Hydrochemical variations and driving mechanisms in a large linked river-irrigation-lake system

Xiaohui Ren; Zhonghua Zhang; Ruihong Yu; Yuan Li; Yang Li; Yuanzhen Zhao

doi:10.1016/j.envres.2023.115596

Hydrochemical variations and driving mechanisms in a large linked river-irrigation-lake system

Environ Res. 2023 May 15:225:115596. doi: 10.1016/j.envres.2023.115596. Epub 2023 Mar 3.

Authors

Xiaohui Ren¹, Zhonghua Zhang¹, Ruihong Yu², Yuan Li¹, Yang Li¹, Yuanzhen Zhao¹

Affiliations

¹ Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, China.
² Inner Mongolia Key Laboratory of River and Lake Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, China; Key Laboratory of Mongolian Plateau Ecology and Resource Utilization, Ministry of Education, Hohhot, 010021, China; Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River, Hohhot, 010018, China. Electronic address: rhyu@imu.edu.cn.

PMID: 36871946
DOI: 10.1016/j.envres.2023.115596

Abstract

A linked river-irrigation-lake system exhibits intricate and dynamic hydrochemical variations, closely related to changes in natural conditions and anthropogenic activities. However, little is known about the sources, migration and transformation of hydrochemical composition, and the driving mechanisms, in such systems. In this study, the hydrochemical characteristics and processes in the linked Yellow River-Hetao Irrigation District-Lake Ulansuhai system were studied, based on a comprehensive hydrochemical and stable isotope analysis of water samples collected during spring, summer, and autumn. The results showed that the water bodies in the system were weakly alkaline with a pH range of 8.05-8.49. The concentrations of hydrochemical ions showed an increasing trend in the water flow direction. Total dissolved solids (TDS) were less than 1000 mg/L (freshwater) in the Yellow River and the irrigation canals, and increased to more than 1800 mg/L (saltwater) in the drainage ditches and Lake Ulansuhai. The dominant hydrochemical types varied from SO₄•Cl-Ca•Mg and HCO₃-Ca•Mg types in the Yellow River and the irrigation canals to Cl-Na type in the drainage ditches and Lake Ulansuhai. The ion concentrations in the Yellow River, the irrigation canals, and the drainage ditches were highest during summer, while ion concentrations in Lake Ulansuhai were highest during spring. The hydrochemistry of the Yellow River and the irrigation canals was mainly affected by rock weathering, while evaporation was the principal controlling factor in the drainage ditches and Lake Ulansuhai. Water-rock interactions including the dissolution of evaporites and silicates, the precipitation of carbonates, and cation exchange were the main sources of hydrochemical compositions in this system. Anthropogenic inputs had a low impact on the hydrochemistry. Therefore, greater attention should be paid in future to hydrochemical variations, especially salt ions, in the management of linked river-irrigation-lake system water resources.

Keywords: Evaporation; Hydrochemical variations; Rock weathering; Stable isotopes; Yellow River-Hetao Irrigation District-Lake Ulansuhai system.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

China
Environmental Monitoring / methods
Groundwater* / analysis
Lakes
Rivers / chemistry
Water
Water Pollutants, Chemical* / analysis
Water Quality

Substances

Water Pollutants, Chemical
Water