• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.135-135
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• 2017

최근 강우-유출 모형은 물리적 현상에 근거한 확정론적 모의 모형과 물리적 성분으로 설명할 수 없는 내용에 대해 통계적으로 접근하는 추계학적 모의 모형 등이 계속 연구되고 있어 자연현상에 가까운 결과를 기대할 수 있게 되었다. 하지만 우리나라의 경우 많은 연구에도 불구하고 돌발성 집중호우, 여름철 집중되는 강우 등으로 인해 재난이 반복적으로 발생하고 있어 모형의 정확성에 대한 논의가 지속되고 있다. 동일한 유역에 동일한 입력자료를 사용하더라도 사용하는 모형에 따라 유출 분석결과는 상이하며 이는 유출 해석에 대한 불확실성으로 작용한다. 본 연구에서는 앙상블 및 블랜딩 기법을 사용하여 각 강우-유출 모형의 불확실성을 고려하여 최적 유출량을 산정하고자 한다. 대상 유역으로는 한강 수계에 있는 중랑천 유역을 선정하였으며, Distributed 모형인 Vflo 모형과 Lumped 모형인 저류함수 모형, SSARR모형, TANK 모형을 이용하여 유출 분석을 실시하였다. 그 후, Multi-Model Super Ensemble(MMSE), Simple Model Average(SMA), Mean Square Error(MSE) 방법 등의 blending 기법을 이용하여 하나의 통합된 형태의 유출 분석 결과를 제시하였으며, 최적 유출량 산정을 위한 blending 기법을 선정하였다. 본 연구를 통해 동일한 강우 시나리오에 대한 여러 강우-유출 모형에 대한 정확도를 확인하였으며, 앙상블 및 블랜딩 기법을 사용하여 유출 분석에 대한 정확도를 향상시킬 수 있을 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.36 no.3 s.134
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• pp.455-464
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• 2003

In this paper, the experiments with installing a rainfall storage tank in the sub-surface were conducted and the reduction rates of the total runoff volume were investigated. The analysis were conducted based upon the variations of the rainfall intensity, surface coverage and surface slope. The reduction rate of the runoff volume was varied from 42.3% to 52.9% with the soil in the bank of the Seung Gi stream. In the experiments, the rainfall intensities were varied from 40mm/hr to 100mm/hr and the results indicate that the direct runoff reduction can be obtained with the installation of the rainfall storage tank in the sub-surface. The variation of the stored volume in the tank is very large in the mild slope but very small in the steep slope with over 3% slope. With this results, the reduction of the direct runoff volume for the longtime flood is expected with the installation of the rainfall storage tank in the region haying the steep slope such as the mountain area.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.797-800
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• 2005

RRFS를 개발하기 위해 NWSRFS 모형, SSARR 모형 및 TANK 모형 등에 대한 유출모형 현황 조사 및 특성 분석을 실시하여 실용성, 합리성, 적절성 중심의 기반모형으로 "수문학적 수문유출성분과 저수지 운영기법이 결합된" SSARR 모형을 선정하였다. 수계내 기상청, 건설교통부, 수자원공사에서 관할하는 강우관측소를 대상으로 관측시점부터 현재까지의 일강우자료 수집하였다. 12개 소유역에 대한 주요지점별 수위자료와 수위-유량 곡선식을 수집, 검토하여 수계 상하류에 위치한 수위관측소의 유출량 비교를 통해 적정 수위-유량곡선식을 선정하였다. 수계내 양수장, 보, 댐, 저수지 등 주요 수리시설물 현황조사를 실시 하였으며, 유역유출분석을 위한 유출모식도는 수자원공사내 DB 구조 및 유역유출 모의 시스템의 입출력 관계 등을 분석하여 구성하였다. 유출모형의 실시간 유역관리의 적용성을 파악하기 위해 과거 생공용수 및 농업용수의 수요량을 조사하였으며, 이들을 고려한 농업용수 수요 예측 시스템을 구축하였다. 유역유출 모의를 위해 SSARR모형의 매개변수 초기치 설정과 모형 보정을 위한 GUI를 개발하였다.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.9-15
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• 2014

This study is aimed at figuring out the reasons of the mass mortality of abalone and the increase in its mortality rate in the sea cage. The study suggests that lack seawater circulation in an abalone aquaculture cage is an important culprit for it. We analyzed the current distribution around a 1/20 scaled-down abalone unit cage of 4 rows and 10 columns by fluid flow visualization technique (PIV : Particle Image Velocimetry). The speed of current in the model cage definitely slowed down in the first column of a unit cage. We also observed currents going down to the bottom of a water tank from the unit cages placed in the middle. The speed of wakes behind inside the row in the middle was slower than that outside the row. Water velocity inside and outside a real abalone cage at Nowha Island adjacent to Wan Island was measured to verify results from the tank test. The speed of current in front of the cage by 2 m was 0.11 m/sec while it was only 0.0009 m/sec inside the cage. It had similar findings with those of a tank test.

• Journal of the Korean Geotechnical Society
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• v.35 no.12
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• pp.123-134
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• 2019

This study presents dynamic responses of circular pipe models as a part of fundamental studies on dynamic stability monitoring of the large circular steel pipe cofferdam with the ship collision. Small-scaled laboratory experiments are performed with a single and bolted circular steel pipes with a diameter, thickness, and height of 30, 0.4, 90 cm, respectively. The bolted circular steel pipe is configured with three segments of 30 cm in height. Circular steel pipe models are embedded in a soil tank, all 1 m in length, width, and height. The thickness of soil in the soil tank is set at 23 cm. The ship collision is simulated with a hammer impacting. The dynamic responses are investigated with different water levels of 25, 40, 55, and 70 cm. Experimental results show that a signal energy decreases with increasing water level. More sensitive reduction in the energy appears for the bolted circular steel pipe. A predominant frequency decreases with increasing water level for both single and bolted steel pipes. The minor reduction in the frequency appears for the bolted circular steel pipe under the water level of 70 cm. This study suggests that the signal energy and frequency response is useful for the dynamic stability monitoring of the large circular steel pipe cofferdam.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.365-372
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• 1998

• KCID journal
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• v.2 no.1
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• pp.30-38
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• 1995

This paper presents three optimization analyses for constructing an irrigation pipe network for upland crop. A Sample network involving a pump and a storage tank is solved using the proposed three analyses. The first analysis is to resolve the sample netw

• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.395-405
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• 2021

When issuing forecasts and alerts for agricultural drought, the relevant ministries only rely on the observation data from the reservoirs managed by the Korea Rural Community Corporation, which creates gaps between the drought analysis results at the local (si/gun) governments and the droughts actually experienced by local residents. Closing these gaps requires detailed local geoinformation on reservoirs, which in turn requires the information on reservoirs managed by local governments across Korea. However, installing water level and flow measurement equipment at all of the reservoirs would not be reasonable in terms of operation and cost effectiveness, and an alternate approach is required to efficiently generate information. In light of the above, this study validates and calibrates the parameters of the TANK model for reservoir basins, divided them into groups based on the characteristics of different basins, and applies the grouped parameters to unmeasured local government reservoirs to estimate and assess inflow. The findings show that the average determinant coefficient and the NSE of the group using rice paddies and inclinations are 0.63 and 0.62, respectively, indicating better results compared with the basin area and effective storage factors (determinant coefficient: 0.49, NSE: 0.47). The findings indicate the possibility of utilizing the information regarding unmeasured reservoirs managed by local governments.

• Journal of Korea Water Resources Association
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• v.33 no.4
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• pp.393-405
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• 2000

Monthly runoff was estimated using TOPMODEL which simulates ground water movement as well as surface runoff in the area of catchment. SAYUN dam which is being operated by Korea Water Resources Corporation was selected for the study, and the topographic factors of the watershed were analyzed using 1/5,000 digital map and GIS software(Arc/Info). The comparison shows good agreement between observed monthly runoff and the computation results simulated by using TOPMODEL. The catchment area of SAYUN dam was modeled by using various grid sizes in order to check the sensitivity of grid size, and the grid size of 180m was found most proper among 6 different sizes. TOPMODEL was also found superior to the existing monthly runoff models such as Kajiyama, KRIHS and Tank. Because the model requires limited number of parameters and considers topographic aspects, it is reckoned to be very useful for practical use.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.3
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• pp.47-59
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• 1994

The irrigation reservoir operation models developed were tested with weather and field data, and the sensitivity of the water requirement deficiency indices(WRDI) were checked with different initial reservoir storages, irrigated areas, and other water uses from the reservoir storage. Seven reservoir release rules were applied to Yongseol Reservoir. Twenty year WRDIs were computed to check performances of those reservoir release rules. Mean WRDIs were 138, 198, 198, 200, 240, 344, and 1033mm for ROM, TOS, COS, CRR, MSC, FAS, and SRC, respectively. The results indicated that ROM contributes consistently to higher operation efficiencies of an irrigation reservoir. The test results of LFROM and SFROM showed that reservoir operation with the proposed optimization technique ROM would be better suited for an irrigation district than those with the other rules. And the proposed model could be used as a tool to improve reservoir operations.