• Journal of the Korean earth science society
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• v.43 no.1
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• pp.119-127
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• 2022

In recent years, the intensity of typhoons has increased due to climate change. It is presumed that the tailings and waste rock in the mining area harm the environment owing to flood damage. The Gangneung area has been affected by the largest typhoons in Korea, including No. 3,693 (1936), Rusa (2002), Maemi (2003), and Megi (2004). This study was based on a case in which high concentrations of arsenic were detected in the surroundings along a stream after floods caused by typhoons. Although the environmental damage-related law clarifies the responsibility of polluters, careful implementation is required in potential natural disaster areas. The pollutants from abandoned mines can be widely exposed due to typhoons as artificial causes may be mixed. To minimize the impact of natural disasters in these areas, it is necessary to improve and link relevant laws. This study is expected to help cope with mixed pollutants in downstream areas.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.1
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• pp.85-97
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• 2017

In recent years, the damage scales of water disasters such as typhoons, tsunamis, and heavy snow have been increasing globally as a result of global warming and climate changes. In particular, the economic loss caused by typhoons has been increasing for overpopulated areas that have undergone economic development and urbanization since the 1960s. In this study, we investigated and analyzed satellite images captured before and after typhoons on the Korean peninsula, including Typhoon Chaba (2016), Typhoon Rusa ('02), and Typhoon Maemi ('03). There was a limitation in utilizing existing satellites. Domestic satellites have mostly been developed and operated for the observation of the weather, ocean, and topography, as well as for use in communication. There are therefore insufficient temporal and spatial observations for water management and disaster response. In this work, we expanded the scope to overseas satellites and collected data from GMS, TRMM, COMS, and GPM. In the future, it will be necessary to develop and launch water resources satellites that can provide sufficient temporal and spatial data analysis units to obtain rapid and accurate water hazard information for the Korean peninsula.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.4 s.15
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• pp.13-19
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• 2004

The tremendous flood damage caused by Typhoon Rusa(2002) was occurred at GangNeung City in GangWon Province. Almost of the city region was inundated and most of the stream channel facilities were damaged by flash flood with heavy rainfalls. We have investigated seriously damaged parts of stream bank and tried to analyze the causes of damages focused on flow characteristics in curved channel. We analyzed the damage aspects of curved channel by examining geomorphological survey and hydrographical characteristics. Strong correlation was shown according to the regression analysis between length of stream and meander wave length, and meander belt and length of stream. Furthermore, enveloped curve was presented between bottom slope of channel and meander belt, and meander ratio and channel width. As a result, special consideration about stream flow characteristics are needed for engineers who design stream banks and channels.

• Journal of Korean Society on Water Environment
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• v.24 no.2
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• pp.185-194
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• 2008

There is increased soil erosion potential at highland agricultural crop fields because of its topographic characteristics and site-specific agricultural management practices performed at these areas. The agricultural upland fields are usually located at the sloping areas, resulting in higher soil loss, pesticides, and nutrients in case of torrential rainfall events or typhoon, such as 2002 Rusa and 2003 MaeMi. At the highland agricultural fields, the soil reconditioning have been performed every year to decrease damage by continuous cropping and pests. Also it has been done to increase crop productivity and soil fertility. The increased amounts of soil used for soil reconditioning are increasing over the years, causing significant impacts on water quality at the receiving water bodies. In this study, the field investigation was done to check soil reconditioning status for potato, carrot, and cabbage at the Doam-dam watershed. With these data obtained from the field investigation, the Soil and Water Assesment Tool (SWAT) model was used to simulate the soil loss reduction with environment-friendly and agronomically enough soil reconditioning. The average soil reconditioning depth for potato was 34.3 cm, 48.3 cm for carrot, and 31.2 cm for cabbage at the Doam-dam watershed. These data were used for SWAT model runs. Before the SWAT simulation, the SWAT ArcView GIS Patch, developed by the Kangwon National University, was applied because of proper simulation of soil erosion and sediment yield at the sloping watershed, such as the Doam-dam watershed. With this patch applied, the Coefficient of Determination ($R^2$) value was 0.85 and the Nash-Sutcliffe Model Efficiency (EI) was 0.75 for flow calibration. The $R^2$ value was 0.87 and the EI was 0.85 for flow validation. For sediment simulation, the $R^2$ value was 0.91 and the EI was 0.70, indicating the SWAT model predicts the soil erosion processes and sediment yield at the Doam-dam watershed. With the calibrated and validated SWAT for the Doam-dam watershed, the soil erosion reduction was investigated for potato, carrot, and cabbage. For potato, around 19.3 cm of soil were over applied to the agricultural field, causing 146% of more soil erosion rate, approximately 33.3 cm, causing 146% of more soil erosion for carrot, and approximately 16.2 cm, causing 44% of more soil erosion. The results obtained in this study showed that excessive soil reconditioning are performed at the highland agricultural fields, causing severe muddy water issues and water quality degradation at the Doam-water watershed. The results can be used to develop soil reconditioning standard policy for various crops at the highland agricultural fields, without causing problems agronomically and environmentally.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.106-120
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• 2006

Natural or man-made disaster has been expected to be one of the potential themes that can integrate human geography and physical geography. Typhoons like Rusa and Maemi caused great loss to insurance companies as well as public sectors. We have implemented a natural disaster management system for a private insurance company to produce better estimation of hazards from high wind as well as calculate vulnerability of damage. Climatic gauge sites and addresses of contract's objects were geo-coded and the pressure values along all the typhoon tracks were vectorized into line objects. National GIS topog raphic maps with scale of 1: 5,000 were updated into base maps and digital elevation model with 30 meter space and land cover maps were used for reflecting roughness of land to wind velocity. All the data are converted to grid coverage with $1km{\times}1km$. Vulnerability curve of Munich Re was ad opted, and preprocessor and postprocessor of wind velocity model was implemented. Overlapping the location of contracts on the grid value coverage can show the relative risk, with given scenario. The wind velocities calculated by the model were compared with observed value (average $R^2=0.68$). The calibration of wind speed models was done by dropping two climatic gauge data, which enhanced $R^2$ values. The comparison of calculated loss with actual historical loss of the insurance company showed both underestimation and overestimation. This system enables the company to have quantitative data for optimizing the re-insurance ratio, to have a plan to allocate enterprise resources and to upgrade the international creditability of the company. A flood model, storm surge model and flash flood model are being added, at last, combined disaster vulnerability will be calculated for a total disaster management system.