『Summary
　Stable isotopes of water, chlorofluorocarbon (CFCs), and ³H/³He were applied in combination with hydrogeochemical data to analyze recharge patterns and nitrate contamination of shallow groundwater systems in a small agricultural area, Yupori, Chuncheon (Korea), where the eastern part is on hill slopes and the western part is low lands. The values of δ¹⁸O and δD indicated that groundwater is derived mainly from summer precipitation, which is more pronounced in the western part than in the eastern part. The apparent groundwater ages using CFC-113 and ³H/³He ranged from 13 to 31 yr, and are younger in the western part than in the eastern part. Dispersion models fit concentrations of ³H and CFC-113 for most wells of the eastern part with intermediate dispersion parameters. Nitrate concentrations were higher in the western part than the eastern part due to the land use pattern and topography. Stable isotopes of water and groundwater ages indicated that higher recharge rate affected by multiple sources of contamination is dominant in the western part whereas limited recharge with weak nitrate sources is considerable in the eastern part. This groundwater flow pattern corresponds to the different nitrate concentrations in the western and the eastern part. Groundwater residence time and recharge rate play an important role in the spatial distribution of NO3 concentration in the study area as well as land use pattern.

Keywords: Environmental tracers; Recharge; Groundwater age; Nitrate; Agriculture』

Introduction
Study area
　Hydrogeology
　Land use
Methods
Results and discussion
　Hydrogeochemistry
　Stable isotopes of water
　The apparent ages of groundwater
　Mean residence time of groundwater
　Nitrate and groundwater recharge rate
Conclusion
Acknowledgments
References