• The Journal of Engineering Research
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• v.8 no.1
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• pp.107-118
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• 2006

The difficulties to build a 3-dimensional water quality model for the coastal water quality improvement and the environmental recovery estimation are the lack of periodic observed data and the many problems to observe continuously. I observed the rainfall and non-point pollutants outflow patterns in Jinhae-Masan basin as mid-step researches for the water quality simulation and management method development in a coastal area. I applied Landsat image system and Geographic Information System to analyze the runoff and non-point pollutants outflow patterns. A water quality simulation model (SWMM) applied to Jinhae-Masan basin with results of the land use distribution, non-point pollution loads, and watershed informations from GIS(IDRISI used). I proposed some improved survey and GIS application methods reflect upon the pollutant characteristics from the observed non-point pollutant outflow patterns.

• Water for future
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• v.14 no.3
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• pp.37-46
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• 1981

The purpose of this paper is to provide a method of estimating the magnitude and frequency of floods on five major streams in Korea such as the Han, the naktong, the Geum, the Seomjin and the Yeongsan. Derivation of the flood frequency formulae is based on the multiple correlation method. For each gaging station in the region, flood frequency curves are drawn by GumbelChow and Weibull plot. where 24 gaging stations are selected for this study. After the station flood-frequency cruves have been prepared, discharges are read at selected recurrence intervals. Each set of discharges is then correlated with basin parameters, using regression equation. The basin parameters that are considered include drainage area, length of main stream, shape facotr, mean basin slope and main channel slope.

• Journal of Soil and Groundwater Environment
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• v.15 no.6
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• pp.1-8
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• 2010

The groundwater level distribution and characteristics of responses to rainfall were examined in the Haean basin of Yangu that has a single stream exit to the east. The groundwater levels showed a circular or elliptical distribution converging the center of the basin with different hydraulic gradients in the north and south regions. The waterlevel elevations exhibited a perfect correlation with topographic elevation ($r^2=0.99$) while the depth to water showed a rather weak correlation ($r^2=0.49$). The water table fluctuation (WTF) method yielded recharge ratios of 6.1~12.65% ($S_y=0.02$) and 15.2~28.5% ($S_y=0.05$). The waterlevels of HG3 well, which is much proximal to a stream, were weakly auto-correlated but they were highly sensitive to direct infiltration from the rainfall event. The shorter regulation times of the HG3 represented a quicker dissipation of the input stress (rainfall).

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.427-435
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• 1999

The Clark unit hydrograph is a three parameter synthetic unit hydrograph procedure that can be used in flood hydrology. The present work is an attempt to estimate parameters of the Clark model in ungaged basin by means of relationships that provides for the hydrologic similarity. The time area concentration curve was determined by analytic method and the Clark model was generalized by being made dimensionless form. Calculation of the concentration time was made with the formula fractal concept used, and the storage coefficient was estimated by the empirical and regional equation. Evaluation on Dongok basin was performed to prove the validity of the proposed model. The derived hydrograph predicted the observed hydrograph fairly well.

• Journal of Korea Water Resources Association
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• v.42 no.1
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• pp.51-60
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• 2009

2/3 of the Imjin River Basin area is located in North Korea, so it was hard to acquire reliable rainfall and hydrological information. This point is one of the factors that has added to flood damage. In this study, flood runoff for the river basin was simulated using hydrological radar, which is installed in an effort to reduce flood damage in the Imjin River Basin, which habitually suffers from flood damage. The feasibility of the distributed flood model was reviewed for the river basin, which is lacking in hydrological data such as rainfall and recent soil data. Based on the hydrograph, observed value was not consistent partially because of insufficient data, but peak discharge and the overall pattern showed relatively precise runoff results which can be applied in actual work.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.237-247
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• 2018

The basin characteristics reflect the attributes of geomorphological pattern of basin and stream networks affect the rainfall-runoff. In order to analyze the relationship between the basin runoff and stream morphometric characteristics, the morphometric characteristics were investigated for 27 water-level observation stations on 19 rivers in the Han River basin using Arc-map. The morphometric characteristics were divided into linear, areal and relief aspects for calculation while the annual mean runoff ratio as a basin response by rainfall was estimated using the measured precipitation and discharge to analyze the rainfall-runoff characteristics. The correlation among the morphometric parameters were schematized to analyze the correlations among them. The multiple regression equation for rainfall-runoff ratio was provided with morphometric parameters of stream length ratio, form factor ratio, shape factor, stream area ratio, and relief ratio and the coefficient of determination was 0.691. The RMSE and MAPE between the measured and the estimated annual runoff rates were found as 0.09, 11.61% respectively, the suggested regression equation showed good estimation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.255-263
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• 2010

In order to prepare the interchange between and the unification of North and South Korea, it is needed to establish the development direction of irrigation reservoirs and formulate technological and political directions for preparing effectively against the demand of agricultural countermeasure information like the analysis of rural comprehensive development projects and the present state of agricultural land of North Korea. The purpose of this research is to construct the database of agricultural productive infrastructures and analyze the present state of irrigation reservoirs of the Yeseong River Basin in North Korea using SPOT-5 satellite imagery. As a result of the research, we were able to not only design classification items but establish method and precedure for producing thematic maps related agricultural productive infrastructure without on-site survey by analyzing present condition related to agricultural water of the basin. And we intend to provide basic data for analyzing suitabile locations of irrigation reservoirs in the basin by performing basin extraction, volume evaluation of the existing reservoirs, scale cultivative lands, benefit area fo the reservoirs, and the existing agricultural water system. In addition, we were able to understand the problem and limit in constructing the database related agricultural productive facilities.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.675-684
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• 1998

This paper presents the empirical formulas for determining the design-width for medium rivers in the Han river basin. The design flood, the watershed ares, and the channel slope of 216 medium rivers in the Han river basin are collected. the design width formulas are then determined by 1) the least squares (LS) method, 2)the least median squares (LMS) method, and 3) the reweighted least squares method based on the LMS (RLS). The six types of formulas are considered to determine the acceptable type for medium streams in the Han river basin. The root mean squared errors (RMSE), the absolute mean (AME) errors, and the mean errors (ME) are computed to test the formulas derived by three regression methods. It si found that the equation related stream width to the watershed area and the channel slope is acceptable for determining the design width for medium streams in the Han river basin. It is expected that the equations proposed by this study be used an index for determining the design-width for medium streams in the Han river basin.

• Journal of Korea Water Resources Association
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• v.33 no.5
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• pp.527-536
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• 2000

This study estimates the pollution load in a basin by regional groups analyzing the relationship between the discharge and pollution load. The study area is placed in the Miho stream basin known as the main tributary of the Kum river. Four major Telemetary streamflow stations are chosen. In this research, discharge and water quality in a dry season and a flood season from the observed discharge in the stream are analyzed. The Rating-Curve and the Pollutograph are drawn analyzing discharge and water quality at the major stations. The characteristics of runoff for each stream are analyzed and the change of water quality are analyzed for rainfall period. The relationship between discharge and water quality has been investigated. The relationship between the discharge and pollution load is analyzed and a representative equation is derived. These relationships permit an estimates of the pollution load at the Miho stream basin. basin.

• Journal of the Korean Geophysical Society
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• v.3 no.1
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• pp.67-74
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• 2000

Subsurface structure of the Bomun basin was studied along three survey tracks of Line-1, Line-2, and Line-3 using geomagnetic, radioactive, and seismic refraction methods. Abrupt changes found at 2.55 km west and 1.6 km east in the profile of magnetic anomaly along Line-1 are correlated with geologic boundary of the basin. Profiles of radioactive intensity also represent abrupt changes at 2.55 km west of Line-1 and at 1.9 km of Line-2. Cretaceous basement rock has relatively high magnetic anomaly of $200\;{\sim}\;500\;nT$ while sedimentary rocks of the Bomun basin have relatively low magnetic anomaly of $-100\;{\sim}\;+100\;nT$. Radioactive intensity also represents charateristic differences between Cretaceous basement and sedimentary rocks of the Bomun basin. Rocks of Cretaceous basement have lower radioactive intensity than the rocks of the Bomun basin. Magnetic anomaly of of the Bomun basin represents lowest anomaly in western part and increases gradullay toward east. This phenomenon is interpreted as a half graben structure dipping westward. Black shale known by previous studies near the western boundary has high magnetic anomalies and low radioactive intensity. This phenomenon provide a possibility of volcanic rock rather than black shale near the western boundary of the basin along Line-1. Sedimentary layers having velocities of 455 m/s, 1904 m/s, and 2662 m/s are developed to have westward dipping of $2.3^{\circ}$ in the central area of the Bomun basin. The result is consistent with a half-graben model dipping westward which were derieved from magnetic anomaly data.