김종필 Kim Jong Pil , 김광섭 Kim Gwangseob , 이기춘 Lee Gichun

DOI: JKWST Vol.53(No.3) 1-11, 2011

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The temporal variability of spring (March, April, May) monthly precipitation, precipitation effectiveness, monthly maximum precipitation, monthly precipitation of different durations, and the precipitation days over several threshold (i.e. 0, 10, 20, 30, 40, and 50 mm/day) of 59 weather stations between 1973 and 2009 were analyzed. Also to analyze the regional characteristics of temporal variability, 59 weather stations were classified by elevations, latitudes, longitudes, river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization. Results demonstrated that trends of variables increase in April and decrease in May except precipitation day. Overall trend of precipitation amount and precipitation effectiveness is same but precipitation effectiveness of several sites decrease despite the trend of precipitation amount increases which may be caused by the air temperature increase. Therefore more effective water supply strategy is essential for Spring season. Regional characteristics of Spring precipitation variability can be summarized that increase trend during May become stronger with the increase of latitude and elevation which is similar to that of Summer season. The temporal variability of variables showed different behaviors according to river basins, inland or shore (east sea, south sea, west sea) area and the level of urbanization.

이성희 Lee Sung Hee , 김태철 Kim Tai Cheol

DOI: JKWST Vol.53(No.3) 13-17, 2011

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There was a transition from participatory irrigation management (PIM) to public irrigation management (PubIM) in Korea when Korea Rural corporation and Community (KRC) merged with Farm Land Improvement Associations (FLIAs), which had managed 60 % of irrigation areas. While making a number of achievements, some problems occurred in the public irrigation management, such as lack of farmers’ participation, increased amount of water usage, and elevating operating costs. Accordingly, this paper suggested ways to increase efficiency in water usage and reduce operating costs under the public management through the motive power of farmers participation. First, WUGs replaced the discarded water management committee should be reorganized to revive the concept of PIM in the form of autonomously reinforced one and the roles and functions of WUGs and the board of representatives should be strengthened. The member of new type of WUGs should participate in the national and regional water management committees as a stakeholder of irrigation water user. And also new type of WUGs initiates not only the management of irrigation water but also the management of irrigation water quality and non-point source pollution in the watersheds. Those additional activities of WUGs should be properly compensated. Second, subsidies (direct payments) should be provided to faithful farmers as an incentive for their labor supply. Third, water fees could be charged to large scale agriculture companies. Fourth, professional managers could be hired, management targets would be adjusted, and incentives should be offered. These efforts are expected to improve the irrigation management by encouraging farmers’ participation under public system.

김용성 Kim Yong Seong

DOI: JKWST Vol.53(No.3) 19-26, 2011

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In order to estimate the viscous effects of clay over a wide range of strain levels, we confirmed the performance of a viscoelastic-viscoplastic constitutive model by simulating cyclic undrained triaxial tests to determine the cyclic strength and deformation characteristics of natural marine clay. The viscoelastic-viscoplastic constitutive model was then incorporated into an effective stress-based seismic response analysis to estimate the effects of an intermediate clay layer on the behavior of sand layers. Seismic response was simulated by the cyclic viscoelastic-viscoplastic constitutive model created with data recorded at Rokko Island, Kobe, Japan. The results show that a cyclic viscoelastic-viscoplastic constitutive model can provide a good description of dynamic behavior including viscoelastic effects, within a small strain range.

리신호 Rhee Shinho , 최세현 Choi Se Hyun , 윤성수 Yoon Seong Soo , 최애순 Choi Ae Soon , 엄대호 Eom Dae Ho

DOI: JKWST Vol.53(No.3) 27-34, 2011

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The definition of a rural theme park was presented and it's development directions were set up as grasping the problems of existing rural theme park. The creation method of a rural theme park was presented through the case study of a design planning. A rural theme park should be designed with consideration to regional characteristics based on the rural amenity. The characteristics of rural theme parks set by theme, unity, integrity, originality, and eco-friendly. And the visit reasons of rural theme park are rural experience, lodging, relaxation or recreation, comfort or easy, and food purchase. A case study area is around Geopo-Ri and Gueum-Ri Okcheon-Gun Chungcheongbuk-Do. The master plan of this area was prepared.

이성행 Lee Seong Haeng , 김하집 Kim Ha Jip , 박영진 Park Young Jin , 함형길 Hahm Hyung Gil , 공보성 Kong Bo Sung

DOI: JKWST Vol.53(No.3) 35-41, 2011

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A model test is carried out to investigate the vibration of truss type lift gate in the four major rivers project. The gate model scaled with the ratio of 1 : 25 is made of acryl panel dimensioned 1.6 m in width, 0.28 m in height in the concrete test flume. Firstly natural frequencies of the model gate are measured and the results are compared with the numerical results in order to verify the model. The amplitudes of the vibration are measured under the different gate opening and water level conditions. The results are analyzed to study the characteristics of the gate vibration according to the small gate opening, the large gate opening and the overflow conditions. These test results presents a basic data for the guide manuals of gate management and a design method to reduce the gate vibration of truss type lift gate. Finally, the vibration of truss type lift gate are assessed in comparison with those of formerly tainter gate.

곽계환 Kwak Kae Hwan , 김경숙 Kim Kyung Suk , 김호선 Kim Ho Sun

DOI: JKWST Vol.53(No.3) 43-51, 2011

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Fiber Reinforced Polymer (FRP)s have various advantages for construction material in that they are noncorrosive and very strong. FRPs are economical and effective for management and maintenance when applied to footbridge, beam or deck of the bridge, girder, and marine structure. For safety, optimal design for standard modulation of the cross section is necessary. Conditions of optimum are possibilities of domestic production, modular assembly, and structure materials cast in compressed area.

이명구 Lee Myung Gu , 송창섭 Song Chang Seob

DOI: JKWST Vol.53(No.3) 53-58, 2011

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This study is analyzed the characteristics of the soil erosion with the geotechnical conditions and rainfall conditions, such as the ground slope, the compaction ratio, rainfall intensity and duration of rainfall etc. To this ends, a series of model test are conducted on clayey sands. From the results, the variation of soil loss is analyzed with the geotechnical and the rainfall conditions. The amount of soil loss is decreased as the increase of compaction ratio and is increased as the ground slope, rainfall intensity and the duration of rainfall.

김영득 Kim Young Deuk , 박필주 Park Pil-ju

DOI: JKWST Vol.53(No.3) 59-64, 2011

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The objective of the study is to develop life cycle inventory (LCI) database of dam, a major facility for irrigation water supply. The types of database developed are three out of nine dams according to the size of the water storage capacity: two kinds larger than 500,000 ㎥ depending on gate for discharging (Type 1) and the other dam smaller than 500,000 ㎥ (Type 2). According to the LCI analysis, type 1 larger than 500,000 ㎥ storage capacity with gate has the lowest environment impact in the 6 impact categories. The impact of the type 1 accounts for 7～35 % of the type 2 for supplying irrigation water. Comparing with the environment impacts of water for other uses such as drinking and industrial water, the impacts of 1 ㎥ irrigation water supply is 4～45 % of the one for industrial water supply and 1～16 % of the drinking water's. The three types of LCI DB on the irrigation water by dams will be useful in the application of Life Cycle Assessment in agricultural products and environmental labelling including carbon footprint since it is complied to the guidelines of LCI DB construction issued by Ministry of Environment and Ministry of Knowledge Economy.

은코모제피템바 Nkomozepi Temba , 정상옥 Chung Sang-ok

DOI: JKWST Vol.53(No.3) 65-73, 2011

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이지완 Lee Ji-wan , 박근애 Park Geun-ae , 조형경 Joh Hyung-kyung , 이규호 Lee Kyo-ho , 나상일 Na Sang-il , 박종화 Park Jong-hwa , 김성준 Kim Seong-joon

DOI: JKWST Vol.53(No.3) 75-82, 2011

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This study refers to the derivation of simple crop yield prediction equation by using KOMPSAT-2 derived vegetation index. For a 1.25 ha small farm area located in the middle part of South Korea, the KOMPSAT-2 panchromatic and multi-spectral images of 31th August 2008, 17th November 2008, and 10th September 2009 were used. The field spectral reflectance during growing period for the 6 crops (rice, potato, corn, red pepper, garlic, and bean) were measured using ground spectroradiometer and the yield was investigated. Among the 6 vegetation indices (VI), the NDVI and ARVI between measured and image derived showed high relationship with the coefficient of determination of 0.85 and 0.95 respectively. Using the 3 years field data, the NDVI and ARVI regression curves were derived, and the yields were tried to compare with the maximum VIs value.

장동수 Chang Dong Su , 연규석 Yeon Kyu Seok , 김기성 Kim Ki Sung , 하선효 Ha Seon Hyo , 김용성 Kim Yong Seong

DOI: JKWST Vol.53(No.3) 83-91, 2011

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This study aimed to investigate the engineering and environmental characteristics of phosphogypsum-cement-soil mixtures composed of phosphogypsum, soil, and a small amount of cement was analysed on the basis of the unconfined compression test, the tensile strength test, the freezing and thawing test, the wetting and drying test, SEM and EDS analysis, XRD analysis and Leaching test. The specimens were manufactured with soil, cement and phosphogypsum. The cement contents was 10 %, and the phosphogypsum contents was 10, 20, 30, and 40 % by the weight of total dry soil. Each specimen was manufactured after curing at constant temperature and humidity room for 3, 7 and 28 days, after which the engineering characteristics of phosphogypsum-cement-soil mixtures were investigated using the unconfined compression test, the tensile strength test, the freezing and thawing test, the wetting and drying test. The basic data were presented for the application of phosphogypsum-cement-soil mixtures as construction materials. To investigate the environmental characteristics, leaching test was performed and the leaching test results were far below than of regulatory requirement of Waste Management Act in Korea. Therefore the results show that phosphogypsum is environmentally safe and can be used as construction materials in environmental aspect.