نتایج جستجو برای: sediment control

تعداد نتایج: 1363410  

2001
Charles H. Luce

Observations of sediment yield from road segments in the Oregon Coast Range show that either heavy traffic during rainfall or blading the road ditch will increase erosion from forest roads. For the fine soils and high quality aggregate surfacing on the study plots, ditch blading increased sediment yield more than traffic equivalent to 12 log trucks per day. The combination of ditch blading and ...

2017
Christine N. Shulse Brianne Maillot Craig R. Smith Matthew J. Church

Concentrated seabed deposits of polymetallic nodules, which are rich in economically valuable metals (e.g., copper, nickel, cobalt, manganese), occur over vast areas of the abyssal Pacific Ocean floor. Little is currently known about the diversity of microorganisms inhabiting abyssal habitats. In this study, sediment, nodule, and water column samples were collected from the Clarion-Clipperton Z...

2009
C. HANS NELSON CARLOTA ESCUTIA

Three case studies are used to exemplify the wide variety of controlling factors that combine to influence the development of modern turbidite systems, and how these vary with location and time. For example, Cascadia Basin in the Pacific Ocean off western North America, which is underlain by the Cascadia Subduction Zone, exhibits the dominant tectonic control of earthquake triggering for turbid...

2017
Jing He Derong Su Shihai Lv Zhaoyan Diao Jingjie Xie Yan Luo

Rising temperature causes a process of phosphorus release, which can be characterized well using phosphorus release rates (VP). The objective of the present study was to investigate the major factors affecting sediment phosphorus release rates through a wetland habitat simulation experiment. The results showed that the VP of different wetland sediments were different and changed with the order ...

Dams control most of the sediment entering the reservoir by creating static environments. However, sediment leaving the dam depends on various factors such as dam management method, inlet sediment, water height in the reservoir, the shape of the reservoir, and discharge flow. In this research, the amount of suspended sediment of Doroodzan Dam based on a statistical period of 25 years has been i...

Journal: :محیط زیست طبیعی 0
مریم زارع دانشجوی کارشناسی ارشد، گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران امیرحسین حمیدیان استادیار گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران هادی پورباقر استادیار گروه شیلات، دانشکده منابع طبیعی دانشگاه تهران، ایران سهراب اشرفی استادیار گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران لیلا وزیری دانشجوی کارشناسی، گروه محیط زیست، دانشکده منابع طبیعی دانشگاه تهران، ایران

industrial activities lead to an increase in heavy metal burden in rivers. sediment and algae (spirogyra sp.) samples were collected from the shoor river to investigate their heavy metal concentrations. dry and ashed samples of algae and sediment were digested using concentrated nitric acid. heavy metals (as, fe, zn and cr) concentration measured using an icp-oes instrument (perkinelmer, usa). ...

2011
Justin Ellis Duncan Hughes Alex Smith

Strategic efforts to abate sediment in impaired watersheds face numerous challenges in achieving tangible water quality improvements that are measurable, attributable to project actions, and focused on principle causative sources. As part of a small watershed sediment control strategy, the Soque River Watershed Partnership will examine the feasibility of conducting sediment source assessments f...

2017
H. J. van Meerveld E. J. Baird W. C. Floyd

Unpaved resource roads have the potential to produce large amounts of sediment and can negatively impact water quality and aquatic ecology. In order to better understand the dominant controls on sediment generation from unpaved resource roads, we did 23 large-scale rainfall simulation experiments on a road section in the Honna Watershed, Haida Gwaii, British Columbia, Canada. The experiments we...

Journal: :مرتع و آبخیزداری 0
سادات فیض نیا استاد دانشکدة منابع طبیعی دانشگاه تهران اصغر کوهپیما باشگاه پژوهشگران جوان، واحد شیراز، دانشگاه آزاد اسلامی، شیراز، ایران حسن احمدی استاد دانشکدة منابع طبیعی دانشگاه تهران علی اصغر هاشمی مرکز تحقیقات کشاورزی و منابع طبیعی سمنان ، سمنان ، ایران

due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of chasht-khoran basin in semnan province: amrovan, atari and ali-abad. samples below 63 μm were separated and 15 fingerprinting propertis was measured. in the first stage comparison of means and differentiation analysis were use...

Journal: :ecopersia 2011
asghar kouhpeima sadat feiznia hasan ahmadi seyed ali asghar hashemi

sediment-related environmental problems pose a serious threat to sustainable land management in many developing countries, including iran. information regarding sediment sources represents a key requirement from the management perspective since identification of sediment sources is a precursor to the design of effective sediment management and control strategies. the fingerprinting approach has...

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