IEG 환경지질연구정보센터

10월 25일(목)․지하수학

212 2007 추계지질과학연합학술대회 초록집

Surface water-groundwater interaction in a hyporheic zone within an alluvial setting underneath agricultural field: use of

hydrochemical mixing model

Kyoung-Ho Kim

․Seong-Taek Yun

․Byoung-Young Choi

․Jong-Wook Jeon

1

Department of Earth and Environmental Sciences, Korea University, [email protected]

2

Korea Atomic Energy Research Institute, 3 Byucksan Engineering Co.

In this study, hydrochemical and hydrogeologic investigations of alluvial groundwater un- derneath an agricultural field were performed to elucidate the surface water-ground water interaction developed in a hyporheic interaction zone. In the study area, a large-scale hypo- rheic zone is developed along long flow paths (>500 m) alongside a meandering stream.

To examine the hydrologic mixing process and flow dynamics within the zone, we conducted a geochemical mixing model using three-dimensional hydrochemical dataset obtained from four multi-level wells and twenty-four shallow (6 m deep) wells. The mixing model is developed based on multivariate statistics and can be used to determine the solutes which can be effec- tively used as hydrologic tracers and to estimate the geochemical reactions in addition to mixing. Using collected hydrogeological data, numerical flow model was also used to calculate the path of hyporheic flow from a stream to alluvial groundwater and was also calibrated with the mixing model using geochemical tracers. The results of this study show that combined use of the mixing and flow models based on hydrogeologic and hydrochemical data is helpful to quantitatively understand the flow and fate of aquatic contaminants in a hyporheic zone.

96