• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.777-784
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• 2018

Since climate change increases the risk of extreme rainfall events, concerns on flood management have also increased. In order to rapidly recover from flood damages and prevent secondary damages, fast collection and treatment of flood debris are necessary. Therefore, a quick and precise estimation of flood debris generation is a crucial procedure in disaster management. Despite the importance of debris estimation, methodologies have not been well established. Given the intrinsic heterogeneity of flood debris from local conditions, a regional-scale model can increase the accuracy of the estimation. The objectives of this study are 1) to identify significant damage variables to predict the flood debris generation, 2) to ascertain the difference in the coefficients, and 3) to evaluate the accuracy of the debris estimation model. The scope of this work is flood events in Ulsan city region during 2008-2016. According to the correlation test and multicollinearity test, the number of damaged buildings, area of damaged cropland, and length of damaged roads were derived as significant parameters. Key parameters seems to be strongly dependent on regional conditions and not only selected parameters but also coefficients in this study were different from those in previous studies. The debris estimation in this study has better accuracy than previous models in nationwide scale. It can be said that the development of a regional-scale flood debris estimation model will enhance the accuracy of the prediction.

• Water for future
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• v.27 no.1
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• pp.89-99
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• 1994

Flood forecasting in Korea has been based on the off-line parameter estimation method. But recent flood forecasting studies explore on-line recursive parameter estimation algorithms. In this study, a simultaneous adaptive estimation of system states and parameters for rainfall-runoff model is investigated for on-line real-time flood forecasting and parameter estimation. The proposed flood routing system is composed of Flood forecasting in Korea has been based on the off-line parameter estimation method. But recent flood forecasting studies explore on-line recursive parameter estimation algorithms. In this study, a simultaneous adaptive estimation of system states and parameters for rainfall-runoff model is investigated for on-line real-time flood forecasting and parameter estimation. The proposed flood routing system is composed of ø-index in the assessment of effective rainfall and the cascade of nonlinear reservoirs accounting for translation effect in flood routing. To combine the flood routing model with a parameter estimation model, system states and parameters are treated with the extended state-space formulation. Generalized least squares and maximum a posterior estimation algorithms are comparatively examined as estimation techniques for the state-space model. The sensitivity analysis is to investigate the identifiability of the parameters. The index of sensitivity used in this study is the covariance matrix of the estimated parameters.-index in the assessment of effective rainfall and the cascade of nonlinear reservoirs accounting for translation effect in flood routing. To combine the flood routing model with a parameter estimation model, system states and parameters are treated with the extended state-space formulation. Generalized least squares and maximum a posterior estimation algorithms are comparatively examined as estimation techniques for the state-space model. The sensitivity analysis is to investigate the identifiability of the parameters. The index of sensitivity used in this study is the covariance matrix of the estimated parameters.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.507-515
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• 2002

Remote Sensing Monitoring and Loss Estimated System of Flood Disaster based on GIS is an integrated system comprised flood disaster information receiving and collection, flood disaster simulation, and flood disaster estimation. When the system receives and collects remote sensing monitoring and conventional investigation information, the distributional features of flood disaster on space and time is obtained by means of image processing and information fusion. The economic loss of flood disaster can be classified into two pus: direct economic loss and indirect economic loss. The estimation of direct economic loss applies macroscopic economic analysis methods, i.e. applying Product (Industry and Agriculture Gross Product or Gross Domestic Product - GDP) or Unit Synthetic Economic Loss Index, direct economic loss can be estimated. Estimating indirect economic loss applies reduction coefficient methods with direct economic loss. The system can real-timely ascertains flood disaster and estimates flood Loss, so that the science basis fur decision-making of flood control and relieving disaster may be provided.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.149-160
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• 2024

Severe casualties and property damage are occurring due to urban floods caused by extreme rainfall. However, there is a lack of research on preparedness, appropriate estimation of flood damages, assessment of losses, and compensation. Particularly, the flood damage estimation methods used in the USA and Japan show significant differences from the domestic situation, highlighting the need for methods tailored to the Korean context. This study addresses these issues by developing an optimized flood damage estimation technique based on the building characteristics. Utilizing the flood prediction solution developed by the Korea Institute of Science and Technology Information (KISTI), we have established an optimal flood damage estimation technology. We introduced a methodology for flood damage estimation by incorporating vulnerability curves based on the inventory of structures and apply this technique to real-life cases. The results show that our approach yields more realistic outcomes compared to the flood damage estimation methods employed in the USA and Japan. This research can be practically applied to procedures for flood damage in urban basement residences, and it is expected to contribute to establishing appropriate response procedures in cases of public grievances.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.410-413
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• 2008

We constructed the regional flood risk and damage magnitude using hazard and vulnerabilities which are climatic, hydrological, socio-economic, countermeasure, disaster probability components for DB construction on the GIS system. Also we developed the Excess Flood Vulnerability index estimation System(EFVS). By the construction of the System, we can perform the scientific flood management for the flood prevention and optional extreme flood defenses according to regional characteristics. In order to evaluate the performance of system, we applied EFVS to Anseong-chen in Korea, and the system's stabilization is appropriate to flood damage analysis.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.111-114
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• 2007

One of future remote sensing techniques for the estimation of damage by storm and flood is the extraction of water area, which could be the basis of measuring the damage by storm and flood and estimate restoration cost. This paper introduces an approach to damage estimation using satellite Image. The project site was Ansung area and a set of Radarsat-1 SAR image at 6.25m resolution was used for the test. Authors investigated methods of SAR image processing such as shadow-effect removal, orthorectification of SAR image and calculation of damage area by flood. Consequetly, this study showed that technique improvement of image processing and the best of result for extracting water area. Also, found the new possibility of damage estimation using satellite image.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1762-1766
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• 2006

In order to protect properties and human lives from disasters such as heavy rainfall, rational Probability Maximum Flood(PMF) estimation procedures for existing dam basins are recently required. This study analyzes the Probable Maximum Flood(PMF) as a part of a counterplan for disaster preventions of hydraulic structures such as dams, according to recent unfavorable weather conditions. In this study, an improvement method of parameter estimation was proposed, being estimated as an appropriate method for application to the unit hydrograph, the time of concentration and storage constant corresponding to the discharge of flood were considered differently when estimating PMF in Hoengseong dam basin.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.3
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• pp.1742-1748
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• 1969

This is a method to determine the boundary line of reservoir flooding area which will be purchased. Until now, flood water level was used as the boundary line. By lowering this line from flood water level, purchasing cost of reservoir flooding area can be cut down. Sometimes, temporary flooding of arable land outside the boundary occurs. During the life of reservoir, flood damage to crop product on of this land must be indemified with net berefit from arable land between the bovndary line and normal water level. Following is the basic formula to determine the line. (Estimated flood damage to crop production of land outside the boundary line $\leqq$ Estimated net beneift from land between the boundary line and normal water level.) Minimum difference between both sides is needed to minimize the purchasing area. Flood damage and net benefit are estimated by hydrologic estimation with rainfall data and crop production estimation.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.163-167
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• 2004

Creeks, defined by creek's improvement law, have strong localities in the flow characteristics and environmental condition. During the recent ten-years, lots of flood damages have occurred rather in the creeks. However, quantity and stream design information are poor while the national-class and local-class streams have sufficient. This causes a problem on improving the safety from flood. This study focuses on assessment of practical applicability for design flood estimation models. For this, Rational formula, Clark's model and Nakayath synthetic unit hydrograph method are estimated by data of the creek comprehensive improvement plan report, etc.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.1B
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• pp.9-20
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• 2012

Recently to overcome limitations of conceptual, hydrological and physics based models for flood stage forecasting, multiple linear regression model as one of data-driven models have been widely adopted for forecasting flood streamflow(stage). The objectives of this study are to compare performance of different multiple linear regression models according to regression coefficient estimation methods and determine most effective multiple linear regression flood stage forecasting models. To do this, the time scale was determined through the autocorrelation analysis of input data and different flood stage forecasting models developed using regression coefficient estimation methods such as LS(least square), WLS(weighted least square), SPW(stepwise) was applied to flood events in Jungrang stream. To evaluate performance of established models, fours statistical indices were used, namely; Root mean square error(RMSE), Nash Sutcliffe efficiency coefficient (NSEC), mean absolute error (MAE), adjusted coefficient of determination($R^{*2}$). The results show that the flood stage forecasting model using SPW(stepwise) parameter estimation can carry out the river flood stage prediction better in comparison with others, and the flood stage forecasting model using LS(least square) parameter estimation is also found to be slightly better than the flood stage forecasting model using WLS(weighted least square) parameter estimation.