نتایج جستجو برای: large river

تعداد نتایج: 1105254  

2012
Jean-Jacques Frenette Philippe Massicotte Jean-François Lapierre

Large rivers represent a significant component of inland waters and are considered sentinels and integrators of terrestrial and atmospheric processes. They represent hotspots for the transport and processing of organic and inorganic material from the surrounding landscape, which ultimately impacts the bio-optical properties and food webs of the rivers. In large rivers, hydraulic connectivity op...

2012
ANTOINE A. KERUZORÉ NIGEL J. WILLBY DAVID J. GILVEAR

1. Large European river floodplains have been intensively reduced through human activities over several millennia. Ecological assessments of natural large river systems remain rare and potentially flawed since they typically omit either the main channel of the river or, more commonly, aquatic habitats that occur naturally in the floodplain of dynamic systems. 2. Surveys were conducted over a lo...

Journal: :Ecology 2008
Jennifer L Tank Emma J Rosi-Marshall Michelle A Baker Robert O Hall

Given recent focus on large rivers as conduits for excess nutrients to coastal zones, their role in processing and retaining nutrients has been overlooked and understudied. Empirical measurements of nutrient uptake in large rivers are lacking, despite a substantial body of knowledge on nutrient transport and removal in smaller streams. Researchers interested in nutrient transport by rivers (dis...

Journal: :محیط شناسی 0
دکتر جلال ولی الهی

the native fishes of iran are imp ortant, since the stock of population are declining and the species of some fishes are in danger , because of industrialization, pollution, dryness, purposeful or accidental introduction of exotic species. the inland water species of iran are import ant, since they have not been yet completely identified. in order to conduct taxonomic revision and survey of pop...

2003
Bradley Pusey Damien Burrows Angela Arthington

The Burdekin River contains a distinctive fish fauna characterised by endemic species and species of biogeographic significance, and by a distinct disjunction in the distribution of many species due to the presence of a large waterfall (now the site of a very large impoundment) located in the lower quarter of the river's length. Downstream of the falls, large estuarine and catadromous piscivore...

2015
Clemens Kittinger Rita Baumert Bettina Folli Michaela Lipp Astrid Liebmann Alexander Kirschner Andreas H. Farnleitner Andrea J. Grisold Gernot E. Zarfel

The Joint Danube Survey 3, carried out in 2013 was the world’s biggest river research expedition of its kind. The course of the second largest river of Europe passes large cities like Vienna, Budapest and Belgrade and is fed from many tributaries like Inn, Thisza, Drava, Prut, Siret and Argeș. During the 6 weeks of shipping the 2375 km downstream the River Danube from Germany to the Black Sea a...

Journal: :تحقیقات نظام سلامت 0
سعید راثی نظامی دانشجوی دکتری، گروه مهندسی عمران- محیط زیست، دانشکده محیط زیست، دانشگاه تهران، تهران، ایران مهرداد نظری ها استادیار، گروه مهندسی محیط زیست، دانشکده محیط زیست، دانشگاه تهران، تهران، ایران اکبر باغوند دانشیار، گروه مهندسی محیط زیست، دانشکده محیط زیست، دانشگاه تهران، تهران، ایران علی مریدی - استادیار، گروه مهندسی منابع آب، دانشکده مهندسی آب و محیط زیست، دانشگاه صنعت آب و برق شهید عباسپور، تهران، ایران

background: the spread of urbanization in floodplains as well as increase of industrial and agricultural activities in river discharges may lead to water pollution by physical, chemical and biological pollutants. one of the major concerns in monitoring the water resources system is indentifying major quality parameters and determining a relationship between physical and chemical parameters. thi...

2011
Juliane B Brown Lori A Sprague Jean A Dupree

SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some ...

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