Using multivariate statistical techniques and geochemical modelling to identify factors controlling the evolution of groundwater chemistry in a typical transitional area between Taihang Mountains and North China Plain. Issue 8 (29th January 2020)

• Record Type: Journal Article
• Authors: Liu, Fei; Wang, Shou; Yeh, Tian‐Chyi Jim; Zhen, Pinna; Wang, Lishu; Shi, Liming
• Is Part Of: Hydrological processes. Volume 34:Issue 8(2020)
• Page Start: 1888
• Page End: 1905
• Publication Date: 2020-01-29
• Subjects: geochemical modelling -- groundwater evolution -- headwater basin -- hydrochemistry -- multivariate statistical analysis -- North China Plain; Hydrology -- Periodicals; Hydrology -- Research -- Periodicals; Hydrologic models -- Periodicals; Hydrological forecasting -- Periodicals; 631.432
• DOI: 10.1002/hyp.13701
• Languages: English
• ISSNs: 0885-6087

Abstract

Abstract: Identifying the key factors controlling groundwater chemical evolution in mountain‐plain transitional areas is crucial for the security of groundwater resources in both headwater basins and downstream plains. In this study, multivariate statistical techniques and geochemical modelling were used to analyse the groundwater chemical data from a typical headwater basin of the North China Plain. Groundwater samples were divided into three groups, which evolved from Group A with low mineralized Ca‐HCO3 water, through Group B with moderate mineralized Ca‐SO4 ‐HCO3 water, to Group C with highly saline Ca‐SO4 and Ca‐Cl water. Water‐rock interaction and nitrate contamination were mainly responsible for the variation in groundwater chemistry. Groundwater chemical compositions in Group A were mainly influenced by dissolution of carbonates and cation exchange, and suffered less nitrate contamination, closely relating to their locations in woodland and grassland with less pronounced human interference. Chemical evolution of groundwater in Groups B and C was gradually predominated by the dissolution of evaporites, reverse ion exchange, and anthropogenic factors. Additionally, the results of the inverse geochemical model showed that dedolomitization caused by gypsum dissolution, played a key role in the geochemical evolution from Group A to Group B. Heavy nitrate enrichment in most groundwater samples of Groups B and C was closely associated with the land‐use patterns of farmland and residential areas. Apart from the high loads of chemical fertilizers in irrigation return flow as the main source for nitrate contamination, the stagnant zones, flood irrigation pattern, mine drainage, and groundwater‐exploitation reduction program were also important contributors for such high mineralization and heavy NO3 − contents in Group C. The important findings of this work not only provide the conceptual framework for the headwater basin but also have important implications for sustainable management of groundwater resources in other headwater basins of the North China Plain. Abstract : (1) Water‐rock interaction predominated in the geochemical evolution of groundwater, and spatial distribution of nitrate contamination was related to land use patterns.(2) Stagnant zones, overuse of fertilizers, mine drainage, and groundwater‐exploitation reduction program may contribute to high groundwater mineralization and heavy nitrate contamination.(3) A conceptual model of hydrochemical evolution was developed in a typical headwater basin of the North China Plain.