نتایج جستجو برای: stream sediment

تعداد نتایج: 93248  

ژورنال: :پژوهش های دانش زمین 0
رضا اسماعیلی استادیار گروه جغرافیا، دانشگاه مازندران قاسم لرستانی استادیار گروه جغرافیا، دانشگاه مازندران

شهرنشینی بیش از سایر فعالیتهای انسانی سیستم های رودخانه ای را تغییر می دهد. سطوح نفوذناپذیر مقدار رواناب و رسوب را افزایش می دهند. بنابراین مورفولوژی رودهای شهری در نتیجه شهرنشینی تعدیل می شود. شهر نور در استان مازندران واقع شده و از روستا به شهر تبدیل شده است. عکس های هوایی و تصاویر ماهواره ای برای مستند کردن پوشش سطح زمین، گسترش محدوده شهری و شبکه زهکشی مورد استفاده قرار گرفته است. سپس، هر کا...

2008
Matthew I. Leybourne Karen H. Johannesson

We have collected 500 stream waters and associated bed-load sediments over an 400 km region of Eastern Canada and analyzed these samples for Fe, Mn, and the rare earth elements (REE + Y). In addition to analyzing the stream sediments by total digestion (multi-acid dissolution with metaborate fusion), we also leached the sediments with 0.25 M hydroxylamine hydrochloride (in 0.05 M HCl), to deter...

Journal: :Environmental science & technology 2011
Patrick Belmont Karen B Gran Shawn P Schottler Peter R Wilcock Stephanie S Day Carrie Jennings J Wesley Lauer Enrica Viparelli Jane K Willenbring Daniel R Engstrom Gary Parker

Although sediment is a natural constituent of rivers, excess loading to rivers and streams is a leading cause of impairment and biodiversity loss. Remedial actions require identification of the sources and mechanisms of sediment supply. This task is complicated by the scale and complexity of large watersheds as well as changes in climate and land use that alter the drivers of sediment supply. P...

Journal: :زمین شناسی اقتصادی 0
مهدی هاشمی گهرویی بهنام شفیعی بافتی غلامحسین شمعانیان حسین تقی زاده

in order to assess the potential of copper mineralization and its associated elements in soltan meydan basaltic formation situated in the north of shahrud, the method of stream sediment and heavy mineral has been used. to achieve this aim, totally 68 samples of sediments (-80 mesh in particle size) and 6 samples of heavy minerals (-20 mesh in particle size) have been collected in an optimized n...

Anomaly separation using stream sediment geochemical data has an essential role in regional exploration. Many different techniques have been proposed to distinguish anomalous from study area. In this research, a continuous restricted Boltzmann machine (CRBM), which is a generative stochastic artificial neural network, was used to recognize the mineral potential area in Korit 1:100000 sheet, loc...

Journal: :Journal of environmental quality 2015
Louise R M Barthod Kui Liu David A Lobb Philip N Owens Núria Martínez-Carreras Alexander J Koiter Ellen L Petticrew Gregory K McCullough Cenwei Liu Leticia Gaspar

The use of sediment color as a fingerprint property to determine sediment sources is an emerging technique that can provide a rapid and inexpensive means of investigating sediment sources. The present study aims to test the feasibility of color fingerprint properties to apportion sediment sources within the South Tobacco Creek Watershed (74 km) in Manitoba, Canada. Suspended sediment from 2009 ...

2004
Eileen Chen D. Scott Mackay

Accurate predictions of sediment yield from distributed models of runoff and sediment yield depends in part of how well matched the model structure is to input data spatial representation. This study investigated how model structure and input data representation affect sediment predictions made using the Soil and Water Assessment Tool (SWAT). The study focused on the integration of two specific...

Journal: :Journal of environmental management 2008
Hubert Chanson Maiko Takeuchi Mark Trevethan

The suspended sediment concentration is a key element in stream monitoring, although the turbidity and acoustic Doppler backscattering may be suitable surrogate measures. Herein a series of new experiments were conducted in laboratory under controlled conditions using water and mud samples collected in a small subtropical estuary of Eastern Australia. The relationship between suspended sediment...

2011
Robert Mckinley David Radcliffe Rajith Mukundan

This study seeks to further our ability to directly determine sediment provenance by utilizing the sediment fingerprinting technique and Rapid Geomorphic Assessments (RGAs) to determine both sediment contributions from potential sources and the stability of stream channels. Two sub basins of the North Fork Broad River (NFBR) were sampled for suspended sediment. Potential sources fall into three...

2012
Derek B. Booth David R. Montgomery John Bethel

Large woody debris (LWD) performs key functions in undisturbed streams that drain lowland forested watersheds, including dissipation of flow energy, stabilization of bedforms and channel banks, entrapment of sediment, and formation of pools. These functions vary between individual channels, however, depending on the size and morphology of the stream, which in turn depend on climate, watershed s...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید