Combined effects of precipitation anomalies and dams on streamwater-groundwater interaction in the Fen River basin, China

Yun Xia; Jun Xiao; Martine van der Ploeg; Wanzhou Wang; Zhi Li

doi:10.1016/j.scitotenv.2024.172704

Combined effects of precipitation anomalies and dams on streamwater-groundwater interaction in the Fen River basin, China

Sci Total Environ. 2024 Jun 15:929:172704. doi: 10.1016/j.scitotenv.2024.172704. Epub 2024 Apr 23.

Authors

Yun Xia¹, Jun Xiao², Martine van der Ploeg³, Wanzhou Wang¹, Zhi Li⁴

Affiliations

¹ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China.
² State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, Shaanxi 710061, China. Electronic address: xiaojun@ieecas.cn.
³ Hydrology and Environmental Hydraulics Group, Wageningen University, Wageningen, the Netherlands.
⁴ State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: lizhibox@126.com.

PMID: 38663590
DOI: 10.1016/j.scitotenv.2024.172704

Abstract

Both water management measures like damming and changes in precipitation as a result of anthropogenic induced climate change have exerted profound effects on the dynamics of streamwater-groundwater interaction (SGI). However, their compound effects on SGI have not been investigated so far. Taking the Fen River of China as an example, this study aims to examine the synergistic impacts of damming and precipitation anomalies on SGI dynamics. The sampling considered the seasonal and interannual variability of precipitation (May and September in 2019 representing a dry year; May and August in 2021 representing a wet year), and long-term daily observational data, including water levels and water discharge, were combined to elucidate the compound effects. Precipitation anomalies and damming exert significant individual and combined influences on SGI. Separately, dams and reservoirs reversed the SGI dynamics, significantly increasing the contributions of streamwater to groundwater from 0 to 29 % to 78 % in the dam-affected areas. Further, the groundwater discharge ratios behind the dam (about 60 %) were three times higher than those in front of the dam. Precipitation anomalies significantly amplified interannual variability in SGI patterns, and groundwater discharge ratios increased by 47 % during the dry period (2019) compared to flood period (2021). The combined influence of precipitation anomalies and dam regulation remarkably changed the lateral, vertical, and longitudinal water exchange dynamics. Precipitation anomalies affected the SGI dynamics at the whole watershed scale, whereas dam regulation regimes exhibited a stronger control at the local scale. The compound effects of dam regulation and precipitation anomalies can result in different SGI patterns under various climate scenarios. More attention should be paid to the interrelated feedback mechanisms between damming, extreme precipitation events, and their impact on the watershed-scale hydrological cycle.

Keywords: Combine effect; Dam regulation; Precipitation anomalies; Streamwater-groundwater interactions; Tracer methods.