نتایج جستجو برای: sediment sources

تعداد نتایج: 323946  

Introduction Many catchment erosion studies focus on formation and land use as the primary source of sediment. It is important to improve information on sediment sources, especially in large catchments and sediment source information which can support catchment management decisions. Erosion control projects need to be understood as the relative contributions of different sediment sources f...

Journal: :desert 2013
k. nosrati h. ahmadi f. sharifi m. mahdavi m.r. sarvati

uncertainty associated with mixing models is often substantial, but has not yet been fully incorporated in models. the objective of this study is to develop and apply a bayesian-mixing model that estimates probability distributions of source contributions to a mixture associated with multiple sources for assessing the uncertainty estimation in sediment fingerprinting in zidasht catchment, iran....

Journal: Desert 2012
F. Sharifi H. Ahmadi K. Nosrati M. Mahdavi M.R. Sarvati

Uncertainty associated with mixing models is often substantial, but has not yet been fully incorporated in models. The objective of this study is to develop and apply a Bayesian-mixing model that estimates probability distributions of source contributions to a mixture associated with multiple sources for assessing the uncertainty estimation in sediment fingerprinting in Zidasht catchment, Iran....

Journal: :مرتع و آبخیزداری 0
کاظم نصرتی دانشیار دانشکدة علوم زمین دانشگاه شهید بهشتی فروزان احمدی دانشجوی دکتری ژئومورفولوژی - مدیریت محیطی، دانشگاه شهید بهشتی علی اکبر نظری سامانی دانشیار دانشکدة منابع طبیعی دانشگاه تهران محمد رضا ثروتی استاد دانشکدة علوم زمین دانشگاه شهید بهشتی

soil erosion is one of the most destructive phenomena which cause significant ecological changes in many areas. soil conservation and erosion control is essential because of the irreparable damage caused by soil erosion. soil conservation programs will not achieve until to find adequate methods of combating land degradation and ways to reduce the sediment. therefore, we need to have enough know...

Recognition of origin of sand dunes is very important in wind erosion control projects. Because of many problems associated with traditional procedures for identifying sediment sources, fingerprinting techniques, based on physical, chemical and organic properties of sediment and source materials, are increasingly being used as a valuable and effective alternative approach to assembling such inf...

2009
K. E. JURACEK A. C. ZIEGLER

The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment (clay and silt) within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources (cropland and grassland), a...

Journal: :مرتع و آبخیزداری 0
سادات فیض نیا استاد دانشکدة منابع طبیعی دانشگاه تهران اصغر کوهپیما باشگاه پژوهشگران جوان، واحد شیراز، دانشگاه آزاد اسلامی، شیراز، ایران حسن احمدی استاد دانشکدة منابع طبیعی دانشگاه تهران علی اصغر هاشمی مرکز تحقیقات کشاورزی و منابع طبیعی سمنان ، سمنان ، ایران

due to successes of fingerprinting method in producing rapid and low-cost information of sediment sources, in this research this method was used in three sub-cathments of chasht-khoran basin in semnan province: amrovan, atari and ali-abad. samples below 63 μm were separated and 15 fingerprinting propertis was measured. in the first stage comparison of means and differentiation analysis were use...

Journal: :desert 0
k. nosrati assistant professor, shahid beheshti university, tehran, iran h. ahmadi professor, science and research branch, islamic azad university, tehran, iran f. sharifi associate professor, forest, range and watershed management organization, tehran, iran m. mahdavi emeritus professor, university of tehran, karaj, iran m.r. sarvati associate professor, shahid beheshti university, tehran, iran

uncertainty associated with mixing models is often substantial, but has not yet been fully incorporated in models. the objective of this study is to develop and apply a bayesian-mixing model that estimates probability distributions of source contributions to a mixture associated with multiple sources for assessing the uncertainty estimation in sediment fingerprinting in zidasht catchment, iran....

Journal: :Journal of environmental quality 2010
R Mukundan D E Radcliffe J C Ritchie L M Risse R A McKinley

Thousands of stream miles in the southern Piedmont region are impaired because of high levels of suspended sediment. It is unclear if the source is upland erosion from agricultural sources or bank erosion of historic sediment deposited in the flood plains between 1830 and 1930 when cotton farming was extensive. The objective of this study was to determine the source of high stream suspended sed...

Journal: :مرتع و آبخیزداری 0
سادات فیض نیا استاد دانشکدة منابع طبیعی دانشگاه تهران سهیلا یونس زاده جلیلی کارشناس ارشد دانشکدة منابع طبیعی دانشگاه تهران حسن احمدی استاد گروه آبخیزداری دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران

due to difficulties in the application of traditional methods for identifying sediment sources, fingerprinting techniques, based on physical, chemical and organic properties of sediment and source materials, are increasingly being used as a valuable and effective alternative approach to obtain such information. the first step in this method is using an appropriate combination of diagnostic prop...

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