• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.6
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• pp.2285-2291
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• 2013

In this study, daily based groundwater recharge was estimated under unsteady state by using groundwater table fluctuation model developed by Kim et al. (2013). This technique analyzes groundwater variation characteristics by using reaction factor related with groundwater flow and specific yield related with recharge. For the application of this model, measured groundwater level at JD Yongdam 1 and JW Konghang for 5 years were used. This model can estimate daily based groundwater recharge and the computed groundwater levels showed good agreement with measured groundwater levels. At JD Yongdam 1 and JW Konghang, the estimated recharges (rates) were 520.4~904.0mm (32.7~61.8%) and 447.4~633.4mm (24.0~45.1%), respectively. The developed model can be suggested as an efficient and precise method to estimate daily based groundwater recharge by using groundwater level data.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.521-532
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• 2018

In recent decades, the dry stream phenomena of small and medium sized rivers have been attracting much attention as an important social problem. To prevent dry stream phenomena, it is necessary to build an infrastructure that manages rivers. To accurately determine the progress of dry stream phenomena, it is necessary to continuously measure the discharge and other hydrological factors for small and medium sized rivers. However, until now, the flow data for small and medium rivers in Korea has been insufficient. To overcome the lack of supporting data for supporting rational decision-making in policy and project implementation, a short- and long-term hydrological model was developed that takes into consideration hydrological changes such as the increase of the impervious area due to urban development and groundwater pumping, the construction of a large-scale sewage treatment plant, the maintenance of stream-oriented rivers, etc. In the developed model, the distributed grid is represented by three layers: Surface flow, interflow, and groundwater flow. The surface flow and intermediate flow flowed along the flow direction, and the groundwater flow was calculated by a two-dimensional groundwater analysis model such that the outflow occurred in all directions without a specific flow direction. The effects of land use and cover on evapotranspiration and infiltration and the effects of multiple landscapes can be simulated in the developed model.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.64-71
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• 2010

National inventory of soil and groundwater contamination is an efficient decision-making tool to identify and manage existing or potential contaminated sources and contaminants. It has been used as basic data for establishing the scheme of regulations and remediation plans of soil and groundwater contamination in developed countries. This study examined classification of existing or potential sources of soil and groundwater contamination from various countries to suggest implications that required for development of classification of soil and groundwater contamination sources in Korea. Each country has provided a list of currently or potentially contaminating activities or landuses and identified some of the potential contaminants related to those contamination sources. Consideration of sources which had not been mentioned or regarded as contamination sources before was suggested for Korea situation. In addition, it is necessary to compile a list of existing data and information as much as possible to develop a detailed and practical list of various contamination sources.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.9-15
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• 2023

In order to properly evaluate the spatio-temporal variations of groundwater flow, the data obtained in field experiments should be corroborated into numerical simulations. Particle tracking method is a simple simulation tool often employed in groundwater simulation to predict groundwater flow paths or solute transport paths. Particle tracking simulations visually show overall the particle flow path along the entire aquifer, but no previous simulation studies has yet described the parameter values at grid nodes around the particle path. Therefore, in this study, a new technical approach was proposed that enables acquisition of parameters associated with particle transport in grid nodes distributed in the center of the particle path in groundwater. Since the particle tracking path is commonly referred to as streamline, the algorithm and codes developed in this works designated streamline analysis method. The streamline analysis method can be applied in two-dimensional and three-dimensional finite element or finite difference grid networks, and can be utilized not only in the groundwater field but also in all fields that perform numerical modeling.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.2
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• pp.153-167
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• 2024

Recently the ground settlement has been increasing in urban area according to development. And, this may attribute a groundwater level drawdown. This study presents an analysis of groundwater level drawdown for circular vertical shaft excavation of ｢◯◯◯◯ double track railway build transfer operate project｣. And, in-situ monitoring data and numerical analysis were compared. So, if we examine the groundwater level drawdown in design, ground conditions should be applied so that the site situation can be reflected. And, groundwater level should be considered a seasonal measurement in order to apply the appropriate groundwater level. It was confirmed a similar predicted value to groundwater level drawdown of in-situ monitoring data.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09c
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• pp.117-124
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• 2010

In the field of soil and groundwater remediation, sustainability was merged into remediation process and green remediation was initiated within the concept of sustainable development. Green remediation was defined and has been already applied to the remediation fields in U.S. In the case of Europe, green remediation has been evaluated for the application of green technology in the remediation industry and they especially defined sustainable remediation following idea of sustainable development. Although green and sustainable remediation is global trends, there are only a few cases about application of green remediation in South Korea. It is needed to develop soil and groundwater remediation technology towards green remediation, considering "Green Growth" as policy direction in South Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.4
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• pp.527-535
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• 2018

Agricultural activities of western Jeju island has suffered from saltwater intrusion seasonally. Objectives of this study are to prove the occurrence of saltwater intrusion in the coastal aquifer and to consider a management plan using MODFLOW-family code SEAWAT model. Model results show that the saltwater-freshwater interface intrudes inland only a few meters and that upconing phenomenon is rather the cause of the severe disaster of the agricultural water contamination. This study selected Gosan area as a representative site to estimate optimal groundwater development regulation against upconing by seasonal pumping for agriculture. The suggested optimal groundwater development estimation method considers the groundwater levels of representative monitoring wells for regulatory alarms.

• Journal of the Korean GEO-environmental Society
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• v.15 no.7
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• pp.39-50
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• 2014

The goal of this work is to develop a framework of methods to entirely evaluate effects of LID (Low Impact Development) on soil-groundwater environmental quality as well as land-scape and ecological factors. For this study, we conducted an extensive literature review. As outcomes, soil-groundwater environmental quality is newly conceptualized as a comprehensive index reflecting (i) groundwater pollution sensitivity (hydrogeological factor), (ii) biochemical contamination, and (iii) biodegradability. The methods of classifying and indexing is shown by combining selection of the items to be measured for soil-groundwater environmental quality and integrating the resulted items comprehensively. In addition, from soil-groundwater environmental quality, land-scape and ecological factors in existing environmental impact assessment a method was developed an overall index which can evaluate effects to environment by using GIS (Geographic Information System) and AHP (Analytic Hierachy Process). For optimizing LID planning, designing and post-evaluation, LCIA (Life Cycle Impact Assessment) was regarded as an appropriate method.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.697-723
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• 2022

Data-driven models to predict groundwater levels 30 days in advance were developed for 12 groundwater monitoring stations in the middle-Jeju watershed, Jeju Island. Stacked long short-term memory (stacked-LSTM), a deep learning technique suitable for time series forecasting, was used for model development. Daily time series data from 2001 to 2022 for precipitation, groundwater usage amount, and groundwater level were considered. Various models were proposed that used different combinations of the input data types and varying lengths of previous time series data for each input variable. A general procedure for deep-learning-based model development is suggested based on consideration of the comparative validation results of the tested models. A model using precipitation, groundwater usage amount, and previous groundwater level data as input variables outperformed any model neglecting one or more of these data categories. Using extended sequences of these past data improved the predictions, possibly owing to the long delay time between precipitation and groundwater recharge, which results from the deep groundwater level in Jeju Island. However, limiting the range of considered groundwater usage data that significantly affected the groundwater level fluctuation (rather than using all the groundwater usage data) improved the performance of the predictive model. The developed models can predict the future groundwater level based on the current amount of precipitation and groundwater use. Therefore, the models provide information on the soundness of the aquifer system, which will help to prepare management plans to maintain appropriate groundwater quantities.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.525-532
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• 2011

In this study, the usefulness of underground dam as a means for the sustainable development of groundwater, and its performance in the management of groundwater resources were analyzed. The fully integrated SWAT-MODFLOW was applied to the Ssangcheon watershed in Korea to evaluate the effectiveness of groundwater dam construction. After construction, the groundwater level raised in the upstream area of groundwater dam while lowered in the downstream area. Also, it is shown that the exchange rate of river-aquifer interactions increased in the upper area of the dam. Since the storage capacity of the aquifer largely increased in the upper area of the dam, the exploitable groundwater could be greatly increased as much. This study demonstrated that a groundwater dam was a very useful measure to increase the available storativity of groundwater aquifers. It also represented that the combined analysis using SWAT-MODFLOW was helpful for the design and opeation of groundwater dam in the Ssangcheon watershed.