경북지방(慶北地方)의 강수(降水) 및 무강수(無降水) 현상(現象) 조사(調査) 분석(分析)

서승덕,전국진,Suh, Seung Duk,Jeon, Kuk Jin 경북대학교 농업과학기술연구소 1987 慶北大農學誌 Vol.5 No.-

In order to determine the design precipitation, the most probable daily precipitation and annual precipitation at every spot are calculated and iso - precipitation line are drawn. Probability of precipitation and drought phenomena of each gage station are analyzied by the method of frequency analysis from the statistical conceptions. The results summarized in this study are as the follows. 1. Annual mean precipitation in kyungpook area are 1044 mm, about 115 mm less than annual mean precipitation of Korea amounts to l1S9mm, and found to regionally unequal. 2. Monthly mean rainfall of July is 242.2mm, 23.2%, August 174.2mm, 16.7%, June 115mm, 11% and September 114.2mm, 10.9% and Rainfall depth of July-August are more than 40% of annual precipition. This shows notable summer rainy weather by typoon and low pressure storm and seasonal unbalance of water supply. 3. The relation among the maximum precipi.tation per day, per two continuous days and per three contnous days are caculated and the latter is found 31.0% increased rate of the first and the last 48.2% increased rate of first. 4. Probability precipitation in Kyungpook area are shown as 9.0%(5 year), 13.3%(10 year), 17.7%(20 year), 23.1%(50 year), 27.0%(100 year) and 31.1%(200 year) increased rate of each recurrence year compared with observed average annual precipitation. 5. From annual precipitation and maximum daily rainfall data probability of precipitation and precipitation isohyetal line are derived which shown as Table 11 and Fig. 8. 6. Drought days are divided 6 class and analysed results are shown on table 12. Average occurrence time of 10-14 continuous drought days are 2.3 time per year, 15-19 days are 0.9 time per year, 20-24 days are one per six years, 30-34 days are once per nine years and over than 35days are once per 25 years.

항구적(恒久的) 한해대책(旱害對策)을 위(爲)한 전천후농업용수(全天候農業用水) 시설(施設)의 농업수문학적(農業水文學的) 배경조사(背景調査) 연구(硏究) (II) (경북지방(慶北地方) 중심(中心))

서승덕 ( Seung Duk Suh ),권무남 ( Moo Nam Kwon ),이기명 ( Ki Myung Lee ),김조웅 ( Cho Ung Kim ) 한국농공학회 1981 韓國農工學會誌 : 전원과 자원 Vol.23 No.1

농업용(農業用) 저수지수역(貯水池水域)의 수질환경(水質環境) 오염원(汚染源) 조사분석(調査分析)

서승덕 ( Suh Seung Duk ),김동훈 ( Kim Dong Hoon ),윤학기 ( Yoon Hak Ki ) 한국농공학회 1994 韓國農工學會誌 : 전원과 자원 Vol.36 No.3

This tudy is to survey and analysis the water quality phase of Agricultural reservoirs through the case study of 18 reservoirs in Kyungpook Province in preparation for prevention disasters from the environmental hazards such as water pollutions. In these cases, the most hazardous pollution acts were Domestic animals excrements firstly, Human living wastge water secondly, Tourist resort sewage and Fertilize waste etc. in regular sequences. In the analysed results, pH, EC, BOD, DO, Cu, Ph, Cd were less than standard values recommended by the Environmental Authority and so they were estimated in scope of the safety value respectively. But few of factors being gradually closed with the hazardous point in the few places. At present, the hazardous environmental acts originated from the Domestic animals excrements, Human living waste water and Fertilize waste etc. in case the agricultural reservoirs, have to strongly be improved much better than before and prepared safety conditions for the rural living and agricultural life sciences.

유역특성(流域特性)에 의(依)한 합성단위도(合成單位圖)의 유도(誘導)에 관(關)한 연구(硏究)(II)

서승덕 ( Seung Duk Suh ) 한국농공학회 1975 韓國農工學會誌 : 전원과 자원 Vol.17 No.2

농촌(農村)의 환경보전(環境保全)에 관(關)한 조사분석(調査分析)

서승덕 ( Seung Duk Suh ) 한국농공학회 1981 韓國農工學會誌 : 전원과 자원 Vol.23 No.4

This study is to be surveyed the rural environmental conditions such as housing, water works, sewerage, road and farm road, land utilization, natural conservation and sightseeing, public damage and disaster, and rural water requirement through the 50 villages (10995 home unit) The brief results summarized in this study are as follows. 1. Modernization of rural housing, toilet room and arrangement of dust materials are getting better than before 10yrs. 2. Water works are highly improved but sewerage problem is still in the serious problems. 3. Rood achievement is quite good but farm road is in still insufficiency 4. Utilization of land resources should be maximaized but land conservation is still insufficient condition and farm land is getting polluted. 5. Natural environmental conservation is much more improved but landscape is still insufficient. 6. Public damages such as water pollution, air pollution, and others are getting greater and greater but meteorological damage should be decreased. 7. Watershed condition is getting better and better but because of the large requiriment of the water use for the crops, agricultural water use should be needed much more than before 10yrs.

수심적분법에 의한 유사량 추정연구

서승덕 ( Suh Seung Duk ),김활곤 ( Kim Hwal Gon ),우효섭 ( Woo Hyo Seop ) 한국농공학회 1996 韓國農工學會誌 : 전원과 자원 Vol.38 No.1

In Korea, total sediment discharge of a river has been estimated simply by using certain sediment transport formulas including, among others, Einstein's formula. Those formular, however, are known not to be reliable enough for the result calculated by them to be used directly to river planning and management. Therefore, the study used the Modified Einstein Procedure to the estimation of total sediment discharge, because this method is reliable estimated by measurement. Here, measurement of sediment discharge used depth integrating method. The major results obtained from the study for estimation by depth integrating method of sediment discharge in Naeseong stream are as follow; 1. The sedeiment characteristics of Naeseong stream are; The distribution of sediment grain size shows that silt and clay are 55% and sand is 45%, and the bed load sediment grain size is constituted that sand contained with the grain size from 0.062mm to 2.0mm is 80% 2. The sediment rating formulas derived from the regression analysis between the sediment discharge and flow discharge are; Seogpo-Gyo : Qs=0.017×10^-4 Q^2.352, where discharge is 10cms<Q<100cms. Songriweon-Gyo : Qs=0.074×10^-4 Q^2.066, where discharge is 10cms<Q<120cms. 3. The sediment discharge fluctuates with the wider range variation than the flow discharge does. As the rate of flow discharge increased, the portion of suspend load in total load increased as well.

경북지역(慶北地域) 농촌공업화(農村工業化) 단지조성사업(團地造成事業)이 지역개발(地域開發)에 기여(寄與)하는 영향평가(影響平價)

서승덕 ( Suh Seung Duk ),천만복 ( Chun Man Bog ),윤학기 ( Yoon Hak Ki ),윤경덕 ( Yoon Kyung Duk ) 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.4

Government has propelled strongly the Agricultural - cum - Industrial region development project in the nation wide. This project will not only provide employment opportunity for rural inhabitants, but also be designed to activate the rural economy. In addition, it will lead to a balanced development between the urban and rural areas. Under this project, building sites of 3 to 30 hactres will be established in the rural area in order to settle factories which are suitable to the rural condition. In this report, the researches which relating to the achievement conditions of planning, design and constructions of the building sites and the contribution conditions of Agri. - cum - Industrial Region development prejects, activated to the rural economy and regional develop ment in the Kyungpook regional areas, were surveyed and studied. On the average evaluation studies the results are as follows : 1. The achievement conditions of the planning, design and construction of the building sites. Very good-27.0 % Good-47.0% Fair-24.0 % Poor-2.0 % 2. The contribution conditions of the Agri. - cum - Industrial factories managements. Very good-17.0 % Good-41.0 % Fair-32.0 % Poor-10.0 %

유역(流域)의 지상적(地相的) 요인(要因)과 저수지(貯水池) 비퇴사량(比堆砂量)과의 관계분석(關係分析)

서승덕 ( Suh Seung Duk ),임흥익 ( Lim Heung Ik ),천만복 ( Cheon Man Bock ),윤경덕 ( Yoon Kyung Duk ) 한국농공학회 1988 韓國農工學會誌 : 전원과 자원 Vol.30 No.4

The purpose of this study is to develop regression equations between annual specific sedi- ment of reservoirs and physiographic factors of watersheds. 122 irrigation reservoirs, which have irrigation areas equal to or larger than 200 ha, located in Korea except Cheju province are used in the analysis. Simple regression analyses between the specific annual sediment and each of the physical characteristic factors of the reservoirs are carried out at first. Then, multiple regression analyses between the annual specific sediment and the physical characteristic factors with high correlation coefficients in the simple regression analyses are made. The results obtained from this study are as follows : 1. The results of the simple regression analyses show that in each province the watershed area, the length of mainstream, the circumferential length of watershed have high cor-relation coefficients (R=0.814-0.986), and that drainage density, reservoir capacity per watershed area, drainage frequency, basin relief have low correlation coefficients (R=0. 387-0.955). 2. The purposed multiple regression equations between the annual specific sediment of reservoirs and three major characteritic factors of watersheds, namely, the watershed area, the circumferential length of watershed, and the length of mainstream, are proposed as given in Table 2. 3. The result of the simple regression analyses with respect to the reservoir elevation except Jeonnam province, which has very different characteristics comparing to other provinces, shows that watershed area, main stream length and circumferential length have high correlation coefficients (R=0.806-0.884) in low-elevation reservoirs and intermediate- elevation reservoirs, but low correlation coefficients (R=0.639-0.739) in high-elevation reservoirs. 4. With respect to the reservoir elevation, the proposed multiple regression equations bet-ween the annual specific sediment of reservoirs and the three major characteristic factors of watershed which have high correlation coefficients are proposed as given in Table 5.

유역특성(流域特性)에 의(依)한 합성단위도(合成單位圖)의 유도(誘導)에 관(關)한 연구(硏究)

서승덕 ( Seung Duk Suh ) 한국농공학회 1975 韓國農工學會誌 : 전원과 자원 Vol.17 No.1

The purpose of this thesis is to derive a unit hydrograph which may be applied to the ungaged watershed area from the relations between directly measurable unitgraph properties such as peak discharge(q_p), time to peak discharge (T_p), and lag time (L_g) and watershed characteristics such as river length(L) from the given station to the upstream limits of the watershed area in km, river length from station to centroid of gravity of the watershed area in km (L_ca), and main stream slope in meter per km (S). Other procedure based on routing a time-area diagram through catchment storage named Instantaneous Unit Hydrograph(IUH). Dimensionless unitgraph also analysed in brief. The basic data (1969 to 1973) used in these studies are 9 recording level gages and rating curves, 41 rain gages and pluviographs, and 40 observed unitgraphs through the 9 sub watersheds in Nak Oong River basin. The results summarized in these studies are as follows; 1. Time in hour from start of rise to peak rate (T_p) generally occured at the position of 0.3T_b (time base of hydrograph) with some indication of higher values for larger watershed. The base flow is comparelatively higher than the other small watershed area. 2. Te losses from rainfall were divided into initial loss and continuing loss. Initial loss may be defined as that portion of storm rainfall which is intercepted by vegetation, held in deppression storage or infiltrated at a high rate early in the storm and continuing loss is defined as the loss which continues at a constant rate throughout the duration of the storm after the initial loss has been satisfied. Tis continuing loss approximates the nearly constant rate of infiltration (Ø-index method). The loss rate from this analysis was estimated 50 Per cent to the rainfall excess approximately during the surface runoff occured. 3. Stream slope seems approximate, as is usual, to consider the mainstreamonly, not giving any specific consideration to tributary. It is desirable to develop a single measure of slope that is representative of the who1e stream. The mean slope of channel increment in 1 meter per 200 meters and 1 meter per 1400 meters were defined at Gazang and Jindong respectively. It is considered that the slopes are low slightly in the light of other river studies. Flood concentration rate might slightly be low in the Nak Dong river basin. 4. It found that the watershed lag (L_g, hrs) could be expressed by L_g=0.253 (L.L_ca)^0.4171 The product L.L_ca is a measure of the size and shape of the watershed. For the logarithms, the correlation coefficient for L_g was 0.97 which defined that L_g is closely related with the watershed characteristics, L and L_ca. 5. Expression for basin might be expected to take form containing theslope as L_g=0.545(L.L_ca/√s)^0.348 For the logarithms, the correlation coefficient for L_g was 0.97 which defined that L_g is closely related with the basin characteristics too. It should be needed to take care of analysis which relating to the mean slopes 6. Peak discharge per unit area of unitgraph for standard duration tr, ㎥/sec/㎢, was given by q_p=10^{-0.52-0.0184Lg}with a indication of lower values for watershed contrary to the higher lag time. For the logarithms, the correlation coefficient q_p was 0.998 which defined high sign ificance. The peak discharge of the unitgraph for an area could therefore be expected to take the from Q_p=q_p. A(㎥/sec). 7. Using the unitgraph parameter L_g, the base length of the unitgraph, in days, was adopted as T_b=0.73+2.073(L_g/24) with high significant correlation coefficient, 0.92. The constant of the above equation are fixed by the procedure used to separate base flow from direct runoff. 8. The width W₇₅ of the unitgraph at discharge equal to 75 per cent of the peak discharge, in hours and the width W₅₀ at discharge equal to 50 Per cent of the peak discharge in hours, can be estimated from W₇₅=1.61/q_p^1.05 and W₅₀=2.5/q_p^1.05 respectively. This provides supplementary guide for sketching the unitgraph. 9. Above equations define the three factors necessary to construct the unitgraph for duration tr. For the duration tR, the lag is L_gR=L_g+0.2(t_R-tr) and this modified lag, L_gRis used in q_p and T_b It the tr happens to be equal to or close to tR, further assume q_pR=q_p. 10. Triangular hydrograph is a dimensionless unitgraph prepared from the 40 unitgraphs. The equation is shown as Qp=K.A.Q/T_p or q_p=0.21 A.Q./T_p The constant 0.21 is defined to Nak Dong River basin. 11. The base length of the time-area diagram for the IUH routing is C=0.9(L.L_ca/√s)^1/3. Correlation coefficient for C was 0.983 which defined a high significance. The base length of the T-AD was set to equal the time from the midpoint of rain fall excess to the point of contraflexure. The constant K, derived in this studies is K=8.32+0.0213 L/√s with correlation coefficient, 0.964. 12. In the light of the results analysed in these studies, average errors in the peak discharge of the Synthetic unitgraph, Triangular unitgraph, and IUH were estimated as 2.2, 7.7 and 6.4 per cent respectively to the peak of observed average unitgraph. Each ordinate of the Synthetic unitgraph was approached closely to the observed one.

저습답(低濕畓)에 있어서 암거배수(暗渠排水) 방법(方法)이 작물수량(作物收量)에 미치는 효과(效果)에 관(關)한 시험연구(試驗硏究)

서승덕 ( Seung Duk Suh ),김조웅 ( Cho Ung Kim ) 한국농공학회 1977 韓國農工學會誌 : 전원과 자원 Vol.19 No.3

Subsurface Drinage Problems arise from many causes. Flatland tends to be poorly drained, particularly where the subsoil permeability is low. There are many wet areas, however, where there is no evident connection between the area of seepage, or a high water table, and the topography of the site. High water tables may occur where the soil is either slowly or rapidly permeable, where the climate is either humid or arid, and where the land is either sloping or flat. This study is to bring light on subjects relating to increasing yield of crop and possibility of double crops a year in water logging paddy fields. Obtained results are briefly summarized as follows: 1. Effect of crop-yield in the plot A resulted 20.2 percent higher than the ordinary plot with yield of brown rice. 2. Possibility of double-crops a year is investigated. Effect of the barley production of the test plot resulted 168.2 percent higher than the other uplands near test plot with the yield of 1977 production and it is 3.8 percent higher compare with the yearly yields. 3. Decreasing depth of water level was measured 23.9mm per day and 14.3mm per day at the test plot and ordinary plot respectively and the amounts of subsurface drainage measured 30mm to 35mm per day. It is required that the relief well should be controled carefully and adequately. 4. Mean depth of ground water levl was measured 0.4∼0.5m regardless the width of corrugated pipe. It is significantly lowere than the ordinary plot(0.15∼0.20m) 5. The ground temperature of the test plot is higher 1 degree of centigarade or more than the ordinary plot and soil moisture content of the ordinary plot is higher 12.4∼27.8 percent than the plot reversely. There should be a relationship between rising of ground temperature and soil moisture.