• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1011-1020
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• 2022

Previous studies for the assessment of submarine groundwater discharge (SGD) were perfomed for areas where a large amount of SGD was observed. Newly developed assessment methods were proposed that was based on an analytic solution using sharp interface model. The proposed mathematical equations used the existing observed groundwater level and hydrogeological data of Jeju Island as input data. The quantitatively assessed FSGD values were compared to the basin-scale recharge estimation values in Seong-San area in eastern Jeju. As a result of the study, it was estimated that the amount of FSGD in the Seongsan area ranges from about 2.65 to 9.15% of the amount of areal-recharge. Through the analysis of the FSGD combined with the analytic model, it is to be provided as a scientific tool to establish a more reasonable coastal water resource management plan.

• Journal of Wetlands Research
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• v.16 no.2
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• pp.173-185
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• 2014

Climate change has caused detrimental phenomena such as heavy rainfall which could aggravate soil erosion. Accordingly, it is needed to evaluate the groundwater recharge, baseflow, and soil erosion for the efficient management of water resources and quality. In this study, future climate change scenarios were applied to the H aean-myeon watershed which is a steep sloping watershed in South Korea to analyze groundwater recharge, baseflow, sediment. Also, the variation of groundwater recharge, baseflow, sediment was analyzed according to the change of slope (5 %). Simulated periods were divided into three terms (2013 ~ 2040 years, 2041 ~ 2070 years, 2071 ~ 2100 years). As a result of this study, average groundwater recharge and baseflow increased by 50 %, 42 %, and sediment decreased by 72 %, respectively. In these regards, the suggested method will positively contribute to hydro-ecosystem and reduction of muddy water at a steep sloping watershed.

• Journal of Soil and Groundwater Environment
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• v.24 no.3
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• pp.24-35
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• 2019

It is known that ${\delta}^{13}C_{DIC}$ (carbon-13 isotope of dissolved inorganic carbonate (DIC) ions) of water increases when dissolved $CO_2$ degases. However, ${\delta}^{13}C_{DIC}$ could decrease when the pH of water is lower than 5.5 at the early stage of degassing. Laboratory experiments were performed to observe the changes of ${\delta}^{13}C_{DIC}$ as $CO_2$ degassed from three different artificial $CO_2$-rich waters (ACWs) in which the initial pH was 4.9, 5.4, and 6.4, respectively. The pH, alkalinity and ${\delta}^{13}C_{DIC}$ were measured until 240 hours after degassing began and those data were compared with kinetic isotope fractionation calculations. Furthermore, same experiment was conducted with the natural $CO_2$-rich water (pH 4.9) from Daepyeong, Sejong City. As a result of experiments, we could observe the decrease of DIC and increase of pH as the degassing progressed. ACW with an initial pH of 6.4, ${\delta}^{13}C_{DIC}$ kept increasing but, in cases where the initial pH was lower than 5.5, ${\delta}^{13}C_{DIC}$ decreased until 6 hours. After 6 hours ${\delta}^{13}C_{DIC}$ increased within all cases because the $CO_2$ degassing caused pH increase and subsequently the ratio of $HCO_3{^-}$ in solution. In the early stage of $CO_2$ degassing, the laboratory measurements were well matched with the calculations, but after about 48 hours, the experiment results were deviated from the calculations, probably due to the equilibrium interaction with the atmosphere and precipitation of carbonates. The result of this study may be not applicable to all natural environments because the pressure and $CO_2$ concentration in headspace of reaction vessels was not maintained constant as well as the temperature. Nevertheless, this study provides fundamental knowledge on the ${\delta}^{13}C_{DIC}$ evolution during $CO_2$ degassing, and therefore it can be utilized in the studies about carbonated water with low pH and the monitoring of geologic carbon sequestration.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.129-129
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• 2018

최근 가뭄, 강우사상의 변화 등의 자연적 요인과 함께 불투수면적의 증가, 지하수 이용의 증가, 지하구조물 공사 등과 같은 인위적 요인에 의한 지하수위 하강이 문제가 되고 있다. 지하수위의 하강은 지하수자원 부족과 같은 1차적 피해뿐만 아니라 지반침하, 생태계 교란, 농작물 피해, 지하수 오염과 같은 2차 피해를 야기할 수 있다. 지하수자원에 문제가 생긴 경우 단기간에 회복되기가 힘들고 투자할 수 있는 자원이 한정된 현 상황에서 지하수자원 관리 방안을 유역에 대해서 일괄적으로 적용하기에 어려움이 있다. 이를 위해 영산강 본류가 흐르는 행정구역을 대상으로 정량적인 분석을 통하여 지하수자원 관리에 취약한 지역을 선정하고 지하수자원 관리 방안을 적용하는 것이 효율적인 방법이 될 수 있다. 본 연구에서는 영산강 본류가 흐르는 7개 시 군을 대상으로 자료를 수집하였고 취약성 지수를 산정하여 지하수자원 관리 취약성 분석을 실시하였다. 7개 시 군의 자료를 수집하고 Re-scale 기법을 적용하여 표준화 하였고, 취약성 지수를 산정하기 위하여 엔트로피 방법을 통해 산정된 가중치를 적용하였다. 최종 취약성 지수를 지도에 나타내 가시화 하고 지하수자원 관리에 취약한 지역에 대하여 지하수자원 관리 방안 및 시설물 개선 등의 계획을 세운다면 지하수자원 관리 부족에 따른 피해에 효과적인 대응이 가능할 것으로 예상된다.

• Journal of Soil and Groundwater Environment
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• v.28 no.6
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• pp.58-70
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• 2023

The improper management of radioactive waste or accidents caused by natural disasters can result in the release of radioactive materials into the surrounding environment, potentially leading to soil and groundwater contamination by radionuclides. In this study, adsorption-desorption behaviors of the radionuclides (cobalt and strontium) in natural soil, montmorillonite, Mn-PILC, Fe-PILC, and fishbone were investigated. Several models were used to predict adsorption isotherms of radionuclides on various absorbents. Adsorption isotherms of cobalt and strontium in several adsorbents were examined at pH 5.5. The amount of sorbed cobalt and strontium were represented fishbone > natural soil > Mn-PILC > Fe-PILC > montmorillonite and natural soil > Mn-PILC > fishbone > Fe-PILC > montmorillonite, respectively. Adsorption datas were fitted with several models such as Freundlich, Langmuir, Sips, Redlich-Peterson, Khan, and Generalized model. The results of curve fitting showed R²> 0.98 in all of adsorption models, except Sr²⁺ adsorption onto montmorillonite. For modified clays (Mn-PILC, Fe-PILC), it is suggested that, unlike natural soils and fish bones, there are not only single adsorption mechanisms but also adsorption mechanisms based on chemical adsorption and surface charge. In the case of fish bones, due to the relatively higher adsorption capacity than modified clays and its characteristic of significant desorption, it is expected more suitable for the removal of radionuclides in aquatic environments than for the immobilization of radionuclides in soil.

• Journal of Environmental Impact Assessment
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• v.22 no.4
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• pp.345-359
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• 2013

The Ministry of Environment established a plan for advancement of livestock manure management in July 2011 and finalized the "Comprehensive Measures for Advancement of Livestock Manure Management" in May 2012 complementing and strengthening the plan. In this process, it was necessary to investigate the status of discharge of livestock manure and its environmental impact, for example on rivers, groundwater, arable outflow water and soil. We investigated types of livestock husbandry, discharge of livestock manure, and production and use of organic fertilizers and presented the improvement measures of livestock manure management and organic fertilizer use. First, it is necessary to come up with measures to calculate appropriate density and numbers of livestock animals and prevent overcrowded breeding. Second, as many of the private livestock manure treatment facilities are out-dated and their long-term aerated reaction tanks are not regularly managed, it is necessary to find ways to improve those facilities through inspection and diagnosis. In addition, since existing public treatment facilities are designed to add clean water to belt filter press, additional water is needed. Therefore, it is necessary to improve belt filter press in order to decrease the extra water. Finally, although large-scale organic fertilizer plants and resources recycling centers produce good organic (liquid) fertilizers with proper components, it is necessary to establish standards for maturity of liquid fertilizers in order to facilitate efforts to turn livestock manure into resources.

• Journal of Environmental Impact Assessment
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• v.10 no.2
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• pp.99-108
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• 2001

This study was performed to develop an information processing system for the sound conservation of soil and groundwater resources. The system contains numerical models and geographic information systems for underground flow and contamination. Multidimensional Finite Element Model for Subsurface Environment (MFEMSE) was invented to analyze underground flow and pollution problems of water and gas phases. Newly developed and conventional models (MODFLOW, MOC3D, MT3D, PMPATH, PEST, UCODE) were integrated with GIS (ArcView) for the construction of an integrated information management system of subsurface environment. This system was applied to the management of three mineral water companies located in clean high mountain basin. Desirable management criteria and operational strategies were suggested using this system. The system was constructed to be applied for the broad sense of decision supporting tools in related topics of this study, so that it can be used not only for the prevention regulations, but also for clean up projects.

• The Journal of Engineering Geology
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• v.24 no.4
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• pp.597-608
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• 2014

It is widely assumed that climate change and other anthropogenically driven processes are having a serious impact on coastal environments. One such impact is saltwater intrusion into coastal aquifers, which has resulted in the loss of groundwater resources. The pattern of saltwater intrusion is strongly dependent on regional hydrogeological characteristics. This study reviews recent qualitative and quantitative research into this problem, and considers relevant case studies. In addition, the characteristics of the aquifers from two representative volcanic islands (Jeju Island, Korea and Oahu Island, USA) are compared. The fundamental theory of density-dependent flow used to model saltwater intrusion processes and the programs that are widely used to simulate saltwater intrusion based on density-driven problems are also investigated. It is expected that the knowledge gained from this review of previous studies can be used to help improve groundwater management practices in Korea and also to inform future interdisciplinary studies.

• Journal of Environmental Health Sciences
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• v.18 no.1
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• pp.58-62
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• 1992

The objective of this study is to investigate the generation rates, composition, propertion and lower heating values of each material in the municipal solid wastes(MSW) as well as the effect of landfill leachate on the environment in Taejon. The results are as follows: 1. The annual average generation rate of MSW in Taejon is approximately 1.7kg/c.d. 2. The weight percent of combustible matters is on average 80 and the lower heating value of MSW is measured to be more than 1,700 kcal/kg after removing the briquette component. 3. It is necessary for us to take a proper management system for leachate treatment in the landfill because it has many problems in the sewage and groundwater. 4. It is recommeded that MSW be treated by multiple methods such as the sanitary landfill, resources and recovery, composting and incineration.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.119-119
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• 2017

기후 온난화로 인하여 빙하의 해빙과 해수의 팽창으로 해수면의 상승 속도는 나날이 증가하고 있다. 우리나라는 2.48mm/yr로 상승하고 있으며, 특히 남해는 2.89mm/yr로 가장 크게 상승하고 있다. 해수면의 상승과 더불어 해수침투 영역 확장을 방지할 수 있는 지하수위 또한 낮아지고 있어 해수침투에 대한 피해를 점차 늘어나고 있다. 해수침투로 인한 피해는 연안지역에서부터 시작하여 점점 영역을 넓혀가고 있다. 해수침투 피해는 직접적으로 토지의 염수화로 지하수의 오염, 농작물의 염수 피해, 주변 생태계의 교란 등으로 나타나고 한 번 염수화가 진행된 지역을 되돌리는 것은 많은 노력과 재화가 들어가게 된다. 이를 방지하기 위해서 많은 연구가 진행되고 있다. 해수침투 범위가 증가하는 것이 해수면의 상승도 큰 영향을 미치지만, 해수침투 쐐기를 구성하는 담수 지하수위가 낮아지면 더욱 가속화된다. 이에 본 연구에서는 남해안의 여수지역을 SEAWAT으로 구성하여, 현재의 상황을 나타내고 지하수위, 해수면, 지하수 이용량, 함양량 등을 대상으로 선형적인 상승 혹은 하강으로 미래의 상황을 나타내었다. 적용된 시나리오에 지하수위 관리 방안을 적용하여 해수침투 영역 저감 효과에 대해서 분석하였다. 지하수위 관리 방안으로는 지하수위 하강 시기에 지하수 이용량 규제, 도심지에서 LID(Low Impact Development) 시설물 중 침투 증진 시설 보강 등을 이용하였으며, 각각의 시나리오를 통해 해수침투 영역 저감 효과 분석을 실시하였다. 지하수위의 관리는 해수침투에 대한 피해 방지와 더불어 지속가능한 지하수 이용을 위한 정책을 마련하기 위한 기초자료로 활용할 수 있을 것으로 보여진다.