• Journal of the Korean association of regional geographers
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• v.12 no.2
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• pp.202-214
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• 2006

In this paper Gumho drainage basin is divided into six geomorphic units (Bohyeon, Palgong, Biseul mountainous areas and Yeongcheon, Gyeongsan, Daegu basin), and physical geographical background and distributional characteristics of geotourism resources in each geomorphic unit are examined. Most(32 sites, 78%) of geotourism resources in Gumho basin reflect geomorphological environment, rest(7 sites, 17%) of them reflect geological environment. There are three geomorphological resources in Bohyeon mountainous areas, eight geomorphological resources in Palgong mountainous areas, and five geomorphological resources and one cultural resource in Biseul mountainous areas. There are two geomorphological resources, one geological resource, one biological resource, and two cultural resources in Yeongcheon basin. Among them one biological resource and and one cultural resource reflect local geomorphological environment. In Gyeongsan basin are there one geomorphological resource, three geological resources, and one biological resource, but one biological resource reflects local geomorphological environment. There are eight geomorphological resources, two geological resources, and three biological resources in Daegu basin. But two biological resources among them reflect local geomorphological environment.

• Journal of Environmental Impact Assessment
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• v.12 no.3
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• pp.161-170
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• 2003

To investigate the characteristics of 17 solid waste landfills in the upper drainage basin of Lake Daechong, the landfill sites were surveyed, the leachate of these landfills were analyzed, and the analysis results were assessed from standpoint of water contamination. Sanitary landfills which are now being operated are relatively well equipped with facilities such as leachate collection, daily soil cover and landfill gas treatment devices. But a few of open-dumping landfills were leaking leachate apparently and were supervised improperly and neglectfully by local governments. Some of sanitary landfills exceeded the COD permission criteria of leachate effluent, and some of open-dumping landfills exceeded SS, T-P, Pb, As, Fe, Mn permission criteria of leachate effluent. To improve the water quality of Lake Daechong which is utilized for supplying drinking water, agricultural water, and industrial water to the great part of Chungchong area, the adequate and prompt measures for preventing Daechong Lake water contamination from landfills leachate is necessary.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.2
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• pp.1-15
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• 2020

In this study, the characteristics of crop damage area by flooding for 113 middle range watersheds during 2000-2016 were analyzed and future crop damage area by flooding were analyzed using 13 GCM outputs such as hourly maximum rainfall, 10-min maximum rainfall, number of days of 80 mm/day, daily rainfall maximum, annual rainfall amount associated with RCP 4.5 and RCP 8.5 scenarios and watershed characteristic data such as DEM, urbanization ratio, population density, asset density, road improvement ratio, river improvement ratio, drainage system improvement ratio, pumping capacity, detention basin capacity, and crop damage area by flooding. A constrained multiple linear regression model was used to construct the relationships between the crop damage area by flooding and other variables. Future flood index related to crop damage may mainly increase in the Mankyung watershed, Southwest part of Youngsan and Sumjin river basin and Southern part of Nackdong river basin. Results are useful to identify watersheds which need to establish strategies for responding to future flood damage.

• Journal of Korea Water Resources Association
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• v.41 no.5
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• pp.491-501
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• 2008

In order to describe runoff characteristics of urban drainage area, outflow from subbasins divided by considering topography and flow path, is analyzed through stormwater system. In doing so, concentration time and time-area curve change significantly according to basin shape, and runoff characteristics are changed greatly by these attributes. Therefore, in this development study of FFC2Q model by MLTM, we aim to improve the accuracy in analyzing runoff by adding a module that considers basin shape, giving it an advantage over popular urban hydrology models, such as SWMM and ILLUDAS, that can not account for geometric shape of a basin due to their assumptions of unit subbasin as having a simple rectangular form. For subbasin shapes, symmetry types (rectangular, ellipse, lozenge), divergent types (triangle, trapezoid), and convergent types (inverted triangle, inverted trapezoid) have been analyzed in application of time-area curve for surface runoff analysis. As a result, we found that runoff characteristic can be quite different depending on basin shape. For example, when Gunja basin was represented by lozenge shape, the best results for peak flow discharge and overall shape of runoff hydrograph were achieved in comparison to observed data. Additionally, in case of considering subbasin shape, the number of division of drainage basin did not affect peak flow magnitude and gave stable results close to observed data. However, in case of representing the shape of subbasins by traditional rectangular approximation, the division number had sensitive effects on the analysis results.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.739-746
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• 1999

Discharge characteristics of organic materials and nutrients were estimated in the catchment area of relaimed area-Saemankeum-. Discharge load of BOD5 was high in the domestic system, while nitrogen and phosphorous were discharged mainly from the livestock system and the land . Load was so dependent on the precipitation that it increased in the rainy season, particulary in nitrogen and phosphorus. Loads from nonpoint sources in this area were higher compared with others.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.5
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• pp.1167-1175
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• 1994

The effects of the calculation method of surface runoff on the estimation of flood in urban drainage basin were analyzed in this study. In comparing with surface runoff methods. RUNOFF, ILLUDAS, SBUH and RRL were investigated. To route the flow in sewer/conduits EXTRAN was applied. The Kings Creek and Gray Haven drainage basin's measured data of rainfall and runoff were used in comparing the computed results. The results show that the greatest effect factor on surface runoff in urban small area is the concentration time. The results estimated by each model which are composed with EXTRAN show that the scheme for surface runoff gives considerable effect on the flood hydrograph in urban drainage system. RUN-EX method gives the most similar simulation results among the surface runoff models, and is more applicable for paved and unpaved basins than others.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.903-916
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• 2023

This study aims to establish basic data for efficient management of rural water by analyzing regional irrigation facilities and benefitted areas in the statistical yearbook of land and water development for agriculture at the watershed level. For 511 domestic rural water use areas, water storage facilities (reservoirs, pumping & drainage stations, intake weirs, infiltration galleries, and tube wells) are spatially distributed, and the benefitted areas provided at the city/county level are divided by water use area to provide agricultural water supply facilities. The characteristics of rural water district areas such as benefitted area, were analyzed by basin. The average area of Korea's 511 rural water districts is 19,638 ha. The average benefitted area by rural water district is 1,270 ha, with the Geum River basin at 2,220 ha and the Yeongsan River basin at 1,868 ha, which is larger than the overall average. The Han River basin at 807 ha, the Nakdong River basin at 1,121 ha, and the Seomjing River basin at 938 ha are smaller than the overall average. The results of this basic analysis are expected to be used to set the direction of various supply and demand management projects that take into account the rational and scientific use and distribution of rural water and the characteristics of water use areas by presenting a quantitative definition of Korea's agricultural water districts.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.514-527
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• 2004

We investigated the distribution and geomorphic development of alluvial fans at Cheongdo- and Hweyang-eup(town) in the Cheongdo Basin, Gyeongsangbuk-do(Province) of Korea. The alluvial fans of study area are formed confluently to the E-W direction at the northern slope of the Mt. Namsan(840 m). They are classified into Higher surface, Middle surface, and Lower surface according to a relative height to a river bed. And the older alluvial fan is, the deeper gravel in the stream deposits is weathered. The magnitude of each surface composing of confluent fans is related to that of the drainage basin. So called fan-basin system of magnitude on the study area is on the positive(+) relation in the study area. The large fans over 1km in radius are found on the basin of andesite rock which is resistant to the weathering and erosion. Moreover there is no tectonic movement in the basin. It means the most important element influenced on the fan formation is not tectonic movement, but the Quaternary climatic change, which is the periglacial climate alternating glacial and interglacial stages during the Quaternary. Therefore alluvial fans would distribute in Korea overall influenced by the Quaternary climatic change.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.4
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• pp.25-32
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• 2023

KDS (Korean Design Standard) for agricultural drainage is a planning standard that helps determine the appropriate capacity and type of drainage facilities. The objective of this study was to analyze the inundation of the agricultural basin considering the current design standard and the critical rainfall duration. This study used the rainfall durations of 1-48 hour, and the time distribution method with the Chicago and the modified Huff model. For the runoff model, the NRCS (Natural Resources Conservation Service) unit hydrograph method was applied, and the inundation depth and duration were analyzed using area-elevation data. From the inundation analysis using the modified Huff method with different rainfall durations, 4 hours showed the largest peak discharge, and 11 hours showed the largest inundation depth. From the comparison analysis with the current method (Chicago method with a duration of 48 hours) and the modified Huff method applying critical rainfall duration, the current method showed less peak discharge and lower inundation depth compared to the modified Huff method. From the simulation of changing values of drainage rate, the duration of 11 hours showed larger inundation depth and duration compared to the duration of 4 hours. Accordingly, the modified Huff method with the critical rainfall duration would likely be a safer design than the current method. Also, a process of choosing a design hydrograph considering the inundation depth and duration is needed to apply the critical rainfall duration. This study is expected to be helpful for the theoretical basis of the agricultural drainage design standards.

• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.10-18
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• 2021

Norovirus (NoV) prevalence was investigated in 100 sewage samples collected from 35 individual septic tanks around the drainage basin of Jaran Bay, Korea in January, May, and July of 2017. Genotypes and diversity of NoV strains detected in sewage samples were also assessed using the conventional RT-PCR and phylogenetic analysis. NoV GI or GII were detected in 22 (22.0%) and 24 (24.0%) samples, respectively. Thirteen genotypes were identified with three dominant genotypes (GI.9, GII.5 and GII.17) and GII.17 showed relatively higher prevalence during the survey period. GII.17 strains were clustered into recombinant type variant or NoV GII.17 Kawasaki variant. NoV GII.17 strains were considered emergent epidemic variants with widespread circulation. NoV surveillance strategy should include both environmental (sewage) and clinical data to reveal minor NoV genotypes likely cause of asymptomatic or underreported infections in the local population.