نتایج جستجو برای: surface sediment

تعداد نتایج: 666636  

Recognition of origin of sand dunes is very important in wind erosion control projects. Because of many problems associated with traditional procedures for identifying sediment sources, fingerprinting techniques, based on physical, chemical and organic properties of sediment and source materials, are increasingly being used as a valuable and effective alternative approach to assembling such inf...

Journal: :international journal of environmental research 2011
h. li y. wang l.q. shi j. mi d. song

dianchi lake is one of the most three seriously eutrophic lakes in china. in the present study, the phosphorus (p) and nitrogen (n) fractions in 37 surface sediments samples collected in the dianchi lake were investigated. the total phophorus (tp) in sediments was divided into two parts: inorganic p (ip) and residual p (res-p). the results showed that the total phosphorus content in surface se...

Journal: :تحقیقات جغرافیایی 0
محمود حبیب اللهیان دانشگاه حکیم سبزواری احمد نوحه گر دانشکده محیط زیست دانشگاه تهران علیرضا کمالی منابع طبیعی محمود حبیب اللهیان دانشگاه حکیم سبزواری معصومه رخبین پردیس دانشگاهی قشم دانشگاه هرمزگان احمد نوحه گر دانشکده محیط زیست دانشگاه تهران

â increase in wastage of soil resources in watershed is a persistent challenge that with increase in population and pressure on natural sources and unstable plantation on gradient farms and soils cause production reduces on farms, and also decrease in daily ratio of farms to population can cause more pressure on lands and natural resources.lavarefin watershed placed in 60 km from bandarabass in...

Journal: :Water research 2011
Yi-Zhang Zhang Xian-Fang Song Akihiko Kondoh Jun Xia Chang-Yuan Tang

Historically, the locations of cities mainly depend on the available water source and the urban river not only supplies the fresh water to city but also receives its wastewaters. To analyze the influences of urban zone on its receiving water river, the Jialu River in Henan Province, China, a typical urban river was chosen. Water and sediment samples were collected along the river in 2007 to ana...

ژورنال: علوم آب و خاک 2018

The study of flow patterns in front of intake has been attracted the attention of researchers during the past decades to explore the mechanism of flow and sediment entry to the intake. In this study, the separation and stream tube dimensions were investigated in water intakes installed to rectangular and trapezoidal main channel. These researches were carried out with experimental and fluent mo...

2003
Andreas Krein Ellen Petticrew Thomas Udelhoven

As many particle-associated contaminants and nutrients are supply controlled, the question of particle source is crucial. In addition, sediment storage has important implications for the delivery and fate of pollutants. Increased accumulations of fine sediment ( < 63 Am) in gravel beds not only modify benthic habitat but also increase the retention time of sediment-associated contaminants in th...

1997
Sharpe G L Curry D W Demichele

Alternative method for the calculation of mean time for the assessment of secondary production by true cohort analysis. Abstract-Particle-scavenged 234Th and *'OPb can be used to trace the fate of particulate matter reaching the deep-sea floor. We used this technique to demonstrate rapid ingestion of particles arriving at the sea floor (at a depth of 4,100 m) by mobile epibenthic holothuroids (...

ژورنال: علوم آب و خاک 2015
خسروی, غلامرضا, صفری, عطا, عبدالهی, حمیدرضا, فتحی‌زاد, حسن, فرهودی, محمدحسین, وهاب‌زاده, قربان,

In this research, sediment production and delivery amount by Darabkola forest roads was estimated using the SEDMODL model. To evaluate the model results, the sedimentation rate in the above roads was directly measured using rainfall simulator. Also, the paired t-test, BIAS, RE and RMSE were used to assess the results. The analysis showed that the rate of sediment production from study roads' su...

Journal: :Coastal Engineering Proceedings 1978

2003
Michael B. Wyatt Harry Y. McSween Jeffrey E. Moersch Phillip R. Christensen

[1] We examine the distribution of Thermal Emission Spectrometer (TES) derived surface compositions in the Oxia Palus region on Mars through high-spatial-resolution mapping and integration with Mars Orbiter Camera and Mars Orbiter Laser Altimeter data sets. We also fit the basalt and andesite-weathered basalt interpretations of TES surface type 1 and type 2 materials into multiple working hypot...

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