کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4686863 1635562 2008 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modelling gravel transport and morphology for the Fraser River Gravel Reach, British Columbia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Modelling gravel transport and morphology for the Fraser River Gravel Reach, British Columbia
چکیده انگلیسی

A two-dimensional (2D) numerical hydrodynamic-morphological model is developed to investigate gravel transport and channel morphology in a large wandering gravel-bed river, the Fraser River Gravel Reach, in British Columbia, Canada. The model takes into count multi-fraction bedload transport, including the effects of surface coarsening, hiding and protrusion. Model outputs together with river discharge statistics were analyzed, producing distributed sediment budget and well-defined, localised zones of aggradation and degradation along the gravel reach. Long-term channel response to gravel extraction from aggrading zones as a flood hazard mitigation measure was also investigated numerically to assess the effectiveness of such an extraction. The total computed sediment budget agrees well with results based on field measurements of gravel transport available to us. This study points to the importance of a number of factors to bedload predictions: the gravel-to-sand ratio, the adequacy of resolving the wandering planform, and the distinction between bed shear stress driving bedload transport and bed resistance on the flow. These are in addition to the physical processes governing the flow field and gravel mobilization. The methodology presented in this paper can provide a scientific basis for gravel management including monitoring and extraction in order to maintain adequate flood protection and navigation, while preserving the ecosystem.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Geomorphology - Volume 95, Issues 3–4, 15 March 2008, Pages 206–222
نویسندگان
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