• 자원환경지질
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• 제39권5호
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• pp.537-554
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• 2006

유성지구 지열수의 산출 특성 및 수리적 연결성을 파악하기 위하여 2002년 3월부터 2005년 6월까지 장기 수위 관측을 실시하였다. 관측된 수위 자료를 이용하여 수위변동 주기 분석을 실시한 결과, 대부분의 관측공에서 0.5일, 1일, 7일 주기성이 확인되었다. 7일 주기성은 온천지대에서의 독특한 양수 행태로 인해 발생되는 인위적 현상으로서, 연구 지역내 관측공들의 수리적 연결성이 양호한 것을 반영하였다. 수위 영향 관계를 분석한 결과, E-W 방향성과 N-S 방향성의 지질구조가 지열수 저류체의 발달 및 지열수 유동에 중요한 규제 요소로 작용되고 있음이 확인되었다. 전반적으로 지열수의 열원과 대수층의 수리적 연결성과는 상호 연관성이 있을 것으로 해석된다.

• 한국농공학회논문집
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• 제58권4호
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• pp.21-35
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• 2016

This study is to evaluate the applicability of SWAT (Soil and Water Assessment Tool) model for multi-purpose dams and multi-function weirs operation in Namhan river basin ($12,577km^2$) of South Korea. The SWAT was calibrated (2005 ~ 2009) and validated (2010 ~ 2014) considering of 4 multi-purpose dams and 3 multi-function weirs using daily observed dam inflow and storage, evapotranspiration, soil moisture, and groundwater level data. Firstly, the dam inflow was calibrated by the five steps; (step 1) the physical rate between total runoff and evapotranspiration was controlled by ESCO, (step 2) the peak runoff was calibrated by CN, OV_N, and CH_N, (step 3) the baseflow was calibrated by GW_DELAY, (step 4) the recession curve of baseflow was calibrated by ALPHA_BF, (step 5) the flux between lateral flow and return flow was controlled by SOL_AWC and SOL_K, and (step 6) the flux between reevaporation and return flow was controlled by REVAPMN and GW_REVAP. Secondly, for the storage water level calibration, the SWAT emergency and principle spillway were applied for water level from design flood level to restricted water level for dam and from maximum to management water level for weir respectively. Finally, the parameters for evapotranspiration (ESCO), soil water (SOL_AWC) and groundwater level fluctuation (GWQMN, ALPHA_BF) were repeatedly adjusted by trial error method. For the dam inflow, the determination coefficient $R^2$ was above 0.80. The average Nash-Sutcliffe efficiency (NSE) was from 0.59 to 0.88 and the RMSE was from 3.3 mm/day to 8.6 mm/day respectively. For the water balance performance, the PBIAS was between 9.4 and 21.4 %. For the dam storage volume, the $R^2$ was above 0.63 and the PBIAS was between 6.3 and 13.5 % respectively. The average $R^2$ for evapotranspiration and soil moisture at CM (Cheongmicheon) site was 0.72 and 0.78, and the average $R^2$ for groundwater level was 0.59 and 0.60 at 2 YP (Yangpyeong) sites.

• 한국항만학회지
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• 제10권1호
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• pp.25-36
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• 1996

Generally, it is pointed out that a nonlinear analysis is needed to estimate accurately the water surface fluctuation and dynamic responses of a floating structure in case of large wave reflection. In this study, a frequency-domain method is applied and newly developed to analyze the nonlinear characteristics of the air-chamber floating breakwater. The air-chamber floating breakwater in this study can control well the wave transformation, motions of the structure and its natural frequency by adjusting the air depth in the chamber. Experiments are carried out to verify the numerical results. It is appeared that the mean water level is setup in the anti-node and setdown in the node, while the nonlinearity in wave profile is larger in the node than in the anti-node. Because of vertical mooring system, the sway, especially the time-independent nonlinear component, plays predominant role in the motion. On the other hand, the time-dependent component, as well as the time-independent one to the tensile force of mooring line contributes greatly, and the time averaged value presents tensional force oriented to the onshore side due drift force.

• 한국지반공학회논문집
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• 제19권6호
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• pp.61-70
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• 2003

사력댐은 점토부터 사석에 이르는 다양하고 복합적인 재료로 구성되어 있고, 이에 따른 제체의 투수성 차이 등으로 인해 건설 후의 거동양상은 아주 복잡하게 나타난다. 특히, 건설 이후 계절적 강우 차이로 야기되는 수위변화는 댐의 거동변화를 야기하며, 이런 특성들은 결과적으로 건설 후 댐 거동의 정형화를 어렵게 한다. 건설 후 댐의 거동은 저수위의 변화, 제체침투 등으로 인해 시간 의존적이며 이러한 거동이 건설 후 댐의 열화현상과 어떠한 관계가 있는가를 조사해보는 것은 중요한 의미가 있다. 건설 후 댐 거동정보는 댐 관리는 물론 설계에도 아주 유용한 정보로써 활용될 수 있다. 본 연구에서는 건설 후 발생 가능한 다양한 수위변화조건을 담수, 수위하강, 반복수위의 형태로 이상화하고, 수위변화속도에 따른 시간의존성 거동을 모델링하기 위하여 변위-간극수압의 결합방정식을 이용한 유한요소 해석을 수행하였다. 해석결과는 하중전이, 수압할렬의 가능성, 응력경로 변화 등의 관점에서 분석하였다. 본 연구결과로부터 실제 댐파괴 사례로부터 발견되는 지반공학적 문제에 대한 정량적 이해와 건설 후 댐관리에 있어 댐에 잔존하는 역학적 능력을 고려하여 수위를 제어하는 것이 중요함을 확인하였다.

• 지구물리와물리탐사
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• 제22권3호
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• pp.160-167
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• 2019

저수지 제체는 3차원 전기비저항 구조로 구성되어 있기 때문에, 전기비저항 격자구조에 담수호의 수위변화에 따른 제체 내부의 침윤선 변동과 함께 담수호의 전기전도도가 고려되지 않는 경우 전기비저항 역산 결과가 왜곡될 수 있다. 이 연구에서는 3차원 전기비저항 탐사 모델링을 통하여, 저수지의 3차원 비저항 구조와 저수지 수위의 변화에 따른 제체 내부의 비저항 변화를 해석하였다. 이 분석 결과에 근거하여 국내 283개소 저수지를 대상으로 3차원 모델링에 의한 2차원 이론자료와 현장 2차원 탐사자료에 대한 역산 결과를 비교하였다. 마지막으로 두 역산의 비가 50% 이상이 되는 저수지를 추가 정밀조사 대상 저수지로 선정하였다.

• 대한토목학회논문집
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• 제14권5호
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• pp.1253-1263
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• 1994

수평흐름에 의한 제체내의 비정상침투류를 실험을 통하여 구명한 것으로 흐름의 속도와 수위의 변동에 따른 제체내에서의 침투류영향을 고려하므로써 하천제방의 안정성증대에 목적을 두었다. 실험은 투수계수가 서로 다른 3가지 모델($K_1=3.52{\times}10^{-1}cm/sec$, $K_2=1.94{\times}10^{-1}cm/sec$, $K_3=4.19{\times}10^{-2}cm/sec$)에 대하여, 각기 흐름의 속도를 60, 70, 80, 90 cm/sec로 변화시키고 동시에 수위를 상승 또는 하강시키는 방법으로 제체내에 발생하는 수위변화를 실험을 통하여 분석하였다. 분석결과 제체내의 침투현상은 제체의 투수계수가 크고, 흐름의 속도가 작을수록 유속의 변화에 따른 영향을 많이 받음을 알 수 있으며, 제외지 수위의 상승과 강하에 따른 배면부 및 표면부에서의 수위가 유속의 영향에 따라 변화함을 알 수 있다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권6호
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• pp.1-8
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• 2010

The groundwater level distribution and characteristics of responses to rainfall were examined in the Haean basin of Yangu that has a single stream exit to the east. The groundwater levels showed a circular or elliptical distribution converging the center of the basin with different hydraulic gradients in the north and south regions. The waterlevel elevations exhibited a perfect correlation with topographic elevation ($r^2=0.99$) while the depth to water showed a rather weak correlation ($r^2=0.49$). The water table fluctuation (WTF) method yielded recharge ratios of 6.1~12.65% ($S_y=0.02$) and 15.2~28.5% ($S_y=0.05$). The waterlevels of HG3 well, which is much proximal to a stream, were weakly auto-correlated but they were highly sensitive to direct infiltration from the rainfall event. The shorter regulation times of the HG3 represented a quicker dissipation of the input stress (rainfall).

• Membrane and Water Treatment
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• 제5권3호
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• pp.197-205
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• 2014

For the first time in Bangladesh, a bench scale membrane bioreactor (MBR) unit was tested in treating a textile wastewater in the industry premises of EOS Textile Mills LTD, Dhaka for three months. The performance of the unit was compared with that of the conventional activated sludge treatment plant, which is in operation in the same premises. The COD and BOD removal efficiency of the MBR unit reached to around 90% and 80% respectively in 20 days whereas the removal efficiency of the conventional treatment plant was as low as 40-50% and 38-40% respectively. The outlet COD and the BOD level for the MBR unit remained stable in spite of the fluctuation in the feed value, while the conventional effluent treatment plant (ETP) failed to keep any stabilized level. The performance of the MBR unit was much superior to that of the functional ETP and the water treated by the MBR system can meet disposal standard.

• The Korean Journal of Ecology
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• 제24권4호
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• pp.253-258
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• 2001

Land use pattern in the Wangsuk river watershed was investigated on the bases of physiognomic vegetation maps made from the aerial photograph interpretation and field check. Landscape structure was analyzed using a GIS program supported by ArcView. Landscape structure depended on the geographical position of the river, such as the upper, middle and lower river. Watersheds of the upper and middle rivers were dominated by forests composed of secondary forest and plantation. But agricultural fields dominated that of the middle and lower river. Urban area and agricultural fields increased in from the upper toward the lower river watersheds. In addition to, a transformation of agricultural pattern into an institutional agriculture was characteristic in the middle and lower river basins. Water qualities of the Wangsuk river were usually better in the order of the upper, middle, and lower river, but they were fluctuated according to the site. Such fluctuation would due to self-purification of the river and land use pattern of the watershed as the non-point source. In this viewpoint, a strategy to manage the water quality in the level of watershed is urgently required.

• 생태와환경
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• 제41권4호
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• pp.547-553
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• 2008

In recent years, attention on the inhabitation environments of animals and plants which coexist with humans is growing more and more, and relevant research is being activated. In habitats of rivers, a lot of factors are interacting, even among them, some elements especially such hydraulic factors as water velocity and water depth, and such geological shapes as gravels, sand and mud are being considered as primary elements. In this study, various field investigations are carried out to determine the relationship between the river habitats of fishes and hydraulic primary elements using high-tech equipments. Furthermore numerical experiments to classify such habitats according to topographical spaces are carried out. In detail, hydraulic field investigations performed in this study can be summarized as topographical survey, discharge measurement, water level fluctuation monitoring and so on. In numerical experiments, the RMA2 model of the commercial program, Surface-Water Modeling System (SMS), which is widely used in conducting a two-dimensional analysis of the flow behavior of a river is utilized. In conclusion, as a result of field investigation, the relationship between water velocity and water depth is obtained. And the relationship between water velocity and water temperature is identified, too. Finally, using above obtained results, the inhabitation environment was classified into Riffle, Glide, Run, Pool, and E.D.Z according to the relationship between water velocity and water depth.