes and contribute to human economic activities.
Most of the indicators classify the current environmental state of small and medium rivers of Zaporizhzhia Region as unsatisfactory. The main reason for this situation is an excessive anthropogenic load on environmental systems of small rivers that have a noticeable reaction to any interference. One of the consequences of this process includes siltation of small rivers. A small river Mokra Moskovka is not an exception to the above-described characteristics of aquatic ecosystems. The river flows through the territory of Zaporizhzhia Region and its lower part of about 11 km long flows in the densely built-up part of the City of Zaporizhzhya. The mouth section of the Mokra Moskovka River is 2.6 km long and runs through the territory of Aleksandrovsky and Kommunarsky districts of Zaporizhzhia from the river's mouth to the Zaporizhzhia-1-Zaporizhzhia-2 railway bridge. Over the years of its existence, the mouth section of the small river's bed silted up considerably and has an unsatisfactory condition. This is due to the rising of the Kakhovka Reservoir water level and daily fluctuations of the Dnipro's water level that together lead to the reverse movement of water masses and emergence of stagnant phenomena within the studied portion of the river's bed. In addition, the outlets of the municipal rainwater drainage system present a significant source of the sediment, debris and pollutants entering the river.
In order to improve the environmental condition of the Mokra Moskovka and remove its silt sediments within the bounds of the city, the riverbed was being cleared during 2004-2013. Our data indicate that the thickness of the river's silt sediments reaches 1.0-1.5 m in some places. To restore and maintain favorable hydrological regime and sanitary condition of the mouth section of the Mokra Moskovka it is planned to clean the mouth section of the river channel from silt sediments using hydromechanization technologies and dredging mechanisms in 2022-2023 (scheduled activities).
The research is aimed at studying the structural organization of the bottom fauna of the estuary section of a small river Mokra Moskovka within the urban ecosystem. The work is based on the results of our own hydrobiological research. During the observation that took place in 2021 53 species of benthic invertebrates were recorded at the mouth of the watercourse. It was found that, out of the total number, 21 species belonged to the macrozoobenthos and 32 – to the benthic microfauna groupings. The conducted saprobiological assessment of the studied river sections for the indicated organisms of micro- and macrozoobenthos revealed that the surveyed part of the watercourse belongs to the α-mesosaprobic zone and is classified as "polluted waters" according to the surface water quality classification. In order to improve the environmental condition of the mouth section of the Mokra Moskovka River it is necessary to implement certain measures of biological water treatment using modern biotechnological solutions developed in Ukraine.
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Et.al, Jaffry Zakaria. "Dynamic and Structure Profiling of Kampar River, Slim River and Sungkai River: White Water Recreation Rivers in the State of Perak, Malaysia". Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n. 3 (10 aprile 2021): 428–31. http://dx.doi.org/10.17762/turcomat.v12i3.747.
Testo completoAbstract (sommario):
In Malaysia, there are many rivers that are being the attraction for white water river activities. Perak, is a state on the west of Peninsular Malaysia has several rivers that are suitable for white water river activities and being among the favourite location for white water river activities enthusiasts. Among the well-known white water rivers in Perak state are Kampar River, Slim River, Sungkai River, Singgor River and Sungai Bernam River. The attraction of a white water river depends on several factors. One of the important factor is the classification of rapid difficulty level. To date, the classification of rapid difficulty level in Malaysia is based on the international standard scale and certified by The International Canoe Federation (ICF). Apart from that, other attraction factors such as river water quality, geographical location, logistics facilities, transportation access, facilities, operator reputations and promotions are among other attraction factors. This present study aims to identify the main attraction factors in the white water rivers in Perak State. Dynamic and structure profiling of the rivers was produced. The white water rivers selected in this study were Kampar River, Slim River and Sungkai River. From the study, Kampar River was identified to be the most preferred river for white water activities compared to Slim River and Sungkai River. Findings from the study was resourceful in the effort of constructing a complete profile of white water rivers structure located in the state of Perak besides promoting white water river activities as a structured recreational tourism activity in Perak.
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Gíslason, Gísli Már, Jón S. Ólafsson e Hákon Adalsteinsson. "Animal Communities in Icelandic Rivers in Relation to Catchment Characteristics and Water Chemistry". Hydrology Research 29, n. 2 (1 aprile 1998): 129–48. http://dx.doi.org/10.2166/nh.1998.0008.
Testo completoAbstract (sommario):
Catchment areas of Icelandic rivers are mostly barren or with little vegetation cover in the highlands, but with heathland and mire vegetation in the lowlands. Chemical composition and nutrient availability in Icelandic rivers are influenced by geology, topography and vegetation cover in the river basins. This seems to determine the density and diversity of benthic invertebrates, species composition of anadromous fish and catch of salmon in Icelandic rivers. Species composition of benthic communities is determined by particulate organic matter drifting downstream from river head-waters. Filter feeding blackfly larvae dominate lake outlets, while algal grazing chironomid larvae dominate rivers not influenced by lakes. In well vegetated catchment basins, lake-fed rivers have higher catches of salmon than non-lake fed rivers. Only a few of the rivers flowing from poorly vegetated areas sustain salmon. Glacial rivers have the lowest density and diversity of benthic invertebrates of all river groups and do not sustain fish populations.
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Hz, Masykur, Bintal Amin, Sofyan Husein Siregar e Jasril. "Water Quality Status of the Rivers in Tembilahan City Based on Physical-Chemical Parameters and Storet Index". Asian Journal of Water, Environment and Pollution 20, n. 1 (23 gennaio 2023): 85–95. http://dx.doi.org/10.3233/ajw230012.
Testo completoAbstract (sommario):
Tembilahan city has several tidal-type rivers flowing into the Indragiri river which encountered a waste pollution problem. This research aims to obtain insight into the water quality of the rivers in Tembilahan City. Characteristics of rivers that flow in urban areas are vulnerable to water quality degradation and environmental pollution due to high anthropogenic activities. Water quality data, which includes physical and chemical properties of water, were obtained from monitoring four rivers as sampling stations representing several rivers in Tembilahan city. The sampling location was determined based on the representativeness of the human activity area. The river water quality status was analysed by using Storet Index. The results showed that the water quality of the rivers in Tembilahan City has a score of -31 which indicates that the rivers are categorised as polluted rivers. Therefore, there is a need for river revitalisation management with the participation of the public sector and the community in Tembilahan City.
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Gogoi, Bijoylakshmi, Devojit Bezbaruah e Yadav Krishna Gogoi. "River terraces assessment to evaluate the regional tectonic activity of the fore parts of Mishmi Block and Manabhum Anticline, North-east India: A conjunctive approach using Field Mapping and Satellite imagery". Disaster Advances 16, n. 8 (15 luglio 2023): 39–54. http://dx.doi.org/10.25303/1608da039054.
Testo completoAbstract (sommario):
Terraces are the remains of a river's old floodplain. They are created when a river channel is downcut into its former floodplain, which is then deserted and subjected to lateral erosion. A former floodplain's downcutting, abandonment and lateral erosion can be caused by local or regional tectonic uplift, changes in the climate and changes in the river's discharge or a combination of these. The 1950 Mw 8.6 Great Assam Earthquake, which completely wrecked the region, occurred in the Mishmi Hills. The study area lacks tectonics research, therefore understanding the region's undulations requires a thorough understanding of terraces. Using ArcGIS 10.4, a digital elevation model (DEM) with a 30m resolution and satellite images form Google Earth Pro was superimposed on the Survey of India's topographic map for this investigation. The goal of the study is to use terrace analysis to comprehend the regional tectonic activity of the entire frontal and foothills of the Mishmi Hills. The Lohit, Dibang and Noa Dihing River are the most notable rivers in the research area. The rivers possess incised valleys and tributaries where different level of terraces may be identified. The terraces of the said rivers and tributaries are the subject of this study. Since the terrace levels vary from valley to valley, it is impossible to correlate adjacent valleys. The terraces are typically found where one of these rivers and one of its tributaries converge. The tectonic influence on various features in the studied area is typically defined through the study of terraces.
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Čanjevac, Ivan, Katarina Pavlek e 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. 1 (14 luglio 2022): 5–30. http://dx.doi.org/10.21861/hgg.2022.84.01.01.
Testo completoAbstract (sommario):
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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Kozaki, Daisuke, Mohd Hasbi bin Ab Rahim, Wan Mohd Faizal bin Wan Ishak, Mashitah M. Yusoff, Masanobu Mori, Nobutake Nakatani e Kazuhiko Tanaka. "Assessment of the River Water Pollution Levels in Kuantan, Malaysia, Using Ion-Exclusion Chromatographic Data, Water Quality Indices, and Land Usage Patterns". Air, Soil and Water Research 9 (gennaio 2016): ASWR.S33017. http://dx.doi.org/10.4137/aswr.s33017.
Testo completoAbstract (sommario):
Water qualities of three suburban rivers, namely, Kuantan, Belat, and Galing rivers, in Kuantan, Malaysia, were examined effectively by using ion-exclusion/cation-exchange chromatography with water quality indices and land usage data. Specifically, we have focused on evaluating and grasping the effect of sewage/household wastewater discharged from housing areas in the Kuantan district on the river water quality. Based on this study, the following beneficial information were obtained effectively: (1) the pollution levels in the three rivers (Kuantan River: Classes I–III, Belat River: Classes I–III, and Galing River: Classes I–V) are linked with the urbanization level of the river basin area; (2) differences in the biological reactions in the different pollution level rivers are understood; (3) Galing River is among the most polluted rivers not only in Kuantan but also in the Peninsular Malaysia, owing to poor water treatment of the sewage/household wastewater discharged from the river basin area.
23
Fernandes, Lina L., Pratima M. Kessarkar, Suresh Suja, Durbar Ray e Mithila Bhat. "Seasonal variations in the water quality of six tropical micro- and mesotidal estuaries along the central west coast of India". Marine and Freshwater Research 69, n. 9 (2018): 1418. http://dx.doi.org/10.1071/mf17181.
Testo completoAbstract (sommario):
Seasonal nutrient dynamics were investigated in four rivers with a microtidal range (Terekhol, Chapora, Sal and Talpona rivers) and were compared with those of two rivers with a mesotidal range (Zuari and Mandovi rivers) along the central west coast of India. Rainfall and freshwater discharge during the wet season led to salinity stratification of the water columns at the mouths of these rivers. Nutrient concentrations in all rivers were higher during the wet season than in the dry season due to considerable land run-off. Based on the estuarine mixing diagrams of the nutrients with regard to salinity, the mesotidal rivers showed greater flushing capacity and acted as corridors for the passage of nutrients between the estuary and open ocean. Conversely, of the microtidal rivers, the Terekhol and Chapora seemed to retain nutrients, whereas there was no indication of the presence of a nutrient sink or source in the Talpona River. The Sal River was eutrophic with high nutrient levels and acted as a source of phosphorus and nitrogen. Thus, the present study clearly illustrates the important role played by minor river estuaries in modifying nutrient concentrations during their transport from rivers to coastal waters and vice versa.
24
(Babu), Kudrat-E.-Khuda, Md Riaduzzaman ., Tahmina Akter e Sumaia Akther. "Negative Effects of the Urban River Pollution on the Environment and Human Health in Bangladesh". Nature Environment and Pollution Technology 22, n. 3 (1 settembre 2023): 1081–96. http://dx.doi.org/10.46488/nept.2023.v22i03.001.
Testo completoAbstract (sommario):
Based on research findings, Bangladesh’s river water, crucial for domestic, agricultural, and industrial use, has long been in a terrible situation. There have been numerous instances of significant contamination in the waterways surrounding Dhaka city, including the Buriganga River, and in Chattogram city, including the Karnaphuli River, over the past 40 years. The existing data demonstrate that other urban rivers, particularly Karatoa, Teesta, Rupsa, Pasur, and Padma, are also in severe condition due to the disposition of huge pollutants. Contaminants flowing with the water have severely polluted the downstream areas of the rivers. High metal concentrations are frequently observed in river water during the dry season. In the Buriganga River and at certain locations in the Turag, Balu, Sitalakhya, and Karnaphuli Rivers, the presence of dissolvable oxygen (DO) is nearly zero. NO3, NO2, and PO4-3 pollution has also occurred in many rivers. Most rivers have Cr, Zn, Fe, Pb, Cu, Cd, Mn, As, and Ni concentrations beyond the legal limit for drinking water. In contrast, some rivers have metal concentrations above the legal irrigation water limit. The majority of the rivers, particularly the peri-urban rivers in Dhaka city, Teesta, Korotoa, Rupsha, Karnaphuli, and Meghna Rivers, have significantly higher metal concentrations, according to sediment data. Metal concentrations in sediment are generally higher than USEPA standards in most rivers. Metal concentrations in fish and crops demonstrate metal bioaccumulation. The trend in metal concentration follows the order of water, fish, and sediment. It has been shown that crops irrigated with tainted water contain dangerous metals. The analysis of daily intake data on carcinogenic and noncarcinogenic substances reveals that consuming contaminated food can seriously impact human health.
25
Shrestha, Madhav K., e Rahul Ranjan. "Territory and status of dolphins in Nepalese rivers: A review". Aquatic Ecosystem Health & Management 26, n. 1 (1 gennaio 2023): 40–48. http://dx.doi.org/10.14321/aehm.026.01.40.
Testo completoAbstract (sommario):
Abstract Nepal is endowed with vast water resources in form of glaciers, lakes, streams and rivers. All the rivers in Nepal are connected to the Ganges River system of India. The major rivers are reliable sources of water and provide habitats for aquatic animals, opportunities for hydropower, and irrigation development in downstream regions. The major rivers of Nepal include the Koshi, Gandaki (Narayani), Karnali, and Mahakali which all drain from north to south. These rivers support abundant wildlife species as well as a number of fishes, amphibians and reptiles. Most relevant to this paper is the Ganges River Dolphin (Platanista gangetica gangetica Roxburgh, 1801). The Ganges River Dolphin preys on fish, mollusks and other aquatic animals. Being a migratory species, the dolphins move from larger rivers to their tributaries, seasonally. This paper is intended to review work on the status of Ganges River Dolphin in Nepalese rivers based on secondary data obtained from different published surveys targeting the dolphin populations. The records show the Karnali River has the largest population, followed by the Koshi and Narayani rivers, with no record of dolphins occupying the Mahakali River in recent years. Recent surveys estimate about 100 dolphins living in Nepal, with 80 estimated in the Karnali River. Different anthropogenic activities including construction work, intensive fishing, pollution and the lack of conservation planning for dolphins have resulted in a decline in number from historic levels. The presence of this aquatic mammal is considered as an indicator of the overall health of the river system. The COVID-19 pandemic and lock down might have caused increased dolphin sightings. Additionally, high pre-monsoon precipitation in recent years have caused higher water levels in smaller rivers, possibly causing the dolphins to return earlier than usual to the major river systems. They were recorded to be present in the Mohana and other small tributaries of the Karnali River as early as first week of June.
26
Erskine, W. D., M. J. Saynor, L. Erskine, K. G. Evans e D. R. Moliere. "A preliminary typology of Australian tropical rivers and implications for fish community ecology". Marine and Freshwater Research 56, n. 3 (2005): 253. http://dx.doi.org/10.1071/mf04078.
Testo completoAbstract (sommario):
Australian tropical rivers are dependent on highly seasonal rainfall and runoff between November and April. They also transport low sediment and solute loads, except where catchments have been disturbed by mining, grazing and cropping. Aquatic habitats or channel units are the physical template influencing fish communities. Pools provide dry-season refuges for fish and channels provide pathways for movement between refuges when streamflows are re-established. A preliminary geomorphological typology of Australian tropical river reaches (excludes estuaries) is proposed that defines nine distinct river types: (1) bedrock rivers (upland channels and gorges); (2) bedrock-confined rivers; (3) avulsive rivers; (4) meandering rivers (confined meandering, laterally migrating unconfined and laterally stable unconfined); (5) straight rivers; (6) floodouts; (7) island- and ridge-anabranching rivers; (8) co-existent mud-braided and anabranching rivers; and (9) extensive freshwater wetlands and billabongs. Many of these have not been recognised overseas and are unique. Channel units differ greatly between river types and contribute to distinctive fish communities in different river types. As expected, fish diversity decreases upstream because of less diverse habitat and natural barriers to fish movement at steps, falls and turbulent cascades and rapids. Fish kills occur in most years and are caused by several different factors that reduce dissolved oxygen.
27
Richardson, Martin, e Mikhail Soloviev. "The Urban River Syndrome: Achieving Sustainability Against a Backdrop of Accelerating Change". International Journal of Environmental Research and Public Health 18, n. 12 (13 giugno 2021): 6406. http://dx.doi.org/10.3390/ijerph18126406.
Testo completoAbstract (sommario):
Human activities have been affecting rivers and other natural systems for millennia. Anthropogenic changes to rivers over the last few centuries led to the accelerating state of decline of coastal and estuarine regions globally. Urban rivers are parts of larger catchment ecosystems, which in turn form parts of wider nested, interconnected systems. Accurate modelling of urban rivers may not be possible because of the complex multisystem interactions operating concurrently and over different spatial and temporal scales. This paper overviews urban river syndrome, the accelerating deterioration of urban river ecology, and outlines growing conservation challenges of river restoration projects. This paper also reviews the river Thames, which is a typical urban river that suffers from growing anthropogenic effects and thus represents all urban rivers of similar type. A particular emphasis is made on ecosystem adaptation, widespread extinctions and the proliferation of non-native species in the urban Thames. This research emphasizes the need for a holistic systems approach to urban river restoration.
28
Ahmad, A. K., A. Hafizah e S. O. Sharifah Aisyah. "Chironomidae (Order: Diptera) diversity in relation to water quality of highland rivers at Cameron Highlands, Malaysia". Journal of Environmental Biology 42, n. 3(SI) (31 maggio 2021): 824–31. http://dx.doi.org/10.22438/jeb/42/3(si)/jeb-14.
Testo completoAbstract (sommario):
Aim: This study aims to determine Chironomidae diversity and distribution in three small rivers at Cameron Highlands in relation to their response to water quality conditions. Methodology: Fifteen sites from three rivers (Palas River, Pauh River and Bertam River) were chosen for water quality measurements and Chironomidae sampling. Water quality was analysed following APHA standard methods and chironomid was identified to genus level. The rivers were classified based on Malaysian’s Water Quality Index (WQI) and macroinvertebrates diversity and distribution was analysed using diversity indices. Comparison between sites and river was undertaken using one-way ANOVA and chironomid appearance in relation to water quality was evaluated using Pearson correlation test. Results: Chironomidae (Order: Diptera) distribution at high altitude rivers in Malaysia is not well documented although this group of insect has a wide range of distribution in tropical region. Based on Malaysian water quality index (WQI), result shows all rivers were in Class I. Although still in Class I, Bertam River has slight lower water quality due to higher ammoniacal nitrogen and total suspended solids. The diversity indices also demonstrate that Bertam Rivers was in stress conditions, and other two were in moderate conditions. Three subfamilies (Chironominae, Orthocladiinae and Tanypodinae) were recorded, which comprises of 1963 individuals. Tvetenia (Subfamily: Orthocladiinae) was the most dominant but only dominated Palas River and Pauh River. Another genus from Orthocladiinae (Crocotopus and Rheocrocotopus) also recorded dominant only in Palas River and Pauh River, but lesser in Bertam River. Only Polypedilum (Subfamily: Chironominae) which was second highest recorded, dominated in all rivers, even highest in Bertam River. Amongst dominant genus, only Polypedilum was found dominant in all rivers, others were only dominating Palas River and Pauh River only. Interpretation: This findings exhibit wide range of adaptations and potential use of Polypedilum as biological indicator. Due to availability of incomplete keys, identification to species level cannot be undertaken. However, this study reveals thirteen different sub-group of Polypedilum based mouthpart organs, which represent different species for tropical ecosystems.
29
Mykhailyk, Olha. "RIVER ECOSYSTEMS OF THE FOREST-STEP AND STEPPE: NATURAL CHARACTERISTICS AND PECULIARITIES OF URBAN DEVELOPMENT". Urban development and spatial planning, n. 83 (14 aprile 2023): 200–210. http://dx.doi.org/10.32347/2076-815x.2023.83.200-210.
Testo completoAbstract (sommario):
Natural features of river ecosystems of forest-steppe and steppe zones are considered. The problems of anthropogenic loading of the rivers of the dissected plains and their coastal areas are indicated. Measures of urban planning organization of coastal territories of river ecosystems of forest-steppe and steppe zones are proposed.
According to the type of river and the natural area of the river basin in Ukraine, there are 3 types of rivers: Polish rivers, rivers of forest-steppe and steppe zones (dismembered plains), and mountain rivers. The most common are the rivers of the dissected plains, to which this article is devoted. These rivers usually have wide valleys, gentle slopes, many rivulets and streams, the speed of the flow of these rivers is 0.2-0.3 m/sec. The geographical location of river basins gives special characteristics to rivers and their coastal areas, which must be taken into account during their urban development.
In order to improve the ecological condition of forest-steppe and steppe river ecosystems, preserve and revive their natural component, and prevent the negative consequences of anthropogenic load on the river ecosystems of the dismembered plains, a complex of measures is required - state draft laws and programs with sufficient funding, scientific research developments, and public support. This publication is devoted to proposals for urban planning organization of coastal areas and preservation of the natural component of river ecosystems of dismembered plains.
The natural state of forest-steppe and steppe river ecosystems will be preserved if the following economic and urban planning measures are carried out: - clearing of riverbeds from excess air-water vegetation; at the same time, reed stalks can be used as fuel and for roofing houses, which is a traditional ecological material;- clearing of springs and wells that have a hydraulic connection with water areas;- a complex of anti-slide measures, - a set of anti-erosion measures aimed at eliminating gullies by filling them in, landscaping them with special-purpose plantings; - protection against flooding; - reclamation of quarries; - banning the discharge of wastewater into rivers, which will preserve surface water resources and the purity of mineral springs; - the continuity of the annual period of carrying out scientifically based ecological releases from reservoirs - from April 15-20 to May 9-10; - establishment of coastal protection strips of rivers, restrictive Green and Blue lines; - improvement of recreational reservoirs; - compliance with the regime of economic activity.
The implementation of the mentioned urban planning measures in combination with the adoption of legislative programs, scientific research, sufficient funding and an active position of the public will definitely lead to the revival and preservation of the natural component of the river ecosystems of the dismembered plains. More than 60% of Ukraine's water resources are formed in the basins of small rivers, therefore improving the ecological condition of small rivers is the key to the revival of medium and large rivers.
30
Lin, Xianbiao, Dengzhou Gao, Kaijun Lu e Xiaofei Li. "Bacterial Community Shifts Driven by Nitrogen Pollution in River Sediments of a Highly Urbanized City". International Journal of Environmental Research and Public Health 16, n. 20 (9 ottobre 2019): 3794. http://dx.doi.org/10.3390/ijerph16203794.
Testo completoAbstract (sommario):
Effects of nitrogen pollution on bacterial community shifts in river sediments remain barely understood. Here, we investigated the bacterial communities in sediments of urban and suburban rivers in a highly urbanized city, Shanghai. Sediment nitrate (NO3−) and ammonia (NH4+) were highly accumulated in urban river. Operation Taxonomic Units (OTUs), Abundance-based Coverage Estimators (ACEs) and Chao 1 estimator in urban rivers were slightly lower than those in suburban rivers, while Shannon and Simpson indices were higher in urban rivers than those in suburban rivers. Proteobacteria, Firmicutes, and Bacteroidetes were the dominant bacterial phylum communities, accounting for 68.5–84.9% of all communities. In particular, the relative abundances of Firmicutes and Nitrospirae were significantly higher in suburban rivers than in urban rivers, while relative abundances of Bacteroidetes, Verrucomicrobia, and Spirochaetes were significantly lower in suburban rivers than in urban rivers. NH4+ was significantly and negatively correlated with abundances of Firmicutes, Nitrospirae, and Actinobacteria. Importantly, the significant and negative effects of sediment NH4+ on bacterial richness and diversity suggested that nitrogen pollution likely contribute to the decrease in the bacterial richness and diversity. The results highlight that nitrogen enrichment could drive the shifts of bacterial abundance and diversity in the urban river sediments where are strongly influenced by human activities under the rapid urbanization stress.
31
Mykhailyk, Olha. "RIVER ECOSYSTEMS OF POLISYA: NATURE, CAUSES OF DEGRADATION, METHODS OF URBAN PLANNING AND LAND REGENERATION". Grail of Science, n. 12-13 (2 giugno 2022): 711–18. http://dx.doi.org/10.36074/grail-of-science.29.04.2022.129.
Testo completoAbstract (sommario):
In this article we have analyzed the current state of the ecosystems of Polesye rivers in Ukraine, the causes of their degradation. We have primarily made recommendations for urban planning and the reclamation of coastal areas of Polesye rivers in urban and suburban areas. Ukrainian rivers are classified into 3 categories: Polesye rivers, mountain rivers and rivers in river-cut valleys. In this article we analyzed the natural features of Polesye river ecosystems and the reasons and factors of their degradation. We have made some recommendations with respect to town-planning and the reclamation of coastal territories: in both urban and suburban zones.The river ecosystem is a naturally balanced formation - disturbance of the coastal area directly affects the state of the riverbed. Maintaining the natural (optimal) functioning of the river ecosystem and its catchment area helps to increase their self-cleaning capabilities and minimize the impact of extreme situations, including low-water years. Any measures for the preservation or reconstruction of the ecosystem of the river and river valley should be aimed at the reproduction of natural complexes, originally characteristic of the area and the landscape.In order to maintain, preserve, protect and restore the ecological balance, the urban organization of coastal areas of Polissya rivers in urban and suburban areas should take into account the presence of wetlands of coastal areas, the number of wetlands, small number of aquatic and air-water plants. features of Polissya river ecosystems. The dominance of the landscape direction of the urban organization of the coastal areas of Polissya will help maintain the natural balance, which is the key to maintaining the purity of Polissya rivers and the stability of coastal areas.
32
Kolesnikova, Evgeniia. "Environmental issues in sustainable use of water from minor and medium rivers in the Yenisei River Basin District". E3S Web of Conferences 163 (2020): 03007. http://dx.doi.org/10.1051/e3sconf/202016303007.
Testo completoAbstract (sommario):
Minor and medium rivers of the Russian North regions are vulnerable to anthropogenic impact. The article deals with the water use problems in the Yenisei River Basin where about 90% of the rivers used for water supply are minor and medium. Aassessment of the main sources of anthropogenic impact at the rivers of the region is given. The article substantiates the main problems in sustainable use of water in the Yenisei River Basin, such as water pollution, regulation of river flow and water resource depletion. The methods of estimation of acceptable water intake are analyzed, empirical and analytical probability curves of water intake values for each season for eleven rivers are built. Environmental flow for eleven rivers, as the average month and average annual values, are calculated.
33
Sheng, Qiang, Wang Xu, Long Chen, Lei Wang, Yudong Wang, Yihong Liu e Linshen Xie. "Effect of Urban River Morphology on the Structure of Macroinvertebrate Communities in a Subtropical Urban River". Sustainability 14, n. 16 (13 agosto 2022): 10046. http://dx.doi.org/10.3390/su141610046.
Testo completoAbstract (sommario):
Channelization is the most common hydraulic modification of urban rivers. Here, we assessed the effects of urban river morphology on benthic communities by analyzing the characteristics of benthic communities at various sites in channelized and natural rivers of the Longgang River system in southern China. We detected four Clitellata species, five Oligochaeta species, one Polychaeta species, 10 Gastropoda genera/species, two Bivalvia genera/species, two Crustacea genera/species, and 14 Insecta genera/species. Insecta and Oligochaeta were the dominant classes in the wet and dry seasons, and Chironomus plumosus was the most dominant species. The density of Clitellata was significantly lower in channelized rivers (0–0.74 ind/m2) than in natural rivers (0.61–4.85 ind/m2). The Shannon’s diversity index was significantly lower in channelized rivers (0.66–1.04) than in natural rivers (0.83–1.28) in the wet and dry season. NH3.N was positively correlated with Shannon’s diversity index, and chemical oxygen demand and river width were negatively correlated with Shannon’s diversity index. When the concentration of total phosphorus (TP) was low (<3 mg/L), it was positively correlated with Shannon’s diversity index. Our findings indicate that river channel morphology affects benthic faunal structure and diversity, but the effects varied among seasons. Minimized channelization will prevent the loss of aquatic biodiversity in subtropical urban rivers, as will preservation of natural rivers.
34
Walks, D. J. "Persistence of plankton in flowing water". Canadian Journal of Fisheries and Aquatic Sciences 64, n. 12 (1 dicembre 2007): 1693–702. http://dx.doi.org/10.1139/f07-131.
Testo completoAbstract (sommario):
Models of river plankton frequently suggest that these passively drifting communities are limited to downstream sections of larger rivers. I examine this hypothesis using a passive drift model for populations in advective environments, followed by a comparison of predicted and observed plankton populations in rivers. Under the scenario of continuous downstream drift, much of the plankton found in rivers is not predicted to occur. However, much of the observed plankton in rivers is explained through the addition of cross-channel flow heterogeneity to the model. Empirical data support the model and predict that many river plankton populations may be drifting downstream at less than 30% of the average rate of downstream flow. Plankton collections in the slower-moving edges of rivers demonstrate densities of up to 240% higher than those in adjacent midchannel flows (p = 0.009). These slow-moving areas are important habitat for river plankton and likely play a large role in planktonic food webs within rivers. These results may help explain why river productivity often decreases as a result of the loss of flow heterogeneity within river channels through human modification to landscapes.
35
Mykhailyk, Olha. "RIVER ECOSYSTEMS OF THE UKRAINIAN CARPATHIANS: NATURAL FEATURES, AND URBAN PLANNING ORGANIZATION OF COASTAL TERRITORIES". Urban development and spatial planning, n. 81 (31 agosto 2022): 263–73. http://dx.doi.org/10.32347/2076-815x.2022.81.263-273.
Testo completoAbstract (sommario):
For each city with a unique natural basis, the connection with the water space determines the historical process and patterns of development, structure and architectural appearance, cultural traditions and way of life, typology and status of urban spaces. An important component of comfortable living conditions in cities is the harmonious coexistence of urban environment with nature: river arteries, green parks, neighborhoods of birds, animals, and waterfowl feed cities with natural energy, balance anthropogenic impact, and neutralize smoke, pollution, car noise. But in the face of powerful growing urbanization, the degradation of the natural component is a sad reality. The natural features of the river mountain ecosystems of the Carpathians are considered. The Carpathians have the highest density of river networks - in this relatively small area, there are about 28 thousand rivers, streams, and streams. The river with its coastal territory, floodplain, coastal meadows, fields, forests is a whole harmoniously connected ecological system - the degradation of one component leads to an imbalance, to the violation of natural ties, to the loss of the integrity of the ecosystem. It is important to preserve the floodplain, which is a natural protection zone for the river, ecotones, and river biocenosis. It is possible to improve the condition of rivers and preserve biodiversity only if balanced management is implemented throughout the river's catchment area. Mountain and foothill regions of the Carpathians are distinguished by the highest specific weight of forests and shrubs in Ukraine (56.1% of the territory) and the lowest agricultural development (36.4%) and plowed land (17%). Carpathian rivers are regulated by dams due to frequent floods - the total rise of water reaches 5 m or more; the width of the dam space is 200-300 m.
The lack of a convenient network of tourist trails along the picturesque Carpathian rivers and streams, bicycle paths, trails for horseback riding, and the improvement of ecological promenade routes limits tourists to visit and have a comfortable rest in this beautiful region of Ukraine. The experience of foreign specialists in the urban planning organization of the coastal areas of mountain rivers proves the importance of a harmonious combination of the natural component with the comfort of the improvement of the coastal zone. The following examples prove the possibility of creating a comfortable coastal environment in difficult mountain conditions, while maintaining the natural balance of the river ecosystem. The landscaping of the coastal areas of mountain rivers in the Czech Republic, Switzerland, and Japan was analyzed. Proposals regarding the urban planning organization of the coastal territories of the mountain river ecosystems of the Carpathians are presented.
36
Shaw, Ed, Debbie Coldwell, Anthony Cox, Matt Duffy, Chris Firth, Beckie Fulton, Sue Goodship et al. "Urban Rivers Corridors in the Don Catchment, UK: From Ignored, Ignoble and Industrial to Green, Seen and Celebrated". Sustainability 13, n. 14 (8 luglio 2021): 7646. http://dx.doi.org/10.3390/su13147646.
Testo completoAbstract (sommario):
Research on urban rivers often seeks to find commonalities to advance knowledge of the effect of urbanisation on rivers, and rightly so. But it is important, also, to develop a complementary understanding of how urban rivers can be distinct, to facilitate a more nuanced view of concepts such as the ‘urban river syndrome’ and of the challenges facing those who wish to create more sustainable urban river corridors. To this end we use the Don Catchment as a case study to illustrate how historic patterns of urbanisation have been fundamental in shaping the catchment’s rivers. Following the Industrial Revolution, the catchment became an industrial centre, resulting in the ecological death of river ecosystems, and the disconnection of communities from stark urban river corridors. Widescale deindustrialisation in the 1970s and 1980s then resulted in a partial ecological recovery of the rivers, and ignited public interest. This history has imbued the catchment’s urban river corridors with a distinctive industrial character that can vary greatly between and within settlements. It has also left a legacy of particular issues, including a high degree of river habitat fragmentation and physical modification, and of negative perceptions of the rivers, which need improving to realise their potential as assets to local communities.
37
Xu, Fei, Yonggang Wang, Xu Wang, Dayong Wu e Yuanyuan Wang. "Establishment and Application of the Assessment System on Ecosystem Health for Restored Urban Rivers in North China". International Journal of Environmental Research and Public Health 19, n. 9 (5 maggio 2022): 5619. http://dx.doi.org/10.3390/ijerph19095619.
Testo completoAbstract (sommario):
The study on ecosystem health evaluation for restored urban rivers is of specific significance to improving river health and realizing the adaptive management for urban river ecosystems. Based on the health definition of restored urban rivers in North China, this study attempted to set up a system of alternative indicators on ecosystem health assessment, including water quality, water regime, aquatic organism, riparian environment, and physical morphology. Additionally, a set of health assessment system was proposed, including selection of assessment indexes and determination of assessment criteria and health classes. Taking seventeen typical restored urban rivers in Beijing as the assessment target, the said system was applied in assessing urban river health in 2016 and 2019. As the assessment results indicated, in 2016, the health statuses of 29 percent of urban rivers were ordinary, while 71 percent of urban rivers were somewhat inferior. In 2019, the health state of only one urban river reached “good” level. The health statuses of 88 percent of urban rivers were ordinary, and 6 percent were somewhat inferior in terms of comprehensive health index. In 2019, the health states of rivers improved significantly compared with that of 2016, which indicated that most urban rivers saw marked improvement in ecosystem health after ecological restoration. The health assessment system proposed in the paper not only could be applied to regular evaluation of restored urban rivers in the north but also was suitable for a contrastive health-state analysis between different years prior to or after the restoration. In order to carry out adaptive management of water ecology in urban rivers, the measures of ecological restoration could be adjusted based on the regular health assessment and health weakness analysis.
38
Dahal, Kamala. "River Culture in Nepal". Nepalese Culture 14 (24 febbraio 2021): 1–12. http://dx.doi.org/10.3126/nc.v14i0.35187.
Testo completoAbstract (sommario):
Most of the world civilizations are developed in the river basins. However, we do not have too big rivers in Nepal, though Nepalese culture is closely related with water and rivers. All the sacraments from birth to the death event in Nepalese society are related with river. Rivers and ponds are the living places of Nepali gods and goddesses. Jalkanya and Jaladeviare known as the goddesses of rivers. In the same way, most of the sacred places are located at the river banks in Nepal. Varahakshetra, Bishnupaduka, Devaghat, Triveni, Muktinath and other big Tirthas lay at the riverside. Most of the people of Nepal despose their death bodies in river banks. Death sacrement is also done in the tirthas of such localities. In this way, rivers of Nepal bear the great cultural value. Most of the sacramental, religious and cultural activities are done in such centers. Religious fairs and festivals are also organized in such a places. Therefore, river is the main centre of Nepalese cultural activities and we can find the remains of ld cultural remains in river basins.
39
Qi, Xuejun, Xing Zhao, Bin Fu, Lanjing Xu, Haibin Yu e Shuyan Tao. "Numerical Study on the Influence of Rivers on the Urban Microclimate: A Case Study in Chengdu, China". Water 15, n. 7 (4 aprile 2023): 1408. http://dx.doi.org/10.3390/w15071408.
Testo completoAbstract (sommario):
The urban heat island phenomenon in large cities is becoming increasingly serious as urbanization continues to develop, seriously affecting the lives of urban residents. Rivers can effectively alleviate urban heat islands and improve the thermal comfort of riverfront space in summer. Thus, the effect of rivers on the urban microclimate environment is studied in this work. A section of the Fu River in the inland city of Chengdu was selected as the research object, and a combination of experimental and numerical simulation methods was employed. ENVI-met software was used to study the river’s influence on the air temperature, relative air humidity, and the thermal comfort of the riverfront space. The measured experimental parameters are first used to verify the accuracy of the ENVI-met software simulation results, which are then employed to carry out simulation research. The simulation results suggest that the different types of underlying surfaces have varying impacts on the air temperature and relative air humidity. Rivers have a significant cooling effect on the regional thermal environment, and roads have a warming effect on the air temperature. The order of influence of different underlying surfaces on air temperature is as follows: rivers > roads > trees. Rivers have an obvious humidifying effect on the air, and roads have little effect on relative air humidity. The order of influence of different underlying surfaces on relative air humidity is as follows: rivers > trees > roads. The results of the outdoor predicted mean vote (PMV) reveal that rivers, trees, and green plants can effectively improve the comfort of individuals downwind.
40
Drozdenko, Tatiana V. "Planktonic algoflora of small rivers in urban conditions (on the example of the Mirozhka and Pskova rivers, Pskov, the Pskov Region)". Samara Journal of Science 12, n. 2 (30 giugno 2023): 30–34. http://dx.doi.org/10.55355/snv2023122104.
Testo completoAbstract (sommario):
The paper studies the planktonic algoflora of the Mirozhka and the Pskova Rivers. The research was carried out in the early autumn period of 2019. The taxonomic composition of the Mirozhka River included 107 species and intraspecific taxa of microalgae, the Pskova river 76 species taxa of algae from 7 phylums: Bacillariophyta, Cyanobacteria, Chlorophyta, Ochrophyta, Cryptophyta, Euglenozoa, Miozoa. The basis of the floral complex in both rivers were diatoms and green algae. The representatives of the Ochrophyta department also made a visible contribution to the species richness of the algoflora of the Mirozhka River. The degree of floral similarity of phytoplankton communities of the Mirozhka and Pskova rivers, calculated using the Sorensen-Chekanovsky index, was 55,7% (51 species of microalgae were common to the rivers). The average phytoplankton abundance in the Mirozhka River was 891,9 thousand cells/l, and in the Pskova river 199,6 thousand cells/l, biomass 366,9 micrograms/l and 79,6 micrograms/l, respectively. According to ecological and geographical analysis, freshwater widespread planktonic forms of microalgae predominated in both rivers, preferring slightly alkaline waters. Beta-mesosaprobionts prevailed in relation to organic matter pollution in rivers (38,5% the Mirozhka River; 41,8% the Pskova River), which indicates moderate pollution of the studied watercourses. The average saprobity index of the Mirozhka River and the Pskova River was 2,1 and 1,9, respectively, which makes it possible to attribute the waters of the studied watercourses to the 3rd class of quality moderately polluted.
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Kędzior, Renata, Małgorzata Kłonowska-Olejnik, Elżbieta Dumnicka, Agnieszka Woś, Maciej Wyrębek, Leszek Książek, Jerzy Grela, Paweł Madej e Tomasz Skalski. "Macroinvertebrate habitat requirements in rivers: overestimation of environmental flow calculations in incised rivers". Hydrology and Earth System Sciences 26, n. 15 (8 agosto 2022): 4109–24. http://dx.doi.org/10.5194/hess-26-4109-2022.
Testo completoAbstract (sommario):
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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Murphy, Michael L., K. V. Koski, J. Mitchel Lorenz e John F. Thedinga. "Downstream migrations of juvenile Pacific salmon (Oncorhynchus spp.) in a glacial transboundary river". Canadian Journal of Fisheries and Aquatic Sciences 54, n. 12 (1 dicembre 1997): 2837–46. http://dx.doi.org/10.1139/f97-178.
Testo completoAbstract (sommario):
Migrations of juvenile Pacific salmon (Oncorhynchus spp.) in the glacial Taku River (seventh order) were studied to assess movement from upriver spawning areas (in British Columbia) into lower-river rearing areas (in Alaska). Differences between fyke-net catches in the river and seine catches in the river's estuary indicated that many downstream migrants remained in the lower river instead of migrating to sea. In particular, age-0 coho salmon (O. kisutch) and chinook salmon (O. tshawytscha) moved downriver from May to November but were not caught in the estuary. Age-0 sockeye salmon (O. nerka), coho presmolts, and other groups delayed entry into the estuary after moving downriver. We tagged groups of juvenile coho (ages 0-2) from the fyke net with coded-wire to determine when they left the river. One-third of all tags recovered from sport and commercial fisheries occurred 2-3 years later, showing that many coho remained in fresh water for 1-2 years after moving to the lower river. Lower-river areas of large glacial rivers like the Taku River can provide essential rearing habitat for juvenile salmon spawned upriver and are important to consider in integrated whole-river management of transboundary rivers.
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Mingazova, N. M., R. S. Dbar, V. M. Ivanova, D. Yu Mingazova, A. A. Galiullina, E. N. Unkovskaya, O. V. Pustovarova et al. "Conditions of estuarine rivers of the Abkhazia Republic and their impact on the Black Sea coast". Marine Biological Journal 1, n. 4 (17 dicembre 2016): 30–39. http://dx.doi.org/10.21072/mbj.2016.01.4.04.
Testo completoAbstract (sommario):
Estuaries play an important role in formation of coastal water quality and the conservation of biological diversity. In 2013–2014 the study of estuarine rivers in Abkhazia Black Sea region and their possible impacts was supported by RFBR grant. A number of large (Bzyb, Kodor, Gumista Kelasur, Galizga) and medium (Aapsta, Hypsta, Basle and others.) Abkhazia rivers have a significant impact on the ecological state of the Black Sea coast because of the runoff of sediments. We have studied a total of 35 rivers flowing into the Black Sea on the coast of Abkhazia and identified hydrological characteristics of these. The maximum flow rate was observed for the Kodor River. Even in the low-flow period the water flow in estuarine areas ranged from 0.323 to 161.3 m3/s. Turbidity in the river at low water was 0,003–0,010 g/m3, for Kelasur river – 0.28 g/m3. Hydrocarbonate-calcium type of water is typical for the rivers of Abkhazia, salinity of most rivers is average. Well water quality characterizes by Galizga, Reprua, Gvandra and Hashipsa rivers. In the phytoplankton of investigated river estuaries were have identified 84 taxa below the rank of genus, in zooplankton – 19 species, in zoobenthos – 105 species and 23 species of fish fauna. In relation to phytoplankton most of the rivers appear to be oligotrophic. When using zoobenthic organisms as bioindicators the rivers were marked as having unfavorable conditions (Suhumka, Aapsta, Maanikvara et al.). The local impact on water quality of the Black Sea has a river experiencing pollution from receipt of sewage, waste and experiencing the impact of grazing. Rivers Bzyb, Kodor, Kelasur and Galizga bring large volumes of high mountain glacier water, which contributes to improving of the state of the Black Sea coast.
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Mat Saad, Azlina, Fadli Fizari Abu Hassan Asari, Salwani Affandi e Azlina Zid. "RIVER POLLUTION: A MINI REVIEW OF CAUSES AND EFFECTS". Journal of Tourism, Hospitality and Environment Management 7, n. 29 (9 settembre 2022): 139–51. http://dx.doi.org/10.35631/jthem.729011.
Testo completoAbstract (sommario):
Pollution of rivers is a serious topic that is frequently brought up by people from all walks of life all around the world including Malaysia. Domestic wastes, industrial pollutants, as well as agricultural wastes, including harmful and dangerous materials, have been discharged into the rivers directly or indirectly. The inflow of these hazardous pollutants not only pollutes river water but also sediment and aquatic life. Rivers, as we all know, are one of the contributors to the clean water supply in most parts of the world. River pollution has an impact on the availability of clean water used for a range of purposes, including domestic, industrial, and agricultural. Pollution, on the other hand, depletes the supply of food derived from rivers, such as fish and shrimp. The health of users, including humans, animals, and plants, will be affected by the consumption and usage of water, as well as the aquatic life of contaminated rivers. This article exposes the harsh reality of river pollution that we must all accept. To protect our rivers, it is critical to determine and know exactly the pollution sources, causes, and effects of the contaminants on rivers’ ecosystems, humans, and animals. When it comes to reducing current river pollution, prevention measures such as public awareness and continuous monitoring are preferable to treatment. In addition, significant research in the area of wastewater monitoring, as well as strict regulations, are required to manage global river pollution. This is important to prevent the continuous pollution of our rivers, which is primarily the result of negligent human actions. For rivers that have been identified as polluted, water treatment technologies including ozonation, chlorination, and aerobic granulation can be applied to remediate the pollutant residues. This is to ensure that the global community receives a clean and safe water supply.
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Chunarov, O. A. "COMPARATIVE ASSESSMENT OF THE INTRA-ANNUAL WATER RUNOFF DISTRIBUTION OF THE RIVERS THE ROS AND UBORT". Hydrology, hydrochemistry and hydroecology, n. 3 (58) (2020): 72–80. http://dx.doi.org/10.17721/2306-5680.2020.3.7.
Testo completoAbstract (sommario):
The article examines the intra-annual distribution of water runoff of the Ros and Ubort rivers, as well as its comparative assessment. The rivers Ros and Ubort were chosen for further research, because according to geographical conditions, river basins belong to natural and regulated water bodies. The rivers Ros and Ubort are characterized by summer-autumn and winter lows, which are disturbed by separate rises in water levels during rains or melting snow. The formation of the main part of river runoff is due to spring flooding. The initial data for studying the intra-annual distribution of runoff were the data of average annual water flow in the confluence of the rivers Ros and Ubort, namely: the river Ros – Korsun-Shevchenkivsky and the river Ubort – Perga for the entire period of hydrological observations. The initial data are the average annual water consumption of the closing sections of the Ros and Ubort rivers for the entire observation period. To confirm (or refute) the changes in the water content of the studied rivers, the homogeneity of some of their runoff characteristics was analyzed by different methods. Statistical methods for estimating the homogeneity of hydrological series are used for quantities that are random and internally independent. The homogeneity of the series of average annual water consumption over a multi-year period is estimated according to the current hydrological posts of the basins of the rivers Ros and Ubort. The analysis of previous publications on the intra-annual distribution of river water runoff for the territory of the studied river basins, the influence of climatic factors on the change of river runoff, as well as summarizes the results of these studies. The intra-annual distribution of river water runoff for years of different water content and separate phases for the basins of both studied rivers is calculated by the season composition method. The comparative characteristics of the obtained results are carried out and the common hydrological characteristics and significant differences in the studied river basins are revealed.
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Nikunj, Keshwala, Maurya Shivam, Gurav Chandrakant A e More Laxman. "Texture and major element geochemistry of channel sediments in the Orsang and Hiren River Basins, Gujarat, India: Implications for provenance and weathering". Indian Association of Sedimentologists 40, n. II (30 dicembre 2023): 57–67. http://dx.doi.org/10.51710/jias.v40iii.310.
Testo completoAbstract (sommario):
Size, shape, degree of sorting, and composition of sediments in the river channels are controlled by climate, lithology, weathering, sorting, and medium of transportation. The present investigation is focused on the grain-size and geochemical analysis of the channel sediments of the Orsang and Hiren river basins. Major outcrops in the study area are Archaean granites, granitic gneisses, Upper Cretaceous to lower Eocene Deccan Volcanic Basalts (DVB), Quaternary sediments and minor proportion of Proterozoic low grade metamorphic rocks. The sediments are poorly to moderately sorted, very finely skewed, suggesting its derivation from heterogenous sources, while the kurtosis value indicates a high-energy depositional environment. The sediments are with gravelly sand texture and the mean grain size is varying from 581.9µm to 1284.2µm. The DVB provenance of the Hiren river basin and granitic provenance of the Orsang river basin is clearly reflected in the texture and geochemical composition of sediments. The TiO2 and Fe2O3 contents of sediments from the Hiren river basin are distinctly higher and are comparable to the basalts of the Saurashtra region of the Deccan Province. Sediments collected after Orsang and Hiren rivers confluence and from Narmada river show higher concentration of felsic sources, indicating that Orsang river's sediment supply significantly outweighs Hiren rivers. The arkosic-litharenite nature points towards less transportation and moderate chemical weathering for the Orsang river sediments. The low Chemical Index of Alteration (CIA) values (Avg. 48.45 and 56.99 for Orsang and Hiren rivers, respectively) and A-CN-K plot also suggest the supply of sediments from minimally weathered detritus under a semi-arid condition.
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Yu, Junshuang. "Does river restoration result in improved environmental heterogeneity?" E3S Web of Conferences 284 (2021): 01002. http://dx.doi.org/10.1051/e3sconf/202128401002.
Testo completoAbstract (sommario):
Rivers can shape diverse landscapes, determine the spatial connectivity of river and terrestrial life, and provide a variety of resources and services. Rivers are often over-bound due to the need for flood control and irrigation. Rivers affected by human disturbance often require restoration to improve the ecosystem services they provide. Environmental heterogeneity is generally considered to be the non-uniform variation of environmental elements in space and/or time. The relationship between variability in physical characteristics of restored rivers and biological communities in the river environment is a highly complex feedback, and studying and summarising changes in environmental heterogeneity following river restoration can help refine methodologies for monitoring river restoration outcomes. This study highlights the variability in river geomorphology and river ecology, and demonstrates the feasibility and necessity of incorporating environmental heterogeneity indicators into river restoration outcome evaluation systems at three levels: hydrological, geomorphological and ecological.
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Journal, Baghdad Science. "The Limnological Effects of River Lesser-Zab on Tigris River, Iraq". Baghdad Science Journal 4, n. 3 (2 settembre 2007): 452–57. http://dx.doi.org/10.21123/bsj.4.3.452-457.
Testo completoAbstract (sommario):
The present study included the physico-chemical parameters of Lesser-Zab river and its effects on Tigris river. Monthly water samples were taken from the two rivers during January to October 1999.There were no signifcant difference in water temperatures. Both rivers were fresh to oligohalin, alkaline and very hard. Close values were determined in total suspended solids in both rivers with little increasing during rainfall period and high discharge. Water was well areated and over saturation was recorded in several occasions. Dissolved oxygen values of Tigris river were influenced by Lesser-Zab. Cations were more dominant than anions in both rivers. In Lesser-Zab, the anions were increased during spring season and declined in summer which their values influenced in Tigris river. The concentration of plant nutrients (NO2,NO3,PO4 and SiO2) were fluctuated during the study period in Lesser-Zab and their effects were cleared on Tigris river.N:P ratio values were indicated the deficiency of nitrogen in both rivers.
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Delina, Aija, Alise Babre, Konrads Popovs, Juris Sennikovs e Baiba Grinberga. "Effects of karst processes on surface water and groundwater hydrology at Skaistkalne Vicinity, Latvia". Hydrology Research 43, n. 4 (7 febbraio 2012): 445–59. http://dx.doi.org/10.2166/nh.2012.123.
Testo completoAbstract (sommario):
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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Kobojek, Elżbieta. "Anthropogenic Transformation and the Possibility of Renaturalising Small Rivers and Their Valleys in Cities – Łódź and Lviv Examples". European Spatial Research and Policy 22, n. 1 (30 giugno 2015): 45–60. http://dx.doi.org/10.1515/esrp-2015-0016.
Testo completoAbstract (sommario):
Rivers used to serve important functions in the development of cities, and river valleys are a part of the urban space. Regardless of several centuries of anthropogenic influences large rivers and their valleys have remained the dominant elements of the cityscape. In the case of small rivers and valleys the situation has been different. The expansion of urban infrastructure often led to an elimination of rivers and their valleys from the developed area. In many cases rivers were directed down straightened concrete ditches and sometimes the locations of their channels were changed altogether. In the city centre, rivers were locked in underground channels, i.e. they vanished from the cityscape. Urban floods, so annoying for the inhabitants, usually occur within river sections which have been utilized intensively and covered with impermeable surface. Even though a river was hidden in underground interceptor pipes, a valley dip remains still accumulating rainfall. The aim of this article is to present the extent of transformation of small rivers and valleys within two large cities located on watersheds: Łódź and Lviv, and the contemporary utilization and the possibility of renaturalising them.