Interactions between the Surface Water and Groundwater of the Red River in Hanoi, Vietnam

Understanding the interactions between surface water and groundwater is critical for effective water management and conjunctive water use planning as these are intimately linked in the hydrologic cycle. This study is the first attempt to determine the spatio-temporal patterns of the interactions between the surface water of the Red River in Hanoi, Vietnam and the groundwater of two main adjacent aquifers, the Holocene unconfined aquifer (HUA) and Pleistocene confined aquifer (PCA). In this study, an integrated surface-groundwater model was developed by coupling two commercial modeling packages: the river flow routing model (MIKE 11) and the ground flow model (MODFLOW). As for the results, this study revealed that there was very high correlation between the river water levels and HUA groundwater levels. The correlation was found decreasing not only with the distance from the river, but also from the upstream to downstream along the river. Upper parts of the river exhibited seasonal interactions of recharge and discharge between the river and aquifer, while the lower parts of the river recharged groundwater almost throughout the year.