WANG J H,  ZHENG K,  DOU J F,  et al. Isotope hydrological analysis of water source for riparian plants in Jiaozuo Section of the Yellow River[J]. Journal of Henan Polytechnic University(Natural Science) , 2024, 43(4): 87-95.

doi:10.16186/j.cnki.1673-9787.2022050078

Received:2022/02/28

Revised:2022/05/30

Published:2024/07/05

Isotope hydrological analysis of water source for riparian plants in Jiaozuo Section of the Yellow River

WANG Jihua1,2,3,  ZHENG Kai1,2,3,  DOU Jingfeng1,2,3,  LI Tao1,2,3,  HUANG Pinghua4

1. Institute of Natural Resources Monitoring and Comprehensive Land Improvement of Henan Province, Zhengzhou 450016, Henan, China; 2. Key Laboratory of Water and Soil Resources Protection and Rehabilitation in the Middle and Lower Reaches of the Yellow River Basin, Ministry of Natural Resources，Zhengzhou 450016, Henan, China; 3. Henan Natural Resources Science and Technology Innovation Center（Investigation and Monitoring of Groundwater Resources), Zhengzhou 450016, Henan, China; 4. School of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China

Abstract: Objectives To investigate the water sources of riparian vegetation. Methods Typical ecological plants in the middle reaches of the Yellow River were selected as the research objects. The study analyzed characteristics of stable hydrogen and oxygen isotopes, chloride ion concentrations, and soil moisture content, and applied the Bayesian mixed model MixSIAR to determine the water sources for riparian vegetation. Results The δ²H-δ¹⁸O diagram shows a soil water line (δ²H=5.74 δ¹⁸O-15.67) with a slope significantly lower than that of the local meteoric water line (LMWL). Soil water lc-excess values (indicating the degree of deviation of soil water isotope points from the LMWL) reveal that soil water isotope δ²H-δ¹⁸O points deviate notably from the LMWL. The δ²H and δ¹⁸O values of xylem water in riparian plants (Phragmites australis and Tamarix chinensis Lour.) closely align with the soil water line. Vertical stratification is observed in soil moisture content, stable isotopes (δ²H, δ¹⁸O), and Cl^- concentration. MixSIAR simulation results suggest that soil water contributes 60.3%~73.6% to the water content of Tamarix and Phragmites australis, while river water contributes 10.3%~24.7%, followed by phreatic water. Corrected calculations indicate an increased contribution rate of river water to plant water, reaching up to 30.3%, while soil water contribution decreased to 53.9%~60.6%. Conclusions The study area exhibits strong hydraulic connections among precipitation, river water, groundwater, and soil water, with significant recharge interactions, while soil water is subject to high evaporation. Soil water is the primary source of plant water, followed by river water. Soil moisture content at different depths  (shallow, middle, and deep) varies with increasing burial depth due to distinct primary water sources, and soil moisture content is a key factor influencing plant water uptake. These findings provide theoretical insights into water utilization mechanisms of typical riparian vegetation.

Key words:Jiaozuo Section of the Yellow River; riparian vegetation; stable hydrogen and oxygen isotopes; Bayesian mixture model; water sources