Water-Sediment Characteristics and Flow-Sediment Diversion Patterns in Typical Bifurcated Channels in the Middle Reaches of Huaihe River

doi:10.11988/ckyyb.20240780

Abstract

Abstract:

[Objective] Current research on water-sediment characteristics of the Huaihe River mainstream mainly focuses on single channels, while studies on water-sediment characteristics, relationships, and diversion patterns in its bifurcated channels are limited. This study selects the typical bifurcated section from Wangjiaba to Nanzhaoji (hereinafter referred to as “Mengwa section”) in the middle reaches of the Huaihe River, aiming to clarify the variations in water-sediment characteristics and diversion patterns of typical bifurcated channels. [Methods] A combination of cumulative anomaly analysis, Mann-Kendall (M-K) trend test, R/S analysis, and Morlet wavelet analysis was used to study the water-sediment inflow characteristics of the bifurcated channels in the Mengwa section from 1985 to 2020. The driving factors of abrupt changes and variation trends in water and sediment conditions were explored. The water-sediment coordination relationships and sediment transport capacity variations were evaluated using water-sediment relationship curves, and quantitative ratios of flow and sediment diversion across bifurcated channels of the Mengwa section were provided. [Results] The annual runoff at Wangjiaba station (total) showed no significant increasing or decreasing trend, while the sediment concentration displayed a pronounced decreasing trend, stabilizing below 0.15 kg/m³ after 2010 and continuing to decrease in the future. An abrupt change occurred around 1995. Sediment retention by reservoirs, agricultural land use changes altering underlying surfaces, and soil and water conservation measures were the primary driving factors of sediment concentration reduction. The sediment coefficient showed a decreasing trend, with external influence coefficient “a” gradually decreasing and sediment transport fitting coefficient “b” gradually increasing. This indicated a continuous reduction in sediment inflow intensity and an enhancement of the channel’s sediment transport capacity, promoting channel scouring. Meanwhile, the main channel cross-section exhibited sustained expansion, indicating an ongoing erosional state in this river section. The flow diversion ratio of the Menghe River was generally positively correlated with total flow in this section. At 2 000 m³/s (low-to-medium flow level), the main channel on the Huaihe River’s southern branch served as the primary flow passage. As the flow increased, the weight diverted through the Meng River progressively rose. Below the flow level of 6 000m³/s, its diversion capacity slightly declined, while at 6 000m³/s, the flow achieved equitable flow diversion with the mainstream of the Huaihe River. The sediment concentration ratios of each bifurcated channel were approximately equal to the ratios of their respective flow sediment transport capacity. [Conclusion] These findings provide theoretical support for sediment concentration calculation models in bifurcated channels during numerical simulations of water and sediment dynamics in the middle reaches of the Huaihe River, while offering a scientific basis for adopting long-distance dredging schemes in the river’s channel regulation strategies.

Key words: bifurcated channel, water-sediment characteristics, driving factors, water-sediment relationship, flow-sediment diversion patterns, middle reach of Huaihe River

CLC Number:

TV147

ZHANG Hui, NI Jin, BEN Peng, WANG Jiu-sheng. Water-Sediment Characteristics and Flow-Sediment Diversion Patterns in Typical Bifurcated Channels in the Middle Reaches of Huaihe River[J]. Journal of Changjiang River Scientific Research Institute, 2025, 42(7): 24-31.

Figures/Tables 13

Fig.1 Schematic diagram of bifurcated channels and distribution of hydrological station network in Mengwa section

Fig.2 Annual variations in runoff and sediment concentration at Wangjiaba station (total)

Fig.3 M-K test statistical curves at Wangjiaba station (total)

Fig. 4 R/S statistical curves of runoff and sediment concentration at Wangjiaba station (total)

Fig.5 Contour maps of real part of wavelet coefficients for water-sediment series at Wangjiaba station (total)

Fig.6 Wavelet variance distribution of water-sediment series at Wangjiaba station (total)

Fig.7 Double cumulative curves of sediment transport and runoff at Wangjiaba station (total)

Fig.8 Variations in annual average sediment coefficient at Wangjiaba station (total)

Fig.9 Water-sediment relationship curves between annual average runoff and sediment transport rate at Wangjiaba station (total)

Table 1 Water-sediment relationship coefficients at Wangjiaba station (total)

时间段	a	b	R²
1985—1995年	0.021	1.527	0.872
1996—2020年	0.007	1.615	0.910

Fig.10 Diversion ratio of Menghe River’s flood diversion channel under different flow levels in Mengwa section

Fig.11 Measured relationship between flow diversion ratio and sediment diversion ratio of Menghe River’s flood diversion channel

Fig.12 Relationship curves between sediment concentration ratio and sediment transport capacity ratio at Wangjiaba station and Shangang station

[1]	QI Zhan-shuo, YAO Shi-ming, ZHU Yu, LIU Xiao-qing. Research Progress on Evolution of Rivers and Lakes in China Based on Remote Sensing Technology [J]. Journal of Changjiang River Scientific Research Institute, 2025, 42(7): 8-17.
[2]	HAN Zhen, WENG Xuan, ZHOU Yi, HANG Jun, CHEN He, GU Wei. Spatiotemporal Distribution and Influencing Factors of Carbon Storage in Chongming Coastal Wetlands [J]. Journal of Changjiang River Scientific Research Institute, 2025, 42(6): 78-86.
[3]	ZHENG Rong-wei, ZHANG Yue, WANG Qing-ming, GUI Yun-peng. Prediction and Attribution Analysis of Future Evolution of ET₀ in Climatic Regions of China [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(8): 44-50.
[4]	LIN Na, ZHANG Di, PAN Jian-ping, FENG Shan-shan, PAN Peng. Long-time Series Ecological Quality Assessment and Influencing Factors Analysis for Changshou District, Chongqing [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(11): 56-62.
[5]	ZHU Peng-fan, LIU Gang, HE Jing, DAI Tang-rui. Vegetation Net Primary Productivity in Dabie Mountains in Recent Two Decades: Spatiotemporal Variation and Driving Factors [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(10): 66-73.
[6]	CAO Yan-min, AN Hong-lei, HAN Shuai. Water Environment Assessment Model and Driving Factors Identification for Xiangjiang River Basin [J]. Journal of Changjiang River Scientific Research Institute, 2023, 40(10): 51-58.
[7]	DUOLAITI Xilinayi, KASIM Alim, REHEMAN Rukeya, LIANG Hong-wu. Water Body Extraction of Ebinur Lake Based on Four Water Indexes and Analysis of Spatial-temporal Changes [J]. Journal of Changjiang River Scientific Research Institute, 2022, 39(10): 134-140.
[8]	ZOU Ji, LIU Ya, LU Jin-you. Abrupt Changes of Hydraulic Characteristics in Curved Bifurcated Channel under Bankfull Discharge [J]. Journal of Changjiang River Scientific Research Institute, 2020, 37(2): 15-20.
[9]	ZHANG Jian, HE Qi-sheng, CUI Tong, SHI Peng-fei, YANG Tao. Information Extraction and Dynamic Changes ofWetland in Jiangsu Coastal Area Based on RS and GIS [J]. Journal of Changjiang River Scientific Research Institute, 2017, 34(4): 144-150.
[10]	ZHOU He, YU Bang-yi, NI Jin. Analysis of Water-sediment Relationship at Lutaizi Hydrological Station on Mainstream Huaihe River [J]. Journal of Changjiang River Scientific Research Institute, 2014, 31(12): 7-10.
[11]	ZUO Li-qin, LU Yong-jun. Effect of Nodes on Branch Evolution in Madang Reach in the Downstream of Yangtze River [J]. Journal of Changjiang River Scientific Research Institute, 2014, 31(10): 72-79.