• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.21-21
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• 2023

현재 구축되어있는 방재시설의 능력은 기후위기로 인해 수용가능한 극한강우량의 범위를 넘어서고 있어 대형화된 홍수로 인한 피해가 꾸준히 발생하고 있다. 이로 인해 잠재적 홍수로 인한 도시회복도 관리와 홍수로 수반되는 피해에 대한 복구의 중요도가 높아지고 있다. 회복도는 도시의 재해 취약성, 저항, 적응, 복구, 완화에 대한 능력을 포괄하는 개념으로써 최근 주목받고 있는 개념이지만 대부분의 연구는 주로 시설에 대한 회복도 평가가 이루어지고 있다 (Sen et al.,2021). 또한 재해 후 도시복구에 관한 연구는 다수 존재하지만 복구에 따른 지역의 회복도 변화와 라이프라인과 같은 주요 시설의 복구에 따른 회복도 차이를 고려한 연구는 미비한 실정이다. 따라서 본 연구에서는 도시침수 발생 후 라이프라인을 고려한 도시복구 우선순위 산정모델을 개발하고 재해관리의 효율성 향상측면에서 도시의 기능적 회복도를 평가하였다. 이를 위해 라이프라인 중 도로 복구결과의 평가를 위하여 리스크 매트릭스 기법을 이용한 도로위험도평가를 수행하였으며 도시의 회복도를 측정하였다. 회복도를 크게 홍수로부터 도시가 받은 영향과 재해복구역량으로 구성하였으며 정량적인 평가를 위해 각각 손상함수와 재해재난목적예비비를 활용하여 산정하였다. 이후 복구우선순위를 산정하였으며 복구와 도시회복도와의 관계를 분석하기 위하여 재해연보 자료를 기초로 회귀분석을 통해 복구비용을 추정하였다 (유순영 등.,2014). 시범지역에 적용한 결과 시설 및 도로 복구에 따른 도시영향의 변화보다 복구비사용으로 인한 재해복구역량의 변화가 더욱 크다는 것을 확인하였다. 이는 재해재난목적예비비의 중요성이 크다는 것을 의미하며 향후 추가적인 인문학적, 법제적 요소가 회복도에 미치는 영향을 연구한다면 도시회복도 향상 및 도시복구에 관한 정책적 의사결정에 큰 도움이 될 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6B
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• pp.561-569
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• 2010

In this study, the impact of climate change on extreme drought events is investigated by comparing drought severity-area-duration curves under present and future climate. The depth-area-duration analysis for characterizing an extreme precipitation event provides a basis for analysing drought events when storm depth is replaced by an appropriate measure of drought severity. In our climate-change impact experiments, the future monthly precipitation time series is based on a KMA regional climate model which has a $27km{\times}27km$ spatial resolution, and the drought severity is computed using the standardized precipitation index. As a result, agricultural drought risk is likely to increase especially in short duration, while hydrologic drought risk will greatly increase in all durations. Such results indicate that a climate change vulnerability assessment for present water resources supply system is urgent.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.124-124
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• 2022

가뭄시 유역 수문량은 하천수/지하수 취·배수, 하·폐수방류량, 용수재이용 등 복잡한 물이용체계에 따른 영향이 크지만 기존 가뭄시 수문량 평가는 이러한 복잡한 물이용체계를 고려하지 않아 정도 높은 예측에 어려움이 있다. 따라서 가뭄시 유력 내 상세물이용체계 및 수문환경특성 인자들의 상호작용 규명을 통한 정도 높은 수문량 평가 기술의 개발이 시급하다. 대하천 주변 광역상수도 공급지역은 가뭄 발생시에도 안정적으로 물이용이 가능하나, 중소하천을 수원으로 하는 하천의 상류지역은 가뭄시 물공급 안정성이 취약하다. 따라서 중소하천을 대상으로 가뭄시 물 공급시설의 효율적 운영, 물부족 위험도 평가, 가용수자원의 최적이용 등 종합적인 대책 마련을 위해서는 신뢰성 높은 수문량(하천유출량 및 수자원가용량) 예측이 필요하다. 가뭄에 따른 중소하천유역의 수문학적 유출거동을 평가하기 위한 해석 모형으로는 국내의 복잡한 유역 수문환경특성을 평가하기 위해 개발된CAT (Catchment hydrologic cycle Assessment Tool)(김현준 등, 2012)을 이용하였다. CAT은 기후변화나 토지이용변화에 따른 유역의 수문환경특성 변동성을 정량적으로 평가하기 위해 개발된 모형이다. CAT은 인위적인 물이용체계 즉, 광역급수, 용수재이용, 지하수 취수, 하천수 취·배수 등을 분석하기 위한 툴을 제공하므로 가뭄시 상세물이용체계에 따른 시·공간적 수문환경특성 분석 및 수문량 평가를 위한 최적의 모형으로 선정하였다. 본 연구에서는 중소하천유역의 수문량 예측기술 실용화 기반을 마련하기 위하여 낙동강, 금강, 영산/섬진강 중권역을 대상으로 정밀 시공간 수문량을 평가하였다. 각 권역별 보정지점을 기준으로 관측유량 자료와 모의자료의 1:1비교를 통해 수문량 예측정확도를 산정하였으며, 모형효율(Nash Sutcliffe Efficiency, NSE) 및 결정계수(Coefficient of Determination, R²)의 권역별 평균은 NSE 72%, R2 79%로 나타났으며, 대부분의 지점에서 70% 이상을 나타내어 환경부 및 지자체의 가뭄시 물관리 정책을 지원하기 위한 실용화 기반을 마련하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.6
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• pp.517-524
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• 2014

The ultimate goal of seismic design is to reduce the probable losses or damages occurred during an expected earthquake event. To achieve this goal, this study represents a procedure that can estimate annual loss probability of a structure damaged by strong ground motion. First of all, probabilistic seismic performance assessment should be performed using seismic fragility analyses that are presented by a cumulative distribution function of the probability in each exceedance structural damage state. A seismic hazard curve is then derived from an annual frequency of exccedance per each ground motion intensity. An annual loss probability function is combined with seismic fragility analysis results and seismic hazard curves. In this paper, annual loss probabilities are estimated by the structural fragility curve of steel moment-resisting frames(SMRFs) in San Francisco Bay, USA, and are compared with loss estimation results obtained from the HAZUS methodology. It is investigated from the comparison that seismic losses of the SMRFs calculated from the HAZUS method are conservatively estimated. The procedure presented in this study could be effectively used for future studies related with structural seismic performance assessment and annual loss probability estimation.

• Journal of Korea Water Resources Association
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• v.52 no.6
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• pp.429-440
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• 2019

The numbers of multi-year droughts due to climate change are increasing worldwide. Boryeong Dam, located in Chungcheongnam-do, South Korea, was also affected by a 4-year drought from 2014 to 2017. Since traditional unilateral decision making processes to alleviate drought damage have, until now, resulted in conflicts between many of the involved groups, the need for active participation from both stakeholders and policymakers is greater than before. This study introduced Shared Vision Planning, a collaborative decision making process that involves participation from various groups of stakeholders, by organizing Water Policy Council for Climate Change Adaptation in Chungcheongnam-do. A Shared Vision Planning Model was then developed with a system dynamics software by working together with relevant stakeholders to actively reflect their requests through three council meetings. Multiple simulations that included various future climate change scenarios were conducted, and future drought vulnerability analysis results of Boryeong Dam and districts, in terms of frequency, length, and magnitude, were arrived at. It was concluded that Boryeong Dam was more vulnerable to future droughts than the eight districts. While the total water deficit in the eight districts was not so significant, their water deficit in terms of spatial discordance was proved to be more problematic. In the future, possible alternatives to the model will be implemented so that stakeholders can use it to agree on a policy for possible conflict resolutions.

• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.368-372
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• 2008

This study evaluates the usefulness and capability of surface electrical resistivity technique for identifying the weak zones or subsurface cavities in karst area with limestone formation. Weak zones or cavities near surface can be potentially dangerous and several problems are associated with collapse of roads or buildings accompanied by subsidence phenomena. In this paper, both two and three dimensional resistivity investigation were conducted to investigate subsidence along a road in Yongweol-ri, Muan-gun, South Korea. The results of the resistivity survey using dipole-dipole array provide a clear view of the weathered regolith, the distribution of weak zones or cavities and bedrock. Several low resistivity areas were identified and subsequent drilling led to the discovery of several weak zone or clay-filled underground cavities. The drilling results show excellent correlation with the resistivity images. It is illustrated, the ability of electrical technique to produce high resolution images of subsurface, which are useful for subsidence assessment. Also the results of this study have demonstrated that two and three dimensional electrical resistivity surveys are useful for delineating the subsidence area. Based on resistivity imaging, the map of hazardous zone has been developed.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.411-418
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• 2007

It is a very difficult thing to estimate an occurrence possibility location and hazard expectation area by landslide. The prediction difficulty of landslide occurrence has relativity in factor of various geological physical factors and contributions. However, estimation of landslide occurrence possibility and classification of hazard area became available correlation mechanism through analysis of landslide occurrence through landslide data analysis and statistical analysis. This study analyzed a damage possibility of a cultual heritage area due to landslide occurrence by a heavy rainfall. We make a landslide prediction map and tried to analysis of landslide occurrence possibility for the cultural heritage site. The study area chooses a temple of Silsang-Sa Baekjang-Am site and made a landslide prediction map. In landslide prediction map, landslide hazard possibility area expressed by occurrence probability and divided by each of probability degrees. This degree used to evaluate occurrence possibility for existence and nonexistence of landslide in the study site. For the prediction and evaluation of landslide hazard for the cultural heritage site, investigation and analysis technique which is introduced in this study may contribute an efficient management and investigation in the cultural heritage site, Korea.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.155-162
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• 2020

Purpose: The purpose of study was to identify problems in disaster recovery resource management and operation through on-site investigation and utilize them as improvement proposal for disaster recovery resources management by local governments. Method: Areas with high natural and social disasters recorded in historical and yearly records of natural and social disasters, related books, and annual reports for 20 years were selected. The DRSS data of the selected local governments were analyzed and the reserve warehouse were selected for field survey. Result: It is analyzed that the current situation in the city hall and district offices is somewhat insufficient due to heavy work by the working-level officials of local governments on the storage of disaster recovery resources. The actual amount of stockpiles and DRSS data are somewhat different or missing because the input method and criteria are not clear at present when inputting the current data. Conclusion: To improve the management of the disaster recovery resource reserve, it is deemed that education of DRSS and training of best practices for the operation of disaster management resources are urgently needed, and that a systematic management of stockpiles using disaster prevention experts will be required.

• Journal of Korea Water Resources Association
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• v.55 no.3
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• pp.205-215
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• 2022

Amidst the global climate crisis, dam operation policies formulated under the stationary climate assumption could lead to unsatisfactory water management. In this work, we assessed status-quo performance of the Yongdam Dam in Korea under various climatic stresses in flood risk reduction and water supply reliability for 2021-2040. To this end, we employed a decision-centric framework equipped with a stochastic weather generator, a conceptual streamflow model, and a machine-learning reservoir operation rule. By imposing 294 climate perturbations to dam release simulations, we found that the current operation rule of the Yongdam dam could redundantly secure water storage, while inefficiently enhancing the supply reliability. On the other hand, flood risks were likely to increase substantially due to rising mean and variability of daily precipitation. Here, we argue that the current operation rules of the Yongdam Dam seem to be overly focused on securing water storage, and thus need to be adjusted to efficiently improve supply reliability and reduce flood risks in downstream areas.

• Journal of Korea Water Resources Association
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• v.40 no.3
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• pp.223-236
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• 2007

Recently in urban area flood damages increase due to local concentrated heavy rainfall. Even in the cities where stormwater drainage systems are relatively well established flood damage still occurs because of the capacity limitations of the existing stormwater drainage systems. When the flood exceeds the capacity limitation of the urban storm sewer system, it yields huge property losses of public facilities involving roadway inundation to paralyze industrial and transportation system of the city. To prevent such flood damages in urban area, it is necessary to develop adequate inundation analysis model which can consider complicated geometry of urban area and artificial drainage system simultaneously. The Dual-Drainage model used in this study is the urban inundation analysis model which combines SWMM with DEM based 2-dimensional surface flood inundation model. In this study, the dual drainage model has been modified to consider the effect of complex buildings in urban area. Through the simulation of time variable inundation process, it is possible to identify inundation alert locations as well as to establish emergency action plan for the residencial area vulnerable to flood inundation.