• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.518-518
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• 2016

Agriculture is the lifeblood of the economy in Ghana, employs about 42% of the population work force and accounts for 30% of the Gross Domestic Product (GDP). Corn (maize) is the major cereal crop grown as staple food under rain fed conditions, covers over 92% of the total agricultural area, and contributes 54% of the caloric intake. Issues of hunger and food insecurity for the entire nation are associated with corn scarcity and low production. The climate changes are expected to affect corn production in Ghana. This study evaluated variations of corn yields based on different climate conditions of rain-fed area in the Dangbe East District of Ghana. AquaCrop model has been used to simulate corn growing cycles in study area for this purpose. The main goal for this study was to predict yield of corn using selected climatic parameters from 1992 to 2013 using different climate scenarios. The Model was calibrated and validated using observed field data, and the simulated grain yields matched well with observed values for the season under production giving an R squared (R2)of 0.93 and Nash-Sutcliff Error(NSE) of 0.21. Study results showed that rainfall reduction in the range of -5% to -20% would reduce the yield from 1.315ton/ha to 0.421ton/ha (-21. 3%) whereas increasing temperature from 1% to 7% would result in the maximum yield reduction of -20.6% (1.315 to 1.09 ton/ha.). On the other hand, increasing rainfall from 5-20% resulted in yield increment of 68% (1.315-2.209 ton/ha) and decreasing temperature produce 7% increase in yield ( 1.315 to 1.401ton/ha). These results provide useful information to adopt strategies by the Government of Ghana and farmers for improving national food security under climate change.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.185-191
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• 1999

In a mean time, arrangement of a arable land is lead by government with same way, same type. It means that there are no considering on characteristic features of region and aspect of ecological environment that can experess its natural charactersistics. Because whenever there is needed to be arranging , most of structure are made by a ward office from a desgin to a execution so that cause many public resentment and durability is very short by a inappropriateness its maintenance. The purpose of this study is divided into four parts ; First, to form the naturally favorable waterside spaces by performing the basic water controlling funtions of the irrigation channel and the drainage channel. Second, to provide the meeting place of the residents and to restrore the ecological system by means of the formation of the naturally favorable waterside spaces. Third, to lead to the optimal design and maintenance that residents want by inviting the residents to participate at the begining stage of planning. A district of this study is located on Songsam(13-14 zone), Samseung-Lee Ganam-Meon Yeoujoo-Gun Jyonggi Province and a length of section is 420m. This study came up with the following results. First, estabished the type of design and area of the area by means of the collected residents' opinions. Seconds, changed the straight line water channel already designed to the curve water channel . Third changed the structure materials of the steel concrete structure to the natural materials . Fourth, change dthe design by area for the ecological system and the meeting place of the residents. Fifth, divided the whole area into fourth area in order to satisfy the residents' requests.

• 대한토목학회논문집
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• 제26권2D호
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• pp.341-347
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• 2006

임하호는 안동호 유역과 지형학적으로 인접되어 있지만 강우강도에 따른 탁수발생에는 큰 차이를 보이고 있으며 이러한 원인을 밝히는 것은 매우 중요하다. 본 연구에서는 안동호와 임하호 유역을 연구대상지로 선정하여 준경험 토사유실모델인 RUSLE 모델을 이용하여 고탁수 발생에 큰 영향을 미치는 토사유실량을 비교 평가하였다. 먼저, 환경부에서 구축한 토지피복도를 기반으로 토사유실에 가장 민감한 농경지비율을 분석한 결과, 안동호유역은 11.88%, 임하호유역은 14.95%로서 임하호유역이 3.07% 높게 평가되었다. 또한 RUSLE 인자의 분석에서는 경작인자를 제외한 모든 인자들이 임하호유역에서 높게 평가되었으며, 이는 시간적인 변화를 보이는 강우자료를 제외한 토양, 지형 그리고 토지피복상태가 임하호유역이 안동호유역에 비해 토사유실에 취약한 구조를 가지고 있음을 의미한다. 토사유실량 평가에서도 안동호와 임하호유역이 각각 1,275,806 ton과 1,501,608 ton으로서, 임하호유역이 안동호유역에 비해 225,802 ton만큼 높게 평가되었다.

• 한국농공학회논문집
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• 제56권2호
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• pp.1-9
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• 2014

A modeling system is constructed by integrating an one-dimensional unsteady flow simulation model and a hydrologic model to simulate flood flows in drainage channel networks of paddy field districts. The modeling system's applicability is validated by simulating flood discharges from a paddy field district, which consists of nine paddy fields and one drainage channel. The simulation results are in good agreement with the observed. Particularly, in the verification stage, the relative errors of peak flows and peak depths between the observed and simulated hydrographs range 8.96 to 10.26 % and -10.26 to 2.97 %, respectively. The modeling system's capability is compared with that of a water balance equation-based model; it is revealed that the modeling system's accuracy is superior to the other model. In addition, the simulations of flood discharges from large-sized paddy fields through drainage channels show that the flood discharge patterns are affected by drainage outlet management for paddy fields and physical characteristics of the drainage channels. Finally, it is concluded that to efficiently design drainage channel networks, it is necessary to analyze the results from simulating flood discharges of the drainage channel networks according to their physical characteristics and connectivities.

• 농업과학연구
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• 제39권4호
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• pp.595-602
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• 2012

Main objective is to examine visitors the image, awareness of Saemangeum to examine its image, awareness, expected projects, and areas of improvement. This can establish measures for publicity and nation-wide participation. Main results are as following. First, visitors are broadly distributed to all age groups. Majority of visiting is travel and rate of returning visit is high as well. Second, the Saemangeum project is positively recognized and it is expected to be a prime development of the west coast in the future. Third, TV has significantly contributed to the visit to Saemangeum but the internet has larger effects in younger generations. Furthermore, rest and experience facilities, accommodations, and food items are major areas of improvement. Fourth, visitors have high expectations for tours, leisure, and ecosystems. Therefore, efforts should be made to become the Mecca of greed-development and cultural tourism. Fifth, many people replied that Saemangeum is an assistance to the national development but water quality management should be continued. In addition, the public participation should be made centrically cultural and economical participations.

• 농촌계획
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• 제7권1호
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• pp.77-88
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• 2001

In order to evaluate the applicability of GWLF model which can efficiently estimate non-point and point source pollutant loadings in rural watershed including urban district, the model was applied to an experimental watershed. The model was calibrated using observed data such as daily runoffs, sediment yields, T-N, and T-P. Simulated daily runoffs and sediment yields by the model using calibrated parameters were in food agreement with the observed data. There were difference between the simulated and observed nutrient loading which was considered resonable. The simulated results by the model showed that T-N, T-P and sediment yields were dependent on the amount of stream runoff discharge and land use. GWLF model is believed to applicable to estimate amount of pollutant loading of non-point source pollution for the water qualify control of agricultural watersheds.

• 한국환경농학회지
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• 제37권3호
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• pp.189-196
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• 2018

본 연구에서는 비점오염 모델에 강우의 질소 농도를 현실적으로 반영하기 위하여 국내 문헌과 3년 동안 관측한 강우 질소 농도를 분석하여 1개시(서울시), 9개도(경기도, 강원도, 충청남/북도, 전북남/북도, 경상남/북도, 제주도) 6개 광역시(부산, 인천, 대전, 울산, 대구, 광주)의 강우시 $NO_3{^-}$, $NH_4{^+}$ 및 T-N의 대표 농도를 제시하였다. $NO_3{^-}$와 $NH_4{^+}$의 평균 농도는 각각 1.88 mg/L와 0.96 mg/L 였으며, T-N은 2.84 mg/L 였다. 이는 환경부에서 제시하고 있는 2015년 전국 $NO_3{^-}$와 $NH_4{^+}$의 평균 농도인 1.98 mg/L와 1.05 mg/L와 비슷한 것으로 나타나 본 연구에서 제시된 각 행정구역별 농도는 타당한 수치로 사료된다. 본 연구결과 행정구역별로 질소농도의 차이가 있는 것으로 나타나 해당지역에 적합한 질소농도의 적용이 필요한 것으로 나타났다. 따라서 비점오염 모델 적용시 다양한 구축자료(수문인자, 지형인자 및 영농활동 인자 등)와 더불어 모델 적용지역의 강우 특성을 적절히 반영하여 오염부하량을 추정하는데 활용이 가능할 것으로 판단된다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2006년도 학술발표회 논문집
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• pp.1586-1590
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• 2006

In order to calculate the actual erosion according to the universal soil loss equation (USLE) and to estimate the impact of land use on soil erosion in Saemangeum, it is important to know the C-factor. Based on the USLE crop-growth stages, the cover-management C-factors were calculated for the main crop and crop rotation systems by National Institute of Agricultural Science and Technology. Combining this result with statistical data about crop cultivation area and crop rotation systems, C-factors of each administrative district in Saemangeum watershed were calculated. The range of C-factors were between 0.28 and 0.35. High C-factor value was obtained with Gimje (C = 0.35) and small C-factor values were found in Wanju (C = 0.28) and Jeongeup (C = 0.29). With this result, calculated annual soil loss was 2,804,483 ton per year. Because of the lack of sufficient statistical data about crop rotation systems, further studies are required on collecting field survey data.

• 한국물환경학회지
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• 제20권4호
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• pp.333-338
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• 2004

This study was carried out to investigate the generation and discharge characteristics of non-point pollutants from farmlands in Nak-dong river basin. Annual unit generation load of nitrogen and phosphorus by fertilization in the test paddy field was almost similar to those calculated by the fertilization standards of district agricultural technology center, but it was extremely higher in case of the test dry field. By comparing annual total generation load of nutrients from fertilization to the data of fertilizer marketing, the accurate forecasting of generation load of pollutants was achieved by marketing data. The annual total discharge ratio of nutrients through infiltration and overflow from the farmland of the test paddy field were 9.5% and 1.1%, respectively, and those in the test dry field were 22.0% and 0.1%, respectively. The monthly discharge load of nutrients were shown the highest proportioned to the discharge load from lands, but it showed higher in phosphorus, which was caused by the intermittent discharge of phosphorus accumulated in drainage.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.50-55
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• 2001

Different polluted water samples were collected from a wastewater treatment plant, agricultural drainage canals, the River Nile, and irrigation canals. The samples were examined for the enumeration of Pseudomonas aeruginosa in the Sohag area, Egypt over a period of one year. A total of 240 isolates were collected and tested for their resistance to 12 common antibiotics and 6 heavy metals. The isolates were found to be less resistant to norfloxacin(1.7%), ofloxacin(4.6%), amikacin(9.6%), tobramycin (10.4), carbenicillin (15.4), and gentamycin (41.3%), yet more sensitive to rifampicin (75%), kanamycin (89.6%), ampicillin (90.8%), chloramphenicol (91.7%), streptomycin (92.9%), and tetracyclin(96.3%). In contrast, 7.1%, 12.9%, 25.4%, and 53.7% of the isolates were resistant to lead, cadmium, mercury, and zinc, respectively. None of the isolates had developed a resistance to silver or molybdenum. The high frequency of metal-antibiotic double resistance existed between lead and amikacin (56.5%), cadmium and ofloxacin (72.7%), zinc and norfloxacin (100%), and mercury and carbenicillin (94.6%). The high occurrence of antibiotic-resistant bacteria in natural water could be related to the widespread use of antibiotics, with possible public health hazard.