• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.23-33
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• 2005

Hydrologic-topographical parameters were extracted using GIS. The use of GIS is more effective and exact than the execution by person. And the purpose of this paper is to extract more efficient size of grid for DEM analysis by applying GIS technology. As a result, when the grid size is less than $100m{\times}100m$ the trend of extracted parameters is similar but when the grid size is over $100m{\times}100m$ the trend of extraction parameters is dispersive. Therefore, it is appropriate to extract hydrologic-topographical parameters the grid size of $100m{\times}100m$ in DEM analysis.

• Water for future
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• v.20 no.2
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• pp.139-150
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• 1987

The present study is to develop the hydrologic analysis procedure for the purpose of drawing the probable isohyetal charts in Korea. In the establishment of optimal distribution types, the eleven continuous probability distribution types included the transformed variable normal distribution (Y-k method) is applied to the annual maximum rainfall depth series in each duration. The optimal selection of distribution is done by Chi-square test and Kolmogorov-Smirnov test in the eui-class interval. The application of probability distribution is checked by the fitting on four durations of annual maximum rainfall data(10 min., 60 min., 6 hrs., and 24hrs.) at four meteorological stations in Korea (Seoul, In Cheon, Bu san, and Kwang Ju). The properties in hydrologic application of the considered distribution and the hydrologic characteristics of the applied rainfall data groups are investigated from the results of this study.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.27-38
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• 2012

This study is to analyse the hydrological behavior of agricultural reservoir using CAT (Catchment hydrologic cycle Assessment Tool). The CAT is a water cycle analysis model in order to quantitatively assess the characteristics of the short/long-term changes in watershed. It supports the effective design of water cycle improvement facilities by supplementing the strengths and weaknesses of existing conceptual parameter-based lumped hydrologic models and physical parameter-based distributed hydrologic models. The CAT especially supports the analysis of runoff processes in paddy fields and reservoirs. To evaluate the impact of agricultural reservoir operation and irrigation water supply on long-term rainfall-runoff process, the CAT was applied to Idong experimental catchment, operated for research on the rural catchment characteristics and accumulated long term data by hydrological observation equipments since 2000. From the results of the main control points, Idong, Yongdeok and Misan reservoirs, the daily water levels of those points are consistent well with observed water levels, and the Nash-Sutcliffe model efficiencies were 0.32~0.89 (2001~2007) and correlation coefficients were 0.73~0.98.

• Korean Journal of Hydrosciences
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• v.7
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• pp.21-35
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• 1996

This Study is to develop the suitable hydrologic models for determination of the size and location of detention storage facilities to restrain stormwater runoff in urban areas. Hypothetical areas of two levels are considered to seize the hydrologic response characteristics. A one-square-kilometer ares is selected for the catchment level, and a 10-square-kilometer area consisting of 10 catchments is adapted at the watershed level as representative of urban drainage area. In this analysis, different rainfall freqyencies, land uses, drainage patte군, basin shates and detention storage policies are considered. Folw reduction effect of detention storage facilities is deduced from storage ratio and detention basin factor. A substantial saving in detention storage volumes is achieved 노두 the detention storage is planned at the watershed level rather than the catchment level. For the application of real watersheds, two watersheds in Seoul metropolitan area-Jamshil 2 and Seongnae 1-are selected on the basis of hydrologic response charactaristics. Through the regression analysis between dimensionless deterntion storage volume, dimensionless upstream area ratio and reduction rate of storage ratio, the regression equations to determine the size and location of detention storage faclities are presented.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.5
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• pp.81-90
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• 2007

Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.

• Journal of the Korean Solar Energy Society
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• v.32 no.4
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• pp.59-64
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• 2012

The correlation between hydrologic performance design parameters of small hydro power(SHP) sites and rainfall condition have been analyzed for major river systems. The model, which can predict flow duration characteristic of stream, was developed to estimate the inflow caused from rainfall. And another model to predict hydrologic performance for SHP plants is established. Based on the models developed in this study, the hydrologic performance characteristics for SHP sites have been analyzed. The results show that the hydrologic performance characteristics of SHP sites have some difference between the river systems. Especially, the specific design flowrate and specific output of SHP sites located on North Han river and Nakdong river systems have large difference compared with other river systems. It was found that the hydrologic performance design parameters such as specific design flowrate and specific output were affected by rainfall condition in basin area of SHP sites.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.1326-1330
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• 2004

This study analyzes the rubber-dam of hydrologic character to be located in a Nagdong-river main stream in Dasamyeon Juggogli of the Dae-gu global city lot the river environment monitoring. The purpose of this research investigates the influence according to the rubber-dam install scientificly. A result natural disposition, prepare the gauge to matte the width of the area of the understanding and the computation of the rating which Apply is possible. Into the result of this research, $Q=898.8h^2-26126h+189886$ edge was computed to the rating. Also this study use the now rate to get for an upside expression and analysis a water balance. Through the officer to be efficient a hereafter seminar zero and processing of the data to be acquired, the supplementation so that this study can share the data to the online. High practical use of the The self-governinig body of the data and data confirmed report which loses in the trust will be achieved.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.683-686
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• 2008

Flood damage has been increased due to the abnormal climate and extreme rainfall. So, quantitative and qualitative hydrologic data should be improved in oder to enhance accuracy of hydrologic forecast. However, research regarding hydrologic data have not been thorough enough. Therefore, in this study, monte carlo simulation was applied to rainfall runoff model to improve the reliability of runoff analysis and risk analysis. Rainfall-Stage-Discharge curve was developed as a consequence of MCS and it is possible to get correct rating curve for high water level.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.654-660
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• 2012

The goal of this paper is to calculate flood elevation by applying temporal distribution of rainfall through HEC-RAS(Hydrologic Engineering Center's River Analysis System) and to automatically create areas of flooding by a user-defined spatial model based on GIS using calculated values of flood elevation and detailed data of topography. Accuracy of topographic data is the most important factor because of deeply changing analysis results of flooding areas of a river. Therefore, this paper suggests a method of attributive and spatial data construction based on the GIS using UIS(Urban Information System, river-related reports, and hydrologic information. Also, we implement an expression system to provide analysis results extracted from the proposed model.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.4
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• pp.517-526
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• 2018

As groundwater recharge shows the heterogeneity in space and time due to land use and soil types, estimating daily recharge by integrated hydrologic analysis is needed. In this work, the SWAT-MODFLOW model was applied to compute daily based groundwater recharge in Jangseong region. The accuracy of the model was evaluated by comparing the observed and calculated values of the unsteady groundwater flow levels after calibrating the observed and calculated flow rates of the stream for a hydrological analysis. The estimated hydrologic components showed a strong correlation with each other and significant spatial variations regarding the groundwater recharge rate in accordance with the heterogeneous watershed characteristics such as subbasin slope, land use, and soil type. Overall, it was concluded that the coupled hydrologic models were capable of simulating the spatial variation with respect to the hydrologic component process in surface water and groundwater. The average recharge rate was estimated at approximately 20.8%.