• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.278-279
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• 2017

북한 대부분이 미계측 지역으로서 자연재해 연구의 기초 데이터인 기상정보가 매우 부족한 실정이다. 이러한 지역은 천리안 기상위성 등 원격탐사 기술을 활용하여 재해 모니터링을 하여야한다. 천리안 기상위성은 기상청에서 운영하는 강우 알고리즘을 이용하면서 재해예측 보다는 일반적인 강우 예보에 중점을 두고 있다. 따라서 기상청 강우 알고리즘은 35 mm/hr를 초과하는 강우에 대해서는 탐지를 하지 못하므로 홍수위험 모니터링에 적합하지 않다. 본 연구에서는 이러한 문제를 해결하기 위해 기존의 천리안 강우강도 알고리즘에 GPM 위성 산출물(L3)과 같은 다중센서 자료를 적용하여 홍수유발 강우까지 측정할 수 있는 추정기술을 개발하였다. 개발된 강우 추정기술은 한국의 기상관측지점 94개소 자료와 비교 검증했을 때, 상관계수가 0.6 이상으로 기존의 알고리즘보다 개선된 강우를 추정할 수 있었다. 따라서 기존의 천리안 강우강도 알고리즘에서 추정하지 못했던 집중호우나 태풍의 강우강도를 정확하게 추정할 수 있으므로 미계측 지역의 홍수위험 모니터링에 도움이 될 것이다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.205-208
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• 2015

재난정보시스템은 재난에 대하여 예방, 대비, 대응, 복구 단계별 활동을 지원하기 위한 정보시스템이다. 재난정보시스템은 여러 형태의 재난에 대하여 여러 수준의 다양한 정보자원을 이용해야 하고 여러 임무를 맡고 있는 다양한 인적자원과 다양한 물적 자원을 활용하여 준비하고 빠르게 대응해야 한다. 재난은 지역별로 대응하게 되는데 기존의 시스템은 해당 지역에 대한 정보만을 파악할 수 밖에 없으며, 통합적인 상황 분석이 부족하고, 지역재난상황에 따라 표준행동에 의한 자동적 실시간 임무부여와 실시간 보고의 처리, 재난관리자의 경험적 지식을 활용될 수 있는 정보시스템화는 미흡한 실정이다. 본 연구에서는 지역단위 홍수대응을 위하여 지역별 재난정보시스템이 P2P 분산연결체제로 재난과 유관한 다른 지역의 재난정보를 공유할 수 있고, 국방, 경찰, 보안 분야에 적용되어온 정보융합(Information fusion)기술과 비즈니스 룰(BRMS)의 규칙기반 지능형 기술을 활용하여 여러 수준의 다양한 정보를 종합 분석하여 통합적인 상황정보를 제공하고, 표준행동(SOP) 요령과 지역 재난관리자의 지식을 활용하여 인적 자원과 물적 자원에 대한 대응계획을 제시하여 대응조치를 선택할 수 있도록 하며, 현장 상황에 따른 실시간 임무 부여와 상황 보고를 처리할 수 있는 지능형 지역 홍수대응 재난정보시스템 프레임워크를 제안한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.147-147
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• 2018

In this article, we use an open source software library: TensorFlow, developed for the purposes of conducting very complex machine learning and deep neural network applications. However, the system is general enough to be applicable in a wide variety of other domains as well. The proposed model based on a deep neural network model, LSTM (Long Short-Term Memory) to predict the river water level at Okcheon Station of the Guem River without utilization of rainfall - forecast information. For LSTM modeling, the input data is hourly water level data for 15 years from 2002 to 2016 at 4 stations includes 3 upstream stations (Sutong, Hotan, and Songcheon) and the forecasting-target station (Okcheon). The data are subdivided into three purposes: a training data set, a testing data set and a validation data set. The model was formulated to predict Okcheon Station water level for many cases from 3 hours to 12 hours of lead time. Although the model does not require many input data such as climate, geography, land-use for rainfall-runoff simulation, the prediction is very stable and reliable up to 9 hours of lead time with the Nash - Sutcliffe efficiency (NSE) is higher than 0.90 and the root mean square error (RMSE) is lower than 12cm. The result indicated that the method is able to produce the river water level time series and be applicable to the practical flood forecasting instead of hydrologic modeling approaches.

• Journal of Information Processing Systems
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• v.17 no.6
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• pp.1097-1114
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• 2021

The primary objective of this work was to discover a solution for the survival of people in an emergency flood. The geographical information was obtained from remote sensing techniques. Through helpline numbers, people who are in need request support. Although, it cannot be ensured that all the people will acquire the facility. A proper link is required to communicate with people who are at risk in affected areas. Mobile sensor networks with field-programmable gate array (FPGA) self-configurable radios were deployed in damaged areas for communication. Ad-hoc networks do not have a centralized structure. All the mobile nodes deploy a temporary structure and they act as a base station. The mobile nodes are involved in searching the spectrum for channel utilization for better communication. FPGA-based techniques ensure seamless communication for the survivors. Timely help will increase the survival rate. The received signal strength is a vital factor for communication. Cognitive radio ensures channel utilization in an effective manner which results in better signal strength reception. Frequency band selection was carried out with the help of the GRA-MADM method. In this study, an analysis of signal strength for different mobile sensor nodes was performed. FPGA-based implementation showed enhanced outcomes compared to software-based algorithms.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.301-302
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• 2023

연구목적:본 논문에서는 기후변화로 기존 도심지 침수 발생이 증가하는 현 상황에서 공동주택 단지에 소규모 우수저류시설을 계획하였을 때 기존 하류부 도심지 침수량 증가율과 기존 도심지 침수량 저감 정도를 분석하고자 한다. 연구방법:미국환경보호청 SWMM 모델을 활용해서 대규모 하수도 모델을 구축하고 시뮬레이션을 통해 하류부 기존 도심지 침수영향을 분석하였다. 구축한 모델은 개발지구, 하류부 기존 도심지, 우수를 방류하는 하천유역 전체를 포함하였다. 연구결과: 대규모 개발행위 시 연구대상지역에서 공동주택 블록별로 최소 우수저류조 용량을 산정하여 시뮬레이션한 결과, 하류부 기존 도심지에서 방재성능목표강우량 1시간 기준 4,893m³, 2시간 기준 25,815m³, 3시간 기준 55,528m³의 침수량을 저감할 수 있을 것으로 나타났다. 결론:본 연구와 같이 하류부 기존 도심지까지 고려한 대규모 침수 시뮬레이션을 실시하였을 때 하류부 도심지 침수가 크게 증가하는 것을 알 수 있고, 개발전 공동주택 단지 블록별로 필요한 우수저류조 용량을 계획하고 개발시 비용 지원 등으로 우수저류조 건설을 권장한다면 하류부 기존 도심지 홍수 부담을 감소시킬 수 있다.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.245-250
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• 2017

Flash floods is defined as the flooding of intense rainfall over a relatively small area that flows through river and valley rapidly in short time with no advance warning. So that it can cause damage property and casuality. This study is to establish the flash-flood warning system using 38 accident data, reported from the National Disaster Information Center and Land Surface Model(TOPLATS) between 2009 and 2012. Three variables were used in the Land Surface Model: precipitation, soil moisture, and surface runoff. The three variables of 6 hours preceding flash flood were reduced to 3 factors through factor analysis. Decision tree, random forest, Naive Bayes, Support Vector Machine, and logistic regression model are considered as big data methods. The prediction performance was evaluated by comparison of Accuracy, Kappa, TP Rate, FP Rate and F-Measure. The best method was suggested based on reproducibility evaluation at the each points of flash flood occurrence and predicted count versus actual count using 4 years data.

• 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.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.345-356
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• 2022

A severe flooding occured at a small urban catchment in Daejeon-si South Korea on July 30, 2020 causing significant loss of property (inundated 78 vehicles and two apartments) and life (one casualty and 56 victims). In this study, a retrospective analysis of the inundation event was implemented using a physically-based urban flood model, H12 with high-resolution data. H12 is an integrated 1-dimensional sewer network and 2-dimensional surface flow model supported by hybrid parallel techniques to efficiently deal with high-resolution data. In addition, we evaluated the impact of the flooding barriers which were installed after the flood disaster. As a result, it was found that the inundation was affected by a combination of multiple components including the shape of the basin, the low terrain of the inundation area located in the downstream part of the basin, and lack of pipe capacity to drain discharge from the upstream during heavy rain. The impact of the flooding barriers was analyzed by modeling with and without barriers on the high-resolution terrain input data. It was evaluated that the flood barriers effectively lower the water depth in the apartment complex. This study demonstrates capability of high-resolution physically-based urban modeling to quantitatively assess the past inundation event and the impact of the reduction measures.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.775-784
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• 2023

With the increasing trend of extreme rainfall that exceeds the design frequency of man-made structures due to extreme weather, it is necessary to review the safety of agricultural reservoirs designed in the past. However, there are no local government-managed reservoirs (13,685) that can be discharged in an emergency, except for reservoirs over a certain size under the jurisdiction of the Korea Rural Affairs Corporation. In this case, it is important to quickly deploy a mobile siphon to the site for preliminary discharge, and this study evaluated the applicability of a mobile siphon with a diameter of 200 mm, a minimum water level difference of 6 m, 420 (m²/h), and 10,000 (m²/day), which can perform both preliminary and emergency discharge functions, to the Yugum Reservoir in Gyeongju City. The test bed, Yugum Reservoir, is a facility that was completed in 1945 and has been in use for about 78 years. According to the hydrological stability analysis, the lowest height of the current dam crest section is 27.15 (EL.m), which is 0.29m lower than the reviewed flood level of 27.44 (EL.m), indicating that there is a possibility of lunar flow through the embankment, and the headroom is insufficient by 1.72 m, so it was reviewed as not securing hydrological safety. The water level-volume curve was arbitrarily derived because it was difficult to clearly establish the water level-flow relationship curve of the reservoir since the water level-flow measurement was not carried out regularly, and based on the derived curve, the algorithm for operating small and medium-sized old reservoirs was developed to consider the pre-discharge time, the amount of spillway discharge, and to predict the reservoir lunar flow time according to the flood volume by frequency, thereby securing evacuation time in advance and reducing the risk of collapse. Based on one row of 200 mm diameter mobile siphons, the optimal pre-discharge time to secure evacuation time (about 1 hour) while maintaining 80% of the upper limit water level (about 30,000 m²) during a 30-year flood was analyzed to be 12 hours earlier. If the pre-discharge technology utilizing siphons for small and medium-sized old reservoirs and the algorithm for reservoir operation are implemented in advance in case of abnormal weather and the decision-making of managers is supported, it is possible to secure the safety of residents in the risk area of reservoir collapse, resolve the anxiety of residents through the establishment of a support system for evacuating residents, and reduce risk factors by providing risk avoidance measures in the event of a reservoir risk situation.

• The Korean Journal of Emergency Medical Services
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• v.6 no.1
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• pp.153-168
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• 2002

Since 1992, conventional fire fighting businesses have been converted into a metropolitan autonomous fire fighting system to be ready for a variety of disasters. However, the corresponding investment has been overlapped due to the non-integration of businesses to prevent any potential disasters, and a series of collaborative systems have been not functioning so well. In the meantime, our fire fighting sector has been trying to set up its own clean and faithful position by abolishing any inconvenient system or outsourcing private sectors, and expanded its work scope from conventional fire fighting even to rescue and emergency works. While focusing on handling disaster, the fire fighting sector has been widely trusted and reliable throughtout our nation. Moreover, our fire fighting sector has secured nation wide mobile organizations, technical personnel by field, special equipments and independent communication network. In addition, the fire fighting sector has knowledges, expertise and capabilities required for managing disasters, while in charge of almost every disaster management works including fire, explosion, collapse, disaster and flood. It becomes an organization for comprehensive disaster management under an absolute national trust, which is based on the system for prevention, preparation and countermeasure against a variety of disasters. Thus, our fire fighting sector must make many efforts and try to modernize conventional education and training. The ways to facilitate rescue and emergency works may include the nurture of technical fire fighting personnel along with modernized equipments, the reinforcement of rescue and emergency education, the facilitation of operating civil defense corps, the facilitation of operating volunteer fire fighting corps, the better arrangement of 119 briefing room for public healthcare in provincial offices, the sterilization of rescue instruments and equipments the better repair education for emergency rescue member, the establishment of regional emergency assistant system and the expansion of fire fighting personnel and equipments. In terms of reinforcing the functions and services of rescue 119 and emergency corps, we must review the following considerations: Building up security system along with operational expansion, building up a system for emergency medical treatment, building up a comprehensive information management system for rescue and emergency, constructing a provincial safety museum and so forth. For the ways to better the works of rescue 119 we can review the following considerations : Improving the education for fire fighting training corps under Jeju Provincial Fire and Disaster Management Department, providing rescue members with more opportunities for clinical practices, enhancing the morale of rescue members, installing a comprehensive briefing room for emergency rescue members, building up medical networks along with reasonable policies for information service, operating the consulting system for rescue 119 and so on. If these requirements are met, it is expected that the fire fighting departments in Jeju province can cope with every accident and disaster a little more rapidly and quickly in compliance with local needs, so that they can keep their own position as a public fire fighting organization which may be trusted by the public.