نتایج جستجو برای: sediment production

تعداد نتایج: 638245  

2013
Roman A. DiBiase Michael P. Lamb

[1] Steep, rocky landscapes commonly exhibit high sediment yields and are especially sensitive to climate, tectonics, and wildfire. Predicting landscape response to these perturbations demands a quantitative understanding of erosion processes. However, existing models for hillslope sediment production and transport do not apply to landscapes with patchy soil and slopes that exceed the angle for...

Journal: :مرتع و آبخیزداری 0
محمد نهتانی دانشجوی دکتری آبخیزداری، دانشکدة منابع طبیعی دانشگاه تهران سادات فیض نیا استاد دانشکدة منابع طبیعی دانشگاه تهران حسن احمدی استاد دانشکدة منابع طبیعی دانشگاه تهران حمیدرضا پیروان استادیار پژوهشکدة حفاظت خاک و آبخیزداری کشور

loess deposit is one of the most important quaternary deposits of northeastern parts of iran which have high erosion rate. this study was performed with field- rainfall- simulator which has a plot area of 1 m2 in gorganrood drainage basin to determine the effective factors on sediment yield. landuse, slope and erosion feature maps were overlaid in gis to obtain land unit map. then on work units...

ژورنال: آبخیزداری ایران 2021

Soils are severely damaged by acid rain; acid rain also leads to excessive dissolving of minerals and valuable nutrients in the soil, which weakens vegetation. In this study, in order to determine the interaction effect between the slope aspect and precipitation intensity relative to acid rainfall in the Aghajari and Gachsaran formations, a part of Margha and Kuhe Gach watersheds of Izeh city w...

Journal: :مرتع و آبخیزداری 0
سیدمسعود سلیمان پور دانشجوی دکتری علوم و مهندسی آبخیزداری، دانشگاه آزاد اسلامی واحد علوم و تحقیقات تهران، ایران مجید صوفی استادیار پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی استان فارس، ایران حسن احمدی استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران

gully erosion has an important role in fars province due to sediment production and enormous damages to land, roads and infrastructures. in this research, 15 gullies were selected to measure their morphometric characteristics. the length, depth, top and bottom width and volume of gully erosion were then measured. influential factors on the sediment production and gully development were analyzed...

2001
Darryl E. Granger Paul F. Muzikar

Dating sediment burial over million-year time scales is crucial in many areas of the Earth sciences and archeology, but is often difficult using traditional techniques. Sediment burial can be dated by the radioactive decay of cosmogenic nuclides, provided that the sediment was exposed to cosmic rays prior to burial. Dating calculations are straightforward if sediment is buried deeply and rapidl...

2015
Tan T. Nguyen Bjarne Landfald

Spatial variations in composition of marine microbial communities and its causes have largely been disclosed in studies comprising rather large environmental and spatial differences. In the present study, we explored if a moderate but temporally permanent climatic division within a contiguous arctic shelf seafloor was traceable in the diversity patterns of its bacterial and archaeal communities...

Aims & Backgrounds: Today, soil erosion and sediment production are considered a danger to humans and their lives, so in areas where soil erosion is not controlled, soils gradually erode and lose their fertility. The aim of this study is to model the relationship between the amount of suspended sediment load and the geomorphic features of the Nirchai River Basin. Methodology: In this study, GIS...

ژورنال: علوم آب و خاک 2003
حسین خادمی, , امیرحسین چرخابی, , محسن شکل‌آبادی, ,

Soil erodibility in arid regions, particularly in less developed soils, greatly depends on parent material. The objectives of this study included comparison of the potential of runoff and sediment production in soils with different parent materials and identification of the highly sensitive parent materials in Golabad watershed, 60 km northeast of Isfahan, with about 160 mm of annual precipitat...

2002
DAVID A. DUNNETTE DAVID P. CHYNOWETH

-Putrefactive hydrogen sulfide production in the upper 4 cm of sediment in two small freshwater and eutrophic Southeast Michigan, U.S.A., lakes ranged from 0.13 to 1.51 with an average of 0.46 mg S l-~ day-~. Sulfate reductive production of hydrogen sulfide at the same sites ranged from 0.7 to 3.2 with an average of 1.54 mg S 1~ dayt. Putrefactive hydrogen sulfide production represented 5.1-53°...

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