• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3B
• /
• pp.297-306
• /
• 2008

In order to determine the effects of lock gate expansion at the Lake Youngsan and Yeongam as well as increase in the width of the connecting channel of the two lakes on flood control downstream of the Youngsan River, an unsteady hydraulic flood routing was conducted by combining the Lake Youngsan and Yeongam as a single connected system. The coupled operation of the two lakes was found to have little effect when the widths of the lock gates and the connecting channel are set at the current level. It was also found that increasing the width of the connecting channel as well as the lock gate of the Lake Yeongam is an effective means of reducing the stage of the Lake Youngsan, whereas an increase in the width of the Lake Youngsan's lock gate had a relatively smaller effect. The extended width of the connecting channel leads to a rise in the stage of the Lake Yeongam. In order to reduce the elevated stage, The Lake Yeongam's lock gate must be expanded along with the Lake Yeongsan's lock gate. The analysis found that the stage of the Lake Yeongsan can be effectively controlled through adjustment of opening and shutting criteria of the connecting channel's lock gate, when diversion discharge between the lakes is increased as a result of expanding the width of the connecting channel.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2005.05b
• /
• pp.900-903
• /
• 2005

본 연구에서는 기상레이더의 원시자료를 홍수해석분야에 적용하기 위해서 먼저 3차원 공간상에서 구면좌표계값을 가지는 레이더 자료를 직교 좌표계로 변환하기 위한 CAPPI 산출 프로그램을 개발하였다. 개발된 모형은 CAPPI 자료의 이용목적에 따라서 다양한 해상도 및 고도에 대한 자료가 필요할 수 있다는 생각하에 임의의 해상도 및 고도 등에 대한 옵션을 사용자가 임의로 지정함으로서 빠르고 효율적으로 계산할 수 있도록 구성하였다. 기상레이더와 연계한 개선된 강우량 자료를 산정하기 위해서 cokriging 기법을 적용하였는데, 강우의 공간적 분포양상 및 경계를 정확하게 묘사할 수 있는 레이더 자료와 한 지점에서 좋은 정확도를 가지는 강우량 자료를 조합한 2차원 정량강우량 산정을 위해서 지형통계학적 분석을 실시하였다. 2002년 태풍 루사에 대해서 본 기법을 적용하였으며, 산정된 2차원 정량강우량은 유역에서의 실시간 홍수량을 산정하기 위해서 이용되었다. 본 연구에서는 기상-강우-유역홍수량 산정에 이르는 통합홍수해석을 실시함으로서 유역 유출량 산정에 대한 새로운 개선된 방향을 제시하고자 한다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.1576-1580
• /
• 2006

The destruction of river and damage caused by flood are suddenly increasing due to the abnormal climate. In the investigation result about the damage, approximate 52% of the destruction of embankment are caused by earth work. Moreover, to recover conveyance of relief channel, bed sediment is dredged about 198 millions $m^3$ with 'the project of bed dredging'. So, the concern for bed sediment is the more increasing, the requiring high quality material for banking and the way for application of bed sediment are also the more increasing. In this paper, properties of bed sediment were analyzed through sedimentary mechanism analysis. Moreover, possibility to build embankment with bed sediment in 6 points which is in catchment of the Nak-dong river was also analyzed. At 6 points, which were selected to survey easily, sediment discharge was analyzed with formula. Moreover, size and permeability were analyzed and the feasibility for material of embankment was proposed. If bed sediment wasn't proper, complementary measures were proposed.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.1017-1021
• /
• 2009

일반적인 설계 홍수량 산정 절차는 분석하고자 하는 대상유역의 수문자료 중 홍수량 자료가 존재하지 않을 경우 강우빈도해석을 실시하고, 만약 홍수량 자료가 존재한다면 유출을 통계분석하여 홍수빈도 해석을 실시하여야 한다. 본 연구에서는 1999$^{\sim}$2008년까지 수위-유량 관측을 실시하여 유출자료를 비교적 충분히 보유하고 있는 서울시 관내 지방하천인 우이천 유역을 대상으로 수위-유량관계곡선을 작성하여 과거 호우사상을 토대로 강우-유출모형의 매개변수를 최적화하였으며, 최적화된 모형을 이용하여 기상청관할 서울지점 시간강우관측 자료를 입력 자료로 유출모의를 실시하였다. 모의된 홍수량계열과 관측유량계열을 사용하여 연최대홍수계열을 구축한 후 홍수빈도해석을 실시하였다. 분석결과 기존의 '확률강우량-단위도' 방법에 비하여 불확실성이 제거된 확률홍수량 추정치의 결과를 얻을 수 있었다.

• Water for future
• /
• v.28 no.6
• /
• pp.133-146
• /
• 1995

Manning's roughness coefficient for the Han River (from Paldang dam to Indo Bridge) is estimated by one-dimensional unsteady flow model, NETWORK. The entire river is divided into two regions, one region of Paldang dam to Kwangjang, and another region of Jamsu Bridge to Indo Bridge, and changes of the roughness coefficient according to changes in discharge are estimated using data of the past flood events. Estimated roughness coefficients are compared with previous results. Finally, the stage variation according to the variation of channel roughness is presented.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2003.10a
• /
• pp.539-542
• /
• 2003

In South Korea, flooding is controlled with large or small reservoirs scattered spatially over the territory. Because recent unexpected hard-rain events requires more flood control capacities, the pre-release system is considered with the most economical alternative. In this case time and volume of discharge should be determined by the simulation. But, existing pre-release simulation system has the problem of specificity. Therefore, GASS is considered to estimate the pre-release time and volume with different configurations of pre-release system. This paper shows that pre-release simulation system could be constructed with arranging GASAtmosphere, GASWatershed, Reservoir, Gate components using GASS. It is also shows that GASS could be used as a foundation for constructing pre-release simulation system that is easy to use and is flexible to reflect the changing configurations of reservoir systems.

• Journal of Industrial Technology
• /
• v.30 no.B
• /
• pp.91-98
• /
• 2010

Recently, there has been enormous damage due to river floodings caused by localized heavy rains. The direct discharge triggered by those torrential rains inflicts severe property damage on the residents of nearby areas. To minimize the possibility of river floodings in case of heavy rains and to predict the possible damage, the management of existing rainfall and water level observatories should be checked and prediction methods based on the characteristics of water usage and floodgate of nearby rivers must be further analyzed. Therefore, this research analyzed the water level change predictions on different spots with a regression equation of rainfall and water levels, using the observation data of the water level observatory in Jeongseon-gun, Gangwon Province and the rainfall observatory which are located on the upper region of the Han river.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.6
• /
• pp.959-970
• /
• 2011

The frequent occurrence of sewer flooding and the intermittent discharge of non-point pollutions into the receiving water body are emerging issues recently due to the climate change and urbanization. These problems might be solved by introducing a multifunctional storage facility. Unlike a single-purpose storage facility, a multi-purpose storage facility should be operated at an instant to meet for flood prevention, reduction of non-point pollution and/or rainwater reuse. Considering various operational combinations it is suggested that prevention of sewer flooding coupled with reduction of non-point pollution is the most effective operational strategy for a multi-functional storage facility.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.4
• /
• pp.69-78
• /
• 1986

The floodwave propagation resulting from the earth dam-break is studied. DBF(Dam-Break Floodwave) model based on the dynamic wave equation is presented by introducing Preissmann scheme and double sweep algorithm. DBF model is applied to the Teton dam, and the numerical results have good agreements with the data observed in the peak elevation profile, the peak discharge, the flood travel time and the flooded area.

• Water for future
• /
• v.18 no.1
• /
• pp.67-73
• /
• 1985

Tidal propagation in the Keum River has been routinely handled by numerical integration of the long fravity wave equation by Dronkers. The dynamic equations include non-linear terms thereby reproducing the shallow water tides. The model was used to compute tidal distribution of the Kum River for aveage spring, mean, neap tidal conditions and further utilised to investigate the waterlevel response within tidal reaches by combined tide and flood discharge effects. The objective of this initial study is to investigate the tidal dynamics of the lower reaches of the Keum River under the condition of before-cross-channel barrage construction.