نتایج جستجو برای: sediment production

تعداد نتایج: 638245  

Journal: :مرتع و آبخیزداری 0
محسن پادیاب دانش آموخته کارشناسی ارشد بیابانزدایی، دانشکده منابع طبیعی، دانشگاه تهران، ایران سادات فیض نیا استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران

importance of sediment storage has been expressed as being higher than that of water in floodwater spreading networks. to determine the contribution of each geological formation in sediment input of gachsaran floodwater spreading station after 12 years of flood spreading, sediment sampling was conducted in 16 points and 0-15 cm depth of the field. using dry sieve analysis, all samples were anal...

Different factors affect the runoff and sediment production during storm conditions. Among different soil properties, clay content is one of the most important bonding agents for aggregation and infiltration. Rock fragments also affect hydrological and erosional processes, but these relationships in various soil clay contents or surface rock fragments may be positive or negative, thus examinati...

2007
Carlos E. Ramos-Scharrón Lee H. MacDonald

A quantitative understanding of both natural and anthropogenic sediment sources is needed to accurately assess and predict the potentially adverse effects of land development on aquatic ecosystems. The main objective of this study was to quantify sediment production and delivery rates in a dry tropical environment on the island of St. John in the eastern Caribbean. One to three years of measure...

Journal: :journal of rangeland science 2014
farhad nourmohammadه taher fatollahه javad mirzaei karim soleimani mahmoud habibnejhad roshan

erosion is one of the important social-economic problems in iraniancatchments that have been posed by surface water vastness and runoff production. so, thestudy of water resources, soil erosion and effective factors is of high importance. gullyerosion also extends in many parts of iran and its study particularly in viewpoint ofsediment yield is therefore very important and should be taken into ...

2006
Adrienne L. Stutes Alina A. Corcoran

The impact of anthropogenic eutrophication on the productivity and metabolism of estuarine sediments has received relatively little attention. In this study, we investigated the separate and combined effects of decreased light availability and sediment nutrient enrichment, 2 of the most important impacts of anthropogenic eutrophication, on sediment primary production and metabolism in 2 eutroph...

Journal: :آب و خاک 0
سلیمان پور سلیمان پور صوفی صوفی احمدی احمدی

abstract gully erosion is a kind of water erosion that has high priority in fars province due to sediment production and enormous damages to land, roads and infrastructures. in this study, 15 gullies were selected and their morphometric characteristics, such as catchment area, soil, cover vegetation and climate were measured. in order to determine influential factors on the sediment production ...

ژورنال: علوم آب و خاک 2017
زارع خورمیزی, مهناز, سلیمانی, کریم, نصرتی, کاظم, کاویان, عطااله,

Obtaining information about relative importance of sediment sources and their contributions on sediment production and thus identification of on-site critical areas is required for implementing soil and water conservations and sediment control programs. For this reason, in this study 35 geochemical tracers and organic carbon were measured in 45 samples of sediment sources and in 11 watershed se...

Journal: :The Science of the total environment 2016
A B Gray G B Pasternack E B Watson M A Goñi J A Hatten J A Warrick

This study is an investigation into the roles of wildfire and changing agricultural practices in controlling the inter-decadal scale trends of suspended sediment production from semi-arid mountainous rivers. In the test case, a decreasing trend in suspended sediment concentrations was found in the lower Salinas River, California between 1967 and 2011. Event to decadal scale patterns in sediment...

2009
Michael Nielsen Armin Gieseke Dirk de Beer Niels Peter Revsbech

The dynamics of the nitrogen intermediates N2O and NO2 in estuarine sediments were studied along a salinity gradient in the eutrophied Weser Estuary (Germany) using microsensors for N2O, NO2, NOx, and O2. During dark incubations in the laboratory of sediment samples from a freshwater site, a brackish water site with fluctuating salinity, and a marine site, the effects of environmental changes i...

2016
Vahid Noroozi Karbasdehi Sina Dobaradaran Iraj Nabipour Hossein Arfaeinia Roghayeh Mirahmadi Mozhgan Keshtkar

In this data article, by using inductively coupled plasma optical spectrometry (ICP-OES), we aimed to (1) determine the concentration levels of As, Ag, Sr, Sn, Sb, and Mo in the sediments and the shells of Trachycardium lacunosum simultaneously in two separated areas (unpolluted and polluted areas) (2) comparison between the metal contents of sediments in the unpolluted and polluted areas as we...

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