• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.909-913
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• 2012

본 연구는 XP-SWMM 2011 모형의 최적 해석범위설정과 월류에 의한 2차원 지표유출량을 포함한 도시유역의 총 유출량 산정에 대한 방법을 연구한 것이다. 하수 및 우수 관망 해석 모형으로 1차원 관로해석과 2차원 지표면 해석이 가능한 XP-SWMM 2011 모형을 이용하였으며, 연구의 대상지역은 최근 연속적인 침수 피해를 일으켰던 광화문 일대로 선정하였다. 발생가능한 빈도별 지속시간별 확률강우량은 Huff의 4분위법을 이용하여 10분 간격으로 분포시켰으며, 기존의 유역 출구점에 기준한 설계기준의 문제점을 제시하고, 월류에 의한 2차원 지표유출수를 포함한 유역 내에서의 총 유출량 산정에 대한 방법을 제시하였다. 모의 결과분석시 기존의 제한된 격자확장 경계조건으로 인한 문제점 극복을 위해 해석범위 설정 시 적합한 격자경계의 설정이 필요함을 확인하였다. 도시유역의 관로유출량과 본 연구에 제시된 지표유출량을 함께 고려한다면 치수계획규모를 설정하는데 주요 판단기준으로 활용될 수 있을 것이다.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.3
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• pp.13-26
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• 2015

Many urban areas in Korea suffer from repeated flood damage during intensive rainfall due to an increase in impervious areas caused by rapid urbanization and deteriorating sewage systems. A centralized stormwater management system has caused severe flood damage in an area that has proven unable to accommodate recent climate change and a rise in precipitation. Most flooding prevention projects that have been recently implemented focus on increasing drainage system capacity by expanding the size of sewer pipes and adding pumping stations in downstream areas. However, such measures fail to provide sustainable solutions since they cannot solve fundamental problems to reduce surface runoff caused by urbanization across the watershed. A decentralized stormwater management system is needed that can minimize surface runoff and maximize localized retention capacity, while maintaining the existing drainage systems. This study proposes a stormwater management corridor for the flood-prone watershed in the city of Dongducheon. The corridor would connect the upstream, midstream, and downstream zones using various methods for reducing stormwater runoff. The research analyzed surface runoff patterns generated across the watershed using the Modified Rational Method considering the natural topography, land cover, and soil characteristics of each sub-watershed, as well as the urban fabric and land use. The expected effects of the design were verified by the retainable volume of stormwater runoff as based on the design application. The results suggest that an open space network serve as an urban green infrastructure, potentially expanding the functional and scenic values of the landscape. This method is more sustainable and effective than an engineering-based one, and can be applied to sustainable planning and management in flood-prone urban areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.5
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• pp.671-683
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• 2018

The flood damage caused by heavy rains in urban watershed is increasing, and, as evidenced by many previous studies, urban flooding usually exceeds the water capacity of drainage networks. The flood on the area which considerably urbanized and densely populated cause serious social and economic damage. To solve this problem, deterministic and probabilistic studies have been conducted for the prediction flooding in urban areas. However, it is insufficient to obtain lead times and to derive the prediction results for the flood volume in a short period of time. In this study, IDNN, TDNN and NARX were compared for real-time flood prediction based on urban runoff analysis to present the optimal real-time urban flood prediction technique. As a result of the flood prediction with rainfall event of 2010 and 2011 in Gangnam area, the Nash efficiency coefficient of the input delay artificial neural network, the time delay neural network and nonlinear autoregressive network with exogenous inputs are 0.86, 0.92, 0.99 and 0.53, 0.41, 0.98 respectively. Comparing with the result of the error analysis on the predicted result, it is revealed that the use of nonlinear autoregressive network with exogenous inputs must be appropriate for the establishment of urban flood response system in the future.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.77-86
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• 2016

In this study, we have created CityGML based 3D information model for drainage facility, manhole and terrain. It conducted analysis of the rainfall-runoff leak through the information model for obtaining interoperability for information integration between city models. The models have advantages to manage the infrastructure information in point of semantic meaning and geometric information by converting the original 2D GIS construction information into the 3D information model. The input values can be automatically generated through the 3D information model of this study, while the values should be entered manually in the conventional method. Also, it can be useful to check the flooding level and related locations by connecting the result of rainfall interpretation and information model.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.5
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• pp.83-95
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• 2024

This study evaluates the effectiveness of different Low-Impact Development (LID) scenarios in mitigating urban flooding in Yeongdeungpo-gu, Seoul, using the Storm Water Management Model (SWMM). Two key areas, an industrial zone, and a mixed residential-commercial zone, were chosen to explore how different LID implementations impact runoff. The study considers six types of LIDs, including green roofs and rain barrels for building-based scenarios; and permeable pavements, infiltration trenches, vegetative swales, and rain gardens for open space-based scenarios. The drainage network map and historical rainfall data from previous flooding events were applied in SWMM for simulation modeling using different LID scenarios: building-based, open space-based, and combined LID methods. Results show that the combined LID approach is the most effective method, reducing runoff by 26.8% and 21.1% and lowering peak runoff volumes by 7.5% and 12.6% for Block I and Block II, respectively. These scenarios demonstrate that Scenario II has a more significant impact compared to Scenario I, despite the amount of coverage area. In general, building-based LID measures alone show the least reduction in both surface runoff and peak runoff volumes. The proposed approach offers a robust solution that can shape a resilient and livable urban future.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.78-83
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• 2018

Recently, due to the rapid industrialization and urbanization, a great number of infrastructure and population were concentrated in urban areas. These changes have resulted in unprecedent runoff characteristics in urban basins, and the increase in impermeable areas leads to the growth of the runoff and the peak flow rate. Although many cities have made a lot of efforts to check and expand the stormwater network, the flash flood or the local torrential rain caused a growing number of casualty and property damage. This study analyzed the stormwater passage rate in a target area using SWMM. By incorporating the flow quantity surpassing the storm sewer capacity, a 2D inland flooding analysis model was applied to route the inundated area and velocity.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.19-19
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• 2015

최근 기후변화로 인해 집중호우 및 게릴라성 폭우의 발생빈도가 증가하고 있다. 또한, 도시화 및 산업화로 인해 불투수지역이 증가하여 첨두강우의 도달시간은 짧아지고, 강우강도는 증가하는 현상을 보이고 있다. 이로 인해 도시유역에서는 우수관의 통수능 부족으로 인한 홍수가 빈번히 발생하고 있다. 본 연구에서는 EPA-SWMM User's manual에서 제공하는 예제 관망도를 이용하여 SWMM 모형 매개변수들 간의 상관관계 분석을 수행하였다. 사전 조사 및 분석을 통해 유역폭, 관조도계수, 불투수유역 조도계수, 투수유역 조도계수, 불투수면적 비율 등 총 5개의 매개변수를 분석 대상으로 선정하였다. 매개변수들 간의 상관관계를 분석한 결과 유역폭-관조도계수, 유역폭불투수유역조도계수, 불투수면저 비율-투수유역 조도계수가 양의 기울기를 가지는 1차 선형함수 형태를 보였다. 즉, 예로 유역폭이 증가하면 관조도계수 또한 증가하는 경향을 보였다. 반대로 유역폭-불투수면적비율, 불투수유역 조도계수-관조도계수의 경우 음의 기울기를 가지는 상관관계를 보였으며 특히, 유역폭-불투수면적비율의 경우 2차 회귀곡선을 가지는 감소경향을 보였다. 본 연구의 결과를 활용하여 향후 우수관 설계를 수행한다면 내수침수 저감에 실무적인 도움을 줄 수 있을 것으로 판단된다.

• Journal of Korea Water Resources Association
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• v.48 no.9
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• pp.729-741
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• 2015

This study examined the applicability of MBLRP (Modified Bartlett-Lewis Rectangular Pulse) rainfall generation model for an urban flood simulation which is a type of Poisson cluster rainfall generation model. This study constructed XP-SWMM model for Namgajwa area of Hongjecheon basin, which is a two-dimensional pipe network-surface flood simulation program and computed a flood discharge and a flooded area with input data of synthetic rainfall time series of 200 years that were generated by the MBLRP model. This study compared the data of flood with synthetic rainfall and flood with corresponding values which were based on design rainfall. The results showed that the flooded area computed with MBLRP model was somewhat smaller than the corresponding values on the basis of the design. A degree of underestimation was from 8% (5 year) to 34% (200 year) and the degree of underestimation increased as a return period increased. This study is meaningful in that it proposes methodology that enables quantifiability of uncertain variables which are related to a flooding through Monte Carlo analysis of urban flooding simulation and applicability and limitations thereof.

• Journal of Korea Water Resources Association
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• v.56 no.1
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• pp.53-62
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• 2023

Recently, due to the influence of climate change, the occurrence of damage to heavy rain is increasing around the world, and the frequency of heavy rain with a large amount of rain in a short period of time is also increasing. Heavy rains generate a large amount of outflow in a short time, causing flooding in the downstream part of the mountainous area before joining the small and medium-sized rivers. In order to reduce damage to downstream areas caused by flooding, it is very important to calculate the outflow of mountainous areas due to torrential rains. However, the sewage network flooding analysis, which is currently conducting the most analysis in Korea, uses the time and area method using the existing data rather than calculating the rainfall outflow in the mountainous area, which is difficult to determine that the soil characteristics of the region are accurately applied. Therefore, if the rainfall is analyzed for mountainous areas that can cause flooding in the downstream area in a short period of time due to large outflows, the accuracy of the analysis of flooding characteristics that can occur in the downstream area can be improved and used as data for evacuating residents and calculating the extent of damage. In order to calculate the rainfall outflow in the mountainous area, the rainfall outflow in the mountainous area was calculated using MIKE SHE among the MIKE series, and the flooding analysis in the downstream area was conducted through MIKE 21 FM (Flood model). Through this study, it was possible to confirm the amount of outflow and the time to reach downstream in the event of rainfall in the mountainous area, and the results of this analysis can be used to protect human and material resources through pre-evacuation in the downstream area in the future.

• Journal of Korea Water Resources Association
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• v.41 no.9
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• pp.929-941
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• 2008

The objectives of this study are to propose a system for combined use of a hydrologic and a hydraulic model for urban flood forecast model and to evaluate the system on the $300km^2$ Jungrang urban watershed area, which is relatively large area as an urban watershed and consequently composed of very complex drainage pipes and streams with different land uses. In this study, SWMM for hydrologic model and HEC-RAS for hydraulic model are used and the study area is divided into 25 subbasins. The SWMM model is used for sewer drainage analysis within each subbasin, while HEC-RAS for unstready flow analysis in the channel streams. Also, this study develops a GUI system composed of mean areal precipitation input component, hydrologic runoff analysis component, stream channel routing component, and graphical representation of model output. The proposed system was calibrated for the model parameters and verified for the model applicability by using the observation data. The correlation coefficients between simulated and observed flows at the 2 important locations were ranged on 0.83-0.98, while the coefficients of model efficiency on 0.60-0.92 for the verification periods. This study also provided the possibilities of manhole overflows and channel bank inundation through the calculated water profile of longitudinal and channel sections, respectively. It can be concluded that the proposed system can be used as a surface runoff and channel routing models for urban flood forecast over the large watershed area.