• Title/Summary/Keyword: Hazard area

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Analysis of Hazard Areas by Sediment Disaster Prediction Techniques Based on Ground Characteristics (지반특성을 고려한 토사재해 예측 기법별 위험지 분석)

  • Choi, Wonil;Choi, Eunhwa;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.12
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    • pp.47-57
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    • 2017
  • In this study, a predictive analysis was conducted on sediment disaster hazard area by selecting six research areas (Chuncheon, Seongnam, Sejong, Daejeon, Miryang and Busan) among the urban sediment disaster preliminary focus management area. The models that were used in the analysis were the existing models (SINMAP and TRIGRS) that are commonly used in predicting sediment disasters as well as the program developed through this study (LSMAP). A comparative analysis was carried out on the results as a means to review the applicability of the developed model. The parameters used in the predictions of sediment disaster hazard area were largely classified into topographic, soil, forest physiognomy and rainfall characteristics. A predictive analysis was carried out using each of the models, and it was found that the analysis using SINMAP, compared to LSMAP and TRIGRS, resulted in a prediction of a wider hazard zone. These results are considered to be due to the difference in analysis parameters applied to each model. In addition, a comparison between LSMAP, where the forest physiognomy characteristics were taken into account, and TRIGRS showed that similar tendencies were observed within a range of -0.04~2.72% for the predicted hazard area. This suggests that the forest physiognomy characteristics of mountain areas have diverse impacts on the stability of slopes, and serve as an important parameter in predicting sediment disaster hazard area.

Evaluation and Prediction of Failure Hazard Area by the Characteristics of Forest Watershed (산림유역 특성에 의한 붕괴 위험지역의 평가 및 예지)

  • Jeong, Won-Ok;Ma, Ho-Seop
    • Korean Journal of Environment and Ecology
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    • v.20 no.4
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    • pp.415-424
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    • 2006
  • This study was carried out to analyze the characteristics of forest watershed factors by using the quantification theory(I) for evaluation and prediction of the failure hazard area. Present $sediment(m^3/yr/ha)$ of erosion control dams were investigated in 95 sites of erosion control dam constructed during 1986 to 1999 in Gyeongnam province. The results obtained from this study were summarized as follows; General condition of class I(Very hazard area) were as follow; Igneous rock in parent rock, coniferous in forest type, below 20year in stand age, below 30cm in soil depth, SCL in soil texture, $31{\sim}40%$ in gravel contents, $S{\sim}E$ in aspect, $2,501{\sim}3,600m$ in length of main stream, $26{\sim}30$ in number of total streams, $6,601{\sim}10,000m$ in length of total streams, over 3 in stream order, over 16 in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class IIl(hazard area) were as follow; Metamorphic rock in parent rock, hardwood in forest type, over $21{\sim}24year$ in stand age, $31{\sim}40cm$ in soil depth, SiCL or SCL in soil texture, $11{\sim}20%$ in gravel contents, $S{\sim}W$ in aspect, $1,501{\sim}2,600m$ in length of main stream, $6{\sim}10$ in number of total streams, $3,501{\sim}5,500m$ in length of total streams, 2 in stream order, $6{\sim}10$ in number of first streams order and over $31^{\circ}$ of slope gradient. General condition of class III(Un hazard area) were as follow; Sedimentary rock in parent rock, mixed in forest type, over 25year in stand age, $41{\sim}50cm$ in soil depth, SiCL in soil texture, below 10% in gravel contents, $N{\sim}W$ in aspect, below 500m in length of main stream, below 5 in number of total streams, below 1,000m in length of total treams, below 1 in stream order, below 2 in number of first streams order and below $25^{\circ}$ of slope gradient. The prediction method of suitable for failure hazard area divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very hazard area was over 4.8052. A score of class II was 4.8051 to 2.5602, it was evaluated as a hazard area, and class III was below 2.5601, it was evaluated as a un hazard area.

Pre-resilience Group Activities Against a Forthcoming Big Flood Disaster in Tokyo Below-Sea-Level Area

  • Ichiko, Taro;Kato, Takaarki;Ishikawa, Kinji
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.3-8
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    • 2011
  • In April 2010, Japan Cabinet Office has published the first countermeasure report for severe flood disasters. This report showed various flood-disaster scenarios and factors that widened damages. One of important suggestions was to transmit precious information for long-distance evacuation. So far, local municipalities have made Flood Hazard Map to inform resident risk and evacuation. In this paper, cognition and effectiveness of a flood hazard map in the down ARAKAWA river Tokyo were measured by social questionnaire survey. In conclusion, there were 3 factors to effect validity of a flood hazard map. There were (1) commitment to their neighborhood organization, (2) experience of Kathleen typhoon in 1947 and (3) level of using targeted river. As results, a logical diagram about a flood hazard map perception was drawn and discussed from a view of community-based approach.

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CURRENT STATUS AND IMPORTANT ISSUES ON SEISMIC HAZARD EVALUATION METHODOLOGY IN JAPAN

  • Ebisawa, Katsumi
    • Nuclear Engineering and Technology
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    • v.41 no.10
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    • pp.1223-1234
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    • 2009
  • The outlines of seismic PSA implementation standards and seismic hazard evaluation procedure were shown. An overview of the cause investigation of seismic motion amplification on the Niigata-ken Chuetsu-oki (NCO) earthquake was also shown. Then, the contents for improving the seismic hazard evaluation methodology based on the lessons learned from the NCO earthquake were described. (1) It is very important to recognize the effectiveness of a fault model on the detail seismic hazard evaluation for the near seismic source through the cause investigation of the NCO earthquake. (2) In order to perform and proceed with a seismic hazard evaluation, the Japan Nuclear Energy Safety Organization has proposed the framework of the open deliberation rule regarding the treatment of uncertainty which was made so as to be able to utilize a logic tree. (3) The b-value evaluation on the "Stress concentrating zone," which is a high seismic activity around the NCO hypocenter area, should be modified based on the Gutenberg-Richter equation.

Probabilistic seismic risk assessment of a masonry tower considering local site effects

  • Ozden Saygili
    • Earthquakes and Structures
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    • v.26 no.3
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    • pp.191-201
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    • 2024
  • A comprehensive probabilistic seismic hazard analysis was carried out in Istanbul to examine the seismotectonic features of the region. The results showed that earthquakes can trigger one another, resulting in the grouping of earthquakes in both time and space. The hazard analysis utilized the Poisson model and a conventional integration technique to generate the hazard curve, which shows the likelihood of ground motion surpassing specific values over a given period. Additionally, the study evaluated the impact of seismic hazard on the structural integrity of an existing masonry tower by simulating its seismic response under different ground motion intensities. The study's results emphasize the importance of considering the seismotectonic characteristics of an area when assessing seismic hazard and the structural performance of buildings in seismic-prone regions.

Estimation of probabilistic hazard for Bingol province, Turkey

  • Balun, Bilal;Nemutlu, Omer Faruk;Benli, Ahmet;Sari, Ali
    • Earthquakes and Structures
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    • v.18 no.2
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    • pp.223-231
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    • 2020
  • Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It occurred since 1900, the seismicity of the region was obtained statistically by considering the earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study, magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may affect the peak ground acceleration according to various attenuation relationships are calculated and using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5, 7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03 g, 0.58 g and 0.24 g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is high and the importance of considering the earthquake effect during construction is emphasized for this region.

Review of Hazard Mapping Information Collected for Local Disaster Prevention by Residents in a Historical Local Town (역사적인 지역 주민들의 지역 재해 예방을 위해 수집 된 위험지도 정보의 검토)

  • Min, Byung-won
    • Journal of Convergence for Information Technology
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    • v.8 no.4
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    • pp.121-126
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    • 2018
  • We are developing a hazard map creation support system for historical local towns. Our system aims at collecting the unique information received from residents and raising resident's consciousness to disasters by recording hazardous locations where residents feel danger in case of disasters. In this paper, we examine the hazard information of the area collected by the residents themselves in using the system. While exchanging opinions, the residents review the validity and completeness of the information gathered by walking around the area. We also consider how to integrate and share it throughout the region. We found that it was possible to gather regional hazard information from the viewpoint of residents in addition to high coverage for each district. Also, by sharing information at the review meeting, the residents were able to newly know the hazard information of other districts that they did not know before. This shows the usefulness of residents to share the dangerous information while examining each cause across the different districts.

Forecasting of Landslides Using Geographic Information System (지형정보시스템을 이용한 산사태 예측)

  • 강인준;장용구;곽재하
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.11 no.2
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    • pp.53-58
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    • 1993
  • Landslides, failure of slope stability by natural or artificial factors, occur loss of life and properties. Recently, landslides hazard area predict statistical methods and field measurements, but there are so many difficulties to find the occurrence system because of its complexity. To predict the landslide harvard region, model area is the Seodong in Pusan where occurred landslides. Database of ground height made the each topography in map scale of 1 : 25,000, 1 : 10,000, 1 : 5,000 and 1 : 1,200. Authors knew to landslide hazard area by the weight of ground height data and slope angle data. Finally, aerial photo analysis is possible find landslide hazard area.

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Application of Drones for the Analysis of Hazard Areas in Mountainous Disaster (산지재해 발생 위험지역 분석을 위한 드론의 적용)

  • Lee, Jeong Hoon;Jun, Kye Won;Jun, Byong Hee
    • Journal of the Korean Society of Safety
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    • v.33 no.3
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    • pp.65-70
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    • 2018
  • Terrain data for disaster analysis in hazardous or disaster areas is not only important but also needs to be built quickly. In particular, the introduction of drones is in the early stages of research using drones in a variety of fields such as shooting, analyzing and managing hazardous areas. It is expected that drone will be faster, safer and more effective than existing data collection method in case of small scale disaster hazard area and disaster area where equipment or manpower input is difficult. Therefore, in this study, drone shooting was performed for hazardous areas in mountainous roads located in Samcheok city, Gangwon province, and ground reference points were measured by RTK-GPS. The measured data were converted into DSM (Digital Surface Model) data by coordinate correction using Pix4D postprocessing program and then applied to the analysis of the hazard area of mountainous area. As a result, it was shown that it is effective to identify the risk by using the basic terrain data obtained from the drones.

Causual Analysis on Soil Loss of Safety Class Oryun Tunnel Area in Landslide Hazard Map (산사태 위험지도에서 안전등급지역인 오륜터널 일대의 토사유실 원인분석)

  • Kim, Tae Woo;Kang, In Joon;Choi, Hyun;Lee, Byung Gul
    • Journal of Korean Society for Geospatial Information Science
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    • v.24 no.1
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    • pp.17-24
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    • 2016
  • At present, summer cloudburst and local torrential rainfalls have increased in this country, because of climatic change. Therefore, studies on prevention of soil loss have been actively proceeded, and Korea Forest Service has offered landslide hazard map. Landslide hazard map divides risks into 5 classes, by giving weight with 9 kinds of elements. In August 25 2014, soil loss occurred in the whole Oryun Tunnel, Geumjeong-gu, Busan, because of local torrential heavy rain. As a result of comparing with landslide hazard map, the area where soil loss occurred in reality is a safety zone on hazard map. Rainfall, soil map, geological map, forest type map, gradient, drainage network, watershed, basin shape, and efflux of the whole Oryun Tunnel where soil loss occurred were analyzed. As a result of an analysis, it is judged that soil, forest type, much efflux and peak discharge, degree of water network and basin shape of a place where landslide occurred are causes of soil loss. It is judged that efflux, peak discharge, and basin shape by the localized rainfall that is not considered in landslide hazard map of them are the biggest causes of soil loss. It is judged that efflux, peak discharge, degree of water network and basin shape by the rainfall are important through a study on a causual analysis on soil loss in the whole Oryun Tunnel where is one of occurrence area where a lot of propertywere lost by the record local torrential rainfalls. A localized torrential downpour should be prepared by considering these elements on judgement of a landslide hazard area.