• Journal of the Korean Geotechnical Society
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• v.30 no.12
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• pp.5-14
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• 2014

Most of slope failures have taken place between June and September in Korea, which cause a considerable damage to society. Rainfall intensity and duration are very significant triggering factors for landslide. In this paper, landslide-triggering rainfall threshold consisting of rainfall intensity-duration (I-D) was proposed. For this study, total 255 landslides were collected in landslide inventory during 1999 to 2012 from NDMI (National Disaster Management Institute), various reports, newspapers and field survey. And most of the required rainfall data were collected from KMA (Korea Meteorological Administration). The collected landslides were classified into three categories: debris flow, shallow landslide and unconfirmed. A rainfall threshold was proposed based on landslide type using statistical method such as quantile-regression method. Its validation was carried out based on 2013 landslide database. The proposed rainfall threshold was also compared with previous rainfall thresholds. The proposed landslide-triggering rainfall thresholds could be used in landslide early warning system in Korea.

• Journal of the Korean GEO-environmental Society
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• v.16 no.7
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• pp.43-53
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• 2015

More than 70 percent of the Korean territory consists of mountain area so development of mountain district is essential to urbanize continuously. Thus, technological developments for risk factors and standards and manuals must be needed to prevent mountain disaster. Risk Management Manual should be made and operated in government legislation related to national disaster, but there is still no Emergency Management Standard Manual and Emergency Response-Practical Manual to prevent mountain disaster. This study suggests the improvement plans that are legislated but not established cleary in the field of disaster in urban area. The main items are like as 1) adaptable standard and practical manual to prevent mountain disaster in urban area, 2) reinforcement between managing department and interagency vertically and horizontally in central and local government organization, 3) Personal SOP (Standard Operating Procedure) not EOP (Emergency Operation Plan), 4) considering 13 items selected by Ministry of Public Safety and Security, 5) schematization with personal action plan, 6) check list to do in the event of mountain disaster, and 7) regular practice per quarter.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.1-8
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• 2018

Extreme climate phenomena are occurring around the world caused by global climate change. The heavy rains exceeds the previous record of highest rainfall. In particular, as flash floods generate heavy rainfall on the mountains over a relatively a short period of time, the likelihood of landslides increases. Gangwon region is especially suffered by landslide damages, because the most of the part is mountainous, steep, and having shallow soil. Therefore, in this study, is to predict the risk of disasters by applying topographic classification techniques and landslide risk prediction techniques to mountain watersheds. Classify the hazardous area by calculating the topographic position index (TPI) as a topographic classification technique. The SINMAP method, one of the earth rock predictors, was used to predict possible areas of a landslide. Using the SINMAP method, we predicted the area where the mountainous disaster can occur. As a result, the topographic classification technique classified more than 63% of the total watershed into open slope and upper slope. In the SINMAP analysis, about 58% of the total watershed was analyzed as a hazard area. Due to recent developments, measures to reduce mountain disasters are urgently needed. Stability measures should be established for hazard zone.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.277-277
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• 2022

급경사 산지하천은 호우 시 퇴적 하상이 붕괴하여 하천 유사량을 급격히 증가시키는 계곡형 토석류가 발생하고 도로와 교량에 피해를 일으키기도 한다. 이러한 하천재해를 저감하기 위하여 돌망태 낙차공을 설치하여 하상 안정을 강화하고 급경사에 따른 유수에너지를 줄일 수 있다. 급경사 하상에 설치한 돌망태 낙차공은 하류부 하상의 국부세굴에 따른 파괴위험이 완경사 하상의 경우에 비하여 높으므로 이를 줄이기 위한 연구가 필요하다. 이 연구에서는 광폭경사조절 개수로에 돌망태 낙차공을 설치하고 낙차공의 채움재가 복류의 특성에 미치는 영향을 파악하기 위하여 수리실험을 하였다. 수리실험에서는 최대 20º까지 경사를 조절할 수 있는 길이 1.44m, 폭 0.14m인 직사각형 단면 개수로에 SUS304 구슬을 사용하여 하상과 돌망태 낙차공을 설치하고 실험하였다. 구슬은 크기에 따라 작은구슬(10.31mm), 중간구슬(15.08mm), 큰구슬(20.63mm)을 사용하고, 하상에는 작은구슬을 깔았다. 낙차공의 크기는 길이 16cm이고 폭과 높이는 12cm이며, 돌망태는 작은구슬을 사용한 단일돌망태와 구슬 크기를 달리한 계층돌망태로 구분하였다. 계층돌망태의 상층은 작은구슬, 중층은 중간구슬, 하층은 큰구슬이 채움재로 사용되었다. 단일돌망태의 공극율은 0.399이고 계층돌망태의 공극률은 상층 0.393, 중층 0.517, 하층 0.54이다. 실험유량의 변화는 낙차공 하단부에서 표면류가 발생하지 않는 범위로 한정하였다. 낙차공 하단에서 상류 68cm 지점의 소류력과 낙차공 내부 복류의 수면경사를 측정하였다. 그 결과 단일돌망태보다 계층돌망태가 소류력과 수면경사가 더 작은 것으로 나타났으며 돌망태의 공극을 통한 통수능 차이 때문인 것으로 판단된다.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.4
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• pp.52-64
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• 2010

This study was carried out to analyze the occurrence characteristics and the influence of forest environment factors on the debris flow of 3 national parks in korea. The results obtained from this study were summarized as follows; The total number of debris flow occurrence was 125 areas. The average length of the debris flow scar was 144m, average width was 20m. And the average area and sediment were $2,854m^2$ and $3,959m^3$ respectively. The factors influencing the debris flow were highly occurred in Metamorphic rock, mixed forest type. And also, slope gradient was $30{\sim}35^{\circ}$, aspect was NE, altitude was over 1,000m, vertical and cross slope was concave (凹), soil depth was below 15cm, stream order was 0 order. The variables of cross slope (complex), deciduous tree, soil depth (over 46cm), cross slope (concave), mixed forest type and altitude (801~1200m) in correlation analysis were significant at 1 % level. The landslide of high mountain area highly tend to change the debris flow in stream bed of torrent. The debris flow in national parks mainly occurred in high mountain area with long ridge and steep slope.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1366-1375
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• 2010

The damage by Debrisflow is occurring repeatedly recently by influences of abnormal climate changes. To reduce damage of Debris flow, primarily establishes the suitable measures and apply, in order to do that it is important for investigate the actual condition of Debrisflow. However, it is difficult to understand the current situation of Debrisflow phenomenon because the limit of technical development. For the reduce damage by future Debrisflow, have to collect data, analysis and preservation base on real status of Debrisflow disasters. This paper will refer to The Proposal of Debrisflow Investigation development have been applied overseas to the The Proposal of Debrisflow Investigation which already proposed it at these papers with bases. And this paper will suggest currently face objective The Proposal of Debrisflow Investigation to be able to do utilization to a Debrisflow occurrence situation and state and further study analysis(2).

• Journal of Industrial Technology
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• v.29 no.A
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• pp.9-17
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• 2009

The main purpose of this work is to analyse damages caused by debris flows during the heavy rainfall at Inje province in Kangwondo, Korea. A series of site investigations have been performed to survey the characteristics of debris flows occurred during the summer season of 2006. It has been found that major losses and costs are triggered by discharge of soil and rock fragments from landslides. During the rainfall unexpectedly high precipitation rate of 113.5mm/hour and 355mm/day was recorded, which could happen at a 80-500 year period. Comparing the period of the rainfall with the time of the landslides, it has been found that the occurrence of the landslides is directly related to heavy rainfalls. At present, several debris barriers have been built at the valleys and natural slopes have been protected by the seed spray method. It is intended to propose an appropriate solutions of restoration of landslide damages and maintenance based on findings from the current study.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.253-253
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• 2016

여러 정부부처 및 지자체에서 도시지역 홍수 피해 및 비점오염원 저감 방안의 해법으로 LID 시설의 설치를 권장하고 있다. 하지만 LID 기술의 국내 도입 기간이 짧아 우리나라 환경에 맞는 LID 시공을 할 수 있는 업체가 한정적이고 시공경험도 많지 않아 시공 비용에 대한 경제성 분석이 어렵다. 이러한 문제점으로 인해 LID 설치 비용의 과대 인식과 실효성에 대한 불안감이 만연하여 시설 설치에 어려움을 겪고 있다. 이와 관련하여 GI&LID 연구단에서 LID 통합설계모듈 등의 모형 개발 연구가 활발히 진행중이나 이에 앞서 금번 연구에서는 SWMM 모형을 이용하여 분석을 수행하였고, 가시적인 비교가 용이하고 최근 가장 큰 피해를 가져왔던 2014년 홍수 사상을 대상으로 연구를 진행하였다. 본 연구에서는 도시내 급경사면이 많고 불투수면적율이 높아 유속이 빠르고 완경사로 변화되는 구간에 홍수 및 토석류가 집중되어 홍수피해에 취약한 부산시 온천천 유역을 대상으로 LID 시설을 모의 설치 및 시뮬레이션 하고 재해연보 상의 홍수피해 복구액과 비교하였다. 이를 통해 LID 시설 설치시 비용-편익을 분석하고 이점을 제시하여 추후 있을 LID 시공 및 관련 연구에 도움이 되고자 한다.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.419-430
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• 2021

This study investigated spatiotemporal trends of sediment-related disasters in North Korea from 1960 to 2019 and post-disaster recovery cases based on a literature review and satellite images. Results showed that occurrence status of sediment-related disasters was initially externally reported in 1995 (during the Kim Jongil era); their main triggering factor was heavy summer rainfall. Furthermore, forest degradation rate was positively correlated with population density (R² = 0.4347, p = 0.02) and occurrence number of sediment-related disasters was relatively high on the west coast region, where both variables showed high values. This indicates that human activity was a major cause of forest degradation and thus, significantly affected sediment-related disasters in mountain regions. Finally, sediment- related disasters due to shallow landslides, debris flow, and slow-moving landslides were observed in undisturbed forest regions and human-impacted forest regions, including terraced fields, opencast mines, forest roads, and post-wildfire areas, via satellite image analysis. These disaster-hit areas remained mostly abandoned without any recovery works, whereas hillside erosion control work (e.g., treeplanting with terracing) or torrent erosion control work (e.g., check dam, debris flow guide bank) were implemented in certain areas. These findings can provide reference information to expand inter-Korean exchange and cooperation in forest rehabilitation and erosion control works of North Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.583-583
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• 2015

근래 게릴라성 호우, 국지성 호우, 짧은 시간에 걸친 집중 호우 등 예측하기 힘든 강우로 인하여 발생하는 피해를 방지하기 위한 방재 사업의 일환으로 각종 연구가 활발히 진행되고 있다. 그러나 원주천 유역, 설마천 유역 등 집중호우로 인해 산사태로 인한 피해가 빈번히 발생, 서울시를 비롯한 전국 도시의 내 외수로 인한 수해피해도 상습적으로 발생하고 있음에도 불구하고 지역 유형별 특성을 반영한 호우피해 대책은 미비한 실정이다. 수재해 사례별 강우특성을 분석하고 유역별 피해저감 대책을 분석하였다. 도시지역의 경우 내 외수로 인한 침수피해가 주로 발생하였고 하천준설, 제방공사, 관로 용량확장, 펌프장 증설 또는 확장을 하는 방법으로 피해를 복구하였다. 농경지의 경우 침수피해나 유실피해가 큰 편이며 2차적으로 오염피해를 유발한다. 우리나라에서는 논으로부터의 영양물질 유출 부하량에 관한 연구는 이미 수행되었으나, 직접적으로 토사유출을 저감하는 적극적인 방법에 대한 연구는 더 수행되어야 할 필요성이 있다고 사료된다. 산지유역의 경우 토석류, 유목등에 의한 피해가 심각하였으며 지금까지의 복구대책으로는 하천의 준설, 사방댐의 설치, 사방댐을 설치한 후 조림(造林)을 설치하여 유사저감 효과를 증대시키는 방법을 포함하여 링네트공법 등 국외에서 개발된 신기술 등이 적용되었다. 대표적 피해유역 유형은 도시, 농경지, 해안, 산지유역으로 분류할 수 있었으며 각 유역별 피해유형을 정리하였다. 앞으로의 연구에서는 기존의 유역별 피해사례 및 강우규모를 바탕으로 최근 강우특성에 적합한 설계기준을 제시하고 특히 유역특성을 반영한 지역 유형별 홍수피해 저감기법에 대해 연구하고자 한다.