• Title/Summary/Keyword: diffusion of volcanic ash

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Case Studies of Predicting Volcanic Ash by Interactive Realtime Simulator (실시간 대화형 화산재 확산 예측 시스템에 의한 화산재 확산 예측)

  • Kim, Hae-Dong;Lee, Jun-Hee
    • Journal of Environmental Science International
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    • v.23 no.12
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    • pp.2121-2127
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    • 2014
  • Analyzing the observational data of volcanic activities around the northern part of Korean peninsula, the odds of volcano eruption increases continuously. For example, the cumulative seismic moment and frequence observed near Mt. Baekdu show a sudden increased values. In this study, predicting the diffusion of volcanic ash for two cases were carried out by using interactive realtime simulator, which was developed during last 2 years as a research and development project. The first case is Sakurajima volcano (VEI=3) erupted in August 2013. The second case is assumed as the volcanic eruption at Mt. Baekdu (VEI=7) under landing circumstance of typhoon Maemi (August 2003) in Korean peninsula. The synoptic condition and ash diffusion for the two cases were simulated by WRF(Weather Research and Forecast) model and Lagrangian dispersion model, respectively. Comparing the simulated result of the first case (i.e., Sakurajima volcano) with satellite image, the diffusion pattern show acceptable result. The interactive realtime simulator can be available to support decision making under volcanic disaster around East Asia by predicting several days of ash dispersion within several minutes with ordinary desktop personal computer.

Retrieving Volcanic Ash Information Using COMS Satellite (MI) and Landsat-8 (OLI, TIRS) Satellite Imagery: A Case Study of Sakurajima Volcano (천리안 위성영상(MI)과 Landsat-8 위성영상(OLI, TIRS)을 이용한 화산재 정보 산출: 사쿠라지마 화산의 사례연구)

  • Choi, Yoon-Ho;Lee, Won-Jin;Park, Sun-Cheon;Sun, Jongsun;Lee, Duk Kee
    • Korean Journal of Remote Sensing
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    • v.33 no.5_1
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    • pp.587-598
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    • 2017
  • Volcanic ash is a fine particle smaller than 2 mm in diameters. It falls after the volcanic eruption and causes various damages to transportation, manufacturing industry and respiration of living things. Therefore diffusion information of volcanic ash is highly significant for preventing the damages from it. It is advantageous to utilize satellites for observing the widely diffusing volcanic ash. In this study volcanic ash diffusion information about two eruptions of Mt. Sakurajima were calculated using the geostationary satellite, Communication, Ocean and Meteorological Satellite (COMS) Meteorological Imager (MI) and polar-orbiting satellite, Landsat-8 Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS). The direction and velocity of volcanic ash diffusion were analyzed by extracting the volcanic ash pixels from COMS-MI images and the height was retrieved by adjusting the shadow method to Landsat-8 images. In comparison between the results of this study and those of Volcanic Ash Advisories center (VAAC), the volcanic ash tend to diffuse the same direction in both case. However, the diffusion velocity was about four times slower than VAAC information. Moreover, VAAC only provide an ash height while our study produced a variety of height information with respect to ash diffusion. The reason for different results is measured location. In case of VAAC, they produced approximate ash information around volcano crater to rapid response, while we conducted an analysis of the ash diffusion whole area using ash observed images. It is important to measure ash diffusion when large-scale eruption occurs around the Korean peninsula. In this study, it can be used to produce various ash information about the ash diffusion area using different characteristics satellite images.

The Analysis of Volcanic-ash-deposition Damage using Spatial-information-based Volcanic Ash Damage Sector and Volcanic Ash Diffusion Simulation of Mt. Aso Volcano Eruption Scenario (공간정보 기반의 국내 화산재 피해 분야와 아소산 화산재 모의 확산 시나리오를 활용한 화산재 누적 피해 분석)

  • Baek, Won-Kyung;Kim, Miri;Han, Hyeon-gyeong;Jung, Hyung-Sup;Hwang, Eui-Hong;Lee, Haseong;Sun, Jongsun;Chang, Eun-Chul;Lee, Moungjin
    • Korean Journal of Remote Sensing
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    • v.35 no.6_3
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    • pp.1221-1233
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    • 2019
  • Estimating damage in each sector that can be caused by volcanic ash deposition, is very important to prepare the volcanic ash disaster. In this study, we showed predicted-Korean-volcanic-ash damage of each sector by using volcanic ash diffusion simulation and spatial-data-based volcanic ash damage sector in previous study. To this end, volcanic ash related base maps were generated by collecting and processing spatial information data. Finally, we showed Korean-volcanic-ash-deposition damages by sector using the collected Mt. Aso volcanic ash scenarios via overlapping analysis. As a result, volcanic-ash-related damages were expected to occur in the 162 and 134 districts for each Aso volcanic ash scenarios, since those districts exceeds the minimum volcanic ash damage criterion of 0.01 mm. Finally, we compared possible volcanic ash damages by sectors using collected and processed spatial data, after selecting administrative districts(Scenario 190805- Kangwon-do, Kyungsangbuk-do; Scenario 190811-Chuncheon-si, Hongcheon-si) with the largest amount of volcanic ash deposition.

Modelsfor Disaster Prevention Education and Training and Scenario for Training on Volcanic Ash Fall (재난재해 교육, 대응훈련 모델과 화산재 대비 훈련 시나리오)

  • Chang, Eunmi;Park, Yongjae;Park, Kyeong
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.1
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    • pp.97-113
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    • 2018
  • Low-frequency geological natural disaster events such as Pohang earthquake have been occurred. As a results, there's a growing recognition on the importance of education and training for low frequency geological disasters in Korea. In spite of many years of scientific researches on volcanic disaster prevention and preparedness on Baekdusan volcano, the results do not provide the proper scenario for the training for volcanic ash event. Fall 3D volcanic ash diffusion model was run based on wind field data for the last five year, assuming Aso Mountain's explosion with volcanic explosion index 5 for seventy two hours. The management criteria values for proper actions in the previous studies were applied to make a scenario for thirteen groups of the disaster response teams such as train transportation, water supply, electrical facilities and human health. The models on the relationship between education and training for disaster prevention and response were suggested to fulfill the scientific and practical training at local level.

Numerical Simulation of Volcanic Ash Dispersion and Deposition during 2011 Eruption of Mt. Kirishima (2011년 기리시마 화산 분화에 따른 화산재 이동 및 침적에 관한 수치모의실험)

  • Lee, Soon-Hwan;Jang, Eun-Suk;Yun, Sung-Hyo
    • Journal of the Korean earth science society
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    • v.35 no.4
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    • pp.237-248
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    • 2014
  • To analyze the characteristics of deposition and dispersion of volcanic ash emitted from Mt. Kirishima on January 26, 2011, several numerical simulations were carried out by using the numerical models including Weather and Research Forecast (WRF) and FLEXPART. The dispersion of ash located under 1 km high tends to be concentrated along the prevailing wind direction on January 26 2011. On the other hand, volcanic ash released on the following day spreads to Kirishima bay due to the intensified high pressure air mass in southern Kyushu. When Siberian air mass was intensified January 26, 2011, the deposition of volcanic ash is concentrated restrictedly in the narrow area along the wind direction of the downwind side of Mt. Kirishima. The development of high pressure air mass over the eruption area tends to induce the intensified horizontal diffusion of volcanic ash. Since the estimated deposition of volcanic ash is agreed well with observed values, the proposed numerical simulation is reasonable to use the assessment on the behavior of volcanic ash.

Detection for Region of Volcanic Ash Fall Deposits Using NIR Channels of the GOCI (GOCI 근적외선 채널을 활용한 화산재 퇴적지역 탐지)

  • Sun, Jongsun;Lee, Won-Jin;Park, Sun-Cheon;Lee, Duk Kee
    • Korean Journal of Remote Sensing
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    • v.34 no.6_4
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    • pp.1519-1529
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    • 2018
  • The volcanic ash can spread out over hundreds of kilometers in case of large volcanic eruption. The deposition of volcanic ash may induce damages in urban area and transportation facilities. In order to respond volcanic hazard, it is necessary to estimate efficiently the diffusion area of volcanic ash. The purpose of this study is to compare in-situ volcanic deposition and satellite images of the volcanic eruption case. In this study, we used Near-Infrared (NIR) channels 7 and 8 of Geostationary Ocean Color Imager (GOCI) images for Mt. Aso eruption in 16:40 (UTC) on October 7, 2016. To estimate deposit area clearly, we applied Principal Component Analysis (PCA) and a series of morphology filtering (Eroded, Opening, Dilation, and Closing), respectively. In addition, we compared the field data from the Japan Meteorological Agency (JMA) report about Aso volcano eruption in 2016. From the results, we could extract volcanic ash deposition area of about $380km^2$. In the traditional method, ash deposition area was estimated by human activity such as direct measurement and hearsay evidence, which are inefficient and time consuming effort. Our results inferred that satellite imagery is one of the powerful tools for surface change mapping in case of large volcanic eruption.

A Case Analysis of Volcanic Ash Dispersion under Various Volcanic Explosivity Index of the Mt. Baegdu (백두산 분화 강도에 따른 화산재 확산 사례 분석)

  • Lee, Soon-Hwan;Jang, Eun-Suk;Lee, Hyun-Mi
    • Journal of the Korean earth science society
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    • v.33 no.3
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    • pp.280-293
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    • 2012
  • In order to clarify the characteristics of dispersion of volcanic tephra emitted from the Mt. Baegdu with various eruption environment, numerical analysis were performed using numerical models, Weather Research and Forecast (WRF) and FLEXPART. Synoptic conditions at 12 October 2010 was adopted because the volcanic ash of Mt. Baegdu can reach the Korean peninsula and its dispersion pattern was compared with different Volcanic Explosivity Index (VEI) and particle size. Predominant size of falling out ash flowing in the peninsular is smaller than 0.5 mm and the ash large than the size is difficult to get in the peninsular due to the its weak ability of truculent diffusion. the difference of ash distribution with various VEI scenarios is not so much but number density of ash in the air is dramatically changed. Volcanic ash tends to be deposited easily in eastern coastal area such as Gangneung and Busan, because of the inflow of ash from East Sea and barrier effect of the Taeback mountains along the east coast of the Korean Peninsula. Accumulated amount of ash deposition can be increased in short period in several urban areas.

Compressing Method of NetCDF Files Based on Sparse Matrix (희소행렬 기반 NetCDF 파일의 압축 방법)

  • Choi, Gyuyeun;Heo, Daeyoung;Hwang, Suntae
    • KIISE Transactions on Computing Practices
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    • v.20 no.11
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    • pp.610-614
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    • 2014
  • Like many types of scientific data, results from simulations of volcanic ash diffusion are of a clustered sparse matrix in the netCDF format. Since these data sets are large in size, they generate high storage and transmission costs. In this paper, we suggest a new method that reduces the size of the data of volcanic ash diffusion simulations by converting the multi-dimensional index to a single dimension and keeping only the starting point and length of the consecutive zeros. This method presents performance that is almost as good as that of ZIP format compression, but does not destroy the netCDF structure. The suggested method is expected to allow for storage space to be efficiently used by reducing both the data size and the network transmission time.

Priority Data Handling in Pipeline-based Workflow (파이프라인 기반 워크플로우의 우선 데이터 처리 방안)

  • Jeon, Wonpyo;Heo, Daeyoung;Hwang, Suntae
    • KIISE Transactions on Computing Practices
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    • v.23 no.12
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    • pp.691-697
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    • 2017
  • Volcanic ash has been predicted to be the main source of damage caused by a potential volcanic disaster around Mount Baekdu and the regions of the Korean peninsula. Computer simulations to predict the diffusion of volcanic ash should be performed according to prevalent meteorological situations within a predetermined time. Therefore, a workflow using pipelining is proposed to parallelize the software used for this computation. Due to the nature of volcanic calamities, the simulations need to be carried out for various plausible conditions given that the parameters cannot be precisely determined during the simulations, even at the time of a volcanic eruption. Among the given conditions, computations need to be first performed for the condition with the highest probability so that a response to the volcanic disaster can be provided using these results. Further action can then be performed later based on subsequent results. The computations need to be performed using a volcanic disaster damage prediction system on a computing server with limited computing performance. Hence, an optimal distribution of the computing resources is required. We propose a method through which specific data can be provided first to the proposed pipeline-based workflow.

The Development of VR based Application for Realistic Disaster Prevention Training (현실감 있는 재난재해 예방 교육을 위한 VR 기반 앱 개발)

  • Kim, Taehoon;Youn, Junhee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.287-293
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    • 2018
  • The Korean peninsula has been known as an area that is free of volcanic disasters. However, recent observations and research results of volcanoes in Far East Asia, including Baedu Mountain and Japanese volcanoes, show that the Korean peninsula is no longer a safe area from volcanic disasters. Since 2012, the Korean government has been developing an IT-based construction technology, VDRS (Volcanic Disaster Response System), for effective volcanic disaster response system. The main users of VDRS are public officers in central or local governments. However, most of them have little experience and knowledge about volcanic disasters. Therefore, it is essential to develop education contents and implement training on volcanic disaster response for effective response in a real disaster situation. In this paper, we deal with the development of a mobile application based on virtual reality (VR) for realistic volcanic disaster response training. The objectives of training are the delivery of knowledge and experience for volcanic disasters. First, VR contents were generated based on spatial information. A 3D model was constructed based on a Digital Elevation Model (DEM), and visualization models for meterological effects and various volcanic disaster diffusion effects were implemented for the VR contents. Second, the mobile application for the volcanic disaster response training was implemented. A 12-step story board is proposed for volcanic disaster experience. The application was developed with the Unity3D engine based on the proposed story board to deliver knowledge of various volcanic disasters (volcanic ash, pyroclastic flows, volcanic mudflow etc.). The results of this paper will be used for volcanic disaster response and prevention training and for more realistic training linked with augmented reality technology in the future.