• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.163-174
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• 2018

Rice cultivation is immensely affected by many climatic factors including temperature, precipitation, etc, and imbalanced climatic conditions negatively affect the growth of rice. In this study, we investigated the effects of different agroclimatic zones of Chungnam Province on rice quality and examined the correlations between climatic characteristics and rice yield components. Average temperatures and rainfall were higher in 'Western Sobaek Inland' than those in the 'South Western coastal zone, and precipitation records showed a wide variation among counties due to typhoons during the examined periods. The average accumulative temperature affecting the magnitude of production during reproductive growth periods was higher in "Cheon-An", "Gong-Ju", "Yeon-Gi (Se-Jong)", "Bo-Ryeong", and "Dang-Jin" counties than those in other counties. The plant height was higher in 'Western Sobaek Inland' counties such as "Yeon-Gi(Se-Jong)" and "Cheon-An", and 'Southern Charyeong Plain' counties such as "Cheong-Yang", "Dang-Jin", and "A-San", than those in other counties. The number of tillers during the 40 days after rice transplantation in "Seo-Cheon" and "Bo-Ryeong" counties increased compared to other counties. This result was relevant to the fact that the date of rice transplantation in those counties was 3 to 4 days later than those in other counties of Chung-Nam Province. The average yield (milled rice basis) was the highest in 'Western Sobaek Inland' zone, showing 3,756 kg ha^-1, followed by 'Southern Charyeong Plain' zone showing 3,621kg ha^-1, and was the lowest in 'South Western coastal zone by 3,315kg ha^-1. "Yeon-Gi(Se-Jong)" and "Dang-Jin" counties showed the highest yields of 4,100kg ha^-1. "Seo-San", "Seo-Cheon", and "Tae-An" counties were relatively lower yields of 3,240~3,280kg ha^-1 in comparison of other counties.

• Magazine of the Korean Society of Hazard Mitigation
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• v.2 no.4 s.7
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• pp.40-47
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• 2002

Since it is important to understand the bio-climatic change in Seoul for ecological city planning in the future, this paper gives an overview on bio-climate analysis of urban environments at Seoul. We analyzed its characteristics in recent years using the observations of 24 of Automatic Weather Station (AWS) by Korea Meteorological Administration (KMA). In urbanization, Seoul metropolitan area is densely populated and is concentrated with high buildings. This urban activity changes land covering, which modifies the local circulation of radiation, heat and moisture, precipitation and creating a specific climate. Urban climate is evidently manifested in the phenomena of the increase of the air temperature, called urban heat Island and in addition urban sqall line of heavy rain. Since a city has its different land cover and street structure, these form their own climate character such as climate comfort zone. The thermal fold in urban area such as the heat island is produced by the change of land use and the air pollution that provide the bio-climate change of urban eco-system. The urban wind flow is the most important climate element on dispersion of air pollution, thermal effects and heavy shower. Numerical modeling indicates that the bio-climatic transition of wind wake in urban area and the dispersion of the air pollution by the simulations of the wind variation depend on the urban land cover change. The winds are separately simulated on small and micro-scale at Seoul with two kinds of kinetic model, Witrak and MUKLIMO.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.507-512
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• 2016

This study was conducted to classify agroclimatic zones in South Korea. To classify the agroclimatic zones, such climatic factors as amount of rainfall from April to May, amount of rainfall in October, monthly average air temperature in January, monthly average air temperature from April to May, monthly average air temperature from April to September, monthly average air temperature from December to March, monthly minimum air temperature in January, monthly minimum air temperature from April to May, Warmth Index were considered as major influencing factors on the crop growth. Climatic factors were computed from monthly air temperature and precipitation of climatological normal year (1981~2010) at 1 km grid cell estimated from a geospatial climate interpolation method. The agroclimatic zones using k-means cluster analysis method were classified into 6 zones.

• Journal of the Korean Geographical Society
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• v.44 no.6
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• pp.691-705
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• 2009

Phytolith analysis was made on a 660cm core from Lake Gyeongpo in the East Sea of Korean Peninsula to clarify the environmental change including climate and agricultural characteristics during the Holocene. From the results of phytolith analysis, six phytoliths assemblage zone(PAZ) were recognized from the base to the surface. PAZ I around 5,000 yr BP suggests the transition from the warm and dry to the cool and wet climatic conditions. The climate of PAZ II(ca. 4,000-2,000 BP) was kept on warm, but repeated between dry and wet conditions. PAZ III(2,000~1,000 yr BP) suggests the expansion of agricultural activities under the warm and humid climatic conditions due to the significant phytoliths production of Paniceae and Oryza sativa. While PAZ IV(1,000~500 yr BP) indicates very cool and dry conditions, PAZ V and IV suggest the warm-dry and cool-humid climatic conditions, respectively. Similar to the results of pollen analysis in the lake, the agricultural activities were recognized by PAZ III around 2,000 yr BP from the results of phytolith analysis, and the rice cultivations such as Oryza sativa have been expanded since 2,000 yr BP or later.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.3
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• pp.175-190
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• 2024

In order to project changes in climate zones across the Korean Peninsula, the Trewartha's climate classification was applied to the SSP-RCP scenario data with a 1km resolution produced by the National Institute of Agricultural Sciences of the Rural Development Administration. Currently, most of the Korean Peninsula (92.3%) belongs to the temperate climate type (D), whereas only some areas (4.9%), such as Jeju Island, belongs to the subtropical climate type (C). According to SSP-RCP scenarios, the temperature is expected to gradually increase due to the influence of global warming during the 21st century, and the subtropical climate type is expected to expand to 14.1 to 48.6% of the total area of the Korean Peninsula in the far future. On the other hand, the temperate zone, which is currently most dominant on the Korean Peninsula, is expected to shrink by 85.8 to 51.4% in the late 21st century. If carbon dioxide emissions continue at the current rate, the entire Korean Peninsula will likely be dominated by subtropical and temperate regions in the distant future. In particular, the subtropical climate type is expected to dominate most of South Korea in the high-carbon scenario, except for highlands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.5
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• pp.985-996
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• 2000

In the coastal zone, to draw up short and medium range weather forecasts, mesoscale pluviogenic systems coming from the sea have to be observed in real time. These observations use remote sensing. However, satellite remote sensing is not sufficient to describe pluviogenic systems; reference to radar long distance observations is indispensable. This paper deals with the corrections, which must be made to long distance radar data if the rainfall field is to be both accurately and quantitatively defined. The error due to vertical variation in the reflectivity factor can be corrected from estimation of the mean profiles or by a climatic adjustment method. Atten-uation in the propagation can be corrected by an iterative polarimetric method. These various correc-tions permit the distance validity limits of radar data to be extended.

• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.481-501
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• 2007

Excessive rainfalls due to climatic changes can trigger an increase in rainfall-induced slope failures that pose real threats to both lives and properties. Many high slopes in residual soils could stand at a steep angle, but failed during or after rainfall. Commonly, these slopes have a deep groundwater table and negative pore-water pressures in the unsaturated zone above the groundwater table contribute to the shear strength of soil and consequently to factor of safety of the slope. Stability assessment of slope under rainfall requires information on rate of rainwater infiltration in the unsaturated zone and the resulting changes in pore-water pressure and shear strength of soil. This paper describes the application of unsaturated soil mechanics principles and theories in the assessment of rainfall effect on stability of slope through proper characterization of soil properties, measurement of negative pore-water pressures, seepage and slope stability analyses involving unsaturated and saturated soils. Factors controlling the rate of changes in factor of safety during rainfall and a preventive method to minimize infiltration are highlighted in this paper.

• Journal of Forest and Environmental Science
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• v.31 no.1
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• pp.7-13
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• 2015

Forest disturbance sometime considered as a tool of management as it believed that mid level disturbance constructs better micro-climatic conditions which ultimately boost up the plant diversity. The effect of different levels of disturbance on species composition and regeneration is very important. Present attempt was carried out in a temperate evergreen oak forest which was under various degree of disturbance. The study area is one of the large ranges of oak forest in Garhwal Himalaya and compensating various types of daily needs of local people. On the basis of IVI values Quercus leucotrichophora holds first position in all the disturbance zones whereas Myrica esculenta upgraded it's rank in highly disturbed zone and showed less impacted species by disturbance. Berberis aristata and Eupatorium adenophorum in shrub layer and Anaphalis adnata and Bidens pilosa in herb layer were found as disturbance friendly species because they attained higher rank in highly disturbed zone whereas Caryopteris foetida was found disturbance-sensitive in shrub layer. The banj oak regenerated well under mid disturbance as compared to no and high degree of disturbance and a sharp downfall in the species diversity was recorded with increasing magnitude of disturbance. Density-diameter curves showed a reverse trend of lower density in higher girth classes. The results of the study should be useful for the forest management strategies.

• Ocean and Polar Research
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• v.28 no.1
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• pp.1-12
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• 2006

Analyses of sedimentological and geochemical parameters from two radiocarbon-dated sediment cores (JM98-845-PC and JM98-818-PC) retrieved from the central part of Isfjorden, Svalbard, in the Arctic Sea, reveal detailed paleoclimatic and paleoceanographic histories over the last 15,000 radiocarbon years. The overconsolidated diamicton at the base of core JM98-845-PC is supposed to be a basal till deposited beneath pounding glacier that had advanced during the LGM (Last Glacial Maximum). Deglaciation of the fjord commenced after the glacial maximum, marked by the deposition of interlaminated sand and mud in the ice-proximal zone by subglacial meltwater discharge, and prevailed between 13,700 and 10,800 yr B.P. with enriched-terrigenous organic materials. A return to colder conditions occurred at around 10,800 yr B.P. with a drop in TOC content, which is probably coincident with the Younger Dryas event in the North Atlantic region. At this time, an abrupt decrease of TOC content as well as an increase in C/N ratio suggests enhanced terrigenous input due to the glacial readvance. A climatic optimum is recognized between 8,395 and 2,442 yr B.P., coinciding with 'a mid-Holocene climatic optimum' in Northern Hemisphere sites (e.g., the Laurentide Ice sheet). During this time, as the sea ice receded from the fjord, enhanced primary productivity occurred in open marine conditions, resulting in the deposition of organic-enriched pebbly mud with evidence of TOC maxima and C/N ratio minima in sediments. Fast ice also disappeared from the coast, providing the maximum of IRD (ice-rafted debris) input. Around 2,442 yr B.p. (the onset of Neoglacial), pebbly mud, characterized by a decrease in TOC content, reflects the formation of more extensive sea ice and fast ice, which might cause decreased primary productivity in the surface water, as evidenced by a decrease in TOC content. Our results provide evidence of climatic change on the Svalbard fjords that helps to refine the existence and timing of late Pleistocene and Holocene millennial-scale climatic events in the Northern Hemisphere.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.597-602
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• 2005

The Late Quaternary palynoflora from an archaeological site in Piseo-ri, Muan, Korea consists predominately of deciduous broadleaved angiosperms and subordinately of herbs and conifers. Dominant taxa are Polypodiaceae, Taxodiaceae-Cupressaceae-Taxaceae, Alnus, Carpinus, deciduous Quercus, Compositae and Gramineae. The palynoflora dated 43,000-18,000 yr BP, corresponding to the last glacial period, is similar to the modern vegetation of the cool temperate deciduous broadleaved forest in the middle part of the Korean Peninsula. Based on palynofloral composition, three palynozones are recognized. Zone I represents a cool temperate deciduous broadleaved forest, composed of Polypodiaceae, Taxodiaceae-Cupressaceae-Taxaceae, Alnus and D. Quercus, and is characterized by persistent occurrence of warm temperate taxa. Zone II shows drastic decrease in Polypodiaceae, Taxodiaceae-Cupressaceae-Taxaceae, and increase in herbs. This zone reflects a cool temperate deciduous broadleaved forest with scattered open grasslands. Zone III is characterized by dominance in herbs and increase in conifers. The palynofloral composition suggests a cool temperate climate, and variation in occurrences of main taxa indicates that climatic conditions gradually became cold and dry.