نتایج جستجو برای: and rivers

تعداد نتایج: 16829769  

2004
Robert Pitt

Most people know that urban runoff is a problem. Few understand just how harmful it can be for rivers and streams. To secure better watershed planning urban runoff control, we must first convince the public and its officials that they are needed. We need to show clearly and convincingly both the nature and the magnitude of the water quality and quantity problems that poorly planned and managed ...

ژورنال: اقیانوس شناسی 2020

Providing faultless proceeding of the engineer in order to protect the rivers, requires understanding the morphological behavior of the river and studying the hydrodynamic phenomena of the area. The intersection of the Karun rivers as the largest and longest river in Iran with the Arvand border river is of considerable importance due to its strategic location. In this paper, using field measure...

1998
John D. Wehr Louis Calder Jean-Pierre Descy

Historically, rivers have served as sources of drinking water, fisheries resources, transportation routes, irrigation supplies, and waste removal systems. Human civilization has had many major effects on rivers, dating back more than 5000 years when Egyptians built dams on the Nile to supply water for crops and human consumption. Today, management of large rivers requires a balance between huma...

ژورنال: سلامت و محیط زیست 2013
امیر مرادی, کیمیا, بانژاد, حسین, علیائی, احسان, کمالی, مهسا,

Background and Objectives: Rivers are the most important resources supplying drinking, agricultural, and industrial water demand. Their quality fluctuates frequently due to crossing from different regions and beds as well as their direct relationship with their peripheral environments. Thus, it is essential to be considered the surveying and predicating changes in the water qualitative paramete...

Erosion and sedimentation that will lead to morphological changes in rivers are found in alluvial rivers. Morphological changes in rivers can cause numerous problems, so studying the shape of alluvial rivers in morphology is very important in morphology science. In this study, morphology changes of the Zohreh River in the Hendijan plain, for a length of about 23 km between latitudes 30´ 49° and...

2004
CARYN C. VAUGHN DANIEL E. SPOONER

—The Poteau River, a major tributary of the Arkansas River, flows through the Ouachita Uplands of eastern Oklahoma and western Arkansas. The river has been harvested for mussels, historically by the Caddo Indians and recently for the pearl industry. We documented the current distribution and abundance of mussels in the river, compared this with historical distributions and examined whether the ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Victor R Baker

The windings of rivers have long fascinated their human observers. For example, Aboriginal legend explains the sinuous pattern of the modern Finke River (Fig. 1) as the creation of the immense and powerful Rainbow Serpent as he emerged during the Dreamtime from deep waterholes. Recently in PNAS (1), a new theory for the general origin of such sinuous flow patterns was published, which follows f...

2001
JASON L. WHITE BRET C. HARVEY

1. We used field surveys to compare the density and mesohabitat-scale distribution of the native coastrange sculpin (Cottus aleuticus) and the prickly sculpin (C. asper) in coastal rivers in north-western California, U.S.A., with and without an introduced piscivorous fish, the Sacramento pikeminnow, Ptychocheilus grandis. We also measured mortality of tethered prickly sculpin in a field experim...

Journal: :پژوهش های جغرافیای طبیعی 0
سعدون سلیمی کارشناسی ارشد آب و هواشناسی سینوپتیک، دانشگاه خوارزمی محمد سلیقه دانشیار گروه آب وهواشناسی، دانشگاه خوارزمی

introduction water vapor can spread in molecular, unstable and erratic phase and can also transfer by convection and advection process. this transfer happens from the earth and ocean surfaces to the atmosphere in hot air. this type of transfer is considered as the main pattern. in the studies of the atmosphere, one of the prominent factors to be considered is the complexity of water vapor and i...

Journal: :iranian journal of ichthyology 0
hamed kolangi miandare department of fisheries, faculty of fisheries and environment, gorgan university of agricultural sciences and natural resources, gorgan, golestan, iran. omid jafari department of fisheries, faculty of fisheries and environment, gorgan university of agricultural sciences and natural resources, gorgan, golestan, iran. hajer ben alaya laboratory of marine biology, university of sciences of tunis, tunisia.

the aim of this study was to access the genetic differentiation of paraschistura sp. in kheirabad and brim rivers (zohreh river system, persian gulf basin), iran. for this purpose, 60 samples including 30 male and 30 female samples from each river were collected. a total of six microsatellite loci (bbar4, bbar7, ic228, ic230, ic434 and ic720) were used and all of them showed high polymorphism (...

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