Yue et al. (2025) Watershed sediment cascades across multiple timescales: Causal relationships with hydroclimate and underlying surface attributes

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-09-10
• Authors: Zewei Yue, Nannan Wang, H. Xiao, Zhihua Shi
• DOI: 10.1016/j.jhydrol.2025.134234

Research Groups

• State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
• State Environmental Protection Key Laboratory of Soil Health and Green Remediation, Huazhong Agricultural University, Wuhan 430070, China
• University of Chinese Academy of Sciences, Beijing 101408, China
• School of Resource and Environmental Sciences, Wuhan University, Wuhan 430070, China
• Jiangxi Academy of Water Science and Engineering, Nanchang 330029, China

Short Summary

This study investigated watershed sediment dynamics and their causal relationships with hydroclimate and underlying surface factors across multiple timescales (event to decadal) in seven subtropical watersheds, revealing a shift in dominant controls from hydroclimate to surface properties at longer timescales.

Objective

• To achieve a comprehensive understanding of sediment cascades from event to decadal scales and their causal relationships with hydroclimate and underlying surface factors.

Study Configuration

• Spatial Scale: Seven subtropical watersheds.
• Temporal Scale: Event to decadal scales, utilizing 40 years of data.

Methodology and Data

• Models used: Multiple wavelet techniques, complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), linear non-Gaussian acyclic model (LiNGAM).
• Data sources: 40-year observational data from seven subtropical watersheds, including timeseries for precipitation, discharge, and suspended sediment concentration (SSC).

Main Results

• Precipitation, discharge, and SSC timeseries exhibited similar episodic patterns (coherence > 0.5) across event to decadal scales.
• SSC was primarily influenced by other hydroclimate and underlying surface factors at annual and longer scales, indicating the nonstationary nature of sediment cascades.
• Strong coherence between hydroclimatic drivers and sediment processes was particularly evident at event, intra-seasonal, and annual scales.
• From short-term (< 5 years) to long-term (> 20 years) scales, the dominance of precipitation in sediment cascades decreased (correlation coefficient, r = 0.47 → 0.18), while the influence of underlying surface properties increased (r = 0.09 → 0.3).
• This shift led to a decoupling of sediment from precipitation and discharge after the year 2000.
• LiNGAM analysis revealed that hydroclimate conditions predominantly influenced soil erosion (causality value = 3.05), while surface properties primarily controlled sediment transport (causality value = 1.39), with both collectively impacting river sediment (causality values = 1.49 and 1.44).

Contributions

• Explored the shaping of sediment cascades by multitemporal environmental features from a novel causality-based perspective.
• Provided new insights into multitemporal sediment patterns and causal relationships within hydrologic systems, addressing a previously elusive comprehensive understanding.

Funding

• Not specified in the provided text.

Citation

@article{Yue2025Watershed,
  author = {Yue, Zewei and Wang, Nannan and Xiao, H. and Shi, Zhihua},
  title = {Watershed sediment cascades across multiple timescales: Causal relationships with hydroclimate and underlying surface attributes},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134234},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134234}
}