남원호 Nam Won-ho , 홍은미 Hong Eun-mi , 최진용 Choi Jin-yong , 조재필 Cho Jaepil , Michael J. Hayes

DOI: JKWST Vol.57(No.2) 1-13, 2015

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The Coupled Model Intercomparison Project Phase 5 (CMIP5), coordinated by the World Climate Research Programme in support of the Intergovernmental Panel on Climate Change (IPCC) AR5, is the most recent, provides projections of future climate change using various global climate models under four major greenhouse gas emission scenarios. There is a wide selection of climate models available to provide projections of future climate change. These provide for a wide range of possible outcomes when trying to inform managers about possible climate changes. Hence, future agrometeorological indicators estimation will be much impacted by which global climate model and climate change scenarios are used. Decision makers are increasingly expected to use climate information, but the uncertainties associated with global climate models pose substantial hurdles for agricultural resources planning. Although it is the most reasonable that quantifying of the future uncertainty using climate change scenarios, preliminary analysis using reasonable factors for selecting a subset for decision making are needed. In order to narrow the projections to a handful of models that could be used in a climate change impact study, we could provide effective information for selecting climate model and scenarios for climate change impact assessment using maximum/minimum temperature, precipitation, reference evapotranspiration, and moisture index of nine Representative Concentration Pathways (RCP) scenarios.

김성준 Seong Joon Kim , 김상호 Sang Ho Kim , 조형경 Hyung Kyung Joh , 안소라 So Ra Ahn

DOI: JKWST Vol.57(No.2) 15-26, 2015

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The purpose of this paper is to develop a software tool, PGA-CC (Projection of hydrology via Grid-based Assessment for Climate Change) to evaluate the present hydrologic cycle and the future watershed hydrology by climate change. PGA-CC is composed of grid-based input data pre-processing module, hydrologic cycle calculation module, output analysis module, and output data post-processing module. The grid-based hydrological model was coded by Fortran and compiled using Compaq Fortran 6.6c, and the Graphic User Interface was developed by using Visual C#. Other most elements viz. Table and Graph, and GIS functions were implemented by MapWindow. The applicability of PGA-CC was tested by assessing the future hydrology of South Korea by HadCM3 SRES B1 and A2 climate change scenarios. For the whole country, the tool successfully assessed the future hydrological components including input data and evapotranspiration, soil moisture, surface runoff, lateral flow, base flow etc. From the spatial outputs, we could understand the hydrological changes both seasonally and regionally.

이수인 Lee Su In , 신민환 Shin Min Hwan , 전제홍 Jeon Je Hong , 박병기 Park Byeong Ky , 이지민 Lee Ji Min , 원철희 Won Chul Hee , 최중대 Choi Joong Dae

DOI: JKWST Vol.57(No.2) 27-36, 2015

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The objective of this paper was to quantitatively analyze the effect of concentrated animal feeding operations (CAFO) NPS pollution on a small watershed water quality. Monitoring was conducted from March to October, 2013. Monthly flow rate and selected water quality at each monitoring site were measured during dry days. Rainy day monitoring also was conducted. Modeling was conducted to evaluate the effect of CAFO NPS pollution on the water quality at the watershed outlet. The highest and mean concentration of selected water quality indices during rainy days were higher than those in dry days in general. The highest TN concentration measured at the CAFP pollution discharge point was 237.831 mg/L. The results revealed that the CAFO NPS pollution sources could be equally blamed for the water quality degradation of the stream. However, the effect of the NPS pollution from CAFOs seemed not to be very influential to the watershed water quality at the outlet. SWAT modeling revealed that the TN load was reduced by 18.95 %, 23.39 % and 30.53 % at the watershed outlet if the TN load at the CAFO NPS pollution discharge point reduced by 20 %, 40 % and 60 %, respectively. It was thought that the natural attenuation processes played an important role. The modeling was based only on the assumption of the load reduction and not verified by the monitored data. Therefore, it was suggested that a long term monitoring studies for the evaluation of the impact of CAFO NPS pollution on the watershed water quality be conducted.

박윤식 Park Youn Shik , 이지민 Lee Ji Min , 정영훈 Jung Younghun , 신민환 Shin Min Hwan , 박지형 Park Ji Hyung , 황하선 Hwang Hasun , 류지철 Ryu Jichul , 박장호 Park Jangho , 김기성 Kim Ki-sung

DOI: JKWST Vol.57(No.2) 37-45, 2015

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Typically, water quality sampling takes place intermittently since sample collection and following analysis requires substantial cost and efforts. Therefore regression models (or rating curves) are often used to interpolate water quality data. LOADEST has nine regression models to estimate water quality data, and one regression model needs to be selected automatically or manually. The nine regression models in LOADEST and auto-selection by LOADEST were evaluated in the study. Suspended solids data were collected from forty-nine stations from the Water Information System of the Ministry of Environment. Suspended solid data from each station was divided into two groups for calibration and validation. Nash-Stucliffe efficiency (NSE) and coefficient of determination (R₂) were used to evaluate estimated suspended solid loads. The regression models numbered 1 and 3 in LOADEST provided higher NSE and R₂, compared to the other regression models. The regression modes numbered 2, 5, 6, 8, and 9 in LOADEST provided low NSE. In addition, the regression model selected by LOADEST did not necessarily provide better suspended solid estimations than the other regression models did.

박종건 Park Jong Gun

DOI: JKWST Vol.57(No.2) 47-56, 2015

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At the present, the mechanized form roads pavement was constructed with plain concrete. Mostly, it was used by welded wire mesh for preventing crack. Cellulose fibers for the reinforcement of concrete offer relatively high levels of elastic modulus, fiber count (per unit weight), specific surface, and bond strength to cement-based materials. The construction of concrete pavement confirmed that cellulose fiber reinforced concrete was applicable to mechanized form roads pavement. In the study, cellulose fibers were used here at 0.08 % volume fraction, which is equivalent to a fiber content of 1.2 kg/ ㎥. Cellulose fiber reinforced concrete were compared with plain concrete. Field test results indicated that cellulose fiber reinforced concrete showed slightly to increase of 28 days compressive strength and improved the initial strength. it tended to increase of splitting tensile strength. Test results showed that the slump and air content tend to decreased. but, the variation of air contends is very little. Also, construction cost of cellulose fiber reinforced concrete is less than about 25.7 % the case of welded wire mesh previously used. Therefore, The cost reduction is expected to be possible in construction site by mechanized form roads pavement.

김기원 Kim Ki Won , 권형중 Kwon Hyung Joong , 김필식 Kim Phil Sik , 박찬기 Park Chan Gi

DOI: JKWST Vol.57(No.2) 57-66, 2015

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The purpose of this study was to improved the durability of a improved movable weir by replacing the improved movable weir’s metal gate with a hybrid steel/glass fiber reinforced polymer composites panel gate. Because the metal gate of a improved movable weir is always in contact with water, its service life is shortened by corrosion. This study made four type of hybrid steel/glass fiber reinforced polymer composites panel gate with different steel gate surface deformation (control, sand blast, scratch and hole), flexural. Fracture properties tests were performed depending on the steel gate surface deformation. According to the test results, the flexural behavior, flexural strength and fracture properties of hybrid steel/glass fiber reinforced polymer composites panel gate was affected by the steel panel gate surface deformation. Also, the sand blast type hybrid steel/glass fiber reinforced polymer composites panel gate shows vastly superior flexural and fracture performance compared to other types.

김황희 Kim Hwang Hee , 김춘수 Kim Chun Soo , 전지홍 Jeon Ji Hong , 박찬기 Park Chan Gi

DOI: JKWST Vol.57(No.2) 67-73, 2015

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This study evaluated the effects of fibers on the void ratio, compressive strength and repeated freezing and thawing resistance of porous vegetation concrete with binder type (non-sintering inorganic binder and blast furnace slag cement) and natural jute fiber volume fraction (0.0 %, 0.1 % and 0.2 %). The natural jute fiber volume fraction affected the void ratio, compressive strength and repeated freezing and thawing resistance. Added of natural jute fiber resulted in improved properties of the void ratio, compressive strength and freezing and thawing resistance. Also, the both compressive strength and freezing and thawing resistance increased with natural jute fiber volume fraction up to 0.1 % and then decreased with fiber volume fraction at 0.2 %.

이슬기 Seul-gi Lee , 장정렬 Jeong-ryeol Jang , 최경숙 Kyung-sook Choi

DOI: JKWST Vol.57(No.2) 75-83, 2015

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This study was aimed to estimate the total application cost and utilization of Turf grass VFS application through the field experiment. The experimental plots were constructed in an upland field of Iksan city within the Saemangeum watershed. Turf grass was transplanted at the down-slope edge of the pollution source area in each of the treated plots. Three rainfall events were monitored during the experiment period, and the rainfall-runoff relationships and NPS pollution reduction effects of the VFS systems were assessed. As results, the reduction ratio of runoff volume ranged 14.1∼64.0 %, while the NPS pollution reduction ratio ranged 9.8∼73.9 % for SS, 24.0∼84.2 % for T-N, 31.6∼80.9 % for T-P respectively. The total cost of VFS application was estimated by considering purchase cost of Turf grass sods and construction and maintenance costs of VFS system as well as the loss caused by giving up crop cultivation for the area needed to construct the VFS. The total cost of the VFS was estimated to be approximately \3,379,000/ha/year for the first year of application, and this cost could be decreased to \1,899,000/ha/year from the second year as the construction cost of VFS could no longer need to be counted afterwards. Apart from the NPS pollution reduction effects, the possible utilization of VFS was examined by detaching Turf grass within 40 % of VFS area for sale during spring time when the VFS systems fully covered. The benefit of selling the detached Turf grass sods was estimated as \1,260,000/ha/year, and also found that the VFS area successfully recovered by the time of the summer period. This benefit could attract farmers to adopt the VFS technique to manage agricultural NPS pollution.

이상현 Lee Sang-hyun , 최진용 Choi Jin-yong , 유승환 Yoo Seung-hwan , 김영득 Kim Young Deuk , 신안국 Shin Ankook

DOI: JKWST Vol.57(No.2) 85-92, 2015

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Since the consumption of the livestock products increased for the past 10 years in Korea, the water use for live animals has become more important in terms of water savings. Therefore, the index connecting water use and livestock products consumption should be required for sustainable water management, and water footprint concept could be suggested as the index. The aim of this study is to estimate the water footprint for livestock products; beef cattle, swine, and broiler chicken. The water footprint for livestock products is divided into direct and indirect water. The direct water includes the drinking and servicing water, and the indirect water includes the water for the cultivation of feed crops. The water footprint of beef cattle was calculated to 17,023.1 ㎥/ton, and direct water was 91.2 ㎥/ton, and indirect water was 16,931.9 ㎥/ton. The water footprint of swine was calculated to 4,235.8 ㎥/ton, and direct water was 129.7 ㎥/ton, and indirect water was 4,106.0 ㎥/ton. The water footprint of broiler chicken was calculated to 2,427.7 ㎥/ton, and direct water was 7.6 ㎥/ton, and indirect water was 2,420.1 ㎥/ton. Also, we compared the water footprint to water demand of water vision 2020 which is the main report for national water management. The water vision 2020 reported only direct water for live animal, but the water footprint includes the direct and indirect water. Therefore, the water footprint could be applied to various fields relating water and food.

홍은미 Hong Eun-mi , 최진용 Choi Jin-yong , 남원호 Nam Won-ho , 이상현 Lee Sang-hyun , 최진규 Choi Jin-kyu , 김진택 Kim Jin-taek

DOI: JKWST Vol.57(No.2) 93-101, 2015

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The purpose of this study is to evaluate the paddy irrigation efficiency using real-time water level monitoring data and intermittent irrigation model in Gimjae, Dong-Jin irrigation district . For this study, the real-time water level data in Gimjae main canal and other secondary canals were collected from 2012 to 2014 and converted to daily discharge using rating curve in each canal. From intermittent irrigation model in paddy, irrigation water requirement was estimated and irrigation efficiency was calculated. The average amount of irrigation water supply per unit irrigation area was 1,011 mm in Gimjae main canal for 12,749 ha irrigation area, 1,011 mm in the secondary canal of upper region and 1,470 mm in the secondary canal of lower region. The median irrigation loss was 43 % in Gimjae main canal, 25 % in secondary canal of upper region and 35 % in the secondary canal of lower region. The larger irrigation area is, the irrigation loss rates tend to decrease in secondary canals. Monthly median irrigation losses in upper region were 10 (June) - 40 % (September) and those in lower region were 25 (May) to 40 % (April, June, August, and September). The results of canal management loss can be available as the basic data for irrigation water management and estimating guideline of optimal irrigation water supply to improve agricultural water use efficiencies.