نتایج جستجو برای: wind erosion

تعداد نتایج: 112342  

Journal: :desert 2008
h. r. azimzadeh m. r. ekhtesasi h. gh. refahi h. rohipour m. gorji

wind erosion is a significant problem on 20 million ha of iran, especially in central plains and coastal areas. winderosion samplers, meteorological equipments and measurement procedure have been developed over the last twocenturies to measure the particles moving across the field in modes of creep, saltation and suspension. in recentresearch as the first technical measurement in iran, wind ero...

Journal: :desert 0
n. mashhadi international research center for living with desert, university of tehran, iran m. hanifehpoor faculty of natural resources, university of tehran, karaj, iran f. amiraslani rs & gis dept., faculty of geography, university of tehran, tehran, iran sh. mohamadkhan natural geography dept., faculty of geography, university of tehran, tehran, iran

aeolian process and subsequently soil erosion are key factors in dryland environments. such phenomena are related not only to geoecological factors (lithology, topography, and climatology) but also to land-use and plant cover changes. formation of new sand dunes in damghan explains the development of human activities over the past. the aim of this study is to explain the land use changes and th...

2006
Brian C. WELCH Robert W. JACOBEL

Ice stratigraphy from deep-penetrating radar data collected during the 2002 US International Trans-Antarctic Scientific Expedition (US-ITASE) traverse shows evidence of a significant erosion surface and drift-filled basin related to a previously undiscovered 1400m subglacial mountain between Hercules Dome (878420 S, 1088W) and South Pole. The 3MHz radar profile crosses three subglacial mountain...

2017
Juan E. Panebianco Mariano J. Mendez Daniel E. Buschiazzo Donaldo Bran Juan J. Gaitán

Wind erosion of freshly-deposited volcanic ash causes persistent storms, strongly affecting ecosystems and human activity. Wind erosion of the volcanic ash was measured up to 17 months after the ash deposition, at 7 sites located within the ash-deposition area. The mass flux was measured up to 1.5 m above ground level. Mass transport rates were over 125 times the soil wind-erosion rates observe...

Background and Amis: The most important environmental challenges facing the West of iran in recent years is the dust phenomenon, that today has become one of the most important problems in arid and semi-arid areas. This phenomenon occurs as a climatic phenomenon in all climatic conditions, that causes adverse social, economic, environmental and commercial impacts. In this research have used dus...

2002
Simon J. van Donk Edward L. Skidmore

Field data need to be collected to test wind erosion models under a broad range of climate, soil, and management conditions. The objective of this study was to test the USDAARS Wind Erosion Prediction System (WEPS) for a field with winter wheat plants in a modest amount of flat residue. A 600 m by 415 m field was selected near Burlington, CO, USA. Big Spring Number Eight (BSNE) samplers were us...

2003
TED M. ZOBECK GEERT STERK ROGER FUNK JEAN LOUIS RAJOT JOHN E. STOUT

Accurate and reliable methods of measuring windblown sediment are needed to confirm, validate, and improve erosion models, assess the intensity of aeolian processes and related damage, determine the source of pollutants, and for other applications. This paper outlines important principles to consider in conducting field-scale wind erosion studies and proposes strategies of field data collection...

2016
L. Kerber

Introduction: Yardangs are wind-eroded ridges common in regions of Mars [1] and in the most arid deserts on Earth. Yardangs have also been documented on both Venus [2] and Titan [3]. Throughout the years, studies of yardangs have concentrated on particular field sites, and therefore conclusions relating to the controlling parameters on yardang morphology have been highly divergent. Many variabl...

2012
J.G.S. Keijsers A. Poortinga A. V. de Groot

Foredune volume is an important factor for coastal safety and depends on the balance between erosion through wave attack and sediment input via aeolian transport. Dune erosion can be simulated with good accuracy, but predictions of aeolian sediment transport into the foredunes are still difficult to make. As part of a larger project that aims to model foredune development over decades, the goal...

Journal: :مرتع و آبخیزداری 0
طیبه مصباح زاده دانشجوی دکتری بیابانزایی، دانشکده منابع طبیعی،دانشگاه تهران ،ایران حسن احمدی استاد گروه احیای مناطق خشک وکوهستانی ، دانشکده منابع طبیعی،دانشگاه تهران ،ایران غلامرضا زهتابیان استاد گروه احیای مناطق خشک وکوهستانی ، دانشکده منابع طبیعی،دانشگاه تهران ،ایران فریدون سرمدیان استادیار گروه مهندسی آب وخاک، دانشکده مهندسی آ ب وخاک، دانشگاه تهران ،ایران

investigation and preparing of wind erosion intensity maps are the main objectives of this research. in this research, the working unit map was prepared and then nine effective factors in wind erosion according to irifr.e.a model are determined at each of seven homogeneous units. according to the results, active sand dunes and landuse change showed the highest value with the rate of annual sedi...

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