• Journal of Korea Water Resources Association
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• v.41 no.8
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• pp.797-806
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• 2008

The geometric properties of the drainage structures are analyzed through depicting the drainage network which is composed of the whole drainage paths in the natural basin defined at the specific scale. The theoretical consideration is performed on the general structures of networks organized by ramification process based on Fractal tree and Horton's law. The drainage network is generated via ArcGIS, ordered by Strahler's ordering scheme and investigated with Strahler's order. As a results of the Richardson's method it is shown that there may exist the distinct behavioral characteristics between overland-flow and channel flow and the natural stream networks would be space-filling Fractals. As a result, it is shown that the values estimated by considering the overland-flow on being applied to the field data give the different results from the empirical method applied until now. As expected, therefore the results obtained from this study are sure to be devoted further researches on the channel networks.

• Journal of Korean Society for Geospatial Information Science
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• v.20 no.1
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• pp.13-20
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• 2012

In this study, the change pattern of hydrological response function as development has been observed. The target watershed was selected Tanbu sub-Basin in the Bocheong Basin. The applied channel networks are composed of 10 cases that are channel networks by strahler's ordering scheme and cases of all grids channel or the hillslope in basin. To each case of grid in basin, channel and hillslope drainage path lengths to outlet of basin are calculated, and hydrological response function was calculated by Nash Model. As results of this analysis, the peak discharge of hydrological response function is increased and peak time is shortened as development of channel networks. And based on statistical characteristics of hydrological response function, mean (lag time) and variance of travel time are reduced exponentially.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.385-394
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• 2011

In this study, optimal parameters of diffusion-analogy GIUH were calculated by separating channel and hillslope from drainage structures in the basin. Parameters of the model were composed of channel and hillslope, each velocity($u_c$, $u_h$) and diffusion coefficient($D_c$, $D_h$). Tanbu subwatershed in Bocheong river basin as a target basin was classified as 4th rivers by Strahler's ordering scheme. The optimization technique was applied to the SCE-UA, the estimated optimal parameters are as follows. $u_c$ : 0.589 m/s, $u_h$ : 0.021 m/s, $D_c$ : $34.469m^2/s$, $D_h$ : $0.1333m^2/s$. As a verification for the estimated parameters, the error of average peak flow was about 11 % and the error of peaktime was 0.3 hr. By examining the variability of parameters, the channel diffusion coefficient didn't have significant effect on hydrological response function. by considering these results, the model is expected to be simplified in the future.

• Water for future
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• v.25 no.4
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• pp.97-107
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• 1992

The purpose of this study is to estimate the flood hydrograph and runoff at ungaged small watershed by using interactive program with geomorphologic and climatic data obtained from the topographic maps following the law of stream classification and ordering by Horton and Strahler. The present model is modified from Allam's interactive program which derives the geomorphologic instantaneous unit hydrograph(GIUH). This program uses the results of Laplace transformation and convolution integral of probability density function in travel time at each station, This program is used to estimate the time to peak, the flood discharge and the direct runoff at San seong station in Bocheong Stream.

• Journal of Korea Water Resources Association
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• v.30 no.1
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• pp.75-82
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• 1997

The stream morphologic characteristics of Wonju stream with small watershed are developed with a regular correlation referred to the Horton-Strahler's lows of stream order. Using Manning's formula and the discharges simulated by NWS-PC rainfallrunoff model that has been applied to the adjacent basin for model calibration and verification, the hydraulic characteristics at Wonju bridge are investigated. The peak discharge and the time to peak of unit hydrograph are analyzed by the calculated geomorphologic parameters. Rather primitive as this study is, these results are provided to be used for geomorphologic instantaneous unit hydropraph of ungaged basins including this study area. Through the reestablishment of rating curve and hydrograph with continuous field observations, the hydrologic and hydraulic characteristics of Wonju stream must be presented.

• Spatial Information Research
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• v.10 no.1
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• pp.107-122
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• 2002

Hydrological characteristics would be utilized to apply such as hydrologic modelling or basin management. This study is to extract hydrological characteristics through DEM and stream network analysis using a hydrologic unit map and digital topographic map in Milyang river basin. OEM and stream network was generated from digital topographic map. Especially stream network was allowed direction, stream order, and topology. As a result of the study, it shows that Milyang river has been changing geologically mature stage into old phase and the landform of Milyang river correspond to Horton-Strahler's law on morphology of stream. This methodology can be applicable to other areas related to hydrological characteristics with vector data.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1174-1178
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• 2010

확산-유추를 기반으로 한 지형학적 순간단위도의 유역의 동역학적 매개변수인 특성유속과 확산계수를 실제수문사상과 수치지형도상의 실제 하천망(Blue line)을 이용해 전역최적화 기법인 Shuffled Complex Evolution(SCE-UA)을 적용하여 산정하여 이를 하천망의 해상도에 따른 유역의 수문응답의 특성을 살펴본 결과 동일한 산정된 유속조건하에서 하천망의 해상도가 커짐에 따라 첨두시간과 지체시간은 작아지는 반면 첨두유량은 커지는 현상을 보였으며, 순간단위도의 형상을 결정짓는 유하시간 분포의 분산은 동수역학적 분산에 비해 지형학적 분산에 지배적인 영향을 받음을 알 수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.1
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• pp.55-64
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• 1987

The schemes synthesizing the instantaneous unit hydrograph(IUH) are presented by using the geomorphologic parameters of a basin. To this end, the channels in the network are numbered according to the Strahler scheme, and the mathematical formulation corresponding to a dynamic probability theory for deriving the geomorphologic IUH(GUH) is refered to the existing techniques adopted by Rodriguez-Iturbe and Valdes. Also, the mean runoff velocity is applied for expressing a dynamic state of flow. The applicability of the GUH to the real drainage basins is tested by using the data observed in a few basins with areas of the order of 9.2, 20, 33.63, and $109.73km^2$ in Korea. The test is carried out by checking the discrepancies between the observed and simulated values for the peak discharge and its time of occurrence which are the most important parameters of an IUH by varing the mean runoff velocity and the inputs. As a result, good agreement is found between them, and it is shown that the variability in peak discharge of hydrograph depends on the mean runoff velocity more than the constant loss rate.

• Water for future
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• v.10 no.1
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• pp.71-77
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• 1977

The stream morphological characteristics of a watershed play a significant role in the analysis of rainfall-runoff relations in a river basin and a quantitative description of these characteristics is essential for determining the appropriate values of physical parameters of a watershed which usually are input data for rainfall-runoff simulation models. In this study the stream morphological characteristics of the Gab River basin, which is one of the three major tributaries of Geum River, was determined quantitatively by the Horton-Strahler's method. The result showed that the Gab River System was developed very closely to the patterns generally described by the laws of Horton. The basic relations concerning the morphological characteristics deriveed in this study are the relations of stream length, and average stream slope, the stream length-drainage area relation, relative height-relative drainage area relation, and the relation between the proportional stream order and drainage area. No correlation analysis was possible between the morphological parameters and the streamflow due to non-existence of the stage gauging stations on the Gab River System.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.55-66
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• 1989

The purpose of this study is to estimate the flood discharge and peak time by the SCS method and the probability method using the geomorpologic parameters obtained from the topographic maps following the law of stream classifying and, ordering by Horton and Strahler. The SCS method and the probability method are used in estimating the times to peak and the flood discharges at An-dong, Im-ha, and Sun-san basins in the Nakdong River system. The results obtained are as follows : 1. The range of the values of the area ratio, the bifurcation ratio and the length ratio agree with those of natural streams presented by Horton and Strahler. 2. Comparisons of the probability method and observed values show that small relative errors of 0-7% of flood discharge, and 0-2hr, difference in time to peak respectivly. But the SCS method shows that large relative errors of 10-40% of flood discharge, and 0-4hr, difference in time to peak. 3. When the rainfall intensity is large, the error of flood discharge estimated by using the probability method is relativly small.