نتایج جستجو برای: uniform rivers

تعداد نتایج: 130445  

Journal: :The Science of the total environment 2002
D J Gilvear K V Heal A Stephen

Hydrology is a primary control on the ecological quality of river systems, through its influence on flow, channel geomorphology, water quality and habitat availability. Scottish rivers are widely perceived to be of high ecological quality, with abundant flow volumes and high water quality. However, historical and current river flow regulations, and land use change have altered the physical and ...

2018
Mohamadreza Masoudinejad Mansour Ghaderpoori Ahmad Zarei Jamal Nasehifar Alireza Malekzadeh Jalil Nasiri Afshin Ghaderpoury

Due to the great possibility of water contamination of many rivers by human activities in Iran, the study of water quality is crucial for water resource protection and human health. High level of phosphorous is the main reason for eutrophication of freshwater systems. The main aim of this study was to investigate the concentration of phosphorus in the rivers feeding into Taham dam in Zanjan, us...

Journal: :J. Systems Science & Complexity 2006
Jing He Xikang Chen Yong Shi

China is experiencing from serious water issues. There are many differences among the Nine Major Rivers basins of China in the construction of dikes, reservoirs, floodgates, flood discharge projects, flood diversion projects, water ecological construction, water conservancy management, etc. The shadow prices of water resources for Nine Major Rivers can provide suggestions to the Chinese governm...

2013
Isoken H. Igbinosa Vincent N. Chigor Etinosa O. Igbinosa Lawrence C. Obi Anthony I. Okoh

Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered fro...

2014
Felicity Shelley Jonathan Grey Mark Trimmer

Methane is oversaturated relative to the atmosphere in many rivers, yet its cycling and fate is poorly understood. While photosynthesis is the dominant source of autotrophic carbon to rivers, chemosynthesis and particularly methane oxidation could provide alternative sources of primary production where the riverbed is heavily shaded or at depth beneath the sediment surface. Here, we highlight g...

2006
B. R. Jha H. Waidbacher S. Sharma M. Straif

Size structure data particularly that of length and weight is very important fisheries management tool, which is also applied to assess the health, habitat and integrity of the rivers. Nepal is tremendously rich in both fisheries and water resource and thus, this analysis is very important. However, this kind of analysis is not common in fisheries studies and hence the size structure informatio...

1998
Albert Galy Christian France-Lanord Louis A. Derry

Himalayan rivers have very unusual Sr characteristics and their budget cannot be achieved by simple mixing between silicate and carbonate even if carbonates are radiogenic. We present Sr, O, and C isotopic data from river and rain water, bedload and bedrock samples for the western and central Nepal Himalaya and Bangladesh, including the monsoon season. Central Himalayan rivers receive Sr from s...

Journal: :journal of mining and environment 2012
v.f navarro torres g zamora echenique r.n singh

hydrographically bolivian poopó lake is located in the basin of desaguadero river and it has over a dozen main tributary rivers and other smaller rivers with lower flow. the mine water discharge from the abandoned and current mining activities polluted these rivers by carrying heavy metals, dissolved and suspended solids which in turn polluted the poopó lake which is considered as an important ...

Journal: :مرتع و آبخیزداری 0
خالد اوسطی استادیار دانشکدة منابع طبیعی دانشگاه کردستان علی سلاجقه استاد دانشکدة منابع طبیعی دانشگاه تهران محمد مهدوی استاد دانشکدة منابع طبیعی دانشگاه تهران پاول کوئنیگر استادیار مؤسسة علوم زمین و منابع طبیعی (bgr) ژئوسنتروم هانوفر، آلمان کامران چپی استادیار دانشکدة منابع طبیعی دانشگاه کردستان آرش ملکیان دانشیار دانشکدة منابع طبیعی دانشگاه تهران

within the climate change debate and its probable impacts on water resources systems, design and operation of management plans based on the assumption of stationary hydrology may cause serious challenge to accurately predict future supplies. therefore this case study is trying to assess trend in hydroclimatic variables of karkheh rivers upstream by applying modified mann-kendall trend test on l...

Background: Iran is located in the global arid zone. With an average rainfall of less than 250 mm. 25 percent is Iran of located in hyper-dry area and 40 percent in the arid area. In 2007, the World Bank report declared the annual reduction of freshwater resources in Iran 6 times more than global standards and indicators. Since at present, in Iran most available fresh water enters the water eco...

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