نتایج جستجو برای: water levels ‎and rivers

تعداد نتایج: 1435696  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1389

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

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...

2015
Lei Zhang Shiguang Shao Cheng Liu Tingting Xu Chengxin Fan Benoit Demars

Nutrient inputs from rivers play an important role in lake eutrophication. To compare the forms characteristics of phosphorus (P) and nitrogen (N) in rivers flowing through rural and urban areas, water samples were collected seasonally from five urban rivers and six rural rivers flowing to Lake Chaohu, China. Higher total phosphorus (TP), particulate phosphorus (PP), soluble reactive phosphorus...

Journal: :The Onderstepoort journal of veterinary research 1981
C J Howell G J Begemann R W Muir P Louw

It was found that the build-up of simuliid numbers subsequent to the construction of dams in the Vaal and Orange Rivers could be successfully prevented by periodic, artificially controlled reductions in the water-levels in these rivers.

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...

2013
E. U. Etim G. U. Adie

Available sources of portable water for drinking, domestic and industrial chores in Nigeria are dwindling because of concomitant increase in population, urbanization and industrial activities. This study assessed the qualities of Surface Water (SW), Sediment (SD) and Tilapia Fish (Oreichromis niloticuss) (TF) samples collected from Asejire, Oni, Ona, Ogun, Ogunpa, Eleyele and Majidun rivers and...

Journal: :Environmental monitoring and assessment 2009
Machiko Kido Yustiawati M Suhaemi Syawal Sulastri Toshiyuki Hosokawa Shunitz Tanaka Takeshi Saito Toshio Iwakuma Masaaki Kurasaki

In Java and Kalimantan in Indonesia, river water plays important roles in human life; for example, for transportation, and economic activities of the inhabitants. However, industrial, agricultural and domestic water is discarded into rivers directly in many developing countries, including Indonesia, since drainage systems have not been completely constructed. In this study, to evaluate the wate...

Journal: :Journal of water and health 2007
Ahmad Houri Saadieh W El Jeblawi

The chemical and microbiological properties of Lebanese perennial coastal rivers were studied during the dry season extending from July to September 2004. The results indicate significant levels of pollution in all eight rivers. Although many physical and chemical variables were within WHO guidelines for drinking water, coliform levels were unacceptably high indicating pollution from untreated ...

Journal: :محیط زیست طبیعی 0
یوسفعلی احمدی ممقانی دانش آموخته کارشناسی ارشد شرکت مهندسان مشاور آب و عمران فرازاندیش، ایران نعمت ا... خراسانی استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران غلامرضا رفیعی استادیار دانشکده منابع طبیعی، دانشگاه تهران، ایران

rivers are one of the most valuable aquatic ecosystems that their physiochemical properties and the biology of their organisms have strong interactions. one of the major rivers in iran, which covers a variety of ecosystems, is called tajan river. in this research, the effect of different pollution sources on water quality of this water body was investigated. samples were collected in seven diff...

2015
Gouthami Rao Joseph N. S. Eisenberg David G. Kleinbaum William Cevallos Gabriel Trueba Karen Levy

The use of contaminated surface water continues to be a pressing issue in areas of the world where people lack improved drinking water sources. In northern coastal Ecuador, many communities rely on untreated surface water as their primary source of drinking water. We undertook a study to explore how microscale river hydrodynamics affect microbial water quality at community water collection loca...

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