• Journal of Environmental Policy
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• v.3 no.2
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• pp.89-112
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• 2004

This Study aims to demonstrate how much flood vulnerability in urban area changed for the past 32 years by using the panel model. At the same time, this study strives to determine the primary factors and to construct an effective counter-plan by means of empirical research. After selecting research hypotheses based on considerations of issues concerning causes for urban flooding, their relevance is put to the test by conducting empirical research in individual case locations. This research verifies the four research hypotheses by using one-way error component regression model. In conclusion, this research has shown that urban land use and local characteristics act as significant flood determinants, with forests acting to reduce flood dangers. Moreover, constructing embankments can no longer represent a reliable flood control policy. The changes in future flood control policies need to incorporate local characteristics and to minimize natural destruction, so that humans and nature can coexist through environmentally friendly flood management policies.

• Journal of the Korean Geophysical Society
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• v.6 no.2
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• pp.107-119
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• 2003

The behavior of pore pressure and effective stress in a highly saturated sand bed under variations in the water pressure in its surface were investigated to determine the mechanism of the collapse of hydraulic structures during flooding or when attacked by storm waves. The vertical, one-dimensional model was used as a basic model to clarify the effect of water pressure variation on only to the vertical direction. The theoretical results show that a sand bed under variations of water pressure is weakened by an increase in excess pore pressure and that under certain conditions the sand bed will liquefy. Although many factors related to water pressure variation and property of the material determine this phenomenon, the mist important factor seems to be the small amount of air present in the sand bed. The theoretical results reported are verified by experiments.

• Journal of the Korean Institute of Navigation
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• v.16 no.1
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• pp.37-64
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• 1992

A study on the changes of the oceanographical environment caused by Mokpo coastal zone development was carried out. Special emphasis was placed on the clarification of the water level changes and coastal current structure and influence of the environmental factors on the coastal area. In order to understand the structure oceangraphical environemnt, such as water temperature, salinity, suspended solids, pH, dissolved oxygen, chemical oxygen demand, biochemical oxygen demand, distribution of bottom sediment, tide and current were measured. To investigated the structure of tide and current for the future development, a numerical analysis was carried out. In certain zones, it was found to be flooding problems near the lowlying commercial area.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.411-412
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• 2023

The purpose of this research and development is to develop a structure module that improves the efficiency and constructability of the layout structure as well as the design development of rainwater permeable storage tank blocks using inorganic binders and aggregates with the aim of reducing greenhouse gas (CO₂) with eco-friendly materials. In addition, for the efficient response to flooding of the developed permeable storage structure, we present a technical solution for combining drone mapping technology and flood monitoring technology that can analyze topographical factors in detail.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.3
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• pp.50-61
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• 2008

Environmental factors and phragmites growth properties at various habitats in Eulsukdo ecological park were investigated to understand major factors affecting phragmites distribution in constructed wetlands. Although phragmites is very important species in wetland ecosystem, it should be controlled to prevent excessive expansion within the restricted park area. The results showed that phragmites dominant sites have the highest LAI among other emerged plants habitats and could adversely affect for waders habitats. Phragmites were also found at the areas with wide ranges of water-depth than other plants, and showed phragmites could be favored for occupying the newly constructed wetlands like Eulsukdo ecological park. The results showed difference in soil redox potential between phragmites dominant and non-dominant sites. Because soil redox potential is affected by wetland hydrology like flooding duration, control of wetland hydrology should be considered for creation and management of constructed wetlands. The results also showed that differences in soil cation exchange capacity, soil salinity, soil organic matter content and site inclination between phragmites dominant and non-dominant sites as well as brackish and freshwater areas. Those abiotic factors can be important considerations for the sustainable wetland management especially for the phragmitest managements in the ecological park.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.61-65
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• 2000

Effects of temperature, soil moisture level, flooding, and soil microflora on decay of root galls in club root disease of Chinese cabbage were examined in the laboratory. Number of days required for complete decay of root galls was 3 days at $32^{\circ}C$ or higher, 12 days at $16{\sim}20^{\circ}C$ and 28 days at $8^{\circ}C$. As soil moisture content goes up, root gall decay became faster resulting 3 days for complete decay under saturated moisture condition at high temperature of $32^{\circ}C$, and 8 days under the same moisture level at $24^{\circ}C$. Soil moisture effect was relatively low at $24^{\circ}C$ compared to $32^{\circ}C$. Stimulation of decay by soil flooding was not observed at $32^{\circ}C$ but became apparent at $12^{\circ}C$. Influence of soil microflora on root gall decay was negligiable. Based on these results, temperature appears to be the most important factor affecting root gall decay in soil. Root gall decay is thought to be affected more easily by other environmental factors under low temperature conditions. Maturity of resting spores of Plasmodioprora brassicae in root galls tended to increase as time prolongs during root gall decay. Density of the resting spores was lower in fresh root galls where their maturity was also low as compared to completely decayed root galls. Number of resting spores in completely decayed root gall was $6.5{\times}10^{6}/g$ tissue and its maturity was over 95%.

• Ocean and Polar Research
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• v.29 no.2
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• pp.135-153
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• 2007

Temporal (seasonal) and spatial distributions and variations of various physico-chemical factors (salinity, temperature, pH, DO, COD, SPM, POC, silicate, DIP, DIN) in surface and bottom waters were studied in the coastal environment with typical macro-tidal range and monsoonal weather condition, Gyeonggi Bay, west coast of Korea. Spacial distribution patterns of these factors were generally similar to each other, and appeared to be inversely related to the distribution pattern of salinity, suggesting that water quality of the study area was primarily controlled by the physical mixing process of Han-River freshwater with nearby coastal seawater. During flooding season, silicate- and nitrogen-rich Han River water directly flowed into offshore as far as $20\sim30\;km$ from the river mouth, probably causing serious environmental problems such as eutrophication and unusual and/or noxious algal bloom, etc. Except the surface water during summer flooding season, high concentrations of nutrients appeared generally in dry season, whereas low values in spring, possibly because of the occurrence of spring phytoplankton bloom. On the other hand, nutrient flux through the estuary seems to be primarily depending on river discharge, sewage discharge and agricultural activities, especially during the rainy season. Also, nutrients in this coastal waters are considered to be supplied from the sediments of tidal-flats, which developed extensively around the Han-River mouth, especially during fall and winter of dry and low discharge seasons, possibly due to the stirring of tidal flat sediments with highly enriched pore-water nutrients by storm. And also, COD and DIN concentrations in the study area consistently increased during the last 20 years, probably because of agricultural activities and increasing discharge of industrial and domestic wastes.

• Journal of the Society of Disaster Information
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• v.16 no.4
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• pp.734-746
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• 2020

Purpose: Increase in the size and number of underpasses rises occurrence of disasters such as fire and flooding inundation in underpasses. In the occurrence of disasters, the underpasses are more vulnerable to expose of crucial disasters than the general roads due to they are built underground. Therefore, The purpose of this paper is to derive system improvement items to prevent and control disasters in underpasses. Method: A hierarchical model of disaster impact factors and alternatives was developed based on prior researches and expert advices on disaster analyses and impact factors in the underpasses. The developed model was employed for surveys of pairwise comparison, and rankings of improvement were determined by applying the AHP method. Result: With a consistency of the surveys, results of relative weights of evaluation criteria(traffic accidents, fire, flooding inundation) and alternatives(law, system/planning, maintenance/human factor/environment) shows that improvement of laws and system related to the fire disaster is a top priority to prevent and control disaster of the underpasses. Conclusion: From experts' point of view, strengthening laws and systems related to disater prevention facilities such as water spray facilities, external(ground) exit in relation to fire in underpasses showed that it is an alternative to prevent disasters and minimize damage to underpasses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.238-250
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• 2020

This study investigated the long-term measures to minimize flood damage in the event of flooding in urban areas. The relationship between urban spatial factors and the impact of flood damage was analyzed, focusing on non-structural measures. The urban spatial factors were categorized into three parts: open space, disaster prevention facilities, and urbanization sectors. Multiple regression analysis was used to investigate how urban spatial factors influence flood damage. As a result of the analysis, the crucial factors, such as the reduced green areas and parks included in the open space sectors, resulted in an increased flood damage potential. The posterior factors, such as the population density and GRDP included in the urbanization sector concurrently led to an increase in the flood damage potential. Therefore, to better adapt to climate change, it is necessary to establish urban spatial plans strategically, such as green areas and parks. Meanwhile, the population density and GRDP are also the main factors causing flood damage. Therefore, when used appropriately in terms of resilience, it will serve as adaptations and recovery.

• Journal of Ship and Ocean Technology
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• v.6 no.4
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• pp.19-76
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• 2002

The author was appointed by the UK Department of Transport as a fellow Assessor with R. A. Williams during Lord Donaldson's Assessment (1995) of the loss of the OBO ship DERBYSHIRE and in 1996 as a UK Assessor for the planning and surveys of the wreck. He relinquished his appointment in October 1997 and was not thereafter Involved in the review and analysis of data gathered. This paper may be considered to be complementary to the reports of the UK and EC Assessors (Williams and Torchio, 1998a and 1998b) which followed that review and analysis. The paper deals with the history and loss of the ship, Including the concept developed in 1995 of 13 possible loss scenarios in a formal safety Risk Matrix of probability and seriousness. It analyses abnormal wave effects on hatch cover collapse, on ship bending, and on flooding of bow spaces and no. 1 hold. The implosion-explosion mechanics during sinking is outlined to explain the devastation of the wreck. The 1996 and 1997 underwater surveys are outlined as are the findings of fact. Each of the final 14 loss scenarios is analysed in the light of the firm and circumstantial survey evidence, plus many other factors of survey experience, analyses and experiments. The updated Risk Matrix speaks for itself and leads to the prime conclusions and major recommendations.