• Title/Summary/Keyword: Climatic factor

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Variations in Accumulation of Terrigenous and Biogenic Materials in the Northwest Pacific Ocean since the Last Interglacial Period

  • Hyun, Sang-Min;Taira, Asahiko;Ahagon, Naokazu;Han, Sang-Joon
    • Journal of the korean society of oceanography
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    • v.33 no.3
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    • pp.80-89
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    • 1998
  • Three cores were taken from the northwest Pacific Ocean (Shikoku Basin) to determine the accumulation rates of both biogenic and terrigeneous fractions since the last penultimate interglacial period. The sediment is characterized by large amounts of terrigenous materials with low biogenic fractions and intermittent volcanic-ash layers, suggesting a hemipelagic origin. Composition of major elements shows no significant differences among sites. Relatively small variation of TiO$_2$/Al$_2$O$_3$ ratios with respect to SiO$_2$ content is the strong evidence for the common origin of terrigenous materials. The fraction of biogenic carbonates varies from near 0% in ash layers to about 35%, with a gradual increase toward the south (St. 4 through St. 6 to St. 20). However, carbonate contents show step-wise increasing tendency from St. 4 through St. 6 to St. 20, which suggests a southward increase of carbonate production. The color reflectance indicates that the sediment of the southern sites contains relatively higher amounts of biogenic carbonates. The mass accumulation rate of terrigenous fractions during the glacial period was 2-3 times higher than that of interglacial period. This enhanced mass accumulation rate of terrigenous materials was concomitant with the high accumulation rate of biogenic fractions. The total sediment accumulation rate is considered as the most important factor controlling mass accumulation rates of the biogenic and terrigenous materials. The enhanced sediment accumulation during the glacial periods is interpreted as a consequence of climate-induced change in the supply of eolian dust from the Asian continent. Enhanced wind strength during the glacial time may have increased transportation of terrigenous materials to the ocean. Thus, variation of sediment accumulation is highly linked with climatic variations.

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Characterization of Hydroxy-interlayered Mineral in Non-Andic Soils from Jeju Island

  • Lee, Gyoo-Ho;Yungoo Song;Ha, Dae-Ho;Moon, Hi-Soo;Moon, Ji-Won
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2001.06a
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    • pp.45-47
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    • 2001
  • Jeju island is composed mainly of volcanic rocks such as basalts, trachytic andesites, tracytes, and sedimentary rocks. About 80% of Jeju soils are classified as Andisols. The amount of annual precipitation in Jeju island is about 1872mm, which is 1.5 times the annual precipitation of south Korea. There is a significant difference In amount of precipitation with regions even within Jeju island. In study area, the annual amount of rainfall is about 1280mm, the lowest in Jeju island while south part of the island has the annual precipitation of 2056mm, though they are only tens of kilometers apart. The parent materials of soils in study area are pyroclastic rocks and tuffs. The soils of non-andic properties have developed in this area since pedogenic process of pyroclastic materials is strongly influenced by climatic factor, especially precipitation. In order to investigate the mineralogical characteristics of soils, X-ray analysis for <0.2 and 2-0.2$\mu\textrm{m}$ size fractions was performed with ethylene glycol solvation, K-, Mg-saturation, heat treatment(110, 330, 550$^{\circ}C$). Acid-oxalate and DCB(sodium hydrosulfite, sodium citrate, sodium bicarbonate) dissolution method was used to assess tile total amounts or Al, si, and hydroxy interlayer or 2:1 layer silicates. XRD was also applied for samples treated with DCB only and DCB-oxalate sequentially. XRD patterns showed that 2:1 and 1:1 layer silicates were found, which are different from soils of Andisols. Vermiculite, chlorite, hydroxy interlayered minreals, and interstratified minerals(vermiculite/chlorite) were observed in 2-0.2$\mu\textrm{m}$ size fractions. After DCB treatments, ethylene glycolated samples with Mg-saturation showed expanded d-spacing, suggesting the possibility of hydroxy interlayered minerals. The amounts of hydroxy interlayered minerals increased in surface soil. Unlike Andisols, short range ordered minerals such as allophane, imogolite and gibbsite were hardly found. Mica and kaolinte existed in small amounts. Results are summarized in Fig 1 and Fig. 2.

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A Study on Costume of Arctic Circles in Pacific Coast (태평양 연안 지역 북극권 복식 특성 연구)

  • 김문숙
    • The Research Journal of the Costume Culture
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    • v.7 no.3
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    • pp.35-49
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    • 1999
  • The North Pacific Arctic region has common factors such as climatic characteristics and similarity of animals inhabiting the region. But also there exists geographical barriers that separates the tribes, different languages between the tribes. Although there are such differences, the clothing and ornaments of the region have relatively similar design and style. And above all possess the ‘spirit’. The tribes find the motives of such ‘spirit’ in human, animal, and soul\`s adaptability to change and in grafting such changes of forms into clothing. Especially as means of pleasing the animal that they vitally rely on, the tribes made the clothing as beautiful as the nature itself and they tried to connect the humans and animals universally through such clothing that have social, artistic, and enchantic conditions. The supply of raw materials of animals has elevated the creativeness one step up and the precise knowledge about fur show their superior techniques in making fur clothing. The use of gutskin has is an excellent example of such knowledge, which is very unique of the region. The gutskin has moderate plasticity and thus can be cut into all sorts of pattern. It harmonizes the functionality and practicality. The worldwide fashion trend is dominated by Western style, but the clothing of this region is still keeping its distinctive folk identity. At the start of the research, Kayak and itelmen tribes of Asia, the tribes of Amur river and Aleut and Tlingit tribes of North America seems to be geographically too far from each other and therefore searching theoretical background for common cultural origins seems to be immoderate. But lighting the fact that geographical adjacency that can be perceived through costume cultural history, is the most important factor that gives mutual influences to costume culture between the neighboring tribes, cultural relative similarity of the costume is influenced by geographical location rather than physical distance between the tribes. Also humans\` adaptability to their environment is seriously contaminated with man-made products. This study on North Pacific Arctic region is telling us many things about our past, present and future.

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Consideration of Trends and Applications of Groundwater Vulnerability Assessment Methods in South Korea (지하수 오염취약성 평가 기법 동향과 국내 적용성 고찰)

  • Kim, Gyoo-Bum
    • Journal of Soil and Groundwater Environment
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    • v.13 no.6
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    • pp.1-16
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    • 2008
  • There are generally two types of groundwater vulnerability assessments. Intrinsic vulnerability is based on the assessment of natural climatic, geological and hydrogeological attributes and specific vulnerability relates to a specific contaminant, contaminant class, or human activity. Several methods to assess groundwater vulnerability, which are based on hydrogeologic setting and socio-economical environment, have been developed in USA and Europe. A Modified-DRASTIC model including a lineament factor has been developed in South Korea, but it still has some limitations. To develop a solid and applicable method in this country, many data of quality, hydraulic features, GIS data, and pollution source, produced from a Basic Survey based on Article 5 of the Groundwater Act and other research projects, need to be collected, analyzed and verified introducing the previous methods.

Ecological Studies on Yeasts in the Waters of the Yeong San River Estuary (榮山江 汽水域의 酵母에 關한 生態學的 硏究)

  • Chun, Soon-Bai
    • Korean Journal of Microbiology
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    • v.22 no.1
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    • pp.1-18
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    • 1984
  • With 156 water samples collected from 39 locations in the Yeong San River estuary during the 12month period from March 1976 to February 1977, the seasonal distribution of yeast and the distributional pattern of yeast on salinity gradient have been investigated. An overall average number of yeast ranged from 52 to 487 viable cells (c.f.u.) per 100ml water sample. The highest count of yeast was obtained in spring while the lowest value came in summer. 933 yeast and one yeast-like fungus pertaining to 14 genera and 83 species were recovered, of which Candida were 29%, Debaryomyces 17.3%, Rhodotorula Glutinis were dominant forms in all locations as well as throughout the year. The population size of total aerobic bacteria, the amount of terrestrial imputs, and some of geographical and/or climatic factor appear to reflect the seasonal distribution of yeast as well as the composition of yeast species in an estuarine environ. Average number of yeast, species diversity, and particularly the number of fermentative and pseudomycelium-producing yeasts increased with decreasing salinity whereas nitrate-utilizing yeasts showed opposite trend, suggesting that salinity gradient can be used as a feasible detector for the distributional pattern of yeast in estuarine habitat.

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The Proxy Variables Selection of Vulnerability Assessment for Agricultural Infrastructure According to Climate Change (논문 - 기후변화에 따른 농업생산기반 재해 취약성 평가를 위한 대리변수 선정)

  • Kim, Sung-Jae;Park, Tae-Yang;Kim, Sung-Min;Kim, Sang-Min
    • KCID journal
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    • v.18 no.2
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    • pp.33-42
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    • 2011
  • Climate change has impacts on not only the average temperature rise but also the intensity and frequency of extreme events such as flood and drought. It is also expected that the damages on agricultural infrastructure will be increased resulting from increased rainfall intensity and frequency caused by climate change. To strengthen the climate change adaptation capacity, it is necessary to identify the vulnerability of a given society's physical infrastructures and to develop appropriate adaptation strategies with infrastructure management because generally facilities related to human settlements are vulnerable to climate changes and establishing an adaptive public infrastructure would reduce the damages and the repair cost. Therefore, development of mitigation strategies for agricultural infrastructure against climatic hazard is very important, but there are few studies on agricultural infrastructure vulnerability assessment and adaptation strategies. The concept of vulnerability, however, is difficult to functionally define due to the fact that vulnerability itself includes many aspects (biological, socioeconomic, etc.) in various sectors. As such, much research on vulnerability has used indicators which are useful for standardization and aggregation. In this study, for the vulnerability assessment for agricultural infrastructure, 3 categories of climate exposure, sensitivity, and adaptation capacity were defined which are composed of 16 sub-categories and 49 proxy variables. Database for each proxy variables was established based on local administrative province. Future studies are required to define the weighting factor and standardization method to calculate the vulnerability indicator for agricultural infrastructure against climate change.

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Changes in plant community structure in relation to climate change and restoration plot areas in Mongolia

  • Lkhavgadorj, Khureltsetseg;Iderzorig, Badamnyambuu;Kwon, Ohseok
    • Journal of Ecology and Environment
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    • v.39 no.1
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    • pp.119-125
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    • 2016
  • Mongolia has one of the strongest climate warming signals on Earth, and over 40% of the human population depends directly or indirectly on pastoral livestock production for their livelihoods. Thus, climate-driven changes in rangeland production will likely have a major effect on pastoral livelihoods . The loss of species dependent mostly on rainfall has resulted in adverse changes in the botanical composition of the steppes . Summer season in 2015 was completely dry until middle of July and, had not enough vegetation cover as last 15 years. The purpose of this study is to check plant community dynamics in Mongolia in relation to climate change in 2014 and 2015. The study sites were selected in mountain-steppe habitat in central Mongolia. In the 2014, there have been registered 81 plant species of 56 genera of 25 families on the investigated sites and, occurred 57 plant species of 44 genera of 21 families in the 2015. It is concluded that the abundance and richness of plants are directly connected to heavily affect by the climatic factor, i.e. amount of precipitation during growing season. As a same like result of climate change, in Mongolian land is going become desertification, and each spring, soil particles from Mongolia are swept up by a cold air mass into the atmosphere and blasts into south east China, Korea and Japan. The Koreans call this phenomenon the "Fifth season" or "Yellow sand", and the Chinese call it "Yellow dragon".

Geographic Variation in Survival Rate and Height Growth of Pinus densiflora S. et Z. in Korea

  • Kim, In-Sik;Ryu, Keun-Ok;Song, Jeong-Ho;Kim, Tae-Su
    • Journal of Korean Society of Forest Science
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    • v.94 no.2 s.159
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    • pp.73-81
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    • 2005
  • This study was conducted to examine the geographic variation among provenances of Pinus densiflora in survival rate and height growth at four test plantations (Jungsun, Chungju, Naju, and Jeju). The plantations were parts of the eleven provenance trials of Pinus densiflora established by Korea Forest Research Institute in 1996. The survival rate and height growth were significantly different among test plantations at $p{\leq}0.01$. Latitude and longitude of test plantation were negatively correlated with survival rate and height growth. On the other hand, annual mean temperature, mean temperature (Nov.~Feb.), extremely low temperature (Dec.~Feb.), and annual mean growing days of test plantation were positively correlated with these two. The relationships between growth variables and geographic variables were analysed with canonical correlation analysis. A considerable amount of variation in survival rate and height growth was explained by latitude, annual mean growing days, extremely low temperature (Dec.~Feb.) and extremely high temperature (Nov.~Feb.) of provenances. It is estimated that up to 47.1% and 67.4% of the genetic variability in survival rate and height growth was attributable to the environmental variability of the provenances, respectively. The response surface curve of survival rate and height growth was plotted against latitude and longitude to examine growth performance of provenances for each test site. Generally, the local provenances showed better survival rate and height growth.

Analysis of Heat Island Characteristics of Coast and Riverside Area Using GIS in Busan (GIS를 활용한 부산지역의 해안·강변지역 열섬특성 분석)

  • Song, Sang Cheol;Kang, In Joon;Son, Myung Chan;Han, Ki Bong
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.3-9
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    • 2013
  • Development of housing, industrial and public lands has been a cause to increase a temperature of a city higher than that of a rural area. Knowing that, the research analyzed temperature changes in a riverside district and a coastal area depending on the land usage and climate change in the areas. Add to this, the study examined a correlation between topographic characteristics and temperature changes. According to the results, the temperature was increased by $1.80^{\circ}C$ in 2007 comparing to 2003 while the wind velocity was reduced by 0.24m/s. In addition, a more number of areas were designated as build-up areas which, in return, decreased the forested land. The analysis on the correlation reported that the riverside district has more of grassland and bare land while the coastal area has more of wooded land and grassland. The study is expected to be used as fundamental data for research on heat island effect which would be different by each regional characteristic as it proposes measures to solve the heat island effect.

A Study on Condition Assessment of the General National Road Bridge Deck (일반국도상 교량 바닥판의 상태 현황분석 연구)

  • Oh, Kwang Chin;Lee, Jun Gu;Shin, Ju Yeoul;Chang, Buhm Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.6
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    • pp.93-101
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    • 2012
  • Bridge deck has a role in a comfortable and safe passage of vehicles. At the same time, it preserves upper structure against the abrasion and shearing due to impact of traffic loads in bridges or has a role to protect the plate from off adverse effect of climatic process as rain, chemicals. Currently, the total number of inspected bridges is 6,248 in the general national road and to maintain effectively, Introduction of GPR system mounted in the vehicle has been considered. In this research, the comparison and analysis of bridge deck condition on general national road has been performed with major variations of superstructure type, span lengths, located region and ages by using 'the current status of road bridge and tunnel' that is provided by MLTM(Ministry of Land, Transport and Maritime Affairs). As a result, Condition assessment grade, superstructure type, age and length were derived as a major factor to determine priority for the condition assessment.