کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6361542 1622764 2010 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A review of sediment dynamics in the Severn Estuary: Influence of flocculation
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات اقیانوس شناسی
پیش نمایش صفحه اول مقاله
A review of sediment dynamics in the Severn Estuary: Influence of flocculation
چکیده انگلیسی

This paper provides a review and critique of the distributions and characteristics of non-cohesive and cohesive sediments within the Severn Estuary, with particular reference to floc properties. The estuary is hyper-tidal and, consequently, highly turbid along most of its length and it generally has two turbidity maxima. In the upper reaches of the estuary, suspended particulate matter (SPM) concentrations can be in excess of 10 g l−1 for river flows up to 50 m3 s−1, rising to over 50 g l−1 during periods of lower river flow. The lower estuary turbidity maximum originates in the vicinity of Bridgwater Bay where SPM concentrations may vary between 0.1-200 g l−1. The formation of fluid mud is coupled to the spring-neap cycle and strong vertical gradients in SPM concentrations produce turbulence damping and drag reduction effects, and hence impair the ability of the flow to transport sediments. Flocculation is an important mechanism for controlling the behaviour of fine sediments and mean settling velocities of flocs vary between 0.8-6 mm s−1. A secondary consequence of flocculation is the formation of mud:sand mixtures in turbid suspensions. Improved understanding of the significance of flocculation processes is crucial as they may exert an influence on the mechanism by which adsorbed contaminants are transported in the system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Marine Pollution Bulletin - Volume 61, Issues 1–3, 2010, Pages 37-51
نویسندگان
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