نتایج جستجو برای: wind erosion index

تعداد نتایج: 504575  

Journal: :مرتع و آبخیزداری 0
طیبه مصباح زاده استادیار گروه احیای مناطق خشک و کوهستانی، دانشکدة منابع طبیعی، دانشگاه تهران حسن احمدی استاد دانشگاه آزاد اسلامی، واحد علوم تحقیقات، تهران غلامرضا زهتابیان استاد گروه احیای مناطق خشک و کوهستانی، دانشکدة منابع طبیعی، دانشگاه تهران فریدون سرمدیان استاد گروه مهندسی خاک، دانشکدة مهندسی خاک، دانشگاه تهران فیروزه مقیمی نژاد کارشناس ارشد مرتعداری، دانشکدة منابع طبیعی، دانشگاه تهران

desertification is specific phenomenon of arid, semi-arid, dry sub humid regions. this phenomenon has a high rate in developing countries such as iran. the main objective of this research was calibration of imdpa model in abuzeidabad (kashan) region with emphasis on land criteria. imdpa model, introduced by iranian researchers to assess desertification intensity in iran. before application, the...

Journal: :آب و خاک 0
سکینه پورمند احمد غلامعلی زاده آهنگر عبدالحمید دهواری

introduction: wind erosion is one of the most important factors in desert environments. prevailing winds can shift sand dunes and affect their accumulation and morphology. also, wind regime determines the direction of sand dune mobility in different ways. therefore, the wind regime, frequency, direction and velocity are supposed to be the most important factors to form the morphology of sand du...

Journal: :international journal of environmental research 0
p. gallardo department of agronomy, university of almeria, spain j. salazar department of economics and business, university of almeria, spain f. j. lozano department of agronomy, university of almeria, spain m. c. navarro department of economics and business, university of almeria, spain c. asensio department of agronomy. university of almeria, spain

the influence of wind erosion on soil productivity was studied applying fan-forced wind in a wind tunnel located in the campo de nijar area in se spain where the main crops are cereals. wind erosion is highly variable depending on the type of soil (aric-haplic calcisols, aric-calcaric cambisols or aric-calcic luvisols, according to iuss working group wrb, 2014) and the time elapsed since the la...

Journal: Desert 2009
M. Ekhtesasi N. Mashhadi

Wind, in the duration of its erosional process, affects considerable changes in a grain's morphologyfrom its removal (detachment) step to sedimentation. In other word, a grain undergoes its gradualevolution during the transit process. In this project, the maturation of Aeolian sand grains had beenstudied upon as based on texture maturity indicator which includes: sorting, mean size grain, round...

2007
B. S. Sharratt

Wind erosion threatens soil productivity and air quality in the Columbia Plateau region of the Pacific Northwest United States. Management practices are sought that will abate erosion, but limitations exist in measuring the effectiveness of these practices in reducing erosion. Portable wind tunnels are ideal tools that can be used to assess the impact of management practices on erosion. A porta...

2011
Michael Lehning Thomas Grünewald

A local to regional assessment of transported snow during snow storms or subsequent periods of strong winds is a prerequisite to reliably predict avalanche danger. Despite the fact that it has received continuing attention for decades, the problem of quantifying snow transport persists. Systems from point measurements to full three-dimensional simulations are in operation but all have their res...

2014
Marjan Padidar Ahmad Jalalian Majid Abdouss Payam Najafi Naser Honarjoo Jaber Fallahzade

Wind erosion is a widespread phenomenon in arid region. The purpose of this study was assessed the capacity of nanoclay to control soil erosion in wind tunnel experiment. The nanoclay isolated from soils was dominant in montmorillonite. A sandy soil from the Khara desert, nearly 100 km East of Isfahan (Central Iran) was used. The soils of this area are structurally unstable and sandy texture ma...

2010
Jason P Field Jayne Belnap David D Breshears Jason C Neff Gregory S Okin Jeffrey J Whicker Thomas H Painter Sujith Ravi Richard L Reynolds

© The Ecological Society of America www.frontiersinecology.org F many scientists, the only dust they think about is the thin film of material that accumulates on their computer monitor on a regular basis. However, dust has enormous relevance to a wide range of ecological processes and environmental management challenges. Dust is fine particulate material that is removed from the land surface by...

2006
N. S. Copeland J. Q. Wu

Wind erosion is a widespread problem in much of the western United States due to arid conditions and persistent winds. Fugitive dust from eroding land poses a risk to both environmental quality and human health. Since the advent of the Clean Air Act in 1971, ambient air quality standards have been set regulating particulate matter in the atmosphere. Agricultural straw has been widely used for e...

Journal: :Journal of environmental quality 2009
N S Copeland B S Sharratt J Q Wu R B Foltz J H Dooley

Fugitive dust from eroding land poses risks to environmental quality and human health, and thus, is regulated nationally based on ambient air quality standards for particulate matter with mean aerodynamic diameter < or = 10 microm (PM10) established in the Clean Air Act. Agricultural straw has been widely used for rainfall-induced erosion control; however, its performance for wind erosion mitig...

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