• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.266-271
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• 2004

지리적으로 이격된 마산과 서부산 지역의 불국사 화강암 분포지에서 정량적인 풍화도를 판별하기 위해 화학적 풍화지수와 등급을 산정하였다. 연구를 위해 채취된 시료에 대해 풍화 생성광물 동정, 전암분석, 산침수에 의한 이온용출 시험을 실시하였으며, 풍화지수와 지형적인 요소와 풍화속도를 고려하여 풍화등급들 산정하였다. 분석 결과 동일한 물리적, 광물학적 특성을 가지고 있으나 풍화에 따라 생성되는 점토광물의 종류와 함량에서 차이를 보여주며, 풍화의 진행 경로과 범위는 매우 상이한 결과를 보여 준다. 이러한 결과는 암석의 풍화가 모암의 조건 외에 지형, 지질구조, 기온, 강수량과 같은 환경적인 요소에 밀접하게 관련되어 있는 것을 의미할 뿐만 아니라 풍화도 산정에서 환경적인 요소에 대한 해석이 반드시 요구된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.307-318
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• 2015

In this study, the efficiency of two-dimensional inundation analysis using road network was demonstrated in order to reduce the simulation time of numerical model in urban area. For this objective, three simulation conditions were set up: Case 1 considered only inundation within road zone, while Case 2 and 3 considered inundation within road and building zone together. Accordingly, Case 1 used grids generated based on road network, while Case 2 and 3 used uniform and non-uniform grids for whole study area, respectively. Three simulation conditions were applied to Samsung drainage where flood damage occurred due to storm event on Sep. 21, 2010. The efficiency of suggested method in this study was verified by comparison the accuracy and simulation time of Case 1 and those of Case 2 and 3. The results presented that the simulation time was fast in the order of Case 1, 2 and 3, and the fit of inundation area between each case was more than 85% within road zone. Additionally, inundation area of building zone estimated from inundation rating index gave a similar agreement under each case. As a result, it is helpful for study on real-time inundation forecast warning to use a proposed method based on road network and inundation rating index for building zone.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.120-120
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• 2019

국내에서는 예측 불가능한 재난으로 인한 침수 피해 발생사례가 증가하였다. 따라서 침수 피해 예측이 더욱 중요해지고 있는 실정이다. 기존에는 주로 수치모형을 통한 침수예측을 하였고, 정보통신기술도 발달해왔지만 아직까지 수치모의에 많은 시간이 소요되기 때문에 침수 피해의 실시간 예측이 힘든 상황이다. 이에 국립재난안전연구원(2017)에서 침수예측을 위한 보간 모델인 SIND(Scientific Interpolation for Natural Disaster) Model을 개발하였다. 이는 보간을 이용한 모델이기 때문에 그동안 사용해왔던 물리 모형보다 간단하다. 그러나 정확한 값이 아닌 보간을 이용한 모델이기 때문에 정확도를 검토할 필요가 있다. 따라서 본 연구에서는 Mapping분야에서 사용하는 CRITIC(CRiteria Importance Through Intercriteria Correlation) 기법을 활용하여 지도의 정확도 검토를 수행하였다. CRITIC은 형상기준, 위치기준, 면적기준을 이용하여 형상유사도를 산정하는 방법이며, 이 기법을 활용하여 국가가 제공한 침수예상도(국립해양조사원, 2010)와 SIND모델 결과 지도를 비교하였다. 형상기준은 지도의 형상을 나타내는 형상지수를 비교하고, 위치기준은 지도의 무게중심의 일치정도, 면적기준은 형상 면적을 비교하는 것이다. 지도는 총 300여개의 매칭 객체 쌍을 가지고 수행하였고, 위험도 등급은 Grade 1부터 Grade 5 까지 분류하여 나타내었다. 연구 대상지역은 ${{\bigcirc}{\bigcirc}}$시이다. 그 결과, 형상유사도는 약 200여개의 매체쌍이 0.80 이상의 값을 나타냈고, 나머지 매체 쌍은 0.75이하의 값을 나타내었다. 위험도 등급이 낮을수록 형상유사도 값은 크게 나타나고, 위험도 등급이 높을수록 형상유사도 값이 작게 나타나는 경향을 보였다. 이는 위험도 등급이 높은 곳의 경우, 해안선의 복잡한 지형형태 때문으로 판단된다. Mapping 분야에서 형상유사도 적합성 기준이 0.75이므로 결과는 60%이상이 정확하다고 판단할 수 있다. 따라서 본 연구에서 검토를 수행했던 간단한 방정식을 이용한 SIND 모델은 정확하다고 판단할 수 있다. 다만, 복잡한 지형과 현재 고려되고 있는 영향인자 외에 다양한 구조물 등을 고려한다면 형상유사도가 향상될 것이라 기대된다.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.83-90
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• 2023

Due to climate change, the occurrence of abnormal rainfall is increasing, and the intensity and scale of damage caused by heavy rain are increasing every year. In addition, as the frequency of heavy rains becomes more frequent, heavy rains often occur continuously, resulting in large flooding damage that has never been seen before in urban area. When near rivers and coastal areas are impermeable areas, the maximum flow increases rapidly as the rainfall intensity increases, so a comprehensive flood risk evaluation is needed considering the characteristics of the basin. In this study, the flood inundation risk evaluation was analyzed by giving scores on evaluation factors as a measure to prevent inundation in subway stations. Through the flood inundation risk evaluation process considering the comprehensive evaluation index, the flood risk evaluation was conducted on five urban railway stations with a large amount of traffic and floating population that had been inundated in the past. It is judged that by comprehensively analyzing this and establishing a inundation risk grade (grade 1 to 4) to establish a flood measure suitable for the risk grade.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.85-97
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• 2022

In this study, a method for an integrated flood risk mapping was proposed that simultaneously considers the flood inundation map indicating the degree of risk and the disaster vulnerability index. This method creates a new disaster map that can be used in actual situations by providing various and specific information on a single map. In order to consider the human, social and economic factors in the disaster map, the study area was divided into exposure, vulnerability, responsiveness, and recovery factors. Then, 7 indicators for each factor were extracted using the GIS tool. The data extracted by each indicator was classified into grades 1 to 5, and the data was selected as a disaster vulnerability index and used for integrated risk mapping by factor. The risk map for each factor, which overlaps the flood inundatoin map and the disaster vulnerability index factor, was used to establish an evacuation plan by considering regional conditions including population, assets, and buildings. In addition, an integrated risk analysis method that considers risks while converting to a single vulnerability through standardization of the disaster vulnerability index was proposed. This is expected to contribute to the establishment of preparedness, response and recovery plans for providing detailed and diverse information that simultaneously considers the flood risk including social, humanistic, and economic factors.

• Geotechnical Engineering
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• v.9 no.3
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• pp.5-22
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• 1993

A series of laboratory tests (physical and mechanical index and engineering design) were conducted on undisturbed granite soils of CW and RS weathering grades in Korea. From these testes it can be concluded that most of physical and mechanical index values are very sensitive to change in weathering grade from CW to RS. Engineering design tests indicate that the unconfined compressive strength and the shear strength parameters are significantly reduced and that the soil becomes ductile and plastic with increasing weathering and saturation. It was found that weathered granite soils have the special characteristics when water saturated: (i) they significantly lose their shear strength(especially cohesion) and unconfined compressive strength, (ii) they are fragile and their grains break down in water as observed in grain size analysis.

• Journal of the Korean housing association
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• v.23 no.5
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• pp.1-8
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• 2012

Recently, there have been frequent occurrence of the damage to lives and properties due to the torrential rain caused by climate change. In consideration of the current situations in which the underlying data related to flooding are lacking, this study conducted to build up the basic data on the flooded areas and suggested methods to secure the evacuation routes that can be accessible to evacuation facilities in the residential buildings. Methods of the study are as follows. First, We calculated the flood risk grades of residential buildings based on elevations, considering the flooding characteristics of the flooded areas in Buk-gu, Daegu. Second, We constructed baseline data on the evacuation routes through site investigation and reviewed of drawing using Arc GIS to identify vulnerability to access to the evacuation facilities, targeting the residential buildings. Third, We carried out the proximity analysis through a near analysis of analysis functions in ARC GIS. Forth, We deduced 115 residential buildings in which access to evacuation facilities is considered to be difficult based on the analysis results. Finally, We proposed extension of a blind alley as a means for achieving connectivity to evacuation facilities. And to evaluate the alternatives presented, we reconstructed route data. As a result, about 53% improvement was identified through the proximity analysis.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.370-370
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• 2017

최근 기후변화와 이상기후의 영향으로 인하여 홍수재해의 시 공간적 패턴은 보다 복잡해지고, 예측이 어려워지고 있다. 이러한 기상이변에 따른 홍수피해를 예방하기 위한 비구조적 대책으로 홍수위험등급 및 범람범위 등의 정보를 포함하고 있는 홍수위험지도의 작성이 필요하다. 실제로 고정밀도 홍수위험지도를 작성하기 위해서는 지형, 지질, 기상 등의 디지털 정보 및 사회 경제와 관련된 다양한 DB를 필요로 하며, 강우-유출-범람해석 모델링을 통해 범람면적 및 침수깊이 등의 정보를 획득하게 된다. 하지만 일부지역, 특히 개발도상국에서는 이러한 계측 홍수 데이터가 부족하거나 획득할 수가 없어 홍수위험지도 제작이 불가능하거나 그 정확도가 매우 낮은 실정이다. 따라서 본 연구에서는 ASTER 또는 SRTM과 같은 범용 DEM 등 지형자료만을 기반으로 한 선형이진분류법(Liner binary classifiers)과 ROC분석(Receiver Operation Characteristics)을 이용하여 미계측 유역 (DB부재 또는 부족으로 강우-유출-범람해석 모델링이 불가능한 북한지역)의 홍수위험지역을 탐지하고, 적용성을 평가하고자 한다. 5개의 단일 지형학적 지수와 6개의 복합 지형학적 지수를 이용하여 Area Under the Curve (AUC)를 계산하고, Sensitivity (민감도)와 Specificity (특이도)가 가장 높은 지수를 선별하여 홍수위험지도를 작성하고, 실제 홍수범람 영상(2007년 북한 함경남도지역 용흥강 홍수)과 비교 분석하였다. 본 연구에서 제시하는 선형이진분류법과 ROC분석 방법은 홍수범람해석을 위한 다양한 기초정보를 필요로 하지 않고, 지형정보만을 사용하기 때문에 관측 데이터가 없거나 부족한 지역에 대해서 우선적으로 홍수위험지역을 탐지하고, 선별하는데 유용할 것으로 판단된다.

• Journal of the Korean GEO-environmental Society
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• v.23 no.3
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• pp.15-22
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• 2022

This study aims to observe the swelling representative rocks in Korea and to suggest improvements in the use of test methods and prior analysis in relation to the weathering of rocks. The swelling test and analysis were performed on the drilling cores obtained for the ground investigation at the domestic highway construction site. For the method of determining the absorption expansion index of rocks, the method proposed in "Standard Methods for Sample Collection and Specimen Preparation" of ISRM and Korean Rock Engineers Standard Rock Test Method was used. The specimen for the measurement of the expansion displacement was cylindrical with a height of 10 cm and a diameter of 5 cm. The existing swelling analysis method evaluates the sensitivity to weathering by using the maximum expansion displacement, but since the classification by bedrock grade is unclear, it is reasonable to use the rate of change of the expansion displacement according to the immersion time. It is necessary to conduct an experiment to distinguish between weathering and fault deterioration. In addition, long-term weathering prediction technology for each cancer type is needed through the expansion displacement analysis of the chemical weathering stage.