• The Journal of Engineering Geology
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• v.18 no.4
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• pp.359-369
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• 2008

For the design and effective management of underground storage caverns, preliminary investigation on the hydrogeologic parameters around caverns and analysis on the groundwater flow must be carried out. The data collection is very imporatnat task for the hydrogeologic design so various hydraulic tests have been performed. When analyzing the injection/fall off test data, existing graphical method to estimate the parameters in Theis' equation is widely used. However this method has some sources of error when estimating parameters by means of human faults. Therefore the method of estimating parameters by means of statistical methods such as regression type is evaluated as a useful tool. In this study, nonlinear regression analysis for the Theis' equation is suggested and applied to the estimation of parameters for the real field interference data around underground storage caverns. Damping parameter which reduce the iteration numbers and inhance the convergence is also introduced.

• Journal of Korea Water Resources Association
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• v.46 no.7
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• pp.745-754
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• 2013

The systematic analysis and evaluation of required energy in the processes of drinking water production and supply have attracted considerable interest considering the need to overcome electricity shortage and control greenhouse gas emissions. On the basis of a review of existing research results, a practical method is developed in this study for evaluating energy in water supply networks. The proposed method can be applied to real water supply systems. A model based on the proposed method is developed by combining the hydraulic analysis results that are obtained using the EPANET2 software with a mathematical energy model on the MATLAB platform. It is suggested that performance indicators can evaluate the inherent efficiency of water supply facilities as well as their operational efficiency depending on the pipeline layout, pipe condition, and leakage level. The developed model is validated by applying it to virtual and real water supply systems. It is expected that the management of electric power demand on the peak time of water supply and the planning of an energy-efficient water supply system can be effectively achieved by the optimal management of energy by the proposed method in this study.

• The Journal of Engineering Geology
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• v.13 no.1
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• pp.67-82
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• 2003

Pumping test data obtained from five natural mineral-water producing companies (Siwon Saemmul, Daejeong Eumryo, Jain Guanguang, Cheongsu Eumryo and Hanju Sikpum) that are located within 1 km radius around Mockcheon area were analyzed. Theis(1935), Papadopulos-Cooper(1967), Hantush(1960, 1962), Hantush-Jacob(1955), Moench(1985), Neuman-Witherspoon(1969), Gringarten-Witherspoon(1969) and Gringarten-Ramey(1974) equations were applied to the pumping test analysis. The result of the pumping test analysis shows that wedge-typed confined aquifer model (Hantush, 1962) and leaky confined aquifer Case-1 model (Moench, 1985) were suitable for the study area. The models match well with geologic structure in the study area which controls aquifer by means of two major thrust faults having Nl8E and NS strikes, respectively.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.188-193
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• 1999

Transport of pollutants in aquifer largely depends on groundwater flow which is governed by aquifer hydraulic parameters. Determination of these parameters and associated groundwater modeling become essential for adequate remediation of contaminate groundwater. The objective of this paper is to analyze groundwater flow and determine the optimum hydraulic parameters by performing groundwater modeling based on sensitivity analysis for unconfined sandy gavel aquifer constructed in a laboratory scale under various boundary condition. Results revealed that the simulated drawdown was lower than the observed drawdown irrespective of boundary conditions. and specific yield (S$_{y}$) had less effect on the grondwater flow than permeability (K) in the aquifer. Water balance analysis showed that the measured drawdown in neighboring observation wells during pumping was higher than either simulated or recovered water table. The indicated that a difference might exist in the water tables between aquifer and wells. The difference was investigated by time domain reflectometry (TDR) measurements on water contents in the region of water table and capillary fringe, and explained by a delayed response of water table during gravitational drainage as the water table was lowered as a result of pumping.g.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.435-440
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• 2010

최근 하천의 기능이 다양화되면서 물 사용 및 배분과 관련하여 각종 갈등이 첨예화 되면서 수리권에 대한 체계적인 정리가 필요하게 되었다. 특히, 각종 수리권의 적용 범위나 한계를 논하기 위해서는 근본적으로 하천의 자연유량과 인공유량에 대한 이해가 우선되어야 하는데 이는 수리권의 본질을 이해하는데 기본적인 사항이다. 하천의 수질개선은 오염원을 저감 또는 제거하는 것과 하천의 유량을 증가시키는 것이다. 특히, 수질개선(Water Quality Improvement)이라는 목표를 달성하기 위해 도입된 물이용부담금제도가 "수질개선사업의 범위가 어디까지인가?"라는 근본적 질문에 대한 명확한 정의가 이루어지지 않는 경우 향후 물이용부담금 제도의 효용성은 저하될 수 밖에 없다. 하천의 수질개선은 세가지 메커니즘에 의해 달성할 수 있는데, 첫번째 메커니즘은 하천의 수량이 일정할 때 하천에 유입되는 또는 유입된 오염물질을 저감시킴으로써 수질개선을 달성하는 것이다. 즉, 유입 오염물질을 제거, 저감하기 위한 하수처리시설의 설치, 운영, 습지 조성, 하천에 유입된 쓰레기나 오염물질의 제거 노력 등을 통한 수질개선이 이에 해당한다. 두번째 메커니즘은 오염원 저감측면이 아닌 하천의 유량을 풍부하게 함으로써 수질개선을 달성하는 것이다. 즉, 일반적으로 확보되는 하천의 유량보다 더 많은 유량을 하천에 흐르게 함으로써 하천 스스로의 자정능력을 키우고 오염물질의 농도를 희석함으로써 수질을 개선하는 방법이다. 해마다 발생하는 하천의 수질오염사고시 다목적댐이나 용수댐에서 희석수를 대량 방류함으로써 수질 사고를 해결하는 경우가 이에 해당한다. 또 하나의 메커니즘은 미래의 오염원이 되는 비점오염원(축산가구, 도로 산림 등)의 소산 노력 등을 통한 적극적인 수질개선이 이에 해당한다. 하천의 수질개선은 이 세가지 메커니즘이 병행하여 작용될 때 그 효과를 최적으로 달성할 수 있다. 향후 물 관리는 빗물 - 댐 하천 - 상수도 - 하수도 - 해수 등 물 순환의 전체 체계에서 이루어져야 하고 효율적인 물 관리를 위해서는 '수량 수질의 통합관리'가 불가피하다는 점에서 물이용부담금의 수량측면에 대한 이해는 물 관리의 효율성을 높이는 중요한 요소이다.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.103-116
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• 2005

Although there have been many researches to construct a database of water distribution networks using GIS, most of them were not linked with an model for the analysis of pipe networks because it is difficult to make spatial data about complex water distribution networks for building a detail model. Therefore, it is necessary to develop the method based on GIS to build geographical data for design of water distribution pipeline systems. In this study, an innovated design support technique using GIS is proposed for a hydraulic analysis model of water distribution networks. With the function of spatial analysis in GIS system, the results from a pipe network model are used to analyze the suitability of the location of pipeline network, the spatial suitability comprised the analysis of the degree of pipe age, the altitude distribution of water pressure, and the water supply system for the customer.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.3
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• pp.245-259
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• 1994

This paper is concerned with the development of a three-dimensional numerical model for coastal circulation and heat transport with improved prediction ability. The model uses fully nonlinear, time-dependent three-dimensional, $\sigma$-transformed equations of motion and equation of heat transport The model was verified with experimental data for wind-driven current in a one-dimensional channel and thermal jets flowing into stagnant waters and applied for unsteady flow induced by tide and thermal jets in coastal waters around Kori nuclear power plant. The model results were in good agreements with experimental data sets for wind-driven current and thermal jet, and field observed data sets in coastal waters. This study has shown that the $\kappa$-$\varepsilon$ turbulence model is applicable to various coastal conditions without any modification of turbulence constants.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.439-449
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• 2019

To prevent the drying-out of streams and to make effective use of stream water and groundwater, it is necessary to evaluate the impact of groundwater pumping on nearby streams. To this end, stream depletion due to groundwater pumping should be investigated in terms of various hydraulic characteristics of the aquifer and stream. This study used the Baalousha analytical solution, which accounts for stream-stage variation over time, to analyze stream depletion due to groundwater pumping for cases where the stream level decreases exponentially and recovers after the decrease. For conditions such as an aquifer transmissivity of 10~100 ㎡ d^-1, storage coefficient 0.05~0.3, streambed hydraulic conductance 0.1~1.0 m d^-1, stream-well distance 100~500 m, and stage recession coefficient 0.1~1.0 d^-1, the contribution of stream water (the dimensionless ratio of stream water reduction rate to groundwater pumping rate) was analyzed in cases where stream level change was considered. Considering the effect of stream-stage recession, the contribution of stream water is greatly reduced and is less affected by the stream-depletion factor, which is a function of the stream-to-well distance and hydraulic diffusivity. However, there is no significant difference in stream depletion under constant- and variable-stage recovery after recession. These results indicate that stream level control can distribute the relative impacts on stream water and aquifer storage during groundwater pumping

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.90-96
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• 2018

Tracer experiments were carried out on two laboratory modes, "without media mode" and "with media mode", to examine the hydraulic characteristics of the anaerobic fluidized bed bioreactor (AFBR). For both configurations, a formula was derived for the hydraulics and data interpretation to obtain the actual characteristics of the reactor. The dispersion model is based on the assumption that carriers are non-reacting and the dispersion coefficient is constant. The model represents the one-dimensional unsteady-state concentration distribution of the non-reacting tracer in the reactors. The experimental results showed that the media increased the mixing conditions in the reactor considerably. For the reactor without media, in the range tested, the dispersion coefficient was at least an order of magnitude smaller than that of the reactor with media. Advective transport dominates and the flow pattern approaches the plug flow reactor (PFR) regime. The dispersion coefficient increased significantly as us, the superficial liquid velocity, was increased proportionally to 0.82cm/s. On the other hand, for the reactor with media, the flow pattern was in between a PFR and a completely mixed flow reactor (CMFR) regime, and the dispersion coefficient was saturated at us=0.41cm/s, remaining relatively constant, even at us=0.82cm/s. The dispersion coefficient depends strongly on the liquid Reynolds number (Re) or the particle Reynolds number (Rep) over the range tested.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.589-601
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• 2021

Artificial recharge technology is a method for solving problems such as groundwater level drop and ground subsidence caused by groundwater withdrawal. This study investigated the applicability of using the hydraulic conductivity of an aquifer to predict injection test results for aquifer restoration. Pumping and injection tests were performed under the same conditions as those for the artificial injection facility located in Icheon, Gyeonggi-do. The hydraulic conductivity of the aquifer, which plays a decisive role in restoring the groundwater level, was derived from the pumping test. A numerical model of a simplified on-site aquifer was constructed, and a transient analysis was applied with the same conditions as the pumping test. The correlation between the measured and the resulting model values is strong (R² = 0.78). The injection test was performed in a sedimentary layer composed of silt sand and clay sand. From the results of the injection test, an empirical formula was derived using Theim's formula, which is a common well analysis solution to determine the parameters of the aquifer from time-level data. The model values from the empirical formula have a high degree of correlation (R² = 0.99) with measured values. Under specific conditions, for areas where it is difficult to conduct an injection test, the formula from this study, which relies on the hydraulic conductivity of the aquifer determined through the pumping test, may be used to predict reliable injection rates for groundwater restoration.