• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.51-59
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• 2021

In Korea, where 64% of the soil is mountainous, typhoons and local rains concentrated in the summer season are frequent in mountainous disasters such as landslides and debris flow. The area of study was the area where the damage to the debris flow was caused by typhoon Mitag in October 2019, and all the houses located in the downstream area were damaged. In this study, numerical simulations were conducted on the area where the damage of earth and stone flow occurred using Hyper KANAKO model that can consider erosion and sedimentation, and the applicability of the model was examined by comparing the actual damage area and the analysis results of the model. As a result of the numerical simulation, the damage area of the debris flow in the target area was 53,875 m², the maximum flow depth was 2.4 m, and the average flow depth was 1.7 m.

• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.29-38
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• 2010

Oegogae wetland is sub-alpine wetland which is formed in piedmont area in Jirisan National Park. Apparently Oegogae wetland seems to be well-protected wetland. Most alpine wetlands are located in the summit area, but Oegogae wetland is located in piedmont area which is transitional zone between the steep slope and relatively flat valley bottom. Oegogae wetland is active in terms of sedimentation and exceeds 1m in depth. Penetration tests show that composing material is soft such as peat and organic-rich sediment. Basal rock of the basin is gneiss and gneissic schist in general, which is good for the formation of wetland because those rocks are easy to form low permeability layer. Baseflow from the wetland takes control of the most of stream flow during the wet season and this is especially true during the dry season. Precipitation during the wet season increases water content and base flow from the wetland.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.182-182
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• 2020

최근 지구 온난화나 기상이변으로 인해 세계각지에서 많은 자연재해가 발생하고 있고 우리나라도 최근 전국 각지에서 국지성호우에 의한 많은 피해가 발생하고 있다. 특히 국지성호우로 인해 발생하는 산간지역의 토석류는 많은 재산피해를 일으키고 있다. 최근 토석, 토사, 혹은 부유 잡목 등의 유출로 인한 피해를 막기 위해 많은 사방댐을 축조하고 있으나 표면침식에 의해서 유출되는 토석량 혹은 토사량을 정확히 예측하지 못한다면 축조된 사방댐은 금방 제구실을 못할 수 있거나 혹은 과대 설계 및 시공되어 건설비를 낭비할 수 있다. 따라서 최적의 사방댐 건설을 위해 정확한 토석량의 산정은 매우 중요한 전제조건이라 할 수 있다. 본 연구에서는 강원도 인제군 산간지역 4곳의 사방댐유역에 대해 토석량 예측모형 MSDPM(Multi-Sequence Debris Prediction Model)과 LADMP(Los Angeles District Method for Prediction of sediments yield)를 이용하여 산정한 토석량과 실제 준설량을 비교하였다. 이를 위해 강원 산간지역에 맞도록 예측모형을 보정하였으며 토석류 유발 강우강도(Threshold Maximum 1-hr Rainfall Intensity)와 토석류 유발 최소강우량(Total Minimum Rainfall Amount)개념을 도입하여 예측모형식을 적용하였다. 위 식이 갖고 있는 대표적 특징 중 하나인 산불계수를 사용해야 하지만 본 연구지역은 산불 피해규모가 미미하여 산불의 영향은 고려하지 않고 토석량을 산정하였다. 두 예측모형의 계산결과와 실제 준설량을 비교해본 결과, MSDPM의 결과가 LADMP의 결과보다 준설량과 더 일치하는 것으로 나타났다. 실제 준설량과 MSDPM의 계산결과는 평균 17.37%의 차이를 나타냈고 LADMP의 계산결과는 평균 41.87%의 차이를 나타냈다. 본 연구에서 사용된 토석량 예측 모형은 앞으로 많은 산지유역의 토석량 예측에 사용이 가능 할 것으로 판단된다. 하지만 본 연구에서 사용된 자료의 제한성 때문에 앞으로 많은 실측 준설자료를 통하여 예측모형식을 보정하는 작업이 우선되어야 할 것으로 판단된다. 이를 위해서 많은 산지유역의 토석량을 장시간 실측하여 데이터를 축적하고 이를 사용하여 다양한 토석량 예측모형을 검보정하는 노력이 필요할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.249-249
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• 2022

국외에서 산지재해를 예방하기 위해 하천 유사량을 계측하는 기존의 재래식 채집기의 문제점을 보완한 간접계측장치인 하이드로폰의 개발 및 실용화를 위한 연구를 수행하고 있다. 하지만 국내의 경우 유사량을 계측하는 기술 수준은 선진국에 비해 기초단계에 머물러 있다. 이러한 문제를 해결하기 위해 국내에서 사용하기 적합한 간접계측장치를 개발하고자 한다. 간접계측장치인 하이드로폰은 횡단구조물의 끝단에 부착하여 설치하는 형태로 개발하였다. 충돌음향 계측을 위한 센서부는 파이프와 마이크로폰으로 구성하였으며, 구조물에 부착하기 위한 고정프레임과 연결장치로 제작되었다. 설치된 계측장치는 하상에서 이동중인 토사가 파이프에 충돌할 때 발생하는 소음을 계측하며 충돌음은 데이터로거로 취득된다. 계측된 음향 데이터는 정확한 소류사량 추정을 위해 충돌 횟수에 착안한 펄스 분석 방법과 진폭의 시간 적분치에 착안한 음압적분치 방법으로 비교·검토를 수행하였다. 소류사량 추정 관계식의 유의성 분석을 수행한 후 펄스 수 기반 추정 관계식과 음압적분치 기반 추정 관계식을 공급 소류사량과 비교시 각각 29%와 33%의 오차율을 나타내는 것을 확인할 수 있었다. 앞서 선정된 소류사량 추정 관계식의 신뢰성을 확보하기 위해 관계식으로 추정할 수 있는 예측구간 및 95% 신뢰구간을 분석하였으며, 분석 결과 펄스 수 기반 추정 관계식은 92.5%, 음압적분치 기반 추정 관계식은 90.9%로 두 관계식 모두 소류사량을 추정하기에 양호한 수준으로 일치하는 것을 확인할 수 있었다. 향후 추가적인 연구를 수행한다면 수문조사 시 부족했던 유사량 측정분야의 확대에 기여할 수 있을 것으로 예상되며, 이와 관련된 사업 및 기술발전에도 기여할 것으로 기대된다.

• Journal of the Korean GEO-environmental Society
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• v.22 no.8
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• pp.5-12
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• 2021

Climate change caused by global warming increases the frequency of occurrence of super typhoons and causes various types of sediment disasters such as debris flows in the mountainous area. This study is to evaluate the behavior of debris flow according to the multiplier value of the precipitation characteristics and the quantity of debris flow according to the typhoon category. For the analysis of the debris flow, the finite difference method for time elapse was applied. The larger the typhoon category, the higher the peak value of the flow discharge of debris flow and the faster the arrival time. When the precipitation characteristic multiplier is large, the fluctuation amplitude is high and the bandwidth is wide. When the slope angle was steeper, water discharge increased by 2~2.5 times or more, and the fluctuation of the flow discharge of debris flow increased. All of the velocities of debris flow were included to the class of "Very rapid", and the distribution of the erosion or sedimentation velocity of debris flows showed that the magnitude of erosion increased from the beginning, large-scale erosion occurred, and flowed downstream. The results of this study will provide information for predicting debris flow disasters, structural countermeasures and establishing countermeasures for reinforcing resilience in vulnerable areas.

• Journal of the Korean Geographical Society
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• v.47 no.4
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• pp.474-489
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• 2012

Last review papers on Korean geomorphology and physical geography had been published in 1997 and 2000 respectively. A proposal to publish a book on Korean geomorphologists' achievement resulted in series of review papers in Journal of the Korean Geomorphological Association. This article aims to summarize these papers and introduce their findings to foreign scholars. On remarkable achievement is a fierce debate on the effectiveness of traditional mountain concept to explain the shape of Korean peninsula, which made the public's understanding of geomorphology widen to the general public. Reflecting public demands, concerns for the effects of coastal facilities on coastal erosion and conservation mind and scientific researches for the coastal sand dunes have increased so much. Geomorphological hazards such as debris flow attracted many concerned scientists, and geotourism-related papers in scientific journals increased thanks to the designation of first geopark in Korea. Research papers submitted to the famous foreign academic journals are increasing in numbers these days.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.77-83
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• 2008

In this study, land cover classification and NDVI evaluation for hazard mitigation precaution are carried out in surrounding areas of Yeongi-gun, Chungcheongnam-do ($132\;km^2$) where a project for multi-functional administrative city is promoted by government. Image acquired from KOMPSAT 2, LANDSAT and ASTER is utilized and comparative evaluation on limitation in classification based on resolution was carried out. The area mainly consists of arable land including mountains, rice fields, ordinary fields, etc thus special attention was paid to the classification of rice fields and ordinary fields. For the classification of image acquired from KOMPSAT 2, segmentation technique for classification of high-resolution image was applied. To evaluate the accuracy of the classification, field investigation was conducted to examine the sample and it was compared with the land usage and classification of land category in land ledger of Korea. Acquired results were made into theme map in shape file format and it would be of great help in decision making of policy for the future-oriented development plan of multi-functional administrative city.

• Journal of Korean Society of societal Security
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• v.2 no.2
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• pp.85-90
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• 2009

In recent days, climatic change cause abnormal weather all over the world and we have a great loss of life and property every year. In Korea, we suffer from landslide problem because large regions of Korea Peninsula are composed of mountain. In order to detect rapidly and to take follow-up measures of disaster, the remote sensing is being used actively as conventional field survey has many restrictions in accessibility because of more time and man power requirement. In additions interferometric SAR is one of the techniques that have our attention because it can provide many kinds of accurate surface information without restriction of atmospheric and ground conditions by using L-band. In this study, we aimed to monitor the displacement of mountain area in Kangwondo and this results will be used for detecting landslide. Also we build the web system for detecting and analyzing the landslide.

• Journal of the Korean Geographical Society
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• v.45 no.1
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• pp.75-94
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• 2010

'Green growth' is the development strategy for the sustainable society through the harmony between the environment and economy. The 'green growth' was defined and accepted by UNESCAP and countries in Asia-Pacific region. OECD also accepted it as their new development policy. 'Green New Deal' was also proposed as a new social/economic policy to response three global crisis: environmental, resources and economic. Social and environmental sustainability are the most important principles of this policy. In Korea, however, the 'green growth' is redefined and used by the government and politicians as an economic policy to support the new technology on energy efficiency and renewable energy. In here, the definitions of green growth in the world and in Korea are analysed and compared, and new term is proposed. Green growth is the development policy to response environmental crisis (ie. climate changes) to transform the society to environmentally and socially sustainable one. The possible contribution of geomorphologic researches to green growth was also proposed.

• Journal of the Korean GEO-environmental Society
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• v.11 no.8
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• pp.15-23
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• 2010

Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. Large rainfall in July 2006 produced several large scale debris flows and many small debris flows that resulted in loss of life and considerable property and railway damage, as was widely reported in the national media. The hazard "debris flow" is still insufficiently researched. Furthermore debris flows are very hard to predict. Flexible Ring net barriers are multi-functional mitigation devices commonly applied to rock fall or floating wood protection in floods, snow avalanches and also mud flows or granular debris flows, if properly dimensioned for the process or processes for which they are intended. Overtopping of the barriers by debris flows and sediment transport is possible, supporting the design concept that a series of barriers may be used to stop volumes of debris larger than are possible using only one barrier. The future for these barrier concepts looks promising because these barriers represent the state of art for such applications and are superior to many other available options.