• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.255-258
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• 2003

Agricultural water use occupies 60% of the total water use in Korea, so variation of the farming pattern and the efficiency of agricultural water use is important for the sustainable water management. For the analysis of agricultural water use, the Yi-dong experimental site was selected. For the monitoring system of the experimental site, four rainfall gauging stations and twenty-six water level gauging stations are established and operated. Analyses of the measured data are processed for the irrigation efficiency of agricultural water and the effect of the variation of farming pattern.

• Journal of Environmental Impact Assessment
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• v.23 no.3
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• pp.220-226
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• 2014

This study investigated temporal-spatial and variations in Geostationary Ocean Color Imager (GOCI) products of parameters total suspended solids (TSS) and chlorophyll-a in the North Marine Areas of East China Sea.GOCI data were collected daily from February 2012 to December 2012. The higher chlorophyll-a values were observed during the investigation period. The relatively large increase in TSS and chlorophyll-a at the sampling stations coupled with typhoon events during the summer rainy period. The abnormal chlorophyll-a concentration was mainly driven by meteorological factors such as typhoon and rainfall in the coastal areas of Jeju and the North Marine Areas of East China Sea. The abnormal high chlorophyll-a concentration at the majority of the coastal stations indicate eutrophication of coastal waters, especially Red tide. The events such as eutrophication and abnormal high chlorophyll-a concentration may potentially influence outbreak of Red Tide, detected with GOCI parameters.

• 한국해양학회지
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• v.6 no.2
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• pp.78-84
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• 1971

A year-long survey of bacteriological water quality for Lake Eui-am in Kang- won Province, Korea, was conducted from June 1970 to May 1971. the purpose of this investigation was: 1) to determinate the seasonal prevalence of fecal pllution bacteria, such as coliforms, fecal coliforms and enterococci, in Lake Eui-am; 2) to correlate these findings with associated microbiological parameters; and 3) to interpret these results with respect to water quality and environmental health. The membrane filter techniques were used, for the determination of these bacteria.Densities of total coliforms, fecal coliforms and enterococci exhibited seasonal variations, the numers of these fecal pollution bacteria being high in summer and fall months in close possitive relation to the amount of rainfall, and being low winter and spring months. On the whole, the level of fecal pollution bacteria in Lake Eui-am is yet quite low There were not any evident correlation among the density of these pollution bacteria. The ratio of fecal coliforms to enterococci of the lake water varied from 0.01 to 4.25 with average of 1.47.

• Journal of Korean Society of Water and Wastewater
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• v.13 no.2
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• pp.74-81
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• 1999

In this study, the hydrological changes due to urbanization were investigated and fundamental theory and characteristics of typical urban runoff model such as CHICAGO Model was studied. Above model was applied for urbanizing Dongsucheon basin, Incheon. The main parameters(CI, CP, CS) which are included in this model depending on runoff results were determined, and dimensionless values such as total runoff ratio($Q_{TR}$), peak runoff ratio($Q_{PR}$), and runoff sensitivity ratio($Q_{SR}=Q_{TR}/Q_{PR}$) were estimated in order to evaluate and compare the characteristics of model based on relative sensitivity analysis. Finally, applied model was proposed based on understanding of work types and established urban runoff models which can simulate well for areal development patterns and urban river basin.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.627-635
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• 2006

Combined sewer overflow (CSOs) is a primary diffuse source degrading water quality of urban streams. In this study, CSOs caused by 5 different rainfall events at an urban watershed located in Daejeon city were monitored for the indicator microorganism concentrations. Event mean concentration (EMC) of the indicator microorganisms were: total coliform = $2.46{\times}10^6CFU/100mL$; fecal coliform = $1.01{\times}10^6CFU/100mL$; E.coli = $5.20{\times}10^5CFU/100mL$; and Fecal Streptococci = $6.08{\times}10^5CFU/100mL$. In addition, coliform concentrations were well correlated with suspended solid concentrations and the first flush effects were identified. Settling tests were carried out to estimate removal rate of indicator organisms by sedimentation from CSOs. As microorganisms are discharged in association with suspended solid, ten minutes of settlement can lower 44% of indicator microorganism leading.

• KCID journal
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• v.14 no.2
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• pp.236-244
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• 2007

Agricultural water demand in North Korea must be considered for the near-future investment in agricultural consolidation projects and to prepare for the future unification. Thus, the objective of this study is to estimate the agricultural water demand of paddy fieldss in North Korea. GIS data including land cover classification map, Thiessen network and administration maps of North Korea, and meteorological data were synthesized. In order to estimate paddy water demand for a 10-year return period, the FAO Blaney-Criddle method and the fixed effective rainfall ratio method were used. The results showed that 4.77 billion $\beta$(c)/year paddy water demand is required for the 512,400 ha of paddy fieldss. Paddy water demand in the three major regions - Hwanghaedo, Pyeongando, Hamgyeongnamdo - was estimated chargong 81.7 percent of total paddy water demand in North Korea.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.78-82
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• 1994

Unusually severe rice blast epidemic sweeped over the rice growing area in Gyeongnam Province and elsewhere in 1993. Leaf blast infection was reached to 33,133 ha, which is about 24.5% of total paddy area and neck blast infection was apparent throughout 4,421 ha. Major factors affecting such an unusual epidemic appeared to be as follow: Firstly, low temperature, frequent rainfall and coincidentally insufficient duration of sunshine through July and August; Secondly, most cultivars possessing low levels of field resistance were cultivated in wide areas: Thirdly, blast fungus population was enough for successive infection under optimum weather condition and most races distributed in field were able to infect most cultivars.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1925-1928
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• 2007

Water cycle analysis was performed for Gunja basin located in metropolitan Seoul using Aquacycle model in order to assess the problems of urban water cycle. From the water cycle analysis of Gunja basin, it was found that 75% of total rainfall occurred in the form of surface runoff, and groundwater recharge only accounted for about 7%. This suggests serious distortion of water cycle which can be attributed to urbanization. Feasibility analysis of reuse scenarios such as rainwater use and wastewater reuse was then performed to examine their influences on improving the water cycle. From the analysis of water reuse options, it was shown that imported water supply savings of 13% can be achieved through rainwater use, and water supply savings of 31% through wastewater reuse.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.243-246
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• 2009

Localized rainfall due to abnormal climate has caused extensive damages killing several tens to hundreds of people for yearly basis. The typhoon 'Lusa' of year 2002 has resulted 5,400 billion won of property damage and the damages for roads were approximated to be 2,860 billion won at 12,377 locations holding 53% damage of total. The recent typhoon, 'Aewinia' of yeat 2006 caused the 1,400 billion-won property damage including sweeping and flooding of 127 roads and 65 rivers, respectively. There are needs to minimize the damages for important structures for repeated heavy rainfalls every year and, especially, because debris flow might be a main cause of road damage, the design criteria and guideline for roads are required to be improved. Therefore, this paper presented design method of debris-flow control structure for road protection.

• Asian Journal of Turfgrass Science
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• v.9 no.4
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• pp.317-329
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• 1995

The study of standing crop of the ground vegetation under the coniferous stands was pursuited in regard of soil nutrients at Kwangnung plantation from May to Octoher, 1971 and 1991. The coniferous stands implied pine and larch associations of which the young stands of each as-sociation were 9~12 years and the older one 40~70 years. The larch stands were more plentiful in species than in the pine stands and the Festuca ovina and Oplismenus burmannii each were dominant species of pine and larch stands. The standing crop of pine stands is from 98.02g /$m^2$ to 385.32g /$m^2$ The standing crops of those stands showed great increase from June to August when the air temperature and rainfall were fairly high. The standing crop has correlation to total nitrogen and organic matter in the soil.