• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.93-98
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• 1999

This study is performed to select irrigation design year from 10-year return period 7-month(April to October) precipitation amount and compare reference crop evapotranspiration at 13 regions by REF-ET model. 1. Seven-month growing season average reference crop evapotranspiration values showed low values of 4.1 ∼4.2mm /day by FAO-24 Corrected Penman method, and 3.6 ∼3.7mm/day by FAP-24 Blaney Criddle method in Chinjin and Ulsan, high values of 4.9mm/day by FAO-24 Corrected Penman method , 4.1mm/day by FAO -24 Blaney Criddle method in Mokpo and Pohang. 2. Estimated seven-month growing season average reference crop evapotranspirations are 4.6mm/day by FAO-24 Corrected Penman method, 3.9,mm/day by FAO-24 Balney Criddle method, 4.0mm/day 1985 Hargreaves method, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.31 no.3
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• pp.15-26
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• 1989

• Magazine of the Korean Society of Agricultural Engineers
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• v.25 no.2
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• pp.86-95
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• 1983

Evapotranspiration is a major factor determining the water consumption in the rice fields. Therefore, realistic evapotranspiration estimates are important to the agricultural water resources planning. In Korea, however, the Blaney-Criddle formula, which was developed under the meteorological condition of western arid United States and the upland cultivation, has been widely used to estimate evapotranspiration from paddy fields. Hence, it has considered that the Blaney-Criddle formula would not be the proper method for the Korean paddy condition. The purpose of this study is to select the most appropriate and realistic method for estimating evapotranspiraion from paddy field in Korea and to derive crop coefficients using the chosen method. The results are summerized as follows. 1. Total seasonal-average evapotranspiration by the field observation was 660mm for Tongil and 621. Ornm for the Japonica variety of rice. The amount of evapotranspiration for Tongil variety was 6% larger than that of the Japonica variety. 2. There was no significant differences in the amount of evapotranspiration among early, middle and late mature varieties, that is, early 638mm, middle 627mm and late 630mm for the whole growing season. 3. The rate of peak evapotranspiration appeared at the beginning of August and was in the range of 7.7-8. Omm/day according to the different mature varieties. 4. The correlation between pan evaporation data and the calculated evapotranspiration using related meteorological data from various methods suggested such as Radiation (FAO), Hargreaves, Christiansen, Hargreaves-Christiansen, Jensen-Haise, showed high statistic significance. Therefore, it seemed to use those formulars in estimating evapotranspiration inste4 of using pan evaporation data. 5. It was concluded from the analysis of field data that the evapotranspiration estimate for Blaney-Criddle method might not be appropriate in Korea. On the other hand, Penman equation showed more accurate estimation at the flourishing stage of rice than the pan evaporation method. 6. The crop coefficients for the Penman and pan-evaporation method were obtained by graphical representation.

• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.3
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• pp.25-35
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• 2009

Climate change due to global warming possibly effects the agricultural water use in terms of evapotranspiration. Thus, to estimate rice evapotranspiration under the climate change, future climate data including precipitation, minimum and maximum temperatures for 90 years ($2011{\sim}2100$), were forecasted using LARS-WG. Observed 30 years ($1971{\sim}2000$) climate data and climate change scenario based on SRES A2 were prepared to operate the LARS-WG model. Using these data and FAO Blaney-Criddle method, reference evapotranspiration and rice evapotranspiration were estimated for 9 different regions in South Korea and rice evapotranspiration of 10 year return period was estimated using frequency analysis. As the results of this study, rice evapotranspiration of 10 year return period increased 1.56%, 5.99% and 10.68% for each 30 years during $2011{\sim}2100$ (2025s; $2011{\sim}2040$, 2055s; $2041{\sim}2070$, 2085s; $2071{\sim}2100$) demonstrating that the increased temperature from the climate change increases the consumptive use of crops and agricultural water use.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.271-274
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• 2003

The objectives of this study are for finding an optimal calculation method comparing observed evapotranspiration with calculated evapotranspiration by Blaney-Criddle, Penman and Penman-Monteith method which are used in many place of Korea. And after appling optimal calculation method, optimal irrigation is presented through calculation of effective rainfall and requirement water considering characteristics of region, crop and soil.

• Journal of Korean Society of Rural Planning
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• v.22 no.4
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• pp.71-80
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• 2016

Meanwhile, reference evapotranspiration(ET0) is important information for agricultural management including irrigation planning and drought assessment, the database of reference evapotranspiration for future periods was rarely constructed especially at districts unit over the country. The Coupled Model Intercomparison Project Phase 5 (CMIP5) provides several meteorological data such as precipitation, average temperature, humidity, wind speed, and radiation for long-term future period at daily time-scale. This study aimed to build a database for reference evapotranspiration using the climate forecasts at high resolution (the outputs of HadGEM3-RA provided by Korea Meteorological Administration (KMA)). To estimate reference evapotranspiration, we implemented four different models such as FAO Modified Penman, FAO Penman-Monteith, FAO Blaney-Criddle, and Thornthwaite. The suggested database system has an open architecture so that user could add other models into the database. The database contains 5,050 regions' data for each four models and four Representative Concentration Pathways (RCP) climate change scenarios. The developed database system provides selecting features by which the database users could extract specific region and period data.

• Journal of Korean Society of Rural Planning
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• v.26 no.3
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• pp.91-102
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• 2020

The purpose of study was analyze the pumping characteristics, Irrigation Efficiency(IE), and irrigation pattern by period of rice growing stage with based on the performance of design irrigation water requirement and operational Galshin Pumping(GP) station in GP irrigation district constructed under rural water development project master plan. GP station was located in Yedang reservoir, Yesan-gun, Chungcheongnam-do and has been supplying irrigation water since 2006. The research data are the Irrigation Water Requirement(IWR) and the Pumping Water Amount(PWA) from 2006 to 2015 at the GP station, which is the supplied amount. The IWR were calculated using the Blaney-Criddle formula of the HOMWRS program, Hydrological Operation Model for Water Resource System, developed by Korea Rural Community Corporation. The Blaney-Criddle formula was used to calculate design irrigation water requirement of Galshin rural water development project master plan. During 2006-2015, the study period, the annual average IWR is 763.2(±149.1)mm, the annual PWA of the GP station is 397.4mm to 1,056.9mm, and those average annual PWA is 643.4(±208.4)mm. The annual IE of GP station 96.5% to 169.0%, and the average annual IE is 124.3%, which is higher than the research results conducted in other pumping stations. Analyzing the irrigation patterns of the GP irrigation district, the IWR Ratio per 10days(IWRR) and the PWA Ratio per 10days(PWAR) of the G P station were obtained. The IWRR is the percentage of IWR for each 10 days of a month to total IWR per year, and the PWAR is the percentage of PWA for each 10 days of a month to total PWA per year. The Kolmogorov- Smirnov(K-S) test results of IWRR and PWAR showed the characteristics classification by rice growing stage and stable normal distribution characteristics. Average IWRR(AIWRR) and Average PWAR(APWAR) are presented as irrigation patterns. Irrigation pattern analysis will be able to standardize comparison, analysis and probability calculation of the pumping station characteristics of different pumping stations and apply to objective evaluation of the pumping station district.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.28-35
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• 1985

This work Was carried out to obtain the most suitable crop coefficient for the paddy rice growing in Taegu area. The result was due to the comparative measurements of evapotranspiration formula in terms of Blaney & Criddle and eight other formulas with those produced by experiment particularly in this area. The crop coefficient, evapotranspiration and transpiration ratio produced by this research are hopefully expected to be of service in the future calculation of evapotranspiration without repeating experiment respectively, whenever the water requirement of paddy rice is planned in Taegu and its vicinity. The accomplished results could be summarized as follows : The maximum amount of evapotranspiration was recorded in the early and middle parts of August. The average reading of evapotranspiration was 6.33mm/day throughout the growth. The evapotranspiration had a highly significant correlation with pan evaporation, solar radiation, sunshine hours and relative humidity of meteorological elements. K and Kc by the use of Blaney & Criddle formula calculated at 0.76 to 1.45 and 0.82 to 1.27, respectively. Its peak value appeared commonly in early August. The ratio of transpiration was 269.03.

• KCID journal
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• v.14 no.2
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• pp.236-244
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• 2007

Agricultural water demand in North Korea must be considered for the near-future investment in agricultural consolidation projects and to prepare for the future unification. Thus, the objective of this study is to estimate the agricultural water demand of paddy fieldss in North Korea. GIS data including land cover classification map, Thiessen network and administration maps of North Korea, and meteorological data were synthesized. In order to estimate paddy water demand for a 10-year return period, the FAO Blaney-Criddle method and the fixed effective rainfall ratio method were used. The results showed that 4.77 billion $\beta$(c)/year paddy water demand is required for the 512,400 ha of paddy fieldss. Paddy water demand in the three major regions - Hwanghaedo, Pyeongando, Hamgyeongnamdo - was estimated chargong 81.7 percent of total paddy water demand in North Korea.

• Water for future
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• v.6 no.1
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• pp.87-99
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• 1973

The calculation of the comsumptive use by crop can be most accurate when it is actually measured. The mankind is not yet able tole grasp all the natural conditions or phenomena. The induces of actual measurement at a representive observatory and the formula abtained from the area werowere made as close as possible, which is called as the Blaney Criddle formcula, published in 1945. In calculating the water require-ment of consumptive use of water by farm crops, a more accurate and reasonable formula should be induced as the factors other than temperature and day-time hours according to the location of project area have also influences. The formula of Mr. Jerald E. Christianen published in 1969 is based on the induces of the records of actural measurements for 3, 928 months at 80 different stations and his formula couers a wider range of functions that calculate water requirement to induce the functions of moisture, wind, velocity, sunshine at elevatons, in addition to temperature and daytime hours in accordance with latitude and was modified to be fit to natural phenomena. The formula is being widely in use in many contries with their modification since it is worth while for usealso in korea, the formula is introduced and explained in the following.