Page 84 - 2025年第56卷第9期

Research on the optimal section parameters for sediment transport in the
wide section of the lower Yellow River

1，2 1

HOU Lin ，ZHANG Hongwu

（1. Pumped-Storage Technological&Economic Research Institute，State Grid Xinyuan Group Company Limited，Beijing 100053，China；

2. State Key Laboratory of Hydroscience and Engineering，Beijing 100084，China）

Abstract：Predicting the stable hydraulic geometry formed by the automatic erosion and sedimentation adjustment of
the riverbed in a sandy river under certain water and sediment conditions is of great significance for engineering appli⁃
cations such as river flood control，regulation，and waterway planning. On the basis of reviewing the existing methods

for solving the optimal river width，this article aims to explore the channel shape that has the maximum sediment

transport capacity. By combining the water flow continuity equation，the sediment carrying capacity formula，the com⁃

prehensive stability index，and the dynamic bed resistance formula based on the friction curve，the parameters of

river width，water depth，flow velocity，slope，roughness，etc. are solved，which are the optimal cross-sectional
characteristic parameters corresponding to the maximum sediment transport capacity of the river channel. The varia⁃
tion law of sediment transport capacity and width of the river channel is revealed. The results show that the equilib⁃
rium sediment transport rate versus river width curve under different flow rates exhibits a trend of first increasing and
then decreasing. At each level of flow，there is an extreme point with the highest sediment transport rate，and the cor⁃

responding river width is the optimal sediment transport river width. Therefore，it can be regarded as the main chan⁃

nel width or modern control line width in the theory of "bundling water and attacking sand". From the system calcula⁃

tion curve，it can be seen that the optimal river width is directly proportional to the sediment discharge and inversely
proportional to the expected indicators for regulation. According to the downstream riverbed conditions and river regu⁃

lation constraints during the normal operation period of Xiaolangdi Reservoir，when the comprehensive stability index
of the riverbed is set to 4，the optimal sediment discharge river widths corresponding to 3000，4000，and 5000 m³/s

are calculated to be 654，754，and 838 m. Under a certain sediment discharge rate，the optimal sediment transport

river width decreases continuously with the increase of remediation requirements. For the wide section of the lower

Yellow River，only the regulating flow rate （bed making flow rate）and the stability index value of the channel regula⁃

tion need to be provided. In addition，this article also establishes the relationship between roughness and hydraulic

sediment factors such as P and Fr ，thereby solving the sediment transport section parameters corresponding to the
A
minimum water flow resistance in the wide section of the lower Yellow River under specific regulation flow and river
regulation expectations.

Keywords：optimal sediment transport cross-section；sand transport river width；the lower Yellow River；water flow

resistance；expected indicators for river regulation
（责任编辑：鲁 婧）

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