• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.63-72
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• 2019

There is an increasing demand for catchment runoff estimation to cope with the natural disasters such as typhoon, extreme rainfall. However, the ungauged catchments are common case in practices. This study suggested a rationalization of conceptual rainfall-runoff model for typhoon flood events in Geum river region. And the developed models were validated based on the observed hydrological data. Therefore, developed regionalization models could estimate catchment runoff for Typhoon flood events. It will be used as basic data for the river management for extreme flood conditions.

• Journal of Environmental Science International
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• v.19 no.3
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• pp.353-363
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• 2010

The most efficient measures to reduce damage from natural disasters include activities which prevent disasters in advance, decrease possibility of disasters and minimize the scale of damage. Therefore, developing of the risk assessment model is very important to reduce the natural disaster damage. This study estimated a typhoon damage which is the biggest damage scale among increased natural disasters in Korea along with climate change. The results of 3-second gust at the height of 10m level from the typhoon 'Maemi' which did considerable damage to Korean in 2003, using the wind data at the height of 700 hPa. September 12th 09 LST~13th 12 LST period by the time a typhoon Maemi approached to the Korean peninsula. This study estimate damage amount using 'Fragility curve' which is the damage probability curve about a certain wind speed of the each building component factors based on wind load estimation results by using 3-second gust. But the fragility curve is not to Korea. Therefore, we use the fragility curves to FPHLM(FDFS, 2005). The result of houses damage amount is about 11 trillion 5 million won. This values are limit the 1-story detached dwelling, $62.51\sim95.56\;m^2$ of total area. Therefore, this process is possible application to other type houses.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.6
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• pp.311-320
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• 2023

When an earthquake occurs, the severity of damage is determined by natural factors such as the magnitude of the earthquake, the epicenter distance, soil properties, and type of the structures in the affected area, as well as the socio-economic factors such as the population, disaster prevention measures, and economic power of the community. This study evaluated the direct economic loss due to building damage and the community's recovery ability. Building damage was estimated using fragility functions due to the design earthquake by the seismic design code. The usage of the building was determined from the information in the building registrar. Direct economic loss was evaluated using the standard unit price and estimated building damage. The standard unit price was obtained from the Korean Real Estate Board. The community's recovery capacity was calculated using nine indicators selected from regional statistical data. After appropriate normalization and factor analysis, the recovery ability score was calculated through relative evaluation with neighboring cities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.69-75
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• 2019

The frequency of natural disasters and the scale of damage are increasing due to the abnormal weather phenomenon that occurs worldwide. Especially, damage caused by natural disasters in coastal areas around the world such as Earthquake in Japan, Hurricane Katrina in the United States, and Typhoon Maemi in Korea are huge. If we can predict the damage scale in response to disasters, we can respond quickly and reduce damage. In this study, we developed damage prediction functions for Wind waves caused by sea breezes and waves during various natural disasters. The disaster report (1991 ~ 2017) has collected the history of storm and typhoon damage in coastal areas in Korea, and the amount of damage has been converted as of 2017 to reflect inflation. In addition, data on marine weather factors were collected in the event of storm and typhoon damage. Regression analysis was performed through collected data, Finally, predictive function of the sea turbulent damage by the sea area in 74 regions of the country were developed. It is deemed that preliminary damage prediction can be possible through the wind damage prediction function developed and is expected to be utilized to improve laws and systems related to disaster statistics.

• Journal of Environmental Impact Assessment
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• v.15 no.6
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• pp.373-383
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• 2006

The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.

• Journal of Forest and Environmental Science
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• v.24 no.3
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• pp.137-142
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• 2008

In this paper, we apply a logistic regression model to the data of snow damage on sugi (Cryptomeria japonica) occurred in Toyama prefecture (in Japan) in 2004 for estimating the risk probability. In order to specify the factors effecting snow damage, we apply a model selection procedure determining optimal subset of explanatory variables. In this process we consider the following 3 information criteria, 1) Akaike's information criterion, 2) Baysian information criterion, 3) Bias-corrected Akaike's information criterion. For the selected variables, we give a proper interpretation from the viewpoint of natural disaster.

• IE interfaces
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• v.21 no.4
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• pp.365-377
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• 2008

In this paper, for constructing the Korean Hazard Information System (KHIS), we conceptually design a hazard evaluation process. We first deal with a hazard evaluation process focused on flood hazard to give the most immense damage and loss. The hazard evaluation process is consist of a damage evaluation process and a loss evaluation process, and is used for transforming hazards from natural disasters into economic measures. The proposed process is developed based on the famous FEMA (Federal Emergency Management Agency)'s $HAZAS^{@MH}$methodology. We modify the FEMA's process to be mutually exclusive and collectively exhaustive, that is all losses from the hazards are included into the estimation process but the losses are not duplicated in the process. In addition to this, we define the loss process specifically by considering the characteristics from the hazard environments of Korea. We can expect that KHIS for evaluating economic losses from natural hazards can be developed based on the conceptual design for the economic loss evaluation process, and KHIS can be used as a useful tool for analyzing the feasibilities of mitigation plans in central/local governments.

• Smart Structures and Systems
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• v.33 no.2
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• pp.119-131
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• 2024

Drift angle is a significant index for diagnosing post-event structures. A common way to estimate this drift response is by using modal parameters identified under natural excitations. Although the modal parameters of shear structures cannot be identified accurately in the real environment, the identification error has little impact on the estimation when measurements from several floors are used. However, the estimation accuracy falls dramatically when there is only one accelerometer. This paper describes the susceptibility of single sensor identification to modelling error and simulations that preliminarily verified this characteristic. To make a robust evaluation from measurements of one floor of shear structures based on imprecisely identified parameters, a novel scheme is devised to approximately correct the mode shapes with respect to fictitious frequencies generated with a genetic algorithm; in particular, the scheme uses constrained minimization to take both the mathematical aspect and the realistic aspect of the mode shapes into account. The algorithm was validated by using a full-scale shear building. The differences between single-sensor and multiple-sensor estimations were analyzed. It was found that, as the number of accelerometers decreases, the error rises due to insufficient data and becomes very high when there is only one sensor. Moreover, when measurements for only one floor are available, the proposed method yields more precise and appropriate mode shapes, leading to a better estimation on the drift angle of the lower floors compared with a method designed for multiple sensors. As well, it is shown that the reduction in space complexity is offset by increasing the computation complexity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.1-9
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• 2020

Acritical function of a nation is to protect its people's lives and properties from natural disasters such as a drought. A drought affects many aspects of human life, including social, economic, and industrial activities. Approximately 75.7% of reservoirs in Korea are over 50 years old.Sedimentation over the years may have caused a situation where storage capacity of the reservoirs is no longer sufficient and compliant with the original reservoir specifications. This study analyzes storage capacities for ten aged reservoirs using the autonomous navigation USV. It compares these capacities with sediment estimated by conventional empirical equations. Comparisons were made to the original specifications for the reservoirs.Storage capacity of six reservoirs decreased in a range between 16.2%-55.3% and storage capacity of 4 reservoirs increased in a range between 1.5%-380.2%. This data was compared to data derived from estimating sediment by empirical equations. Yoon's equation(1982) appeared more accurate than Sur's equation(1988) in Uhlinzi and Yongpo reservoirs, and Sur's equation(1988), however, appeared more accurate than Yoon's equation in Daegok, Ugok2 and Ochi reservoirs. The significant ranges of sedimentation shown in this study suggest that it is worth continuously surveying reservoirs to ensure their efficient management and operation.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.1023-1034
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• 2008

The size and frequency of the natural disaster related to the severe storms are increased for recent decades in all over the globe. The damage from natural disasters such as typhoon, storm and local severe rainfall is very serious in Korea since they are concentrated on summer season. These phenomena will be more frequent in the future because of the impact of climate change related to increment of $CO_2$ concentration and the global warming. To reduce the damage from severe storms, a short-range precipitation forecasting model using a weather radar was developed. The study was conducted as following four tasks: conversion three-dimensional radar data to two-dimensional CAPPI(Constant Altitude Plan Position Indicator) efficiently, prediction of motion direction and velocity of a weather system, estimation of two-dimensional rainfall using operational calibration. Results demonstrated that two-dimensional estimation using weather radar is useful to analyze the spatial characteristics of local storms. If the precipitation forecasting system is linked to the flood prediction system, it should contribute the flood management and the mitigation of flood damages.