نتایج جستجو برای: 1 gypsum in reducing sediment concentration diminished 35 min after runoff initiation whereas

تعداد نتایج: 17723790  

Journal: :Journal of environmental quality 2004
I C Daverede A N Kravchenko R G Hoeft E D Nafziger D G Bullock J J Warren L C Gonzini

Excessive fertilization with organic and/or inorganic P amendments to cropland increases the potential risk of P loss to surface waters. The objective of this study was to evaluate the effects of soil test P level, source, and application method of P amendments on P in runoff following soybean [Glycine max (L.) Merr.]. The treatments consisted of two rates of swine (Sus scrofa domestica) liquid...

ژورنال: علوم آب و خاک 2013
خزایی, مجید , شفیعی, اردشیر , ملایی, علی ,

The present study aimed to compare the effect of land cover on runoff and sediment with different coverage levels in Mehrian watershed. The study was carried out in a plot with the dimensions 3 × 2 meters during one year, in three different treatments (including without coverage, grass treatment and integrated treatment having brush and grass coverage) and in three replications. At the end of e...

2014
Su Ding Yunping Xu Yinghui Wang Xinyu Zhang Liang Zhao Jiaping Ruan Weichao Wu

Polycyclic aromatic hydrocarbons (PAHs) were analyzed for surface sediments and a sediment core from the Yellow River-dominated margin. The concentration of 16 USEPA priority PAHs in surface sediments ranged from 5.6 to 175.4 ng g(-1) dry weight sediment (dws) with a mean of 49.1 ng g(-1) dws. From 1930 to 2011, the distribution of PAHs (37.2 to 210.6 ng g(-1) dws) was consistent with the socio...

INTRODUCTION Soil erosion and its issues are among the most important environmental challenges. In many areas, soil erosion affected valuable natural resources and soil fertility. The recognition of the factors affecting runoff and soil erosion, and the determination of their issues are essential for soil and water management conducive to sustainable development. The assessment and analysi...

Journal: :مرتع و آبخیزداری 0
مسعود مؤمنی محمود کلباسی2 احمد جلالیان حسین خادمی

the discharge of total suspended sediments (tss) and dissolved nutrients from watersheds into receiving waters is a serious problem when natural vegetation is degraded by agriculture or overgrazing. this study was conducted in soolegan watershed to investigate land use change and overgrazing effects on phosphorus loss (dissolved & particulate), particle size associated loss of p and effect of t...

2016
Gerard F Ricardo Ross J Jones Peta L Clode Andrew P Negri

Suspended sediments produced from dredging activities, or added to the sediment budget via river runoff, are a concern for marine resource managers. Understanding the impact of suspended sediments on critical life history stages of keystone species like corals is fundamental to effective management of coastlines and reefs. Coral embryos (Acropora tenuis and A. millepora) and larvae (A. tenuis, ...

افیونی, مجید, حیدرپور, منوچهر, رستمیان, رخساره, عباسپور, کریم, موسوی, سید فرهاد,

Soil erosion is an important economical, social and environmental problem requiring intensive watershed management for its control. In recent years, modeling has become a useful approach for assessing the impact of various erosion-reduction approaches. ِDue to limited hydrologic data in mountainous watersheds, watershed modeling is, however, subject to large uncertainties. In this study, SWAT200...

اسماعیلی, روح اله, خوجه, نصیر, قدوسی, جمال,

According to the importance of loss areas, which have embarrassed a wide region of Golestan province and its important role in formation of the sediment of Gorgan river, more accurate recognition of types of loss erosion seems essential in order to providing necessary function for erosion and sediment problems in them, specially gully erosion. So, in this study we are going to providing regress...

Journal: :Chemosphere 2008
Martin A Locke Robert M Zablotowicz Krishna N Reddy R Wade Steinriede

Conservation tillage mitigates soil loss in cropland because plant residues help protect the soil, but effects on pesticide movement in surface runoff are not as straightforward. Effects of soil disturbance on surface runoff loss of chlorimuron and alachlor were evaluated utilizing runoff trays. Soil in the trays was either disturbed (tilled) and kept bare or was not tilled, and existing decomp...

Journal: :اکو هیدرولوژی 0
مسعود عشقی زاده دانش‏ آموختۀ دکتری علوم و مهندسی آبخیزداری دانشگاه یزد محمد تقی دستورانی دانشیار، دانشکدۀ منابع طبیعی و کویر شناسی، دانشگاه یزد حمید رضا عظیم زاده استاد، دانشکدۀ منابع طبیعی و محیط زیست، دانشگاه فردوسی مشهد

in this research introduced the lapsus model as a runoff, erosion and sediment model in iran. this model for the first time has operatedin iran at kakhk paired catchment of gonabad. lapsus model is a landscape evolution model that can estimate the runoff, erosion and sediment at the four stage include: calculate the effective rainfall, runoff routing, calculate the capacity of sediment transpor...

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