Differences in hydrogeochemistry between shallow and deep aquifers in the Baiyangdian basin, China

Huaming Guo,Yi Chen,Haitao Li,Kai Zhao,Wei Xiu,Lingbao Weng,Zhaoli Shen,O Chudaev,R Millot,O Shouakar-Stash,R Harmon,Y Kharaka

doi:10.1051/e3sconf/20199807009

Abstract

Groundwater is the dominant long-term water resource for agricultural irrigation and industrial production in the Baiyangdian basin, North China Plain. Groundwater and pore-water were investigated to evaluate chemical evolution and geochemical processes in shallow and deep aquifers. Results show that both shallow groundwater and shallow pore-water had higher TDS, Ca2+, Mg2+, SO42-, and HCO3- concentrations than deep groundwater and deep pore-water. Generally, concentrations of groundwater major ions were higher than those of pore-water in shallow aquifers, while they were slightly lower in groundwater than in pore-water from deep aquifers. Water isotopes showed the meteoric origin of groundwater and pore-water, although evaporation signature was traced in shallow groundwater. Shallow groundwater also experienced carbonate dissolution and silicate weathering. Silicate weathering and evaporite dissolution were the major hydrogeochemical processes in deep aquifers. This study indicated that deep groundwater has better water quality, but is vulnerable to contamination from shallow groundwater with high TDS and NO3- concentrations.

Highlights

Groundwater is generally the dominant long-term water resource for agricultural irrigation and industrial production in arid-semiarid areas [1,2,3], where groundwater quantity and quality are very important for ecological maintenance and social sustainability [4]
This study is to investigate major chemical distributions of groundwater and pore-water and evaluate geochemical processes occurring in different aquifers, which would improve our understanding of chemical evolution of groundwater and help in sustainably managing water resources
Higher SO42concentrations than Cl- was observed in shallow groundwater, while SO42- concentrations were lower than those of Cl- in deep groundwater (Fig. 2)

Summary

Introduction

Groundwater is generally the dominant long-term water resource for agricultural irrigation and industrial production in arid-semiarid areas [1,2,3], where groundwater quantity and quality are very important for ecological maintenance and social sustainability [4]. The North China Plain (NCP) is the largest alluvial plain in eastern Asia with serious water shortage, which poses great restrictions on economic development [1, 5]. The Baiyangdian lake, the largest shallow (mean depth

Methods

Results

Conclusion