• Coupled systems mechanics
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• 제11권6호
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• pp.505-524
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• 2022

Floods represent extreme hydrological phenomena that affect populations, environment, social, political, and ecological systems. After the catastrophic floods that have hit Europe and the World in recent decades, the flood problem has become more current. At the EU level, a legal framework has been put in place with the entry into force of Directive 2007/60/EC on Flood Risk Assessment and Management (Flood Directive). Two years after the entry into force of the Floods Directive, Bosnia and Herzegovina (B&H), has adopted a Regulation on the types and content of water protection plans, which takes key steps and activities under the Floods Directive. The "Methodology for developing flood hazard and risk maps" (Methodology) was developed for the territory of Bosnia and Herzegovina, following the methodology used in the majority of EU member states, but with certain modifications to the country's characteristics. Accordingly, activities for the preparation of the Preliminary Flood Risk Assessment for each river basin district were completed in 2015 for the territory of Bosnia and Herzegovina. Activities on the production of hazard maps and flood risk maps are in progress. The results of probable climate change impact model forecasts should be included in the preparation of the Flood Risk Management Plans, which is the subsequent phase of implementing the Flood Directive. By the foregoing, the paper will give an example of the development of the hydrodynamic model of the Zujevina River, as well as the development of hazard and risk maps. Hazard and risk maps have been prepared for medium probability floods of 1/100 as well as for high probability floods of 1/20. The results of LiDAR (Light Detection and Ranging) recording were used to create a digital terrain model (DMR). It was noticed that there are big differences between the flood maps obtained by recording LiDAR techniques in relation to the previous flood maps obtained using georeferenced topographic maps. Particular attention is given to explaining the Methodology applied in Bosnia and Herzegovina.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.187-187
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• 2016

High intensity of population distribution in deltaic setting especially in Asia tends to have increased and causes coastal flood risk due to lower elevations and significant subsidence. Maximum or peak discharge of flood always causes numerous deaths and huge economic losses. New technology of spatial satellite image has been applied to analyze flood damage. In this research, the relationship of nightlight intensity associated with flood damages has been determined during 1992-2013 with spatial resolution of 30 arc sec ($0.0083^{\circ}$) which is nearly one kilometer at the equator in whole six countries along the Mekong River (i.e., China, Myanmar, Lao PDR, Thailand, Cambodia and Vietnam). ArcGIS Hydrological Flow Length Tool has been used to determine the distance of each pixel areas from the rivers and streams. Statistical analysis results highlight the significant correlation R = 0.47 between nightlight digital number and economic damages per unit area (US$/km2) and R = 0.62 for number of affected people for unit area ($people/km^2$). The areas near by the Mekong River and its tributaries correspond to high flood damage. This spatial analysis result is going to be prestigious key information to the regions and all related stakeholders for decisions and mitigation strategies.

• 한국도로학회논문집
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• 제15권3호
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• pp.75-83
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• 2013

PURPOSES: In this study, flood mitigation effect of drainage asphalt concrete pavement were analyzed by a SWMM 5.0 program in order to evaluate the low impact development (LID) based on the drainage asphalt concrete pavements. METHODS: In order to determine the porosity parameters of drainage asphalt concretes, the specimen mixtures were manufactured using the conditions presented in the previous study. The numerical simulation was conducted using the SWMM 5.0 program considering the flood mitigation effect of drainage asphalt concrete pavements. The effect of flood reduction can be observed when drainage asphalt concrete pavements were applied to Mokgamcheon watershed. The flood mitigation effect analysis of Mokgamcheon watershed as well as continuous simulation of subwatershed runoff were performed through this study. RESULTS : The analysis of drainage asphalt concrete pavements was carried out for evaluating the effect on runoff, resulting in: the peak flow decreases up to 1.26~9.53% after drainage asphalt concrete pavements applied in the SWMM 5.0 program furthermore, the discharge decreases up to 0.55~4.11%. CONCLUSIONS: As a result, the reduced peak flow and discharge were found through the SWMM 5.0 program. It can be concluded that the flood is effectively reduced when the drainage asphalt concrete pavements are used.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.235-235
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• 2015

This study investigates the impact of event characteristics on runoff dynamics during extreme flood events observed in a $8.5km^2$ experimental watershed located in South Korea. The 37 most extreme flood events with event rainfall in excess of 50 mm were analysed using an event-based rainfall-runoff model; the Revitalised Flood Hydrograph (ReFH) routinely used for design flood estimation in the United Kingdom. The ReFH model was fitted to each event in turn, and links were investigated between each of the two model parameters controlling runoff production and response time, respectively, and event characteristics such as rainfall depth, duration, intensity and also antecedent soil moisture. The results show that the structure of the ReFH model can effectively accommodate any nonlinearity in runoff production, but that the linear unit hydrograph fails to adequately represent a reduction in watershed response time observed for the more extreme events. By linking the unit hydrograph shape directly to rainfall depth, the consequence of the observed nonlinearity in response time is to increase design peak flow by between 50% for a 10 year return period, and up to 80% when considering the probable maximum flood (PMF).

• 한국수자원학회논문집
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• 제44권3호
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• pp.231-248
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• 2011

본 연구에서는 기후변화 요소를 반영하여 홍수취약성지표 (Flood Vulnerability Index, FVI)를 개발하였고 이를 북한강 유역의 6개 중권역에 적용하였다. 기후변화 요소를 고려하기 위해 IPCC의 CGCM3 모형의 A1B와 A2 시나리오를 이용하였고 일단위로 축소화하기 위해 SDSM (Statistical Downscaling Model) 모형을 이용하였다. 홍수취약성 인자를 선정하기 위해 지속가능성 평가모형인 추진력-압력-상태-영향-반응 (Driver-Pressure-State-Impact-Response, DPSIR) 모형을 이용하였고 기후변화로 인한 홍수유출의 특성분석은 연속유출모의모형인 HSPF (Hydrological Simulation Program-Fortran)를 이용하였다. 본 연구에서 개발된 홍수취약성지수는 유역의 현상태 및 기후변화의 영향으로 인한 잠재적 취약성을 정량적인 하나의 지수로 간결하게 표현할 수 있어서 장기 수자원 및 유역관리 정책수립에 사용될 수 있을 것으로 기대된다.

• 한국농공학회논문집
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• 제63권1호
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• pp.11-25
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• 2021

The objective of this study was to analyze the impact of activation functions on flood forecasting model based on Artificial neural networks (ANNs). The traditional activation functions, the sigmoid and tanh functions, were compared with the functions which have been recently recommended for deep neural networks; the ReLU, leaky ReLU, and ELU functions. The flood forecasting model based on ANNs was designed to predict real-time runoff for 1 to 6-h lead time using the rainfall and runoff data of the past nine hours. The statistical measures such as R2, Nash-Sutcliffe Efficiency (NSE), Root Mean Squared Error (RMSE), the error of peak time (ETp), and the error of peak discharge (EQp) were used to evaluate the model accuracy. The tanh and ELU functions were most accurate with R2=0.97 and RMSE=30.1 (㎥/s) for 1-h lead time and R2=0.56 and RMSE=124.6~124.8 (㎥/s) for 6-h lead time. We also evaluated the learning speed by using the number of epochs that minimizes errors. The sigmoid function had the slowest learning speed due to the 'vanishing gradient problem' and the limited direction of weight update. The learning speed of the ELU function was 1.2 times faster than the tanh function. As a result, the ELU function most effectively improved the accuracy and speed of the ANNs model, so it was determined to be the best activation function for ANNs-based flood forecasting.

• 한국농공학회논문집
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• 제58권1호
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• pp.39-51
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• 2016

Extreme floods occur more often recently as the frequency of extreme storm events increase due to the climate change. Because the extreme flood exceeding the design flood can cause large-scale disasters, it is important to predict and prepare for the future extreme flood. Flood flow is affected by two main factors; rainfall and land use. To predict the future extreme flood, both changes in rainfall due to the climate change and land use should be considered. The objective of this study was to simulate the future design flood in the Hwangguji river watershed, South Korea. The climate and land use change scenarios were derived from the representative concentration pathways (RCP) 4.5 and 8.5 scenarios. Conversion of land use and its effects (CLUE) and hydrologic modelling system (HEC-HMS) models were used to simulate the land use change and design flood, respectively. Design floods of 100-year and 200-year for 2040, 2070, and 2100 under the RCP4.5 and 8.5 scenarios were calculated and analyzed. The land use change simulation described that the urban area would increase, while forest would decrease from 2010 to 2100 for both the RCP4.5 and 8.5 scenarios. The overall changes in design floods from 2010 to 2100 were similar to those of probable rainfalls. However, the impact of land use change on design flood was negligible because the increase rate of probable rainfall was much larger than that of curve number (CN) and impervious area.

• 한국수자원학회논문집
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• 제55권5호
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• pp.345-356
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• 2022

2020년 7월 30일 대전광역시 서구 A 아파트에서 새벽에 발생한 집중호우로 차량 78대와 아파트 2개 동이 침수되어, 사망 1명, 이재민 56명의 피해가 발생하였다. 본 연구에서는 1차원 관거-2차원 지표 흐름(1D-2D) 통합 해석 모형인 H12 모형과 고해상도 지표면 자료를 이용하여 침수 사상을 재현하고, 원인을 분석하였다. 또한, 침수 재해 발생 이후 A 아파트 주위에 설치된 침수방어벽의 침수 방어 효과를 분석하였다. 분석 결과, 좁고 가파른 유역형상, 주변 대비 고도가 낮은 대상 지역의 지형적 요인과 폭우로 인해 상류로부터 급속히 발생한 유출이 하류 저지대에서 배수되지 못해 발생한 침수 재해로 분석되었다. 침수방어벽의 효과를 분석하기 위해 고해상도 지표면 입력자료를 변경하여 침수방어벽 설치 전후를 모의하여 비교한 결과, 설치 후 A 아파트 단지 내 침수 수위가 낮아져 홍수 저감효과가 뛰어난 것으로 평가되었다. 본 연구를 통해 초고해상도 물리 기반 모형을 이용한 침수 원인 분석 및 저감 대책의 정량적 평가가 가능함을 확인하였다.

• 환경영향평가
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• 제18권6호
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• pp.461-467
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• 2009

This paper provides two case studies of environmental impacts with socio-economic values. The first case is on flood protection levees conducted from 2003 to 2004 in Phu Tan district, An Giang province. The impacts were found by comparing full flood protection levees area (FFPL) to non-full flood protection levees area (NFFPL). Participatory Rural Appraisal (PRA) tools per each group of rich, middle, and poor people were used to list the impacts. Then, major impacts were selected by ranking and interviewing 60 households per site, and assessed by Cost Benefit Analysis (CBA) in rice production from 1996 to 2002 between two areas. The tested research indicated moving system of NFFPL to that of FFPL lost about 11 million VND/ha/year. The second case is on impacts of Penaeid shrimp farming conducted in Duyen Hai District, Tra Vinh Province in 2004-2005. Ninety households and 12 local officials were interviewed. Four PRAs were conducted and 36 water samples were taken inside and outside shrimp pond to measure values of DO, COD, Fe total, TSS, N-$NO_3{^-}$, N-$NH_4{^+}$, P-$PO{_4}^{3-}$, and Chlorophyll-a. Research results showed only 36.7% of the households got profit from shrimp farming. Highest financial efficiency was 0.72 for the semi-intensive system. Tested water indicators showed surface water quality did not match Vietnamese standard for surface water in coastal area (TCVN 5943-1995) and in rain. The water was very muddy and contaminated by organic aluminum. Summarily, the impacts were clarified more obviously via adding socio-economic values to assessment. Importantly, the values were transformed to household's income which is an indicator for policy-makers to consider the impacts obviously. Besides, data of different group of people impacted are cases contributing to consideration of the impacts in an appropriate social level.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.325-331
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• 2016

본 연구에서는 홍수 시 부유물의 충돌하중을 고려하여 교량의 홍수 취약도 곡선을 도출하였다. 자연재해에 의해 불가피하게 발생하는 사회기반시설물의 손상 또는 기능 손실은 심각한 인명피해 뿐만 아니라 국가적으로 사회적, 경제적 손실을 불러올 수 있다. 따라서 국가주요시설물을 재난으로부터 효과적으로 유지관리하기 위해 취약도 곡선은 중요한 도구로 사용되고 있다. 특히 한국은 산지 지형이 많이 형성되어 있고 하절기에 강수량의 2/3이상이 집중되어, 홍수 피해 가능성이 매우 높다. 홍수 시 교량 파괴의 주원인으로는 부유물의 충돌과 하상세굴이 있는데, 부유물의 충돌은 여러 가지 불확실성으로 인하여 상대적으로 연구가 부족한 실정이다. 본 연구에서는 FERUM-ABAQUS 기반의 취약도 해석 시스템을 도입하여, 홍수시 부유물의 충돌에 대한 교량의 취약성을 평가하였다. 교량의 취약도 해석을 효과적으로 수행하기 위하여 한계상태함수, 손상도 지수, 확률변수, 유한요소모델, 취약도 해석 소프트웨어 시스템을 주로 고려하였으며, 가속도 및 변위 응답해석을 통하여 모델 상태를 확인하였다. 다음으로는 홍수 시 부유물 충돌에 발생 가능한 다양한 파라미터를 기반으로 교량의 취약도 곡선을 성공적으로 도출하였다.