Comparison of groundwater age models for assessing nitrate loading, transport pathways, and management options in a complex aquifer system

Hydrological Processes
By: , and 

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Abstract

In an aquifer system with complex hydrogeology, mixing of groundwater with different ages could occur associated with various flow pathways. In this study, we applied different groundwater age estimation techniques (lumped parameter model, and numerical model) to characterize groundwater age distributions and the major pathways of nitrate contamination in the Gosan agricultural field, Jeju Island. According to the lumped parameter model, groundwater age in the study area could be explained by the binary mixing of the young groundwater (4-33 years) and the old water component (>60 years). The complex hydrogeologic regimes and local heterogeneity observed in the study area (multi-layered aquifer, well leakage hydraulics) were particularly well reflected in the numerical model. The numerical model predicted that the regional aquifer of Gosan responded to the fertilizer applications more rapidly (mean age: 9.7-22.3 years) than as estimated by other models. Our study results demonstrated that application and comparison of multiple age estimation methods can be useful to understand better the flow regimes and the mixing characteristics of groundwater with different ages (pathways), hence, to reduce the risk of improper groundwater management plan arising from the aquifer heterogeneity.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Comparison of groundwater age models for assessing nitrate loading, transport pathways, and management options in a complex aquifer system
Series title Hydrological Processes
DOI 10.1002/hyp.11465
Volume 32
Year Published 2019
Language English
Publisher Wiley
Contributing office(s) WMA - Integrated Modeling and Prediction Division
Description 16 p.
First page 923
Last page 938
Country South Korea
Other Geospatial Jeju Island