دورية أكاديمية
Morphometric properties of alternate bars and water discharge: a laboratory investigation
| العنوان: | Morphometric properties of alternate bars and water discharge: a laboratory investigation |
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| المؤلفون: | M. Redolfi, M. Welber, M. Carlin, M. Tubino, W. Bertoldi |
| المصدر: | Earth Surface Dynamics, Vol 8, Pp 789-808 (2020) |
| بيانات النشر: | Copernicus Publications, 2020. |
| سنة النشر: | 2020 |
| المجموعة: | LCC:Dynamic and structural geology |
| مصطلحات موضوعية: | Dynamic and structural geology, QE500-639.5 |
| الوصف: | The formation of alternate bars in straightened river reaches represents a fundamental process of river morphodynamics that has received great attention in the last decades. It is well-established that migrating alternate bars arise from an autogenic instability mechanism occurring when the channel width-to-depth ratio is sufficiently large. While several empirical and theoretical relations are available for predicting how bar height and length depend on the key dimensionless parameters, there is a lack of direct, quantitative information about the dependence of bar properties on flow discharge. We performed a series of experiments in a long, mobile-bed flume with fixed and straight banks at different discharges. The self-formed bed topography was surveyed, different metrics were analyzed to obtain quantitative information about bar height and shape, and results were interpreted in the light of existing theoretical models. The analysis reveals that the shape of alternate bars highly depends on their formative discharge, with remarkable variations in the harmonic composition and a strong decreasing trend of the skewness of the bed elevation. Similarly, the height of alternate bars clearly decreases with the water discharge, in quantitative agreement with theoretical predictions. However, the disappearance of bars when discharge exceeds a critical threshold is not as sharp as expected due to the formation of so-called “diagonal bars”. This work provides basic information for modeling and interpreting short-term morphological variations during individual flood events and long-term trajectories due to alterations of the hydrological regime. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2196-6311 2196-632X |
| Relation: | https://esurf.copernicus.org/articles/8/789/2020/esurf-8-789-2020.pdf; https://doaj.org/toc/2196-6311; https://doaj.org/toc/2196-632X |
| DOI: | 10.5194/esurf-8-789-2020 |
| URL الوصول: | https://doaj.org/article/c33368da84424b91a7565290942a3b0b |
| رقم الأكسشن: | edsdoj.33368da84424b91a7565290942a3b0b |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 21966311 2196632X |
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| DOI: | 10.5194/esurf-8-789-2020 |