• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.3.1-14
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• 2002

Many human lives and properties have been damaged by the annually occurring natural disasters. Among them, a typhoon accompanying a gale and a localized torrential downpour induce a first order damages. In this study, states, scales and other characteristics of slope failure induced by the typhoon Rusa, which damaged the whole Korea peninsular on August 30th for 3 days, were analyzed. In addition, permanent measures for slope failure are conducted to prepare natural disasters. Since the key factor on the slope failure is considered to be a rainfall. The characteristics of domestic rainfall and typhoon are investigated, and then failure forms and some characteristics of slope failure are analyzed. By comparing with the data of existing slopes, the hazard of slope failure is examined. There fundamental results could be applied to the future measures of slope failure.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.9-17
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• 2018

PURPOSES : The frequency and severity of natural disasters such as torrential rain or typhoons have become increasingly significant worldwide. Events such as summer typhoons and localized torrential downpour can cause severe damages to a residential area and road networks, resulting in serious harm to the daily lives of people, especially in rural areas by isolating residents from road networks. An immediate and emergency repair technology for the collapsed road networks is urgently needed. This study introduces a new technology to repair road bases or slopes. METHODS : The development of new technology for emergency and permanent repair consists of first, packing of cement paste-coated gravel, second, combining appropriate equipment, and third, conducting a field applicability test. In this research, the compressive strength of cement pastecoated gravel, gravel-netting concrete properties, and packing efficiency were determined, and a full scale field mock-up test was carried out. RESULTS : The compressive strength of the cement paste-coated gravel concrete satisfied the required limit for road base of 5 MPa after 7 days. With appropriate netting materials and packing size, gravel-netting concrete was successful up to a slope of 1:1.5. The full scale field mock-up test showed efficiency in the field and penetration resistance performance. CONCLUSIONS : The new technology of emergency and permanent repair for damaged road bases and slopes, introduced in this study, showed satisfactory performance. The technology is expected to be applied in the field when construction procedures and quality specifications are made.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.171-178
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• 2005

It is unavoidable to be formed slopes under special circumstance of Korea where 70% of the whole area are composed of mountains when civil engineering projects such as roads, site developments are increased with industrial development and horizontal expansions of urban area. Moreover, stability of the slopes become one of quite important issues under special meteorological characteristics that over two-thirds of annual average rainfall are concentrated in summer season and the localized torrential downpour are getting more frequent recently. Resulting in these circumstances, partial slope failures by debris flow of the high water content soils are occurred frequently in cutting soil slopes. In this case of debris flow slope failure, slope declination method are selected for their stable recovery because it is impossible to recover entirely by existing recovery methods. Seeding or special grass planting methods are followed separately without exception. The method by which entire recover with bigger stability ratio would be possible and grass planting work would be done simultaneously is developed. In this study, the results of the tests including a real construction history in a failed slope using developed method are described

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1602-1610
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• 2005

In this study was investigated and analyzed of damage characteristics for infrastructures by typhoon that have been many occur. The objective Structures were the road and hydraulic structure. The road structure was included the cut-slopes, retaining walls and bridges. The hydraulic structure is divided with the dike, small-scale dam, reservoir and floodgate. The analysis result of the bridge damage cause is river bottom height increase and passage ability decrease. The principal damage reasons of the cut-slope structure are weakening the ground due to the localized torrential downpour and drainage defective. Also, the principal damage reasons of the small-scale dam, reservoir, dike and the floodgate are continuous collapse of dike beside the floodgate.And we divided a typhoon damage occurrence cause with artificial and natural. As the result of analysis, the many damage occurrence cause will be removed by system improvement and technical development.

• 한국해양학회지
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• v.30 no.2
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• pp.125-137
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• 1995

CTD, light transmission and tidal current data obtained off the Keum estuary in August, 1991 and 1992 were analyzed to look into the plume movement and the vertical structure of the plume changing with tidal currents. When the river plume was developed by a localized torrential downpour, the initial plume showed a surface lens of low salinity in the section south of the Yeon-Do. The axis of surface lens moved with tidal currents which flows mainly northeastward and southwestward tn the study area and the excursion of the lens axis reached 7 km. The plume during the ebb period showed a symmetric lens structure of low salinity which extends vertically to 3 m below the surface. During the flood period the plume deepened to 6 m below the surface in its northen side forming a sharp salinity front, which results in an asymmetric lens. We suggest that the salinity front with deepened plume moved to the north repeatedly, resulting in temperature increase and salinity decrease in the northern region off the estuary. When the river discharged continuously the large volume over 20 days, the plume forming surface lens extended to the Sybidongpa-Do and deflected to the north.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.520-532
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• 2017

Large-scale natural disasters such as typhoon and localized torrential downpour cause widespread human and property damages. Recently, management systems using GIS are being developed to manage such disasters from various angles. Integrated disaster management encompasses diverse areas such as prediction through the computation of disaster information and field support for response. The development of disaster information systems must also consider the installation of various computation modules. Furthermore, GIS is generally included for realistic description of the field situation and for spatial operations. This study aims to develop the core module of a visualization platform for the 3D GIS services of integrated disaster information using Unity engine This system will enable integrated disaster management from various angles, encompassing disaster prevention experts, field support personnel, and citizens.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.75-82
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• 2004

Surface and bottom sea water samples were harvested from the 5 stations in the marine ranching ground of Tongyeong coastal water from year 2000 to 2002. Cell number of heterotrophic bacteria was determined by using the plate counting method to explore the variation of the cell population of heterotrophic bacteria. Sea water samples collected in summer (in July and August) contained much larger number of heterotrophic bacteria than those harvested in spring, autumn and winter. Heterotrophic bacteria were usually more abundant in surface sea than in bottom sea water. However the reverse was true for sea water collected in December 2001 and February 2002 due to suspended solids accumulating more abundantly in seabed area because of the slower convective current of the sea water in winter. Number of heterotrophic bacteria did not have a strong relationship with frequency of typhoon indicating that the path and powerfulness of the typhoon, localized torrential downpour and temperature variation accompanying the typhoon should be considered all together at the same time as well as the frequency of typhoon to explain clearly the variation of cell number of heterotrophic bacteria. The dominant species isolated from the marine ranching ground of Tongyeong were identified to be Pseudomonas fluorescens, Pseudomonas stutzeri, Acinetobacter lwoffii and Sphingomonas paucimobilis.

• Korean Journal of Environmental Biology
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• v.25 no.3
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• pp.273-278
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• 2007

The cell numbers of heterotrophic bacteria inhabiting the surface and bottom sea water harvested from the 5 stations in the marine ranching ground of Tongyeong coastal waters in $2003{\sim}2007$ were examined, and species composition of the heterotrophic bacterial population and dominant species were analyzed as well. Sea water samples collected in summer season contained much higher number of heterotrophic bacteria than those harvested in winter, spring and autumn seasons due to the higher sea water temperature. However the cell number of heterotrophic bacteria did not show a significant dependence on the location of the sampling stations. The cell number of heterotrophic bacteria in the surface sea water harvested in October 2003 and in September 2004 was not discernibly different from that in the bottom sea water and sometimes the former was even fewer than the latter because of the typhoon and localized torrential downpour. The number of heterotrophic bacteria decreased every year. The main bacterial species were Pseudomonas fluorescens TY1, Pseudomonas stutzeri TY2, Acinetobacter lwoffii TY3, Sphingomonas paucimobilis TY4, Burkholderia mallei TY5, Pasteurella haemolytica TY6, Pasteurella multocida TY7, Comamonas acidovorans TY8, Actinobacillus ureae TY9 and Chryseobacterium indologenes TY10. P. fluorescens TY1 and A. lwoffii TY3 were found to be the dominant species.

• Spatial Information Research
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• v.19 no.5
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• pp.1-11
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• 2011

This study mainly focused on the method of accurately extracting damage information in the im agery change detection process using the constructed high resolution aerial im agery. Bongwha-gun in Gyungsangbuk-do which had been severely damaged from a localized torrential downpour at the end of July, 2008 was selected as study area. This study utilized aerial im agery having photographing scale of 30cm gray image of pre-disaster and 40cm color image of post-disaster. In order to correct errors from the differences of the image resolution of pre-/post-disaster and time series, the prelim inary phase of image processing techniques such as normalizing, contrast enhancement and equalizing were applied to reduce errors. The extent of the damage was calculated using one to one comparison of the intensity of each pixel of pre-/post-disaster im aged. In this step, threshold values which facilitate to extract the extent that damage investigator wants were applied by setting difference values of the intensity of pixel of pre-/post-disaster. The accuracy of optimal image processing and the result of threshold values were verified using the error matrix. The results of the study enabled the early exaction of the extents of the damages using the aerial imagery with identical characteristics. It was also possible to apply to various damage items for imagery change detection in case of utilizing multi-band im agery. Furthermore, more quantitative estimation of the dam ages would be possible with the use of numerous GIS layers such as land cover and cadastral maps.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.1 s.39
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• pp.39-46
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• 2007

Most areas in Kangwon Province are mountainous and vulnerable to landslide due to the rainy season in summer and the localized torrential downpour triggered by abnormal climate. In particular, the rainfall is one of direct reasons for landslide. In accordance with the analysis of the relevance between the landslide areas and the accumulated rainfall for four months, there are severe damages of landslide to the areas having more than 1,100 mm of rainfall during three(3) months. Further, it indicates that the more the accumulated rainfall is the greater the size of landslide. These analyses show that the rainfall causes the possible and potential landslide in the vulnerable areas. And also, it means that there exist strong possibilities of landslide even in the areas of lower vulnerability if the amount of rainfall is above certain standard level. Accordingly, in this study we stored the GIS database on the causes and factors of landslide in the southern parts of Kangwon province and conducted simulations on the change of distribution of vulnerable areas by varying the rainfall conditions and by using the evaluation data of landslide vulnerability. As such a result, we found that the landslide could potentially occur if the amount of rainfall is 200 mm and more.