Chen et al. (2025) Lateral groundwater-river exchanges estimation via actively heated fiber optics based thermal response test

Identification

• Journal: Journal of Hydrology
• Year: 2025
• Date: 2025-11-21
• Authors: Zi Chen, Hui Yu, Shijia Mei, Hai Yang, Teng Xu, Zhengyang Jia, Hong Zhang, Yuehua Jiang, Yun Li, Quanping Zhou, Jie Li, Yuping Chen
• DOI: 10.1016/j.jhydrol.2025.134641

Research Groups

• MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, China
• Nanjing Center, China Geological Survey, Nanjing, China
• Lower Changjiang River Bureau of Hydrology and Water Resources Survey, Changjiang Water Resources Commission, Nanjing, China
• Key Laboratory of Watershed Eco-Geological Processes, Ministry of Natural Resources, Nanjing, China
• State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, China
• Jiangsu Coal Geological and Geophysical Survey Team, Nanjing, China

Short Summary

This study introduces a novel data assimilation framework combining Actively Heated Fiber Optics Based Thermal Response Testing (ATRT) with Normal Score Ensemble Smoother with Multiple Data Assimilation (NS-ES-MDA) to accurately quantify lateral groundwater-surface water exchange fluxes by characterizing non-Gaussian hydraulic conductivity fields. The framework effectively resolves aquifer heterogeneity and localizes flux variations, showing enhanced accuracy under rapid flow reversal conditions.

Objective

• To develop and evaluate a novel data assimilation framework that integrates Actively Heated Fiber Optics Based Thermal Response Testing (ATRT) with the Normal Score Ensemble Smoother with Multiple Data Assimilation (NS-ES-MDA) for estimating non-Gaussian hydraulic conductivity fields and lateral groundwater-surface water exchange dynamics.

Study Configuration

• Spatial Scale: Localized riverbank scale, focusing on aquifer heterogeneity and localized groundwater-surface water exchanges, evaluated with varying borehole densities (3, 6, 9) at a tidal-influenced Yangtze River site.
• Temporal Scale: Dynamic, short-term processes, particularly under rapid flow reversal conditions, reflecting tidal influences.

Methodology and Data

• Models used: Actively Heated Fiber Optics Based Thermal Response Testing (ATRT), Normal Score Ensemble Smoother with Multiple Data Assimilation (NS-ES-MDA).
• Data sources: Synthetic ATRT observations generated from models based on a tidal-influenced Yangtze River site.

Main Results

• The integrated ATRT and NS-ES-MDA framework successfully captures non-Gaussian hydraulic conductivity fields and localized groundwater-surface water exchanges.
• Configurations with at least 6 boreholes and 500 realizations achieved lower root mean square error and ensemble spread, effectively resolving aquifer heterogeneity and localizing flux variations.
• The framework demonstrated robust performance across diverse hydrological conditions, with enhanced Nash-Sutcliffe efficiencies observed under repeated flow-direction reversal situations.
• Estimated flux remained relatively accurate even with limited prior biases in lithology proportion (gravelly sand and silt loam).

Contributions

• Proposes a novel data assimilation framework (ATRT + NS-ES-MDA) for high-resolution characterization of groundwater-surface water interactions.
• Demonstrates the capability of the framework to estimate non-Gaussian hydraulic conductivity fields and localized lateral exchange fluxes.
• Highlights the significant improvement in inversion accuracy of localized groundwater-surface water exchanges when ATRT observations are collected under rapid flow reversal conditions.
• Shows the robustness of the framework against limited prior biases in lithology proportions.
• Advances the methodology for quantifying groundwater-surface water exchange fluxes in complex, dynamic environments.

Funding

• Not specified in the provided text.

Citation

@article{Chen2025Lateral,
  author = {Chen, Zi and Yu, Hui and Mei, Shijia and Yang, Hai and Xu, Teng and Jia, Zhengyang and Zhang, Hong and Jiang, Yuehua and Li, Yun and Zhou, Quanping and Li, Jie and Chen, Yuping},
  title = {Lateral groundwater-river exchanges estimation via actively heated fiber optics based thermal response test},
  journal = {Journal of Hydrology},
  year = {2025},
  doi = {10.1016/j.jhydrol.2025.134641},
  url = {https://doi.org/10.1016/j.jhydrol.2025.134641}
}