• 한국환경과학회지
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• 제25권1호
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• pp.135-146
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• 2016

This study analyzed fluctuations of ground water level of ground water wells developed in Seongsan watershed of Jeju Island until 2013 using MODFLOW, a numerical analysis model. Ground water level shows greater fluctuations from increase of pump capacity compared to the number of ground water wells. The development of ground water at the top of watershed was found to have direct influence on ground water level. Ground water wells developed until 2013 were used to continue pumping for 50 days, and ground water level of coastal region was reduced below 50% compared to the standard water level. In addition, the range of fluctuation of water level was large in the east coast region, which represents the direction of flow of ground water.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1076-1082
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• 2006

This study measured the change of media properties using Time domain Reflectometry (TDR) and Tensionmeter (TM) to measure volumetric water content of soil affecting in land subsidence and pollutant diffusion under saturation/unsaturated condition by water-level fluctuations. Also, actual water content compared their changes aspect by dry oven test for quantitative determinations of these measured values. In the case of TM, initial unsaturated condition confirmed that range in dimension of each other different according to their establishment depth, but measured values of TM can know that is shown measured value in almost similar measuring range under drain condition after the first injection. Also, the results of TDR showed that can measure enough change of volumetric water content in saturation/unsaturated condition by water-level fluctuations. Therefore, we are judged that TDR measurement equipment is very effective to measure the variations of volumetric water content and water-level being caused in groundwater level fluctuations.

• 한국농공학회지
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• 제30권4호
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• pp.117-126
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• 1988

This paper attempts to characterize general tendency in water level fluctuations at paddy fields, that may be important to efficient irrigation water uses Banweol district was chosen to be the study area, and water levels among irrigation practice parameters were measured daily throughout the irrigation periods of 1985-1986. Time series analyses showed that water levels at fields have strong serial correlationships. A rather long term periodicity was also observed from spectral analyses. Correlationships between water levels at adjacent fields ranged 0.4-0.9, indicating wide variations in irrigation practices. The water levels showed little correlationships with meteorological factors like evapotranspiration, nor with irrigation practices like water supply rates. Standard errors of the average water levels were computed for different number of field plots within a block. The results indicated that low level areal coverage of gauging plots may be applied for field monitoring of daily water level fluctuations.

• 한국지하수토양환경학회지:지하수토양환경
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• 제12권4호
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• pp.54-59
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• 2007

본 연구에서는 수학적 모델링을 통해 강우에 기인하는 지하수위 변동예측 준-해석학적 모델을 개발하였다. 개발된 모델은 홍천 지역의 지하수위 변동을 예측에 적용되었으며 이를 위하여 지하수 변동 관측자료 및 강우자료가 이용되었다. 개발된 모델은 비선형 파라미터 예측 코드를 활용하여 2003년 지하수위 변동을 예측하도록 적정되었으며 이렇게 최적화에 이용된 입력 파라미터는 그 다음해인 2004년 지하수위 변동을 예측하는데 활용되었다. 강우자료에 기초한 2004년 지하수위 변동 예측은 RMS 오차가 0.18 m로 관측지하수위의 표준편차가 0.44 m인 것으로 미루어 보았을 때 대체로 양호한 것으로 판단된다. 또한 본 연구에서는 개발된 모델을 이용하여 지표 피복의 변화에 기인하는 함양율 감소 시 발생되는 지하수위 변동 예측 및 양수에 의한 인공적인 지하수위 강하를 모사하는데 적용하였다. 본 연구의 결과는 보다 정확한 지하수위 변동 예측증 위해서는 지하수 함양율을 상수로 적용하는 것이 적절치 않으며 강우 패턴의 함수로 결정되어야 함을 보인다.

• 대한지하수환경학회지
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• 제6권1호
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• pp.33-41
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• 1999

한강은 조석의 영향을 직접 받고 이로 인하여 강과 인접한 대수층은 주기적인 수위변화를 보인다. 한강수위는 팔당댐의 방류량, 각 지천에서의 유입량, 상수원인 취수장에서 양수량, 그리고 조석영향 등의 복합적인 작용으로 결정된다. 한강과 인접한 대수층의 수위변화를 파악하고 이를 이용하여 한강에 인접한 대수층 수리시스템을 분석해 보고자 하였다. 한강수위의 주기적인 변화 양상으로 수리지질학적 특성을 구할 수 있다. 조석영향으로 투수량 계수를 추정하면 9.39$\times$$10^1$~4.02$\times$$10^3$$m^2$/day의 값을 보인다. 한강수위 변화는 큰 시간적인 지연 없이 주변 대수층의 지하수위에 영향을 주는 것으로 관찰되었다. 조석에 의한 한강수위 변화에 따라 인접한 대수층 지하수의 흐름특성을 규명하기 위해 3차원 유한차분 모델인 MODFLOW를 이용하였다.

• 한국농공학회지
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• 제30권3호
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• pp.95-105
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• 1988

This study refers to the development of a hydrologic model simulating daily inflow and release rates for irrigation reservoirs. A daily - based model is needed for adequate operation of an irrigation reservoir sufficing the water demand for paddy fields which is closely related to meteorological conditions. And the objective or this study is to develop a Daily Irrigation Reservoir Operation Model(DIROM) combining the inflow and the release models which depicts the daily water level fluctuations of an irrigation reservoir, and to evaluate the applicability of the model. DIROM was applied to four reservoirs and daily water levels were simulated and compared to the observed data. The model behaviour was also compared with that of a ten - day based model, Reservoir Operation Study(ROS) which has been applied for determining the design capacity of reservoirs. Various combinations of measured and simulated inflow and release rates for tested reservoirs were used to define the daily water level fluctuations. Simulated release rates and measured inflow data resulted in larger errors, and simulated inflow and release rates produced the smallest errors in water level comparison. Two resevoir operation models, DIROM and ROS were applied to the same reservoir and the simulation results compared. The computational errors of DIROM ware smaller than those of ROS, and DIROM was more sensitive to meteorological conditions. DIROM demonstrated its potenial applicability in water management and operation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권5호
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• pp.65-76
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• 2013

The water-table fluctuation (WTF) method has been often used for estimating groundwater recharge by analysis of waterlevel measurements in observation wells. An important assumption inherent in the method is that the water level rise is solely caused by precipitation recharge. For the observation wells located near a stream, however, the water-level can be highly affected by the stream level fluctuations as well as precipitation recharge. Therefore, in applying the WTF method, there should be consideration regarding the effect of stream-aquifer interactions. Analysis of water-level hydrographs from the National Groundwater Monitoring Wells of Korea showed that they could be classified into three different types depending on their responses to either precipitation recharge or stream level fluctuations. A simple groundwater flow model was used to analyze the errors of the WTF method, which were associated with stream-aquifer interactions. Not surprisingly, the model showed that the WTF method could greatly overestimate recharge, when it was used for the observation wells of which the water-level was affected by streams. Therefore, in Korea, where most groundwater hydrographs are acquired from wells nearby a stream, more caution is demanded in applying the WTF method.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1982년도 제24회 수공학 연구발표회 논문초록집
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• pp.3-24
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• 1982

The relations between tidal fluctuation and freshwater discharge are stuied dy use of observed data in the estuarine region of the Nagdong Rivre. Damping modulus which represents the resistance to propagation of tidal wave is estimated, and it is verified that when the fresh water discharge is lower than 300 m/sec., the elevation of mean-water-level at Gupo is the same as mean sea-water-level.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.188-191
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• 2008

The Tonle Sap, Cambodia, is a huge lake and periodically flooded due to monsoon climate. The incoming water causes intensive flooding that expands the lake over vast floodplain and wetland consisting mainly of forests and shrubs. Monitoring the water-level change over the floodplain is essential for flood prediction and water resource management. A main objective of this study is flood monitoring over Tonle Sap area using ALOS PALSAR. To study double-bounce effects in the lake, backscattering effect using ALOS PALSAR dual-polarization (HH, HV) data was examined. InSAR technique was applied for detection of water-level change. HH-polarization interferometric pairs between wet and dry seasons were best to measure water level change around northwestern parts of Tonle Sap. The seasonal pattern of water-level variations in Tonle Sap studied by InSAR method is similar to the past and altimeter data. However, water level variation measured by SAR was much smaller than that by altimeter because the DInSAR measurement only represents water level change at a given region of floodplain while altimeter provides water level variation at the central parts of the lake.

• International Journal of Naval Architecture and Ocean Engineering
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• 제1권2호
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• pp.57-63
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• 2009

Numerical simulations have been carried out on the flooding system of a dry located at the south coasts of Iran. The main goals of seawater flow haracteristics in the intake channels conditions of the flooding system are imposed in the modeling. The upstream boundary condition is the tidal fluctuations of sea water level. At the downstream, the gradually rising water surface elevation in the dry described in a transient boundary condition. The numerical results are compared with available laboratory a good agreement is obtained. The seawater discharge through the flooding system and the required time to filling up the dry dock is determined at the worst case. The water current velocity and pressure on the rigid boundaries are discussed.