GIS 와 농업정보망을 이용한 동적 의사결정 지원시스템

정하우,김대식,이정재,최진용,김한중 ( Ha Woo Chung,Dae Sik Kim,Jeong Jae Lee,Jin Yong Choi,Han Jung Kim ) 한국농촌계획학회 1997 농촌계획 Vol.3 No.1

Penman식(式)에서 보정계수(補正係數) (C)가 잠재증발산량(潛在蒸發散量)에 미치는 효과(效果) -수원지방(水原地方)의 수도(水稻)에 대하여-

정하우 ( Chung Ha Woo ),김성준 ( Kim Seong Joon ),임정남 ( Im Jung Nam ) 한국농공학회 1988 韓國農工學會誌 : 전원과 자원 Vol.30 No.3

The purpose of this paper is to know the effect of Adjustment factor (C) in Penman equation In the modified Penman equation by Doorenbos and Pruitt (1977), Potential Evapotranspiration(PET) was calculated in cases of (1) neglecting Adjustment factor (C=1, 0, A), (2) fixing Day/Night wind ratio (URATIO) to 2.0(B-l) and computing daily URATIO (B-2), and was compared with Actual Evapotranspiration (AET) for paddy fields in Suwon (1985-1986). The followings are a summary of this study results ; 1. Using 1985-1986 meteorological data, daily average PET in cases of A, B-1, B-2 were 4.61 mm/day, 4.81 mm/day and 5.36 mm/day respectively and daily average AET was 4.26 mm/day. The increment ratios of PET based on case A were 100%, 104.34% and 116.27%. 2. The range of Adjustment factor (C) in cases of B-1, B-2 were 0.916-1.140 and 0.922-1.392 respectively. 3. The regression coefficient(r) between AET and PET in cases of A, B-1, B-2 were 0.928, 0.924 and 0.915 respectively.

역청재료(瀝靑材料)가 흙-시멘트의 강도(强度) 및 내구성(耐久性)에 끼치는 영향(影響)에 관(關)한 연구(硏究)

김종옥 ( Jong Ok Kim ),정하우 ( Ha Woo Jung ) 한국농공학회 1978 韓國農工學會誌 : 전원과 자원 Vol.20 No.1

This study was intended to investigate the effects of bituminous material content of soil-cement mixtures on their durability. For the purpose, unconfined compressive strength test, Freeze-thaw test, and wet-dry test were performed with three types of soil. Each type of soil was mixed with three levels of cement content and each soil-cement mixture was mixed with four levels of bituminous material content. For the unconfined compressive strength test, Freeze-thaw test and wet-dry test, 324, 108, and 108-specimens were prepared respectively. Unconfined compressive strength was measured at age of 7-days, 14-days and 28-days using 108-specimens in each age. The soil-cement loss rate due to freeze-thaw and wet-dry were calculated after 12 cycles of test using 108-specimens in each test. The results are summarized as follows : 1. Optimum moisture content was increased with increase of cement content, but maximum dry density was changed irregulary with increase of the cement content. 2. The unconfined compressive strength was increased with increase of cement content, bituminous material content and curing age. Cement is more effective factor than bituminous material on unconfined compressive strength of soil-cement Mixture. 3. It is estimated as the most economical cement content that the recommended cement content of A.S.T.M. because increasing rate of unconfined compressive strength at age of 28-days was low when cement content is above the recommanded cement content of A.S.T.M. among all types of soil. 4. Although a portion of cement content is substituted for bituminous material, the necessary unconfined compressive strength can be obtained. 5. The soil-cement loss was more influenced by wet-dry than Freeze-thaw 6. The bituminous material is more effective on the decrease of soil-cement loss than increase of unconfined compressive strength 7. The void ratio of soil-cement mixture was changet irregularly with increase of cement content, but that was decreased in proportion to the increase of bituminous material content. 8. The regression equation between the unconfined compressive strength and soil-cement loss rate were obtained as table 7.

밭작물(作物) 소비수량(消費水量)에 관한 기초적(基礎的) 연구(硏究)(III)-고추 및 가을 무우-

김철기 ( Kim Choulkee ),김진한 ( Kim Jim Han ),정하우 ( Jung Ha Woo ),최홍규 ( Choi Hong Kyu ),권영현 ( Kwun Yong Hyun ) 한국농공학회 1990 韓國農工學會誌 : 전원과 자원 Vol.32 No.1

The purpose of this study is to find out the basic data for irrigation plans of red pepper and radish during the growing period, such as total amount of evapotranspiration, coefficent of evapotranspiration at each growth stage, the peak stage of evapotranspiration, the maximum ten day evapotranspiration, optimum irrigation point, total readily available moisture and intervals of irrigation date. The plots of experiment were arranged with split plot design which were composed of two factors, irrigation point for main plot and soil texture for split plot, and three levels ; irrigation point with pH1.7-2.0, pF2.1-2.4 and pF2.5-2.8, at soil texture of sandy soil, sandy loam and silty clay for both red pepper and radish, with two replications. The results obtained are summarized as follows. 1. 1/10 exceedance probability values of maximum total pan evaporation during growing period for red peppr and radish were shown as 663.6 mm and 251.8 mm. respectively, and those of maximum ten day pan evaporation for red pepper and radish, 67.1 mm and 46.9 mm, respectively. 2. The time that annual maximum of ten day pan evaporation can he occurred, exists at any stage between the middle of May and the late of August for red pepper, and at any stage between the late of August and the late September for radish. 3. The magnitude of evapotranspiration and its coefficient for red pepper was occurred large in order of pF1.7-2.0 pF2.1-2.4 and pF2.5~2.8 in aspect of irrigation point and the difference in the magnitude of evapotranspiration and of its coefficient between levels of irrigation point was difficult to be found out due to the relative increase in water consumption resulted from large flourishing growth at the irrigation point in lower water content for radish. In aspect of soil texture they were appeared large in order of sandy loam, silty clay and sandy soil for both red pepper and radish. 4. The magnitude of leaf area index was shown large in order of pF2.1-2.4, pF2.5-2.8, and pFl.7-2.0, for red pepper and of pF2.5-2.8, pF2.1-2.4, pFl.7-2.0 for radish in aspect of irrigation point, and large in order of sandy loam, silty clay, sandy soil for both red pepper and radish in aspect of soil texture 5. 1/10 exceedance probability value of evapotranspiration and its coefficient during the growing period for red pepper were shown as 683.5 mm and 1.03, respectively, while those of radish, 250.3 mm and 0, 99. respectively. 6. The time that the maximum evapotranspiration of red pepper can be occurred is in the middle of August around the date of ninetieth to hundredth after transplanting, and the time for radish is presumed to be in the late of September, around the date of thirtieth to fourtieth after sowing. At that time, 1/10 exceedance probability value of ten day evapotranspiration and its coefficient for red pepper is assumed to be 81.8 mm and 1.22, respectively, while those of radish, 49, 7 mm and 1, 06, respectively. 7. Optimum irrigation point for red pepper on the basis of the yield of raw matter is assumed to be pFl.7-2.0 for sandy soil, pF2.5-2.8 for sandy loam, and pF2.1-2.4 for silty clay. while that for radish is appeared to be pF2.5-2.8 in any soil texture used. 8. The soil moisture extraction patterns of red pepper and radish have shown that maximum extraction rates exist at 7 cm deep layer at the beginning stage of growth in any soil texture and that extraction rates of 21 cm to 35 cm deep layer are increased as getting closer to the late stage of growth. And especially the extraction rates have shown tendency to be greatest at 21cm deep layer from the most flourishing stage of growth for red pepper and at the last stage of growth for radish. 9. The total readily available moisture on the basic of the optimum irrigation point become 3.77-8.66 mm for sandy soil, 28.39-34.67 mm for sandy loam and 18.40-25.70 mm for silty clay for red pepper of each soil texture used but that of radish that has shown the optimum irrigation point of pF2.5-2.8 in any soil texture used. 12.49-15.27 mm for sandy soil, 23.03-28.13 mm for sandy loam, and 22.56~27.57 mm for silty clay. 10. On the basis of each optimum irrigation point. the intervals of irrigation date at the growth stage of maximum consumptive use of red pepper become l.4 days for sandy soil, 3.8 days for sandy loam and 2.6 days for silty clay, while those of radish, about 7.2 days.

밭작물소비수량(作物消費水量)에 관한 기초적(基礎的) 연구(硏究)(II) -마늘 및 오이-

김철기 ( Kim Choul Kee ),김진한 ( Kim Jin Han ),정하우 ( Jung Ha Woo ),최홍규 ( Choi Hong Kyu ),권영현 ( Kwun Yong Hyun ) 한국농공학회 1989 韓國農工學會誌 : 전원과 자원 Vol.31 No.3

The purpose of this study is to find out the basic data for irrigation plans of garlic and cucumber during the growing period, such as total amount of evapotranspiration, coefficients of evapotranspiration at each growth stage, the peak stage of evapotranspiration and the maximum evapotranspiraton, optimum irrigation point, total readily available moisture, and intervals of irrigation date. The plots of experiment were arranged with split plot design which were composed of two factors, irrigation point for main plot and soil texture for split plot, and three levels ; irrigation points with pF 1.7~2.1, pF 2.2~2.5, pF 2.6~2.8, for garlic and those with pF 1.9, pF 2.3, pF 2.7, for cucumber, soil textures of silty clay, sandy loam and sandy soil for both garlic and cucumber, with two replications. The results obtained are summarized as follows 1. There was the highest significant correlation between the avapotranspiration of garlic and cucumber and the pan evaporation, beyond all other meteorological factors considered, as mentioned in the previous paper. Therefore, the pan evaporation is enough to be used as a meteorological index measuring the quantity of evapotranspiration. 2. 1/10 probability values of maximum total pan evaporation during growing period for garlic and cucumber were shown as 495.8mm and 406.8mm, respectively, and those of maximum ten day pan evaporation for garlic and cucumber, 63.8mm and 69.7mm, respectively. 3. The time that annual maximum of ten day pan evaporation can be occurred, exists at any stage between the middle of May and the late of June(harvest period) for garlic, and at any stage of growing period for cucumber. 4. The magnitude of evapotranspiration and of its coefficient for garlic and cucumber was occurred in the order of pF 1.7~2.1>pF 2.2~2.5>pF 2.6~2.8 and of pF 1.9>pF 2.3>pF2.7 respectively in aspect of irrigation point and of sandy loam>silty clay>sandy soil in aspect of soil texture for both garlic and cucumber. 5. The magnitude of leaf area index was shown in the order of pF 2.2~2.5>pF 1.7~2.1>pF 2.6~2.8 for garlic and of pF 1.9>pF 2.3>pF 2.7 for cucumber in aspect of irrigation point, and of sandy loam>sandy soil>silty clay in aspect of soil texture for both garlic and cucumber. 6. 1/10 probability value of evapotranspiration and its coefficient during the growing period for garlic were shown as 391.7mm and 0.79 respectively, while those of cucumber, 423.lmm and 1.04 respectively. 7. The time the maximum evapotranspiration of garlic can be occurred is at the date of thirtieth before harvest period and the time for cucumber is presumed to be at the date of sixtieth to seventieth after transplanting, At that time, 1/10 probability value of ten day evapotranspiration and its coefficient for garlic is presumed to be 65.lmm and 1.02 respectively, while those of cucumber, 94.8mm and 1.36 respectively. 8. In aspect of irrigation point, the weight of raw garlic and cucumber were increased in the order of pF 2.2~2.5>pF 1.7~2.1>pF 2.6~2.8 and of pF 1.9>pF 2.3>pF 2.7 respectively. Therefore, optimum irrigation point for garlic and cucumber is presumed to be pF 2.2~2.5 and pF 1.9 respectively, when the significance of yield between the different irrigation treatments is considered. 9. Except the mulching period of garlic that soil moisture extraction patterns were about the same, those of garlic and cucumber have shown that maximum extraction rate exists at 7cm deep layer at the beginning stage after removing mulching for garlic and at the beginning stage of growth for cucumber and that extraction rates of 21cm to 35cm deep layer are increased as getting closer to the late stage of growth. 10. Total readily available moisture of garlic in silty clay, sandy loam, sandy soil become to be 18.71~24.96mm, 19.08~25.43mm, 10.35~13.80mm respctively on the basis of the optimum irrigation point with pF 2.2~2.5, while that of cucumber, 11.81mm, 12.03mm, 6.39mm respectively on the basis of the optimum irrigation point with pF 1.9. 11. The intervals of irrigation date of garlic and cucumber at the growth stage of maximum consumptive use become to be about three and a half days and one and a half days respectively, on the basis of each optimum irrgation point.