• Journal of Korea Water Resources Association
• /
• v.41 no.9
• /
• pp.919-927
• /
• 2008

Flow exchanges between stream and groundwater are assessed on urban streams in Daegu, Korea. Two rivers and 25 streams with the total length of 240 km run through the study area. The interaction between surface water and groundwater was estimated using Darcy's method. The study was conducted by dividing the basin into 16 smaller watersheds, and for comparison purposes. Groundwater level, surface water level, hydraulic conductivity, thickness of aquifer, and the distance between the well and the nearest stream were used for quantifying the interaction. To investigations the groundwater interaction in the watersheds, the amount of effluent seepage from groundwater to the stream, the amount of influent seepage from the stream to groundwater, and the amount of annual interaction between surface water and groundwater were computed. The total amount of effluent seepage from the groundwater to stream in the basin was approximately $72{\times}10^6m^3/year$. The total amount of influent seepage from the stream to groundwater was approximately $35{\times}10^6m^3/year$. It appeared that the total amount of annual interaction between surface water and groundwater was approximately $108{\times}10^6m^3/year$ and the total groundwater flow balance was approximately $37{\times}10^6m^3/year$. The annual amount of interaction between the surface water and groundwater was the largest in the Goryung Bridge Basin($29{\times}10^6m^3/year$) and the least in the Dalchang Dam Basin($0.2{\times}10^6m^3/year$). The results show that flow exchanges between stream and groundwater are very active and that there are significant difference among the smaller watersheds. Finally, the results indicate that it is necessary to further investigate to more precisely understand the interaction characteristics between surface water and groundwater in urban areas.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2004.03b
• /
• pp.839-846
• /
• 2004

The objective of this study is the evaluation of the tunneling effect on the groundwater-surface water interaction. The designed tunnel line is laid beneath the Gapo-cheon, which runs throughout study area. And, the pre-evaluation of the tunnel-influence on the Gapo-cheon is urgently needed. However, it is very difficult to find out the similar domestic and/or foreign cases. In this study, we would exclude the numerical modeling technique with insufficient data. Instead of the evaluation of the tunneling effect on the groundwater-surface water interaction with the numerical modeling, we monitored the flow rate of surface water at various point. We measured the flow rate of surface water at 5 points. With the results of surface flow, we can conclude that 39% of flow rate in Gapo-cheon is contributed by the groundwater discharge, as baseflow.

• Journal of Soil and Groundwater Environment
• /
• v.28 no.2
• /
• pp.1-11
• /
• 2023

Groundwater-surface water interaction was evaluated using water quality parameters (temperature and electrical conductivity), distributions of stable water isotopes (δ²H and δ ¹⁸O), and Rn-222 in lagoon water, groundwater, and seawater at three coastal lagoons (Songji (SJ), Youngrang (YR), and Sunpo (SP) Lagoon) in South Korea. From the results of composition and distributions of δ²H and δ¹⁸O, it was found that groundwater fraction of lagoon water in YR Lagoon (76%) was slightly higher than those of SJ (42%), and SP (63%) Lagoon. Based on Rn-222 mass balance model, groundwater discharge into SJ Lagoon in summer 2020 was estimated to be (3.2±1.1)×10³ m³ day^-1, which showed a similar or an order of magnitude higher than the results of previous studies conducted in coastal lagoons. This study can provide advanced techniques to evaluate groundwater-surface water interaction in coastal lagoons, wetlands, and lakes, and help to determine the effects of groundwater on coastal ecosystems.

• The Journal of Engineering Geology
• /
• v.21 no.1
• /
• pp.45-55
• /
• 2011

We examined the interactions between surface and groundwater through (1) flowmeter logging, (2) measurements of seasonal and vertical changes in temperature within a well, and (3) geochemical analyses of water samples from nine groundwater-monitoring wells. At two wells adjacent to a stream, subsurface water was found to flow from the stream to a surrounding alluvial fan, and the seasonal change in groundwater temperature is similar to those of surface water and air. Geochemical analyses at two wells indicated hydro-geochemical features affected by streamwater inflow, showing seasonal variations. Accordingly, these two wells are located in an area with active interaction between surface water and groundwater. The Thermochron I-button used in the present study is useful for this type of study of groundwater?surface water interaction because of its low cost and small size.

• Journal of Soil and Groundwater Environment
• /
• v.26 no.6
• /
• pp.144-156
• /
• 2021

This study examined hydrogeological characteristics of groundwater and surface water interaction in the fresh-saline water mixed zone of East Coast lagoon area, Korea, using several technical approaches including hydrological, lithological, and isotopic methods. In addition, the fresh-saline water interface was evaluated using vertical electrical conductivity (EC) data. For this purpose, three monitoring wells (SJ-P1, SJ-P2, and SJ-P3) were installed across the Songji lagoon at depths of 7.4 to 9.0 m, and water level, EC, and temperature at the wells and in the lagoon (SJ-L1) were monitored using automatic transducers from August 1 to October 21, 2021. Isotopic composition of the groundwater, lagoon water, and sea water were also monitored in the mid-September, 2013. The mixing ratios calculated from oxygen and hydrogen isotopic composition decreased with increasing depth in the monitoring wells, indicating saline water intrusion. In the study area, the interaction of groundwater-surface water-sea water was evident, and residual salinity in the sedimentary layers created in the past marine environment showed disorderly characteristics. Moreover, the horizontal flow at the lagoon's edge was more dominant than the vertical flow.

• Journal of Korea Water Resources Association
• /
• v.42 no.1
• /
• pp.21-31
• /
• 2009

The characteristics, intensity and direction of groundwater.surface water interactions are controlled by groundwater head gradients, hydraulic conductivity and by the riverbed geometry. As a result of the spatial heterogeneity of these factors and the subsequent variability of the impact of these interaction processes, the water balance is also characterized by highly variable spatial patterns and temporal dynamics. However, spatially detailed studies concerning the spatio-temporal variability of the extent and intensity of surface-groundwater interactions have been limited to the investigation of cross-sections or small stream reaches. Thus, the extensive study on the watershed based interaction between surface water and groundwater is to be analyzed. In this study, the intensity and the spatial extent of interactions along the stream were found by using integrated SWAT-MODFLOW model. This integrated modeling approach was applied to Anyangcheon watershed in Korea. The effluent stream characteristics were found in the watershed, namely, baseflow was annually discharged except heavy rainy periods. The intensity and the spatial extent of surface-groundwater interactions in different sub-watersheds were found on a daily basis. The influential extent of surface-groundwater interaction become larger as the watershed elevations are lower.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.287-287
• /
• 2023

Surface water-groundwater interaction (SWGI) is an important hydrological process that influences both the quantity and quality of water resources. However, regional scale SWGI model calibration and uncertainty analysis have been a challenge because integrated models inherently carry a vast number of parameters, modeling assumptions, and inputs, potentially leaving little time and budget to explore questions related to model performance and forecasting. In this study, we have proposed the application of iterative ensemble smoother (IES) for uncertainty analysis and calibration of the widely used integrated surface-subsurface model, SWAT-MODFLOW. SWAT-MODFLOW integrates Soil and Water Assessment Tool (SWAT) and a three-dimensional finite difference model (MODFLOW). The model was calibrated using a parameter estimation tool (PEST). The major advantage of the employed IES is that the number of model runs required for the calibration of an ensemble is independent of the number of adjustable parameters. The pilot point approach was followed to calibrate the aquifer parameters, namely hydraulic conductivity, specific storage, and specific yield. The parameter estimation process for the SWAT model focused primarily on surface-related parameters. The uncertainties both in the streamflow and groundwater level were assessed. The work presented provides valuable insights for future endeavors in coupled surface-subsurface modeling, data collection, model development, and informed decision-making.

• Journal of Korea Water Resources Association
• /
• v.53 no.spc1
• /
• pp.755-764
• /
• 2020

In South Korea, 850 standard watersheds and 7,807 KRF catchment areas have been used as basic maps for water resources policy establishment, however it becomes necessary to set up new standard maps with a more appropriate scale for the integrated managements of surface water-groundwater as well as water quantity-quality in the era of integrated water management. Since groundwater has a slow flow velocity and also has 3-D flow properties compared to surface water, the sub-catchment size is more effective than the regional watershed for the evaluation of surface water-groundwater interaction. The KRF catchment area, which has averagely a smaller area than the standard watershed, is similar to the sub-catchment area that generally includes the first-order or second-order tributaries. Some KRF catchment areas, which are based on the surface reach, are too small or large in a wide plain or high mountain area. Therefore, it is necessary to revise the existing KRF area if being used as a unit area for integrated management of surface-water and groundwater. A unit watershed with a KRF area of about 5 to 15 ㎢ can be effective as a basic unit for water management of local government considering a tributary composition and the location of groundwater wells, and as well it can be used as a basic tool for water demand-supply evaluation, hydrological observation system establishment, judgment of groundwater permission through a total quantity management system, pollution assessment, and prioritizing water policy, and etc.

• Journal of Wetlands Research
• /
• v.15 no.1
• /
• pp.43-50
• /
• 2013

The groundwater-surface water interaction of Searsville Lake area, California, US was analyzed using 3-dimensional groundwater model. This study especially focuses on investigating the groundwater head drawdown near the lake when the abrupt decline of the lake water table occurs due to the implementation of the options to remove the accumulated sediments along the dam. The result of the investigation revealed that the groundwater head drawdown near the lake is not significant enough to adversely affect the wetland habitat of the area regardless of the hydrogeologic parameters of the aquifers. We expect this result provides useful information to the similar Korean case studies in which the surface water level abruptly changes due to the operation of the hydraulic gates of dams and wiers and the corresponding environmental impact should be considered.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1945-1949
• /
• 2009

It is fact that many research is advanced about management and security of water resources according to serious problem which is raising its head that conservancy and management of water resources development of population and industry. Ground water of water resources is the source of water resources security with surface water, so it have to be continuous exploitation and research however, until now it researched in separate way from surface water, and it become connect each other for the research in actual condition in recent times. The research analyzed the recharge at the SWAT model, interpreted by used GMS/MODFLOW model for ground water flow change.