• Journal of Korea Water Resources Association
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• v.31 no.3
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• pp.253-267
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• 1998

In this study, ILLUDAS and SWMM were applied for Dongsucheon basin, Incheon and Test basin, Cheongju. The main parameters (II, IA, IS, SI, SR, SS) which are included in those of each model depending on runoff results were determined, and sensitivity ratios were estimated in order to evaluate and compare the characteristics of each modEL. Total runoff ratio for almost parameters turned out to have a linear relation to the rainfall durations and the scale of basin area but have nothing to do with rainfall distributions. Sensitivity ratios turned out to have a linear relation for the infiltration and soil parameters of ILLUDAS as well as all parameters of SWMM. ronoff sensitivity ratios for almost parameters were smaller than 1.0 because the impacts of total runoff were bigger than those of peak runoff. And runoff sensitivity ratio was equal to 1.0 for the roughness coefficient of SWMM. Total runoff ratio, peak runoff ratio and runoff sensitivity ratio for the selected parameters of those models were presented asthe tables and figures according to the scale of basin area, rainfall durations such as 60, 120, and 180 minutes and Huff's 4th quartiles rainfall distributions. Keywords : ILLUDAS, SWMM, parameter, sensitivity analysis, sensitivity ratio.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.423-426
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• 2003

The purpose of this paper is to estimate Agricultural water demand at irrigation area of sumjin reservoir, the Dongjin River basin, which consist of multi-wide water supply system and complicated irrigation channel and supplementary irrigation facilities.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.174.4-175
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• 2001

No Abstract, See Full Text

• Journal of Wetlands Research
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• v.18 no.4
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• pp.413-423
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• 2016

Effects of the design flood share of the Kyeongpo retarding basin, which has a function for flood control of the Kyeongpo river assigned to the Kyeongpo prickly water lily wetland, on the Kyeongpo lake and the downstream of Kyeongpo river were analyzed on the bassis of the hydraulic experiments and the numerical simulations using RMA-2 model. Reproducing a complex water flow system of the area of Kyeongpo lake, the unsteady flow simulations were performed. The data obtained in hydraulic experiments were used to determine parameters of the numerical model which simulated the flows for various flood scenarios in the downstream area of Kyeongpo river. With increasing the design flood share rates in the retarding basin, the water level was increased in the lake and is decreased in the river. The characteristics of flood flow interaction between Kyeongpo river and Kyeongpo lake were understood. These results may be used to management the Kyeongpo lake during flood season.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.617-626
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• 2006

In this study 3-month SPI data from 59 stations over the Korean peninsula are analyzed by deriving and spatially characterizing the EOFs. Also, the coefficient time series of EOF are applied to the multi-variate time series model to generate the time series of 10,000 years, to average them to estimate the areal average, and to decide the maximum drought severity for given return periods. Finally, the drought prevention ability is evaluated by considering the effective storage of dam within the basin and the size of agricultural area. Especially for the return period of 30 years, only the Han river basin has the potential to overcome the drought. Other river basins like the Youngsan river basin, which has a large portion of agricultural area but less water storage, are found to be very vulnerable to the rainfall-sensitive agricultural drought.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.3
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• pp.60-70
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• 1999

The purpose of this study is to analyze the spatial change of water quality pollutant in the upper-stream of Kumho River basin. For this purpose, it compared with ground survey data of water quality measurement, using GIS and Landsat TM image, and then constructed a database of water quality pollutants in the watershed by Arc/Info. Also the land cover classification maps of 1985 and 1997 were prepared using maximum likelihood classification. This study detected and analysed the classified images to produce the area of land cover change per sub-basin. In addition, choropleth maps were prepared with spatial change value of water quality pollutants, and overlay analysis was carried out with weight score for each layer. The results of this study revealed that population, animals and fruit orchards were main factors in the spatial change of water pollution of Kumho River basin. The Comparision of pollutions by sub-basins showed a high pollution value in Daechang-chun and Omok -chun stream which follows through the urban area.

• Economic and Environmental Geology
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• v.32 no.2
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• pp.189-201
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• 1999

Paleomagnetic and rock magnetic investigations have been carried out for the Cretaceous Hanyang Group, exposed in the Yongyang Sub-Basins within the Kyeongsang Basin, eastern South Korea. A total of 452 oriented core samples was drilled from 31 sits for the study. The in-situ site mean direction is more dispersed than the mean direction after bedding correction, indicating that the fold test is positive at 95% confidence level. In addition, the stepwise unfolding of the characteristic remanent magfold test is positive at 95% confidence level. In addition, the stepwise unfolding of the characteristic remanent magnetization reveals that a maximum value of k is observed at 90% unfolding. Furthermore, the rock magnetic investigations and electron microscope observations of the representative samples show that the main magnetic carrier of the Hayang Group is the detrital specular hematite of single and pseudo-single domain sizes with negligible contribution of pigmentary hematite grains. These results collectively imply that the ChRM direction is the primary component acquired at the time of the formation of the strata. Provided the primary nature of the ChRM, a magnetostratigraphic correlation between polarities of the studied formation and the Geomagnetic Time Scale indicates that the Hayang Group in the Yongyang Sub-Basin can be correlated to the Cretaceous Long Normal superchron. The paleomagnetic pole position from this study is significantly different from those of the Hayang group in the Euiseong the Milyang sub-Basins. Rather the paleomagnetic pole position of the Hayang Group of the study area is closer to that of the Quaternary period or present time of the Korean Peninsula. It is hypothesized that the study area might be rotated about 25$^{\circ}$ aticlockwise with respect to the Euiseong and Milyang Sub-Basins after the formation of the strata and aquisition of the ChRM, although there is not enough geologic evidence supporting the rotation hypothesis.

• Economic and Environmental Geology
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• v.36 no.1
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• pp.9-15
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• 2003

Two piston cores, obtained from the southwestern Ulleung Basin in East Sea, were analyzed to study the geochemical characteristics of the late Quaternary sediments and to detect any changes in sedimentary environment. The results show that the capacity of Total Organic Carbon is remarkably higher (average 1.8%) than that known from general open-sea. According to tephrochronology from known eruption ages, the sedimentation rates are high, ranging from 12.1 to 14.9 cm/kyr. The ratios of nitrogen and TOC (average 6.18-7.42) imply that the organic matter in the study area would be of oceanic origin. The correlation between sedimentation rates and sulfur contents suggests that the study area may be on the whole anoxic and somewhat high in primary productivity. During the Termination 1, inflows of organic matters were high. The sedimentary environments are characterized by rapid rates of sedimentation, and high anoxic values were compatible with accumulation of organic matters.

• Journal of Korean Society of Disaster and Security
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• v.12 no.4
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• pp.53-61
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• 2019

Occurrences of debris flow are a serious danger to roads and residential located in mountainous areas and cause a lot of property loss. In this study, two basins were selected and spatial data were constructed to simulate the occurred debris flow from mountainous areas. The first basin was to use the Terrestrial LiDAR to scan the debris flow occurrence section and to build terrain data. For the second basin, use drones the sediment in the basin was photographed and DSM (Digital surface model) was generated. And to analyze the effect of the occurrence of debris flow on downstream side, FLO-2D, two-dimensional commercial model, was used to simulate the flow region of the debris flow. And it was compared with the sedimentation area of terrestrial LiDAR and drone measurement data.

• Economic and Environmental Geology
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• v.20 no.3
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• pp.203-209
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• 1987

The gravity measurement has been conducted at 69 points with an interval of about 1km along the national road between Masan and Busan through Kimhae to study on the subsurface geology and structure of Kyongsang basin. The Bouguer gravity anomalies were obtained from the observed gravity values, and interpreted by means of the Fourier-series method and Talwani method for 2-dimensional body. The depth of Conrad discontinuity is about 14.8km at the west end of survey line, and increases smoothly to about 13.6km at the east end. But it is uplifted by about 500m between Yangsan and Dongnae faults. The depth of the basement of Kyongsang basin is about 4.8km at the west end. It decreases gradually passing Masan, and reaches the maximum depth of 5.6km at the 15km east of Masan. Hereafter, it starts to increase to 4.3km at the east end. It is also uplifted by about 500m between Yangsan and Dongnae faults. The Bulgugsa granites which cause two low Bouguer gravity anomaly zones are distributed in the vicinity of Masan at depth of about 3.5km and Kimhae area at depth of about 5.3km. Diorite, granodiorite, aplite, and felsite are distributed with various depth of about 1~1.7km, and Jusasan andesitic rocks, except porphyritic one located at the west of Kimhae, are distributed with depth of about 1km. Three fracture zones associated with faults are located at the places where v-shaped Bouguer gravity anomalies are appeared.