우리나라 홍수량(洪水量) 공식(公式)들의 비교연구(比較硏究)

고재웅,Ko, Jae Ung 대한토목학회 1988 대한토목학회논문집 Vol.8 No.1

The design flood formulas in Korean river are reviewed from the early historical stage of the river improvement projects to the present situation. The 11 different formulas are selected for the comparative purpose of the each results at the same rainfall and basin characteristics under the same size of the basin. The max. and min. values of the design flood discharge for the same basin deviated almost as large as 400% according to the formula used without respect to the basin size. The remains have big scattering within those deviations. The steps to derive the design flood are very complicated and tedious time consuming process at present applications. However the reaults computed through the steps are quationable in accordance with the lengths of the hydrological historic records and the accuracy of the data observation technique in view of the engineering judgement. The purpose of this review will give the one of the simplest and the reasonable approach to eliminate misleading the determination of the design flood peak. 우리 나라의 하천종합개발계획(河川綜合開發計劃) 수립의 기준이 되는 계획홍수량(計劃洪水量) 결정수단으로 활용되어 왔던 홍수량공식(洪水量公式) 들을 조사하였다. 이들 가운데 11종(種)의 홍수량(洪水量) 공식(公式)을 선정하여 유역규모(流域規模)에 따른 계획비홍수량(計劃比洪水量)을 계산 비교하였다. 강우조건과 유역조건이 가능한 범위까지 같은 경우가 될 수 있게 하여 검토한 바 같은 유역에서 극치들의 변동폭이 400%나 되는 편차를 가지며 이런 범위안에서 각공식 별로 서로 많은 차이를 보여 주게 됨을 알 수 있었다. 지금 쓰이고 있는 홍수량(洪水量) 산정의 절차는 무척 복잡하고 많은 노력(努力)을 거쳐서 어렵게 결정하고 있으나 성과(成果)는 사용된 수문자료(水文資料)의 기간(期間)이나 정도(精度)에 좌우되어 공학적(工學的)인 판단(判斷)의 타당성이 결여된 경우가 많았음을 경험하였다. 따라서 보다 단순하면서 합리적(合理的)인 수단의 개발을 기왕의 홍수량(洪水量) 공식(公式) 비교에서 얻을 수 있었다.

韓國河川 洪水流量의 頻度分析에 관한 연구

高在雄(Ko Jae Ung) 대한토목학회 1977 대한토목학회지 Vol.25 No.4

한국하천의 홍수빈도분포형 비교 연구

강권수(Kang Kwon Su),고재웅(Ko Jae-Ung) 대한토목학회 2003 대한토목학회 학술대회 Vol.2003 No.10

포스터 발표 : 수질관리 ; SRT 시스템에 의한 비점오염물질 처리능력 평가

최이송 ( I Song Choi ),오종민 ( Jong Min Oh ),장준영 ( Jun Young Chang ),고재웅 ( Jai Ung Ko ),박재영 ( Jae Young Park ) 대한상하수도학회 2006 공동추계 학술발표회 논문집 Vol.2006 No.-

우리나라 河川의 形態學的 特性과 流出

高在雄 建國大學校 附設 産業技術硏究所 1992 논문집 Vol.17 No.-

The morphological characteristics and main channel bed slopes are evaluated. The main result of correlation between catchment area and main stream length in Korea is good agreement with given by Eagleson(1970). The flow resistance equations available for this purpose are Mannings and Chezy formula and those are reformed using geometry of main channel cross sections. Energy slopes for the conditions of design flood are expressed in the functions of river length. Data from Naktong and Geum River are used to derive the standardized design width of the each cross sections. The coefficient of river characteristics are defined to compute the discharge and also the width of the design flood for the purpose of higher accuracy of the formula. This approximation could be used to the design width of the river based on morphological and geometrical characteristics of the river system.

韓國河川의 洪水特性에 관한 硏究

高在雄,文濟吉 건국대학교 1979 學術誌 Vol.23 No.2

This study presents the hydrological and statistical Analysis of the flood charateristics in Korean Rivers. The area selected for study were Han, Naktong, Geum, Yeongsan, and Seomjin River. Twenty four gauging stations in the rivers were selected for the analysis of the basin max. daily rainfall and food peak discharge records. The purpose of this study was to set up the accurate way of estimating the frequency of the max. daily rainfall and flood peak discharge of the basin. The following five methods of the rainfall frequency analysis were applied to each station; 2 parameter lognormal, 3 parameter lognormal, Type I extremal (Gumbel method), Pearson Type III, and log-Pearson Type III. The regression equations were established between the depth of max. daily rainfall given any reccurrence interval and the basin area. Three methods of flow frequency analysis currently in common use were applied in this study, the Hazen, Type I extremal, and log-Pearson Type III. The three methods involved not only the computation of the statistics appropriate to the distributions, but alto the relating of these statistics to basin and climatologic characteristics. Methods for regional analysis were used for this study to compare the results of regional flood frequency made by three methods and appraises the relative reliability of these methods. The correlation graph and the dimensionless flood frequency curves are the end products of this analysis. On the basis of the regional study of the rainfall frequency and the flood frequency, the following conclusions were reached : (1)The larger the basin area are the less the depth of rainfall for same recurrence interval based upon the results of the rainfall frequency analysis of the max. daily rainfall in the basins. (2)There are no significant differences between each basin in rainfall depth for same recurrence interval. Derivation of the depth of indicated recurrence interval are estimated as follows : P100 = 725A-0.140 P50 = 595A-0.128 P20 = 415A-0.114 P10 = 355A-0.101 P5 = 280A-0.093 P2 = 150A-0.056 (3)Three parameter lognormal is the best fits probability function for the frequency analysis of the max. daily rainfall statistics in Korean Rivers. (4)Combining records for all stations in a hydrologically homogeneous area tends to reduce the sampling error associated with a non representative sample. The results of the regional flood frequency study provides the meaningful yardsticks for determining the design flood. (5)The mean annual flood, defined as the discharge corresponding to a recurrence intervall of 2.33 years are each correlated with basin and climatologic parameters in the homogeneous region. Only drainage area was the statistically significant parameter. Regression equations for Q2.33 are obtained as follows. Han River Basin : Q2.33=5.53A0.772 Naktong River Basin : Q2.33=43.16A0.492 Geum River Basin : Q2.33=20.28A0.593 Yeongsan and Seomjin : Q2.33=1.36A0.972 (6)The most remarkable results pointed out in this study is the coincidence of the regional flood frequency curves for the five river basins. This means that the whole Korean Rivers have the hydrologically homogeneity. (7)Advantages of the regional flood frequency relation and max. daily rainfall frequency derivation in thin study are that those relation can be applied to ungaged sites in the region wherever.

log-Pearson Type Ⅲ에 의한 洪水頻度解析

高在雄 건국대학교 부설 산업기술연구소 1976 논문집 Vol.2 No.-

The principle of analyzing flood magnitudes on a probability basis is almost universally accepted because its use permits economic consideration, as well as hydrologic factors, to govern the planning and design of water use or control projects. The methods of flood frequency analysis currently in common use are the Hazen, Pearson Type Ⅲ, Gumbel, Gamma and graphical distribution-free method. There is no universal acceptance of any single method of making the flood frequency analysis. Flood frequency methods are continually modified or applied in new way for specific engineering applications. The Hydrology Committee of the United States Water Resources Council recommended the log-Pearson TypeⅢ distribution for adoption as a base method for flow frequencies on the basis of current use by Federal Agencies, availability of detailed instructions, computer programs, and flexibility in application. The long-Pearson TypeⅢ distribution was used in this study for determining flood frequencies at 24 gaging stations in the major Korean rivers. Around 20 years annual series of maximum peak discharges at each stations were available for this study. To regionalize the statistics of the log-Pearson Type Ⅲ distribution, mean, standard deviation and coefficient of skew of the logarithms of peak discharge are each correlated with basin in the homogeneous region. On the basis of an application test of the log-Pearson Type Ⅲ distribution for flood frequency analysis in Korean rivers, the following conclusions were reached: 1)The value of mean of the peak discharges (M) were correlated with the drainage areas(A) as statistically significant. The regression equation for whole river basins are as follows: M= ?? or logM=0.906+0.698logA 2)The use of weighted mean of the value of standard deviation within a basin of hydrologic homogenuity were arrived reasonable results. It was founded that the poor correlation results between the value of standard deviation of the annual max. series of peak discharges and drainage areas were resulted. 3)The coefficient of skew varies from-1.6 to 0.5 which means that the zero coefficient of skew as in the United States are hardly expected in Korean rivers. 4)Because the flood events for a single station is a short random sample, it may not be representative of the long-term distribution of flood series at the gaging station. Combining records for all stations in a hydrologically homogenous area tends to reduce the sampling error associated with a non representative sample. 5)Advantages of this study is that it can be easily applied to ungaged sites in all Korean rivers as a base method of flood frequency analysis.

流砂의 始動에 관한 實驗的 硏究

高在雄 건국대학교 부설 산업기술연구소 1984 논문집 Vol.9 No.-

The initiation of sediment transport is determined from an "average Shields curve" at the present. A Considerable amount of scatter of experimental points in average Shields curve by many authors is mainly due to the inconsistency in the determining of the critical stage, and the fact that the experimental results corresponding to granular materials possessing different geometric properties are plotted on the same system of coordinates. In this paper experimental runs for twenty different size distibutions of sand bed materials were performed in 12m long and 0.5m wide channel and slope adjustable. The bed materials used in the experiements were natural river sand. The mixture of the grain size range from 0.019 mm to 6.0 mm. Five family of the dimensionless grain size distribution curves are represents the twenty different size distributions. The study results show the fairly well agreement with Yalin's suggestion. In this paper five family of Shields curve has been established where each individual curve would represent a particular geometry of granular material. Then the critical tractive force was correlated with the median size of the granular bed materials. The relationship is concluded as follows; ?? = 0.009 ??

漢江下流部 水害輕減을 爲한 調査 硏究

金漢星,高在雄,李相鎔,玄義泰,柳興根 건국대학교 1974 學術誌 Vol.17 No.1

The effect of reducing flood magnitudes, flood stages, and flood damage by upstream reservoir regulation are investigated in this study. The analytical procedures which has been established newly, are treated through this study for 7 index stations and same numbr of reaches. The method of this study could be expressed briefly as following procedures. Using stage-frequency relations and the potential damage survey data, damage-frequency relations are established, and from this, average annual flood damages computed. By holding out portions of the floods with various amounts of flood control storage in 6 reservoirs in the basin, routing were made to establish modified stage-frequency relations. From damage frequency relation, average annual damages are computed with and without condition of each control volume. The study result are concluded as follows; (1) The relationtship of corresponding water level between nearby stations are useful tools to adjust error of the data due to observation error and change of the gaging location. (2) The number of records about 10 years could not be applied for the statistical methods of flood frequency analysis. (3) The regional skew factors are recommended to apply flood frequency study by the log-Pearson Type III method. (4) The effect of damage reductions are greatly affectedin accordance with the routed flood. Therefore application of the Typical Tributary Contribution Flood are reasonable for this type of study. (5) In the North Han, effect of damage reduction due to the lacation of control point are gradually increased from upstream to downward until the confluence of North and South Han. (6) In the South Han, control effect are increased from Chungju to Yeoju where the maximum effect are analyzed and then decrease gradually until the confluence. (7) Better hydrologic and topographic combinations for the flood control are existed in South Han to compare with North Han in this study results.

人工輕量骨材 콘크리트의 强度特性에 關한 基礎的 硏究

文濟吉,高在雄 건국대학교 1980 學術誌 Vol.24 No.2

Cement concrete is widely used as typical construction material through its high compressive strength and durability. In spite of its numerous advantages, it has some restrictions to use as structural materials due to its heavy weight. Recently, the rapid advance of modern science and technology made the structures became mammoth type on a scale. Therefore, it has been urged to reduce the weight of concrete so as to reduce the weight of aggregate so called Light-Weight aggregate. Moreover, the extensive shortage of natural aggregate and the increase in social needs of the protection of nature have made the development of the artificial light-weight aggregates an urgently confronted subject. In this paper, the compressive strength, tensile strength, bending strength, young's modulus and poison's ratio of Artificial light-weight aggregate concrete (specimens 10cm × 20cm sylinders and 15cm × 15cm × 60cm beams) were studied. Then the crack growth and stress distribution, deflection of the Artificial light- weight aggregate reinforced concrete (beam 10cm × 20cm × 180cm) under the loading conditions. The study results are concluded as follows : 1.The specific gravity of the artificial light-weight aggregate was 1.16, and the unit weight of the concrete was about 1.8 t/m3. 2.The slump values were about 1.5cm in the case of the cement content 340 kg/m3 and the water cement ratio 55%. 3.The compressive strength of the concrete was related to the cement content of a given slump rather than water cement ratio, therefore the volume of the cement is more than that of normal weight concrete to produce the required strength. In the case of a given cement content and slump, the more the natural sand was used, the more the compressive strength was increased. 4.The strength ceiling was improved by reducing the maximum size of aggregate. 5.The tensile strength was about 12 percent of the compresive strength. 6.The bending strength was about 20 percent of the compressive strength and it ranged from 1.5 times to 1.8 times of the tensile strength. 7.The modulus of elasticity was higher than that of equal weight concrete derived from the formula. 8.The Poison's ratio were ranged from 0.17 to 0.20. 9.The deflection of reinforced concrete beam was similar to the value calculated by the formula of initial deflection using the modulus of elasticity up to 40% of the maximum load of low part, and was similar to the value by the formula of initial deflection using the secant modulus as each stresses per straines of concrete above 40%.