• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.421-430
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• 2015

Rural Development Administration has recently developed mid-late maturing rice cultivars with high quality. This study was conducted to select suitable mid-late maturing rice cultivar in major cultivation areas of Gangwon Province among domestic breeding cultivars for 2 years from 2013 to 2014. The average air temperature during the experiment in 2013 and 2014 was higher $0.6{\sim}1.1^{\circ}C$ in Chuncheon, $1.0{\sim}1.3^{\circ}C$ in Gangreung, and $0.1{\sim}0.7^{\circ}C$ in Cheolwon than normal year. Precipitation in ripening period was higher 52.5 mm in 2013, but lower 176.4 mm in 2014 than normal year in Chuncheon, lower 103.1 mm in 2013 and higher 42.9 mm in 2014 in Gangreung, lower 225.9~322.7 mm in Cheolwon. Duration of sunshine in ripening period was higher 142 hours in Chuncheon, 108 hours in Gangreung, and 94 hours in Cheolwon than normal year in 2013, higher 20~21 hours in Chuncheon and Gangreung, and 82 hours in Cheolwon than normal year in 2014. Milled rice yield of 'Samgwangbyeo' and 'Daebobyeo' was 594 kg per 10a, and 578 kg for 'Jinsumibyeo' in Chuncheon in plain area. For Gangreung in east coastal area, the yield of 'Daebobyeo' was 555 kg per 10a, 'Hopumbyeo' was 554 kg, and 'Chilbobyeo' was 546 kg. For Cheolwon in mid-mountainous area, the yield was 504 kg per 10a for 'Daebobyeo' and 489 kg for 'Haiamibyeo'. But there was no difference in milled rice yield among cultivars tested in the study at each area. Head rice ratio of 'Haiamibyeo', 'Jinsumibyeo', and 'Mipumbyeo' in Chuncheon was 94.2~95.6% higher than the other cultivars. In Gangreung head rice ratio of 'Hopumbyeo', 'Haiamibyeo', and 'Samgwangbyeo' were 85.2~88.3% but there was no difference among cultivars except 'Gopumbyeo' and broken rice ratio of 'Haiamibyeo', 'Samgwangbyeo', and 'Mipumbyeo' were low as 7.5~8.5% and palatability of 'Mipumbyeo' was higher than the other cultivars. Head rice ratio of 'Daebobyeo' was the highest as 89.2% and there was no difference in broken and chalky rice ratio and palatability among cultivars in Cheolwon. Considering rice yield and quality in major cultivation areas of Gangwon Province, suitable mid-late maturing rice cultivars were 'Samgwangbyeo', 'Haiamibyeo', and 'Jinsumibyeo' in Chuncheon, 'Daebobyeo' and 'Chilbobyeo' in Gangreung, and 'Daebobyeo' and 'Haiamibyeo' in Cheolwon. The results obtained in the study imply that the selected cultivars with high yield and quality and suitability to Chuncheon, Gangreung, and Cheolwon, respectively could be recommended to rice cultivating farmers in the regions with high priority.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.2
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• pp.111-117
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• 2008

We estirmted the yearly and monthly variation in discharge from the Nakdong River Barrage. We studied the total monthly discharge, the mean daily discharge, and the maximum daily discharge based on the observational discharge data for the 11-year period 1996-2006. We also examined the correlation between the discharge and the meteorologiml factors that influence the river inflow. The results from this study are as follows. (1) The total monthly discharge for 11 years at the Nakdong River Barrage was $224,576.8{\times}10^6\;m^3$: The daily maximum was in 2003, with $56,292.3{\times}10^6\;m^3$. The largest daily mean release discharges occurred in August with $52,634.2{\times}10^6\;m^3$ (23.4% of the year), followed by July and September in that order with 23.1 and 17%, respectively. (2) The monthly pattern of discharge could be divided into the flood season for the period July-September (discharge =$1000{\times}10^6\;m^3$/day), the normal season from April to June and October (discharge=$300{\times}10^6\;m^3$/day), and the drought season from December to March (discharge < $300{\times}10^6\;m^3$/day). (3) Periods of high temperature, low evaporation loss, and short sunshine duration produced a much higher discharge in general. Conditions of low rainfall and high evaporation loss, as was the rose in 2003, tended to reduce the discharge, but high rainfall and low evaporation loss tended to increase the discharge as it did in 200l. (4) The dominant wind directions during periods of high discharge were NNE (15.5%), SW and SSW (13.1%), S(12.1%), and NE (10.8%) This results show that it run bring on accumulation of fresh water when northern winds are dominant, and it run flow out fresh water toward offslwre when southern winds are dominant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.252-263
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• 1997

Temperature and salinity were observed in Kugum Suro Channel in February, April, August and October 1993. Temperature ranged from $7.0^{\circ}C\;to\;25.0^{\circ}C$ throughout the year and its variation was about $18^{\circ}C$. The maximum temperature difference between surface and bottom was less than $0.75^{\circ}C$ for a year, which meant that the temperature stratification in Kugum Suro Channel was considerably week. Salinity had also a small variation range of less than $0.5\%_{\circ}$. Salinity varied from $34.0\%_{\circ}$ in April to $30.0\%_{\circ}$ in August and its fluctuation patterns were quite similar to the seasonal variations of the precipitation and the duration of sunshine observed at Kohung Weather station. Seasonal variation of sea water density in T-S diagram showed that the water mass in Kugum Suro Channel could be largely affected by regional atmospheric conditions. Temperature increased in ebb tide and decreased in flood tide, but salinity decreased in ebb tide and increased in flood tide for a day. The period of fluctuations in temperature and salinity measured for 25 hours was nearly coincident with the semi-diurnal tide which was predominant in that region. Stratification parameters computed in Kugum Suro Channel areas were less than $4.0J/m^3$ the year round, which indicated that vortical mixing from the bottom boundary caused by tidal current played an important role in deciding the stratification regime in Kugum Suro Channel. In estimating the equation which defines stratification and mixing effects in the observed areas, the tidal mixing term ranged from $4.7J/M^3\;to\;14.1J/m^3$ was greater than any other terms like solar radiation, river discharge and wind mixing.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.146-157
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• 2019

One of the most distinctive features of the South Korean rural environment is that the variation of weather or climate is large even within a small area due to complex terrains. The Geospatial Schemes based on Topo-Climatology (GSTP) was developed to simulate such variations effectively. In the present study, we reviewed the progress of the geospatial schemes for production of farm-scale agricultural weather data. Efforts have been made to improve the GSTP since 2000s. The schemes were used to provide climate information based on the current normal year and future climate scenarios at a landscape scale. The digital climate maps for the normal year include the maps of the monthly minimum temperature, maximum temperature, precipitation, and solar radiation in the past 30 years at 30 m or 270 m spatial resolution. Based on these digital climate maps, future climate change scenario maps were also produced at the high spatial resolution. These maps have been used for climate change impact assessment at the field scale by reprocessing them and transforming them into various forms. In the 2010s, the GSTP model was used to produce information for farm-specific weather conditions and weather forecast data on a landscape scale. The microclimate models of which the GSTP model consists have been improved to provide detailed weather condition data based on daily weather observation data in recent development. Using such daily data, the Early warning service for agrometeorological hazard has been developed to provide weather forecasts in real-time by processing a digital forecast and mid-term weather forecast data (KMA) at 30 m spatial resolution. Currently, daily minimum temperature, maximum temperature, precipitation, solar radiation quantity, and the duration of sunshine are forecasted as detailed weather conditions and forecast information. Moreover, based on farm-specific past-current-future weather information, growth information for various crops and agrometeorological disaster forecasts have been produced.