Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer
Sediment supply plays an essential role in river morphology. However, the specific impact of sediment supply on river morphology is not apparent. According to the hydrograph boundary layer (HBL) concept, upstream riverbed changes caused by the imbalance between sediment supply and the capacity can p...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-12-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/13/23/3437 |
| _version_ | 1797507086883487744 |
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| author | Huang Dai Toshiki Iwasaki Yasuyuki Shimizu |
| author_facet | Huang Dai Toshiki Iwasaki Yasuyuki Shimizu |
| author_sort | Huang Dai |
| collection | DOAJ |
| description | Sediment supply plays an essential role in river morphology. However, the specific impact of sediment supply on river morphology is not apparent. According to the hydrograph boundary layer (HBL) concept, upstream riverbed changes caused by the imbalance between sediment supply and the capacity can propagate only a limited length and have a negligible effect on the riverbed beyond such a short length. We performed a two-dimensional morphodynamic calculation to test the concept of HBL, which was proposed under a one-dimensional simulation, meaning that the concept of HBL is still valid for plane changes in river morphology. We employed an unsteady flow with equilibrium or constant sediment supply in a straight, modeled gravel-bedded channel with an unerodible bank to simulate alternate bar morphodynamics. The results show that regardless of the sediment supply condition, the alternate bar features formed downstream of the HBL are considerably similar. This suggests that sediment disturbance at the upstream end has a negligible effect on the mobile-bed dynamic processes, including alternate bar formation and development downstream of the HBL. |
| first_indexed | 2024-03-10T04:42:37Z |
| format | Article |
| id | doaj.art-8d38319463884bbd98b63dd773b5df38 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T04:42:37Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-8d38319463884bbd98b63dd773b5df382023-11-23T03:15:35ZengMDPI AGWater2073-44412021-12-011323343710.3390/w13233437Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary LayerHuang Dai0Toshiki Iwasaki1Yasuyuki Shimizu2Graduate School of Engineering, Hokkaido University, Sapporo 0608628, JapanFaculty of Engineering, Hokkaido University, Sapporo 0608628, JapanFaculty of Engineering, Hokkaido University, Sapporo 0608628, JapanSediment supply plays an essential role in river morphology. However, the specific impact of sediment supply on river morphology is not apparent. According to the hydrograph boundary layer (HBL) concept, upstream riverbed changes caused by the imbalance between sediment supply and the capacity can propagate only a limited length and have a negligible effect on the riverbed beyond such a short length. We performed a two-dimensional morphodynamic calculation to test the concept of HBL, which was proposed under a one-dimensional simulation, meaning that the concept of HBL is still valid for plane changes in river morphology. We employed an unsteady flow with equilibrium or constant sediment supply in a straight, modeled gravel-bedded channel with an unerodible bank to simulate alternate bar morphodynamics. The results show that regardless of the sediment supply condition, the alternate bar features formed downstream of the HBL are considerably similar. This suggests that sediment disturbance at the upstream end has a negligible effect on the mobile-bed dynamic processes, including alternate bar formation and development downstream of the HBL.https://www.mdpi.com/2073-4441/13/23/3437alternate barssediment transportsediment supplyhydrograph boundary layergravel-bed riversnumerical simulation |
| spellingShingle | Huang Dai Toshiki Iwasaki Yasuyuki Shimizu Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer Water alternate bars sediment transport sediment supply hydrograph boundary layer gravel-bed rivers numerical simulation |
| title | Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer |
| title_full | Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer |
| title_fullStr | Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer |
| title_full_unstemmed | Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer |
| title_short | Effect of Sediment Supply on Morphodynamics of Free Alternate Bars: Insights from Hydrograph Boundary Layer |
| title_sort | effect of sediment supply on morphodynamics of free alternate bars insights from hydrograph boundary layer |
| topic | alternate bars sediment transport sediment supply hydrograph boundary layer gravel-bed rivers numerical simulation |
| url | https://www.mdpi.com/2073-4441/13/23/3437 |
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