نتایج جستجو برای: depth of erosion

تعداد نتایج: 21173270  

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...

شهنواز, یاسر, علی پور, حمید, غلام نیا, اعظم, هاتفی اردکانی, امیرحسین, هاشمی نسب, سیده نگار,

Wind erosion is important in areas with less than 150 mm of rainfall Measuring the extent and severity of wind erosion in many countries, including Iran, there is no station to measure wind erosion sediments and so the deposition estimation methods rely on empirical models so that in many cases there are measurement errors. With estimates wind and water erosion and deposition potential compared...

2008
A. J. Roberts D. J. Georgiev D. V. Strunin

Floods, tides and tsunamis are turbulent, yet conventional models are based upon depth averaging inviscid irrotational flow equations. We propose to change the base of such modelling to the Smagorinksi large eddy closure for turbulence in order to appropriately match the underlying fluid dynamics. Our approach allows for large changes in fluid depth to cater for extreme inundations. The key to ...

  Soil organic carbon (SOC) is a principal component in soil quality assessment. Knowledge of SOC and total nitrogen (TN) stocks are important keys to understand the role of SOC in the global carbon cycle and, as a result, in the mitigation of global greenhouse effects. SOC and TN stocks are functions of the SOC concentration and the bulk density of the soil that are prone to changes, influe...

Journal: :International dental journal 2005
Thomas C Abrahamsen

Historically, the dental literature has revealed various causes of tooth wear, yet it has failed to provide a conclusive method of differentiation and diagnosis of the condition. The categories of tooth wear encountered most commonly in dental practice are abrasion and erosion. The major causes of wear from abrasion are bruxism and toothpaste abuse, and the major causes of wear from erosion are...

2011
KENNETH T. NICHOLSON S. J. SIBENER TIMOTHY K. MINTON

The erosion of highly-ordered pyrolytic graphite (HOPG) caused by exposure to hyperthermal atomic oe p) atoms was explored. Profilometry has revealed that the overall erosion yield is linear with respect to increasing atomic oxygen exposure at a constant sample temperature of 373 K. Atomic force microscopy (AFM) was employed to image the eroded material that contains numerous nanoscale to micro...

The lack of water in arid and semi-arid areas has become a serious crisis, endangering living conditions. Sloping lands in the geographical and natural areas of Central Province have always been critical areas as sources of sediment production and erosion. Meanwhile, these areas provide valuable capacity for productive employment and conservation of water and soil resources through the construc...

2011
Mehrad Kamalzare Christopher Stuetzle Zhongxian Chen Thomas F. Zimmie Barbara Cutler Randolph Franklin

The overall intent of this research is to develop numerical models of erosion of levees, dams and embankments, validated by physical models. The physical models are performed at 1-g and at high g’s using a geotechnical centrifuge. The erosion is modeled in detail, from beginning to end, that is from the time the levee is overtopped until the levee is breached. Typical quantities measured as a f...

2004
Paul M. Schenk David A. Williams

[1] We have discovered a prominent >190 km long, 0.5– 6 km wide lava channel on Io. The channel is sinuous with interior islands andmay be associatedwith the active Tawhaki Patera hotspot. Photoclinometric analysis of the Galileo images indicates that this channel, provisionally named Tawhaki Vallis, is 40 – 65 m deep. Although a constructional contribution cannot be ruled out, the depth, morph...

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