نتایج جستجو برای: soil initial moisture and silt percent affect on soil erosion

تعداد نتایج: 18582098  

2012
E. A. Carter

Three studies conducted in Alabama evaluated impacts associated with a clear cut harvest in three physiographic regions. Machine impacts were assessed via tabulation of soil disturbance classes, measurement of bulk density and soil strength, or a combination of the two. Soil disturbance classes were similar among all locations with untrafficked areas comprising approximately 20 percent of the h...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده جنگلداری و مهندسی چوب و کاغذ 1391

درک الگوی توزیع مکانی ماکروفون خاک بدلیل اثرات آن روی فرآیندهای اکوسیستم بسیار مهم است. لیکن اطلاعات کمی در این خصوص وجود دارد. درمورد تنوع زیستی ارگانیسم ها وجانداران خاکزی که ازاجزای مهم وکلیدی درهرسیستم اکولوژیکی هستند و در بهبود حاصلخیزی خاک و تولیدات زمین وپایداری اکوسیستم ها(ازطریق فرآیندهای بیولوژیک)نقش عمده دارند تحقیقات کمی انجام شده است. این تحقیق جهت بررسی الگوی مکانی پارامترهای تنوع...

Journal: :مرتع و آبخیزداری 0
حمزه سعیدیان کارشناس ارشد آبخیزداری، دانشکده منابع طبیعی، دانشگاه تربیت مدرس، حمیدرضا مرادی استادیار دانشکده منابع طبیعی، دانشگاه تربیت مدرس فرج ا... ترنیان senior expert of range management

using of different systems of soil plough after changing unconsciously and non-scientific of land use, other soil physical and chemical characteristics affected. this fact, especially in marginal lands and mountainous regions is more visible. this research compared with the purpose of studying land use changing on some soil physical and chemical characters like very tiny sand percent, ph, ec, c...

1998
F. FeÂ

Large-scale simulation of the soil-derived dust emission in semi-arid regions needs to account for the in ̄uence of the soil moisture on the wind erosion threshold. Soil water retention consists of molecular adsorption on the soil grain surface and capillary forces between the grain. Interparticle capillary forces (characterized by the moisture tension) are the main factor responsible for the in...

Journal: :Journal of nematology 1976
B B Brodie

Population densities of Belonolaimus longicaudatus, Pratylenchus brachyurus, and Trichodorus christiei were determined from soil samples taken weekly in Tifton, Georgia during a 14-month period (except for April and May) at 15-cm increments to a depth of 105 cm. Belonolaimus longicaudatus predominately inhabited the top 30 cm of soil that was 87-88% sand, 6-7% silt, and 5-7% clay. No specimens ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی 1391

in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...

Soil erosion is a global challenge, seriously threatening soil and water resources andenvironmental qualities. One of the important factors to consider in the process of runoffgeneration and soil erosion is the physical and chemical properties of soils under differentland-uses. The aim of this study is to estimate soil erosion and runoff in rangeland, rain-fedand abandoned rain-fed agriculture ...

امامی, سیدنعیم, جلالیان, احمد, خسروی, عباس,

     The Occurrence of more than 400 landslides in Chaharmahal and Bakhtiari province shows a special sensitivity against erosion in this terrain. To investgate the role of the soil physical, chemical and mineral properties on the occurrence of the landslides in Afsar-Abad, Do ab Samsami in the west of Chaharmahal and Bakhtiari, were drilled six boreholes in sliding boundary and safe restrictio...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده فنی و مهندسی 1390

sange siyah dam is located two kilometers down the kabod khani village. the environ of ghorrve city in kurdestan province. this is an clay core dam. in this dam instrumentation is performed in three section and consist of electrical piezometers, total pressure cells, settlement cells and so on. the main objective of instrumentation is to control the behavior of dam body and foundation, end else...

حمیدرضا فولادمند, ,

  Soil particle size distribution and bulk density are used for estimating soil-moisture characteristic curve. In this model, soil particle size distribution curve is divided into a number of segments, each with a specific particle radius and cumulative percentage of the particles greater than that radius. Using these data, soil-moisture characteristic curve is estimated. In the model a scale f...

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