An Integrated Modeling Approach to Study the Surface Water-Groundwater Interactions and Influence of Temporal Damping Effects on the Hydrological Cycle in the Miho Catchment in South Korea

Integrated surface water-groundwater (SW-GW) models could be used to assess the impacts of climate change or variability on the hydrological cycle. However, the damping effects of the hydrological system have rarely been explored via integrated SW-GW modeling. This paper presents an integrated modeling study in a typical humid area, the Miho catchment in Korea, using an integrated model called Groundwater and Surface-water FLOW (GSFLOW). The major findings of this study are as follows: (1) The simulated results from 2005 to 2014 indicate that the temporal variability in the streamflow, stream-groundwater interactions and groundwater recharge are dominated by the precipitation, while the temporal variability in the evapotranspiration (ET) is controlled by the energy conditions; (2) Damping effects can affect the hydrological cycle across different temporal and spatial scales. At the catchment scale, the soil zone and aquifer play a dominant role in damping the precipitation on monthly and annual time scales, respectively; (3) Variability in the capacity to buffer earlier precipitation is found at small spatial scales, such as streams, and larger spatial scales, such as the whole catchment. This variability could affect the water balance at larger spatial scales and affect the hydrography recession at smaller spatial scales.