Yu et al. (2026) Measuring hydrological functional connectivity and its associations with flood processes in river network plains: Insights from flow smoothness and continuity

Identification

• Journal: Journal of Hydrology Regional Studies
• Year: 2026
• Date: 2026-09-11
• Authors: Zhihui Yu, Miao Lu, Qiang Wang, Youpeng Xu, Qiaoling Dong
• DOI: 10.1016/j.ejrh.2026.103958

Research Groups

• Department of Earth Science and Engineering, Cultivation Base of Shanxi Key Laboratory of Mining Area Ecological Restoration and Solid Wastes Utilization, Shanxi Institute of Technology, Yangquan, 045000, China
• College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou, 225000, China
• School of Civil & Environmental Engineering and Geography Science, Ningbo University, Ningbo, 315211, China
• School of Geography and Ocean Science, Nanjing University, Nanjing, 210023, China

Short Summary

This study proposes a new indicator, Hydrological Functional Connectivity Index (HFCI), which integrates flow smoothness and continuity to quantify channel-scale functional connectivity. The HFCI was applied to the Central Taihu Plain in eastern China, revealing generally good functional connectivity with a mean value of 0.72 during 1970–2019.

Objective

• Develop a Hydrological Functional Connectivity Index (HFCI) based on flow smoothness and continuity.
• Characterize the spatiotemporal dynamics of HFCI under hydraulic regulation in the Central Taihu Plain during 1970–2019.
• Quantify the stratified associations between HFCI and flood process indicators using GeoDetector.

Study Configuration

• Spatial Scale: The study focused on the Central Taihu Plain, a region located in the core of the Yangtze River Delta in eastern China.
• Temporal Scale: The study covered a period of 50 years (1970–2019), with two-stage representation of river morphology: the 1980s dataset was assigned to 1970–1989, and the 2010s dataset to 1990–2019.

Methodology and Data

• Models used: The study employed a combination of flow smoothness and continuity indices (FSI and FCI) to calculate HFCI.
• Data sources: The data sources included sluice records (1950–2019), channel cross-sectional data, daily rainfall and concurrent water levels for 1970–2019, and annual 30 m impervious surface maps for 1972–2019.

Main Results

• The mean HFCI of the entire plain was 0.72 during 1970–2019, indicating generally high functional connectivity.
• The interannual variations of the HFCI in the Central Taihu Plain and its hydrological subdivisions showed a trend of initial increase followed by a decrease.
• Relatively high values occurred mainly in the interior channel networks of WCXY and YCDM, whereas lower values were concentrated along reaches adjacent to the Yangtze River and in zones surrounding major urban flood control enclosures and regulated outlets.

Contributions

• The study provided a new indicator (HFCI) that integrates flow smoothness and continuity to quantify channel-scale functional connectivity.
• The results highlighted the importance of considering both structural and functional connectivity when evaluating hydrological connectivity.
• The study demonstrated the potential of HFCI in quantifying the associations between hydrological functional connectivity and flood process indicators.

Funding

• This research was supported by the National Natural Science Foundation of China (Grant No. 51879018) and the Key Research Program of the Chinese Academy of Sciences (Grant No. XDA23050104).

Citation

@article{Yu2026Measuring,
  author = {Yu, Zhihui and Lu, Miao and Wang, Qiang and Xu, Youpeng and Dong, Qiaoling},
  title = {Measuring hydrological functional connectivity and its associations with flood processes in river network plains: Insights from flow smoothness and continuity},
  journal = {Journal of Hydrology Regional Studies},
  year = {2026},
  doi = {10.1016/j.ejrh.2026.103958},
  url = {https://doi.org/10.1016/j.ejrh.2026.103958}
}