• 한국방재학회 논문집
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• 제6권3호
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• pp.69-76
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• 2006

본 연구에서는 침수위험이 큰 도시하천내에 건설된 도로의 침수로 인한 피해를 미연에 방지하고 적절한 교통통제계획, EAP 등을 수립하기 위한 수문, 수리학적 분석과정을 제시하였다. 연구대상지역으로 우리나라의 대표적 도시하천인 중랑천 유역의 좌우안에 위치한 동부간선도로를 선정하고 비상대처계획 수립을 위한 기초자료를 작성하였다. HEC-HMS에 의하여 유출 해석을 실시하였으며, UNET을 이용하여 주요 지점 및 구간별 침수특성을 분석하였다. 이문철교부근(하구에서 약 9.5 km)과 월릉교부근(하구에서 약 11.5 km)에서 침수위험이 가장 높아 이문철교부근은 10년 빈도시에, 월릉교부근의 좌안도로는 20년 빈도시에 각각 침수가 되는 것으로 나타났다. 누가강우량과 지속시간을 고려한 침수특성 분석결과 강우 지속시간 7시간 이하에서 누가강우량이 250 mm이상일 경우에는 월계1교지점의 위험홍수위(EL.17.84 m)를 초과하는 것으로 분석되었다. 한강의 배수위를 고려하지 않은 경우에는 C2(월계1교-중랑교, 좌안), C1(월계1교-중랑교, 우안), D(중랑교-군자교)구간순으로 침수위험이 높은 것으로 나타났으나 배수위를 고려한 경우에는 D2(중랑교-군자교, 좌안), E(군자교-용비교)구간의 침수위험이 오히려 높은 것으로 분석되었다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2011년도 학술발표회
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• pp.15-15
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• 2011

The radar observation system in Japan is operated by two governmental groups: Japan Meteorological Agency (JMA) and the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan. The JMA radar observation network is comprised of 20 C-band radars (with a wavelength of 5.6 cm), which cover most of the Japan Islands and observe rainfall intensity and distribution. And the MLIT's radar observation system is composed of 26 C-band radars throughout Japan. The observed radar echo from each radar unit is first modified, and then sent to the National Bureau of Synthesis Process within the MLIT. Through several steps for homogenizing observation accuracy, including distance and elevation correction, synthesized rainfall intensity maps for the entire nation of Japan are generated every 5 minutes. The MLIT has recently launched a new radar observation network system designed for flash flood observation and forecasting in small river basins within urban areas. It is called the X-band multi parameter radar network, and is distinguished by its dual polarimetric wave pulses of short length (3cm). Attenuation problems resulting from the short wave length of radar echo are strengthened by polarimetric wavelengths and very dense radar networks. Currently, the network is established within four areas. Each area is observed using 3-4 X-band radars with very fine resolution in spatial (250 m) and temporal (1 minute intervals). This study provides a series of utilization procedures for the new input data into a real-time forecasting system. First of all, the accuracy of the X-band radar observation was determined by comparing its results with the rainfall intensities as observed by ground gauge stations. It was also compared with conventional C-band radar observation. The rainfall information from the new radar network was then provided to a distributed hydrologic model to simulate river discharges. The simulated river discharges were evaluated again using the observed river discharge to estimate the applicability of the new observation network in the context of operations regarding flood forecasting. It was able to determine that the newly equipped X-band polarimetric radar network shows somewhat improved observation accuracy compared to conventional C-band radar observation. However, it has a tendency to underestimate the rainfall, and the accuracy is not always superior to that of the C-band radar. The accuracy evaluation of the X-band radar observation in this study was conducted using only limited rainfall events, and more cases should be examined for developing a broader understanding of the general behavior of the X-band radar and for improving observation accuracy.

• 한국수자원학회논문집
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• 제55권2호
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• pp.135-145
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• 2022

본 연구는 지방하천의 하류구간을 대상으로 위성항법시스템(GNSS)과 드론 RGB (D-RGB), 드론 LiDAR (D-LiDAR) 측량성과 비교를 통해 측량방법의 정확도와 수공 실무의 드론 실용화를 검증하고자 한다. 이를 위해 지상기준점(GCP)과 검사점(CP) 좌표 값 측량결과의 우수성을 확인하고 그 결과를 HEC-RAS 모형에 적용하여 수리특성을 분석하고자 한다. 본 연구는 소유역인 연구대상지역을 세 방법의 정확도 비교를 위해 6개 GCP와 3개 CP를 설치하고 측량오차의 정확도 평가를 수행함으로써 D-LiDAR 측량성과가 우수한 것을 확인하였다. 이들 방법에 의한 소하천 수로구간의 100년 빈도 계획 홍수량에서 평균 하상고의 D-RGB와 D-LiDAR 성과는 2.30 m, 1.80 m, 평균 홍수위 성과는 4.73 m, 4.25 m로 D-LiDAR 성과가 우수하였다. 따라서 소하천 수로구간의 지형공간정보 획득에 드론 장비를 이용한 측량기법으로 D-LiDAR 측량이 유용한 방법이며 효율적인 방안으로 추천한다.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.509-516
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• 2020

1960년대 이후 경제발전을 위한 하천 개수사업, 도시화에 따른 소하천의 복개 등으로 많은 하천이 오염되고 파괴되었다. 지금까지의 연구는 측량된 하천 지형인자를 이용해 하천을 분석한 연구가 많았으나, 홍수 시와 같이 유량이 급격히 변하는 경우에는 측량이 쉽지 않다. 또한, 이전까지의 연구는 주로 하천의 횡단면에 대한 연구가 많아 하천 종단면에 대한 정보가 부족한 실정이다. 본 연구에서는 정보엔트로피 이론을 이용하여 하천 유역에 대한 평균 하천 경사, 하천 경사, 하천 종단고도를 실시간으로 산정할 수 있는 식을 제시하였으며, 충청북도 지방하천 기본계획에서 얻은 달천 유역과 부산 온천천, 동천 기본계획에서 얻은 하천 특성인자 실측 자료와 비교를 통해 적용성을 분석하였다. 이를 위해 정보엔트로피 이론에 실측 자료를 이용하여 비선형 회귀분석을 이용해 매개변수를 산정한 후 하천별 종단고도 엔트로피식을 산정하였으며, 평균 하천 경사를 산정하였다. 본 연구에서 제시한 식의 적용성을 R²로 분석한 결과, R²가 모두 0.96이상의 값으로 나타나 하천 특성인자를 산정하는데 신뢰도 높은 결과를 얻을 수 있을 것으로 보인다.

• 환경영향평가
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• 제20권6호
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• pp.797-813
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• 2011

Frequently occurring flood and drought due to abnormal climate and global warming have increased the necessity of an effective water resources control and management of river flows. The various hydraulic structures are constructed in river as part of an effective water resources management. It is very important to analyse characteristics of flow according to installing hydraulic structures in this situations. The objective of this study is to investigate the hydraulic behaviors of flow considering affections of hydraulic structures using 2-D numerical model. To do this, both RMA-2 model and developed RAM2 model are used to analyse flow phenomena before and after installation of hydraulic structures in Nakdong river. As a result of, the water surface elevation at upstream regions increased about 22cm~66cm and the velocity around the structures sharply increased after installation of structures. The measures for the rise of water surface at upstream and local scour due to high velocity around the structures must be established when the structures is constructed.

• 산업기술연구
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• 제25권B호
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• pp.19-25
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• 2005

To use land more efficiently under urbanization trend, Kangwon Province often covers open channels of creeks and uses them as parking lots or roads. A covered open channel section tends to form a rectangular culvert. Therefore, a creek with covered open channels can function as a storm drain. At the time of light rainfall, there are no significant differences except water flowing pattern between a creek with a covered open channel and a creek without it. Recently, however, the frequent occurrence of heavy rainfalls limited at a small, definite area has become problematic. When the heavy rainfall causes the carrying capacity of a creek to be exceeded,the creek with covered open channel has a more serious problem than the creek without it has. Therefore, we made an interpretation of data and conducted hydraulic model experiment to come up with economical solution to this problem.

• 물과 미래
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• 제26권4호
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• pp.35-46
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• 1993

홍수시 교량에 의한 수위상승 효과를 해석하기 위하여 1차원 동역학적 방정식을 방정식으로 하고 교량부의 수위변동에 따른 흐름조건식을 내부경계조건으로 도입하였으며 이에 대한 Jacobian 메트릭스를 유도하여 해석하였다. 가상하도에 대한 모의실험결과 교량에 의한 수위상승에 영향을 미치는 주요인자는 교량에 의한 하도단면의 수축정도, 하도경사, 하도부의 조도계수, 유량계수등으로 나타났고 교량을 월류하는 경우에 유량계수의 영향은 비교적 작은 것으로 검토되었다. 본 연구에서의 해석기법을 태풍 그래디스(Gladys)로 인한 수영강 상류부의 홍수에 적용하여 그 활용성을 입증하였다. 계산결과치는 그 당시 조사된 홍수흔적치 등과 비교하여 합리적인 범위내에서 일치되었으며, 교량 상류부에서의 수위상승효과는 1.08~1.53m로 나타났다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.624-628
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• 2008

Two-dimensional flow analysis is a way to provide good estimates for complex flow features in flow around islands and obstructions, flow at confluence and flow in braided channel. One of difficult problems to develop a two-dimensional hydraulic model is to analyze dry and wet area in river channel. Dry/wet problem can be encountered in river and coastal engineering problems, such as flood propagation, dam break analysis, tidal processes and so on. The objective of this study is to develop an accurate and robust two-dimensional finite element method with dry/wet technique in complex natural rivers. The dry/wet technique with Deforming Grid Method was developed in this study. The Deforming Grid Method was used to construct new mesh by eliminating of dry nodes and elements. The eliminated nodes and elements were decided by considering of the rising/descending velocity of water surface elevation. Several numerical simulations were carried out to examine the performance of the Deforming Grid Method for the purpose of validation and verification of the model in rectangular and trapezoidal channel with partly dry side. The application results of the model were displayed reasonable flow distribution.

• 한국수산과학회지
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• 제28권5호
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• pp.607-623
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• 1995

A numerical model of hydraulic resistance by hanging aquaculture facilities is developed and applied to a model basin and a field. A drag stress term formulated by the quadratic law of drag force is introduced Tn the equations of motion for a two-dimensional depth-averaged flow. In the model basin, numerical experiments ave tarried out for the various shape of obstructions, string density and layout of facilities etc.. The flow pattern around the facilities is affected sensitively by the density of string and the layout of facilities. On the other hand, the velocity decay due to the hanging oyster aquaculture facilities is observed in Kamak bay, where the maximum velcocity decay rate is $25\%$ in spring tide. The model is also applied to the field, Kamak bay. The velocity decay rate in the model is comparable with the field measurement data. The velocity decreases around the down-stream area of the facilities, .hut it increases in the other region. The water elevation decreases during the flood and it increases during the ebb.

• International Journal of Ocean System Engineering
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• 제2권1호
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• pp.37-49
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• 2012

An analysis of potential flooding by storm surge and wave run-up and overtopping can be used to evaluate protection afforded by the existing storm protection system. The analysis procedure can also be used to evaluate various protection alternatives for providing typhoon flood protection. To determine risk, the storm surges for both historical and hypothetical are compiled with tide conditions to represent high, slack and low water for neap, spring and mid range tides to use with the statistical procedure known as the Empirical Simulations Technique (EST). The EST uses the historic and hypothetical events to generate a large population of life-cycle databases that are used to compute mean value maximum storm surge elevation frequency relationships. The frequency-of-occurrence relationship is determined for all relevant locations along the shoreline at appropriate locations to identify the effect using the Empirical Storm Simulation (EST). To assist with understanding the process, an example is presented for a study of storm surge analysis for Freeport, Texas. This location is in the Gulf of Mexico and is subject to hurricanes and other tropical storms that approach from the Atlantic Ocean.