• Journal of Forest and Environmental Science
• /
• 제34권6호
• /
• pp.481-489
• /
• 2018

In this study, the succession and stand dimension attributes related to the disaster prevention function of Pinus thunbergii coastal forests were examined after damage from Diplodia tip blight. In 2015, 101 years after the Taisho eruption, field investigations were performed on the vegetation, soil thickness, and pH of surface soil of P. thunbergii coastal forests in western Sakurajima (Hakamagoshi plot) and Taisho lava flows in southeastern Sakurajima (Seto plot). The Hakamagoshi plot had more woody plant species with larger basal areas than that in the Seto plot. The mean age and height, maximal age and height of plant species, and H/D ratio were all larger in the Hakamagoshi plot than in the Seto plot. These results may be explained by the relatively smaller effect of volcanic ash and gas on forests in the Hakamagoshi plot compared to the Seto plot, resulting in a more suitable environment for many plant species. Although P. thunbergii coastal forests in Sakurajima are currently recovering from damages owing to Diplodia tip blight, there has not yet been a sufficient recovery compared to the results from a 1997 study. Furthermore, the results of assessment based on the H/D ratio and abundance of trees in P. thunbergii forests indicate that both regions are not yet effective in disaster prevention. Thus, it is necessary to establish Pinus trees, which can adjust to harsh environments like coastal areas and are resistant to volcanic ash and gas, to enhance the disaster prevention function of P. thunbergii coastal forests in volcanic regions. It may also be helpful to establish coastal forests with ectotrophic mycorrhizal fungi and organic matter coverage. Additionally, it is necessary to ensure the continuous maintenance of stand density and soil quality, and further develop efforts to prevent Diplodia tip blight and promote forest recovery.

• 국제학술발표논문집
• /
• The 6th International Conference on Construction Engineering and Project Management
• /
• pp.54-55
• /
• 2015

Increase of impervious areas due to expansion of housing area, commercial and business building of urban is resulting in property change of stormwater runoff. Also, rapid urbanization and heavy rain due to climate change lead to urban flood and debris flow damage. In 2010 and 2011, Seoul had experienced shocking flooding damages by heavy rain. All these have led to increased interest in applying LID and decentralized rainwater management as a means of urban hydrologic cycle restoration and Natural Disaster Prevention such as flooding and so on. Urban development is a cause of expansion of impervious area. It reduces infiltration of rain water and may increase runoff volume from storms. Low Impact Development (LID) methods is to mimic the predevelopment site hydrology by using site design techniques that store, infiltrate, evaporate, detain runoff, and reduction flooding. Use of these techniques helps to reduce off-site runoff and ensure adequate groundwater recharge. The contents of this paper include a hydrologic analysis on a site and an evaluation of flooding reduction effect of LID practice facilities planned on the site. The region of this Case study is LID Rainwater Management Demonstration District in A-new town and P-new town, Korea. LID Practice facilities were designed on the area of rainwater management demonstration district in new town. We performed analysis of reduction effect about flood discharge. SWMM5 has been developed as a model to analyze the hydrologic impacts of LID facilities. For this study, we used weather data for around 38 years from January 1973 to August 2014 collected from the new town City Observatory near the district. Using the weather data, we performed continuous simulation of urban runoff in order to analyze impacts on the Stream from the development of the district and the installation of LID facilities. This is a new approach to stormwater management system which is different from existing end-of-pipe type management system. We suggest that LID should be discussed as a efficient method of urban disasters and climate change control in future land use, sewer and stormwater management planning.

• 한국안전학회지
• /
• 제38권5호
• /
• pp.1-7
• /
• 2023

This study analyzes the operational characteristics of 311 aged and non-aged residual current circuit breakers (RCCBs) in low-voltage consumer contexts. It investigates the influence of external temperature and harmonics based on the rated current multiples. To simulate temperature variations, a convectional oven was used around the circuit breakers. Additionally, the generation of harmonic reference signals and data measurement for overcurrent experiments were conducted using NI SCXI, myDAQ, and LabVIEW. An observation revealed that as the ambient temperature increased, the operating time of RCCBs decreased in the time delay region. This was attributed to the faster response or bending of the bimetal, which is the tripping element. However, aged RCCBs encountered challenges with tripping outside the protective curve. The operating time of the circuit breakers exhibited an acceleration influenced by the order and content of harmonic currents, potentially leading to malfunctions. Aged RCCBs demonstrated faster operating times than their non-aged counterparts. However, the difference in operating time varied based on the manufacturer's and operating environment of the RCCBs. Frequent malfunctions of RCCBs can result in power outages. In cases where these circuit breakers fail to operate, they can lead to secondary damages, including electrical fires and shocks. Consequently, it is imperative to consider the operating environment of RCCBs and provide appropriate replacement cycles to mitigate these risks.

• 지질공학
• /
• 제27권4호
• /
• pp.393-403
• /
• 2017

최근 10년간(2005~2014) 산지재해 발생현황을 분석해 보면 산지재해 발생 총면적은 4,393 ha, 연평균 인명피해는 7명, 연평균 산지재해 복구비는 798억원으로 사회 경제적 피해가 발생하였다. 산지재해는 1차적으로 산지사면에서 산사태가 발생되어 2차적으로 계류를 따라 토석류로 이동 및 확산되면서 산지 하부지역의 시설지와 주거지에 피해를 발생시킨다. 이러한 산지재해의 발생원인은 자연적인 요인으로 태풍, 국지성 강우 등이 있으며, 인위적인 요인으로 산지 개발로 인한 산지지반의 훼손 등이 있다. 본 연구에서는 연구지역을 3개 유역으로 구획하고, 산지유역의 지형, 지질, 산림 특성을 고려하여 FLO-2D 분석 결과를 반영한 토석류 취약성 평가 방안을 제시하였다. 또한 잠재적 산지재해에 대한 조사, 분석, 평가 방안에 따라 산지사면 및 계류에 대한 취약성 분석을 통해 잠재적 산지재해의 발생 위험유역을 평가하였다. 이를 통해 산림유역 기반의 종합적인 재해방지시설 계획의 수립 방안을 제시하였다.

• Spatial Information Research
• /
• 제19권5호
• /
• pp.1-11
• /
• 2011

본 연구에서는 기존에 구축된 고해상도 항공영상을 이용한 영상변화 탐지과정에서 보다 정확도 높은 풍수해 정보를 추출하는 방법에 대해 연구하였다. 연구 대상지역은 2008년 국지성 호우로 인해 큰 피해를 입은 경상북도 봉화군의 춘양면 일대를 선정하였다. 연구에서 활용된 항공영상은 해상도 30cm의 피해 전 흑백영상과 40cm의 피해 후 칼라 영상을 사용하였다. 영상분석에 있어 전처리 단계로서 피해 전 후 영상의 해상도 차이나 시계열적인 차이로 인한 오차 보정을 위하여 노멀라이징과 대비강조, 이퀄라이징의 기법을 적용하여 오차를 최소화하였다. 피해규모는 피해 전 후 영상을 구성하는 각 화소의 밝기 값을 1:1로 비교하는 방식으로 산정하였으며, 이 과정에서 피해 전 후 화소 밝기의 차이 값을 설정하여 조사자가 원하는 피해규모를 추출할 수 있도록 임계치를 설정하였다. 최적의 영상처리 및 임계치 선정의 결과는 오차매트릭스를 이용하여 확인하였다. 본 연구의 결과는 피해정보 추출 과정에서 동일한 제원을 갖는 항공영상을 이용하여 신속한 자연재해로 인한 피해규모의 산출이 가능하도록 하였다. 아울러 피해 전 후 다중밴드 영상을 추가로 확보하여 활용한다면 보다 다양한 피해항목에 대한 적용이 가능할 것으로 판단되었다. 나아가 토지피복분류도나 지적도 등 다양한 주제도를 영상변화 탐지에 활용한다면 정량적인 피해규모의 산출도 가능할 것으로 사료된다.

• Spatial Information Research
• /
• 제20권1호
• /
• pp.9-18
• /
• 2012

최근 우리나라는 여름에 집중호우로 인한 산사태로 그 피해가 계속되고 있다. 이러한 산사태는 매년 반복적으로 발생하고 있으며 급격한 기후의 변화로 인해 앞으로 그 발생빈도가 높아질 것으로 예측된다. 우리나라는 인구의 81.5%가 도시지역에 거주하고 있으며 서울에만 약 1,055만 명이 거주하고 있다. 2011년 18명의 사망자가 발생한 서초동 산사태와 동일한 조건에 인접한 대지는 서울시에서 약 9%에 달한다. 도시에서 발생하는 산사태는 그 규모는 작으나 인구가 집중하는 도시의 특성으로 인해 큰 재난을 야기할 가능성이 있다. 현재까지는 산사태의 취약성과 발생 원인을 규명하기 위한 노력이 지속되어 왔으나 산사태 발생 시 재난지역의 범위에 관한 예측 연구가 새롭게 요구되고 있다. 이에 본 연구에서는 산사태의 물리적 확산형태를 분석하기 위하여 셀룰러 오토마타(Cellular Automata, CA) 기반의 산사태 재난지역 확산모델을 구축하였다. 이동규칙, 지형에 의한 장애물을 변수로 하는 SCIDDICA(SmartComputational Innovative methoDs for Debris flow simulation with Cellular Automata)모델과 침전 및 침식에 따른 변화를 적용한 CAESAR(the Cellular Automaton Evolutionary Slope And River model)모델을 적용하여 2011년 7월 서초동 산사태를 대상으로 정확도를 비교하였다.

• 농촌계획
• /
• 제22권2호
• /
• pp.121-129
• /
• 2016

A disaster can be defined in many ways based on perspectives, in addition, its types are able to classify differently by various standards. Considering the different perspectives, the disaster can be occurred by natural phenomenon that is like typhoon, earthquake, flood, and drought, and by the accident that is like collapse of facilities, traffic accidents, and environmental pollution, etc. Into the modern society, moreover, the disaster includes the damages by diffusion of epidemic and infectious disease in domestic animals. The disaster was defined by natural and man-made hazards in the past. As societies grew with changes of paradigm, social factors have been included in the concept of the disaster according to new types unexpected by new disease and scientific technology. Change the concept of social disasters, Ministry of Public Safety and Security (MPSS) has provided the regional safety index, which measures the safety level of a local government. However, this regional safety index has some limitation to use because this index provides the information for city unit which is a unit of administrative districts of urban. Since these administrative districts units are on a different level with urban and rural areas, the regional safety index provided by MPSS is not be able to direct apply to the rural areas. The purpose of this study is to determine the regional safety index targeting rural areas. To estimate the safety index, we was used for 3 indicators of the MPSS, a fire, a crime, and an infectious disease which are evaluable the regional safety index using an accessibility analysis. For determining the regional safety index using accessibility from community centers to public facilities, the safety index of fire, crime, and infectious disease used access time to fire station, police office, and medical facility, respectively. An integrated Cheongju, targeting areas in this study, is mixed region with urban and rural areas. The results of regional safety index about urban and rural areas, the safety index in rural area is relatively higher than in the urban. Neverthless the investment would be needed to improve the safety in the rural areas.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2003년도 봄 학술발표회 논문집
• /
• pp.131-136
• /
• 2003

Landslide is a natural disaster frequently noticed In korea during monsoon season in flicting nationwise damages on human lives, properties, transportation networks, construction sites, etc. This study is about landslide characteristic in rainfall. This study selects seven sites that occured in 2001 and 2002. So elect areas divide and studied special quality by carcinoma by igneous rock, metamorphic rock, sedimentary rock. According to study finding, because igneous rock area is very thin into 1m interior and exterior soil layer, failures happened much rock and soil interface. There was place that depth of soil layer becomes about 2∼3m being area that receive serious weathering case of metamorphic rock. Therefore, at collapse much debriflow occurrence expect. Case that sedimentary rock area is broken through stratification looked. When see such results, it may become many helps to study characteristics of landslide occurrence area grasping collapse special quality by rock type.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2004년도 학술대회지
• /
• pp.111-116
• /
• 2004

We surveyed the coastal structure damages due to the typhoon 'Mae-mi' which heavily struck Korean peninsula in September 12, 2003. The survey revealed the typhoon induced high tides and strong winds were the main causes especially in Busan areas. Though some experimental real time coastal monitoring stations captured the typhoon movements at the critical time, more systematic and complete systems should be implemented to save human lives and properties from huge typhoon disasters.

• 산업기술연구
• /
• 제25권B호
• /
• pp.165-170
• /
• 2005

This paper presents a development of the Data Logger System to transmit the outcome of the waterlevel measuring instrument using the pressure sensor by means of the CDMA network. In or order to set up the real time monitoring the waterlevel measurement system, we have designed the waterlevel sensor, communication terminal and repeater, and data logger. Furthermore, its application for the GIS(Geographical Information System) with management sever system and software solutions have also been developed to minimize the property damages from the flood disaster which occurs every year in the river.