Details of a Researcher - Kohiyama, Masayuki

Papers - Kohiyama, Masayuki

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Validity Study of EDES Application to Taiwan Chi-Chi Earthquake Disaster

Kohiyama, M., Hayashi, H., Maki, N., and Hashitera, S.

21st Asian Conference on Remote Sensing 1 407-412 2000.12

Research paper (international conference proceedings), Joint Work

The authors are developing the Early Damaged Area Estimation System (EDES), which provides the information as to the estimated impacted areas after any significant earthquake based on nighttime lights observed by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS). The estimation method is based on the detection of significant reductions or loss of lights in nighttime images following the event, for it can be expected that city lights will observably decrease after a large earthquake. In the 1999 Taiwan Chi-Chi Earthquake Disaster, there was a countrywide power cut due to the damage of the transmission facilities in Chungliao and Tienlun. The post-event image seems to reflect this influence in appearance compared with a pre-event image, but the further investigation is needed because the gain setting of OLS changes along with lunar phase and elevation, and visible-near infrared (VNIR) band imagery only provides relative light intensity. This paper presents a new method to estimate damaged areas based on a radiance-calibrated image and a method to estimate gain and radiance of observed VNIR imagery, and the validity of the estimation result of EDES application to the Chi-Chi Earthquake is discussed using the electric load data before and after the earthquake.

Development of Early Damaged Area Estimation System (EDES) Using DMSP/OLS Nighttime Imagery

Masayuki KOHIYAMA, Haruo HAYASHI, Norio MAKI, Shin HASHITERA, Masashi MATSUOKA, Herbert W. KROEHL, Christopher D. ELVIDGE and V. Ruth HOBSON

Journal of Social Safety Science (Institute of Social Safety Science) ( 2 ) 79-86 2000.11

Research paper (scientific journal), Joint Work, Accepted

The Early Damaged Area Estimation System (EDES) is proposed to support emergency response in a disaster. EDES provides the geographic information of possible impacted areas within 24 hours after an earthquake on the Internet The estimation method is based on the detection of significant reductions or loss of lights in nighttime imagery observed by the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS). Noise in suburban areas and cloud influence in a pre-event image are addressed by using a cloud-free stable lights image derived from a time series of OLS observations. Appropriate geographic information is discussed to support relief activities and to contribute a reduction in the digital divide problem in global disaster management activities.

International Collaboration for the Early Damaged Area Estimation System Using DMSP/OLS Nighttime Images

Hayashi, H., Hashitera, S., Kohiyama, M., Matsuoka, M., Maki, N., Fujita, H., and Elvidge, C. D.

IEEE 2000 International Geoscience and Remote Sensing Symposium 6 2697-2699 2000.07

Research paper (international conference proceedings), Joint Work

In the Hanshin-Awaji earthquake disaster, the lack of information about where the earthquake damaged areas were prevented early and effective emergency responses and relief. Since then, the national and some local governments in Japan have developed GIS-based damage estimation systems, but few other countries have such systems as yet. Nighttime city lights decreased significantly after a large earthquake, and the DMSP/OLS imagery is suitable for the early estimation of the damaged areas. The damaged areas of the 1999 Kocaeli earthquake in Turkey and 1999 Ji-Ji earthquake in Taiwan were estimated by using DMSP, and the results showed a good match with the real reported damage. We propose a new program through international collaboration to support emergency response and relief activities by providing information as to the estimated impacted areas within the first 24 hours after any significant earthquake. This program consists of the following steps: (1) acquire the earthquake hypocenter data through the Internet, which is for example announced by the USGS. (2) Determine the sampled area of the images by the attenuation formula of earthquake ground motion. (3) Obtain corresponding both time-wise and area-wise DMSP/OLS nighttime images from NOAA/NGDC. (4) Estimate the damaged areas by analyzing the statistically significant decrease in the light intensity of the images. (5) Create a thematic map to present the estimation results as geographic information. (6) Disseminate the resulting map widely and quickly through the WWW.

Earthquake Damaged Area Estimation Using DMSP/OLS Night-time Imagery: Application for Hanshin-Awaji Earthquake

Takashima, M., Hayashi, H., Kimura, H., Kohiyama, M., Kroehl, H. W., Elvidge, C. D., and Hobson, V. R.

IEEE 2000 International Geoscience and Remote Sensing Symposium 1 336-338 2000.07

Research paper (international conference proceedings), Joint Work

After the Marmara earthquake disaster in Turkey (Aug.1999), Kohiyama et al. proposed a method to estimate the impacted area of the earthquake using visible and near-infrared (VNIR) satellite imagery provided by the Defense Meteorological Satellite Program's Operational Linescan System (DMSP/OLS), and succeeded in estimating the impacted area of the Marmara earthquake disaster and the Ji-ji earthquake disaster in Taiwan (Sep. 1999) based on their method. They assumed that the brightness of the area would decrease if the buildings collapsed or blackout occurred due to the earthquake. Then, those areas whose brightness decreased significantly after the earthquake compared with before the earthquake were estimated as the impacted area. The purpose of the present study is to check the validity of the above mentioned method by the application for the Hanshin-Awaji Earthquake (05:46 Jan. 17, 1995) in which the more detailed and various types of damage data due to the earthquake are available as compared with the verification in Turkey.

Proposal for the Effective Building Damage Assessment for Disaster Management

Masayuki KOHIYAMA, Kei HORIE, Norio MAKI, Haruo HAYASHI and Satoshi TANAKA

Journal of Structural and Construction Engineering (Transactions of AIJ) (Architectural Institute of Japan) ( 531 ) 189-196 2000.05

Research paper (scientific journal), Joint Work, Accepted

Effective damage assessment in terms of disaster management is proposed, which consists of both visual survey based on damage patterns of buildings for prompt service and resurvey for citizen's assent to the assessed damage. Problems which Nishinomiya City encountered in issuing certification of building damage reveals an extent of visual survey and necessity of resurvey in issuing process. Difference between two visual surveys of buildings damaged by the Hanshin-Awaji Earthquake Disaster in Tsukiji District, Amagasaki City shows difficulty in finding differential settlement caused by liquefaction and integrated damage patterns of buildings are proposed for effective field investigation.

Development of Building Damage Chart for Post Disaster Management

Horie, K., Maki, N., Kohiyama, M., Lu H., Tanaka, S., Hashitera, S., and Hayashi, H.

12th World Conference on Earthquake Engineering (International Association for Earthquake Engineering) 8 2000.01

Research paper (international conference proceedings), Joint Work

It is found from the questionnaire about the victim’s need for information regarding livability and house repair that the victims needs the information about housing options at the first one week after the Great Hanshin-Awaji Earthquake. However, Building Safety Evaluation, which was the first damage assessment for the individual houses, conducted 6 days after the earthquake from January 23rd to February 9th, 1995. The information needs of the victims cannot be sufficiently fulfilled. The building damage assessment must be conducted both quickly and exactly. It is conceivable that building damage survey using the damage chart is effective. This paper evaluates the effectiveness of the damage chart for damage assessment, and classifies photographic data that are linked to the geographic information systems (GIS) database of Nishinomiya City, based on the damage chart. In addition, we develop the damage chart of wooden structures affected by liquefaction from the case of Amagasaki City.

Human Casualty Estimation Due to Urban Earthquake

Lu H., Kohiyama, M., Maki, N., Tanaka, S., and Hayashi, H.

12th World Conference on Earthquake Engineering (International Association for Earthquake Engineering) 8 2000.01

Research paper (international conference proceedings), Joint Work

Since the 1995 Hanshin-Awaji earthquake disaster, damage estimation analyses for potential earthquake hazards have been carried out by many administrative organizations in Japan. One of the key issues in these analyses is to estimate the number and spatial distribution of human casualties as accurately as possible. We focused on Nishinomiya City, which was one of the most heavily damaged cities in the Hanshin-Awaji earthquake disaster, and constructed a built environment database of Nishinomiya City. Using this database, constructions of the age and sex of individuals and the spatial distribution of the dead, as well as the relationships between the ages of houses and ages of the dead were investigated. This paper provides a technique of constructing a relational geographic information system (GIS) database with several different types of data. Using this GIS database and through Weibull analysis, we arrived at two conclusions regarding the distribution of the age and sex of the dead caused by the earthquake. (1) The earthquake mortality rate distribution of the under-50-year-old age group exhibits a constant occurrence pattern, and that of the over-50-year-old age group exhibits an increasing occurrence pattern. (2) The high ratio of the aged living in relatively old houses is one of the reasons resulting in the higher mortality rate of the aged than that of the young.

A Study on Damaged Building Data of the 1995 Hyogo-ken Nanbu Earthquake

Kohiyama, M., Mizukoshi, K., Ishida, H., Torisawa, K., and Tsugawa, T.

12th World Conference on Earthquake Engineering (International Association for Earthquake Engineering) 8 2000.01

Research paper (international conference proceedings), Joint Work

Fragility functions of buildings, which show the relation between seismic intensity and building damage ratio, are used for estimation of building damage caused by an earthquake. Fragility functions are formulated statistically by data of seismic intensity and building damage ratio on cell units and area size of the cells should be considered to calculate damage ratios. In this paper, the characteristics of damage ratio data are discussed using GIS (geographic information system) data of buildings damaged by the 1995 Hyogo-ken Nanbu Earthquake. First, the two databases of the different parties, which concerns buildings damaged by the earthquake, were compared in terms of the method of each survey and their criteria of damage ranking. It was found that the criteria of damage ranking of the two databases do not differ much, but numbers of damaged buildings and the damage ratios in each rank differ remarkably from each other. Secondly, based on the damage ratios in terms of various cell sizes, it is pointed out that the adequate cell size ranges from 10,000 m2 to 200,000 m2 from the viewpoints of the number of target buildings in the unit and the resolution of the damage distribution.

Use of DMSP-OLS Images for Early Identification of Impacted Areas Due to the 1999 Marmara Earthquake Disaster

Hashitera, S., Kohiyama, M., Maki, N., Hayashi, H., Matsuoka, M., and Fujita, H.

20th Asian Conference on Remote Sensing 2 1291-1296 1999.11

Research paper (international conference proceedings), Joint Work

The effective international disaster response and relief in a large-scale disaster such as the earthquakes in Turkey and Taiwan become possible by the effective distribution of limited resources, both human and physical. Therefore, identifying the spatial distribution of damaged areas is essential on first step.
A method for the early identification of earthquake damaged areas is proposed based on night-light data obtained by the US DMSP (Defense Meteorological Satellite Program)-OLS (Operational Linescan System). The significance in the data of night-light intensity between before and after the reduction in Marmara earthquake disaster in Turkey on August 17, 1999 can be used to estimate possible impacted areas.

A Study on the Occurrence Mechanism of Human Casualty in Nishinomiya City due to the 1995 Great Hanshin-Awaji Earthquake

Hengjian LU, Masayuki KOHIYAMA, Norio MAKI, Haruo HAYASHI, Satoshi TANAKA and Akiyoshi NISHIMURA

Journal of Social Safety Science (Institute of Social Safety Science) ( 1 ) 151-156 1999.11

Research paper (scientific journal), Joint Work, Accepted

In order to reduce human casualties and to set up a correct estimation of death caused by earthquake, it is important to make clear the related factors effecting human casualty. This study focused on Nishinomiya City, which was one of the most heavily damaged city in the 1995 Hanshin-Awaji Earthquake Disaster and a construction of age and sex of the dead is investigated. The investigations prompted two conclusions: (1) The distribution of the earthquake mortality rate of the under-50-year-old age group exhibits a constant occurrence pattern of Weibull distribution, and that of the over-50-year-old age group exhibits an increasing occurrence pattern. (2) The high ratio of the aged living in relatively old houses is one of the reasons resulting in the higher mortality rate of the aged than that of the young.

Study on Cell Size for Building Damage Ratio Based on Data of the 1995 Hyogo-ken Nanbu Earthquake

Masayuki KOHIYAMA, Kaoru MIZUKOSHI, Hiroshi ISHIDA, and Kazuaki TORISAWA

Journal of Structural and Construction Engineering (Transactions of AIJ) (Architectural Institute of Japan) ( 522 ) 137-142 1999.08

Research paper (scientific journal), Joint Work, Accepted

Characteristics of damage ratio data were discussed using GIS data of buildings damaged by the 1995 Hyogo-ken Nanbu Earthquake. A regression analysis of the damage ratio for two kinds of area unit showed that damage ratios reported by Kobe University were about 60% of those reported by Building Research Institute. An analysis of damage ratios according to different cell areas revealed that the adequate cell size for data collection ranges from 10,000 to 200,000 m^2 from the viewpoints of the number of target buildings in the unit and the resolution level for the damage distribution.

Development of GIS-Aided Loss Estimation System for Earthquake Hazard

Masayuki KOHIYAMA, Kaoru MIZUKOSHI, Hiroshi ISHIDA, Shigeru NAGATA, Hiroyuki KANEKO, Masaru MATSUMOTO, Harumi YASHIRO, and Yoshiaki OGANE

AIJ Journal of Technology and Design (Architectural Institute of Japan) ( 7 ) 187-191 1999.02

Research paper (scientific journal), Joint Work, Accepted

A loss estimation system for earthquake hazard capable of evaluating all of Japan was developed. A GIS (Geographic Information System) for personal computers is utilized for this system, which assists in interactive selection of the assumed earthquake and representation of the estimated results on a computer screen. Source parameters of the assumed earthquake can be derived from a database of active faults and historical earthquakes. Earthquake ground motion, liquefaction and earthquake-triggered fire are considered in order to estimate building damage ratios. An insurance company's exposure can quickly be estimated by linking this system to an insurance contract database.

Shape Optimization of a Double-Layer Space Truss Described by a Parametric Surface

Ohsaki, M., Nakamura, T., and Kohiyama, M.,

International Journal of Space Structures 12 ( 2 ) 109-119 1997.04

Research paper (scientific journal), Joint Work, Accepted

A method is presented for finding the optimal configuration of a double-layer space truss described by a parametric surface. The number of design variables is drastically reduced, without sacrificing the smoothness of the upper layer surface, by using the control net parameters as design variables. The coordinates of the lower nodes are defined by using a vertical or normal offset vectors from the upper surface. Curvatures of the curve associated with the lower polygon are calculated for evaluating feasibility and regularity of the a double-layer lattice space truss. In the examples, a feasible optimum design, which minimizes compliance under constraints on structural volume, are successfully found by using the proposed method. It is shown that the optimal solutions strongly depend on the specified ratios of the cross-sectional areas of the members.

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