نتایج جستجو برای: sediment source

تعداد نتایج: 452323  

Journal: :desert 2013
a. kouhpeima s. feiznia h. ahmadi s.a. asghar hashemi h. ghadimi

this contribution determines suitable fingerprinting properties for sediment source discrimination within theamrovan and atary catchments in semnan province, iran. these catchments are representative of a range of geology formations and should therefore provide a meaningful basis for a general assessment of the degree of sediment source discrimination afforded by a range of fingerprint properti...

Journal: :desert 0
a. kouhpeima msc.graduate, university of tehran and member of young researcher club of islamic azad university, shiraz branch, shiraz, iran s. feiznia professor, faculty of natural resources, university of tehran, karaj, iran h. ahmadi professor, science and research branch, tehran islamic azad university, iran s.a. asghar hashemi researcher, agriculture and natural resource research center, semnan, iran h. ghadimi graduate student, faculty of natural resources, university of tehran, karaj, iran

this contribution determines suitable fingerprinting properties for sediment source discrimination within theamrovan and atary catchments in semnan province, iran. these catchments are representative of a range of geology formations and should therefore provide a meaningful basis for a general assessment of the degree of sediment source discrimination afforded by a range of fingerprint properti...

Journal: :ecopersia 2012
asghar kouhpeima sadat feiznia

today fingerprinting techniques are increasingly adopted as an alternative and more direct and reliable means of assembling sediment source information. one of the principal assumptions of sediment fingerprinting is that potential catchment sediment sources can be distinguished on the basis of their physical, geochemical and biological properties or fingerprint properties. however, while the so...

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: :ecopersia 2011
asghar kouhpeima sadat feiznia hasan ahmadi seyed ali asghar hashemi

sediment-related environmental problems pose a serious threat to sustainable land management in many developing countries, including iran. information regarding sediment sources represents a key requirement from the management perspective since identification of sediment sources is a precursor to the design of effective sediment management and control strategies. the fingerprinting approach has...

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: :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: :The Science of the total environment 2005
D E Walling

Recent years have seen a growing awareness of the wider environmental significance of the suspended sediment loads transported by rivers and streams. This includes the importance of fine sediment in the transport of nutrients and contaminants, including phosphorus (P). Sediment source exerts a key control on the physical and geochemical properties of suspended sediment, including its P content,...

Journal: :journal of tethys 0

sediments are generally regarded as the sink for dissolved elements carried out to the sea by rivers. in order to study the source and mechanism of metal transport in sea water, 123 surface sediment samples were taken by using grab sampler in the northwest part of the persian gulf in summer. grain size analysis and geochemical analysis by icp-oes were carried out on samples after sample prepara...

Journal: :مرتع و آبخیزداری 0
کاظم نصرتی دانشیار گروه جغرافیای طبیعی، دانشکده علوم زمین، دانشگاه شهید بهشتی، ایران سعیده جلالی دانش آموخته ژئومورفولوژی، دانشکده علوم زمین، دانشگاه شهید بهشتی، ایران

identifying sediment sources is one of important factors in selecting of appropriate method of erosion control and soil conservation. the main objective of this study is to estimateuncertainty and contribution of forest roads to sediment yield in ziarat drainage basin, gorgan city using geochemical tracers. for this purpose, 47 soil samples were collected from different sources with different l...

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