• Title/Summary/Keyword: climatic variation

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Warming Trend of Coastal Waters of Korea during Recent 60 Years (1936-1995)

  • Kang Yong Q.
    • Fisheries and Aquatic Sciences
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    • v.3 no.3_4
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    • pp.173-179
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    • 2000
  • Recent changes in the coastal sea surface temperatures (SST) in Korea are studied by time series analysis of daily SST data during the last 60 years (1936-1995) at 18 coastal observation stations of the National Fisheries Research and Development Institute. The climate of coastal SST in Korea are rapidly changing in recent years. General trends of coast SST changes in Korea are as follows. The annual averages of SST are increasing. The annual ranges of SST variation are decreasing. The winter SST are increasing while the summer SST have a decreasing tendency. Climatic changes in coastal SST in recent 30 years (1965-1995) are more pronounced than those in the last 60 years (1936-1995). The observed trend of coast SST implies that the climate in Korea shows a tendency to shift from temperate zone to subtropical zone.

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Estimation of Groundwater Recharge with Spatial-Temporal Variability (시공간적 변동성을 고려한 지하수 함양량의 산정방안)

  • Kim, Nam Won;Chung, Il Moon;Won, Yoo Seung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.691-695
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    • 2004
  • In recent years, mary studies for efact estimation of groudwater recharge has been performed. They can be categorized into three groups : analytical method by means of groundwater recession curve, water budget analysis based on watershed, and the method using groundwater model. Since groundwater recharge rate shows the spatial-temporal variability due to hydrogeological heterogeneity, existing studies have various limits to deal with these characteristics. The method of estimating daily recharge rate with spatial-temporal variation based on rainfall-runoff model is suggested in this study for this purpose. This method is expected to enhance existing indirect method by means of reflecting climatic conditions, land use and hydrogeological heterogeneity.

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Climate change and design wind load concepts

  • Kasperski, Michael
    • Wind and Structures
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    • v.1 no.2
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    • pp.145-160
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    • 1998
  • In recent years, the effects of a possible climate change have been discussed in regard to wind loading on buildings and structures. Simple scenarios based on the assumption of global warming suggest an increase of storm intensities and storm frequencies and a possible re-distribution of storm tracks. Among recent publications, some papers seem to verify these scenarios while others deny the influence of climatic change. In an introductory step, the paper tries to re-examine these statements. Based on meteorological observations of a weather station in Germany, the existence of long-term trends and their statistical significance is investigated. The analysis itself is based on a refined model for the wind climate introducing a number of new basic variables. Thus, the numerical values of the design wind loads used in modern codes become more justified from the probabilistic point of view.

야생 차나무 ( Thea sinensis L. Var. Bohea ) 의 Isogyme Patterns. ( Isogyme Patterns of Tea ( Thea Sinensis L. Var. Bohea ) in the Sourthern Area of Korea )

  • 안상득
    • Korean Journal of Plant Resources
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    • v.4 no.1
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    • pp.13-16
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    • 1991
  • Tea plant has been mllainly grown in shade aild wet flace of several temple surroundings for a long years in sourthern area of Korea, since it has been introduced about1,000 years ago In those rlaces, it has been mostly grown in semi-wild, but recentlycultivated in a part of Bosung-gun, Cheonnanl province. External forms of tea plantwere considered that those have a little changed according to geographic andclimatic conditions of growing places. To investigate how is the variation of teaplant by the difference of environment conditions under growing places, we had ex-amined the protein and isozyme patterns of seeds of tea plant. In spite of difference ofgeographic and climatic conditions, the patterns of catalase, esterase, acid phosphat-ase isozyme and protein showed the same aspects.

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Examining the factors influencing leaf disease intensity of Kalopanax septemlobus (Thunb. ex Murray) Koidzumi (Araliaceae) over multiple spatial scales: from the individual, forest stand, to the regions in the Japanese Archipelago

  • Sakaguchi, Shota;Yamasaki, Michimasa;Tanaka, Chihiro;Isagi, Yuji
    • Journal of Ecology and Environment
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    • v.35 no.4
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    • pp.359-365
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    • 2012
  • We investigated leaf disease intensity of Kalopanax septemlobus (prickly castor oil tree) caused by the parasitic fungus Mycosphaerella acanthopanacis, in thirty natural host populations in the Japanese Archipelago. The disease intensity observed for individual trees were analyzed using a generalized additive model as a function of tree size, tree density, climatic terms and spatial trend surface. Individual tree size and conspecific tree density were shown to have significant negative and positive effects on disease intensity, respectively. The findings suggest that the probability of disease infection is partly determined by dispersal of infection agents (ascospores) from the fallen leaves on the ground, which can be enhanced by aggregation of host trees in a forest stand. Regional-scale spatial bias was also present in disease intensity; the populations in northern Japan and southern Kyushu were more severely infected by the fungus than those in southwestern Honshu and Shikoku. Regional variation of disease intensity was explained by both climatic factors and a trend surface term, with a latitudinal cline detected, which increases towards the north. Further research should be conducted in order to understand all of the factors generating the latitudinal cline detected in this study.

Seasonal Variation in Carcass Characteristics of Korean Cattle Steers

  • Piao, M.Y.;Baik, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.3
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    • pp.442-450
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    • 2015
  • Climate temperature affects animal production. This study was conducted to evaluate whether climatic conditions affect beef carcass characteristics of Korean cattle steers. The monthly carcass characteristics of Korean cattle steers (n = 2,182,415) for 8 yr (2006 through 2013) were collected from the Korean Institute for Animal Products Quality Evaluation. Daily climate temperature (CT) and relative humidity (RH) data were collected from the Korean Meteorological Administration. Weather conditions in South Korea during summer were hot and humid, with a maximum temperature of $28.4^{\circ}C$ and a maximum RH of 91.4%. The temperature-humidity index (THI), calculated based on CT and RH, ranges from 73 to 80 during summer. Winter in South Korea was cold, with a minimum temperature of $-4.0^{\circ}C$ and a wind-chill temperature of $-6.2^{\circ}C$. Both marbling score (MS) and quality grade (QG) of Korean cattle steer carcasses were generally best (p<0.05) in autumn and worst in spring. A correlation analysis showed that MS and QG frequencies were not associated (p>0.05) with CT. Yield grade (YG) of Korean cattle steer carcasses was lowest (p<0.05) in winter (November to January) and highest in spring and summer (May to September). A correlation analysis revealed that YG frequency was strongly correlated ($r{\geq}0.71$; p<0.01) with CT and THI values. The rib eye area, a positive YG parameter, was not associated with CT. Backfat thickness (BT), a negative YG factor, was highest in winter (November and December). The BT was strongly negatively correlated ($r{\leq}-0.74$; p<0.01) with CTs. Therefore, the poor YG during winter is likely due in part to the high BT. In conclusion, YG in Korean cattle steer carcasses was worst in winter. QGs were not associated with winter or summer climatic conditions.

Evaluation of F$_1$ Hybrids Between RD$_1$ and Bivoltine Breeds of the Silkworm (Bombyx mori L.) for Exploitation in Dry Zones

  • Singh, Ravindra;Rao, D.Raghavendra;Baro, Pranakrishna;Choudhary, Nazia;Gangopadhyay, Debnirmalya;Kariappa, B.K.;Dandin, S.B.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.2
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    • pp.199-205
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    • 2004
  • With the main objective to know the feasibility of exploitation of F$_1$ hybrids in semi arid and arid climatic conditions of India, the present study was carried out by utilising RD$_1$ as female parent and six bivoltine silkworm breeds viz., CSR$_2$, CSR$_4$, CSR$_{5}$, CSR$_{17}$, CSR$_{18}$ and CSR$_{19}$ along with NB$_4$D$_2$ as male parents. Different hybrids exhibited their superiority for various economic characters during different seasons. Among F$_1$ hybrids, RD$_1$${\times}$CSR$_{5}$ was adjudicated as the best hybrid in terms of expression of significant positive hybrid vigour over mid parental value for five economic characters namely hatching %, cocoon yield, cocoon weight, cocoon shell weight and filament size, highest multiple trait average evaluation index value of 56.77 and comparatively uniform cocoon size with coefficient of variation (CV%) of 3.80 and Standard Deviation (SD) of 7.99 during September - October 2003. Results of the present study revealed that the F$_1$ hybrid RD$_1$${\times}$CSR$_{5}$ can be successfully exploited on commercial in semi arid and arid climatic conditions in India. India.dia.

Change of AMC due to Climatic Change (기후변화에 따른 선행토양함수조건(AMC)의 변화)

  • Yoo, Chulsang;Park, Cheong Hoon;Kim, Joong Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.3B
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    • pp.233-240
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    • 2006
  • One of the main factor that effects on the CN's value in SCS Curve Number method for the estimation of direct runoff is the antecedent soil moisture condition (AMC). It is also common to use the AMC-III in hydrologic practice, which provides the largest runoff as possible. In this paper, AMC defending on the rainfall characteristics is analyzed using daily rainfall data at rainy season (June~September) of the Seoul station from 1961 to 2002. The probability mass function of AMC is also investigated to analyze the variation of AMC based on climate change, scenarios from several General Circulation Model (GCM) predictions. As a results we can find that the occurrence of AMC-I is reduced, and AMC-III is increased, whereas AMC-II does not change.

The annual variation pattern and regional division of weather eatropy in South Korea (남한의 일기엔트로피의 연변화유형과 지역구분)

  • ;Park, Hyun-Wook
    • Journal of the Korean Geographical Society
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    • v.30 no.3
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    • pp.207-229
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    • 1995
  • The characteristics of weather and climate in South Korea has great influences on the annual variation pattern and the appearance of the prevailing weather. The purpose of this paper is to induce the quantity of the weather entropy and annual variation pattern using the information theory and the principal component analysis. And author tried to classify the region according to the variation of its space scale, The raw materials used for this study are the daily cloudiness and precipitation during the years 1990-1994 at 69 stations in South Korea. It is divided into four classes of fine, clear, cloudy and rainy. The rcsults of this study can be summarized as follows: 1. Thc characteristics of annual variation pattern of weather entropy can be chiefly divided into five categories and the accumulated contributory rate of these is 73.1%. 2. Annual variation pattern of the first principal component reaches smaller in May, April and September than national average, and becomes greater when the winter comes. This weather entropy's quantity(Rs1) is positive in most area to the western sife of Soback Mountains and negative in most seaside area to the eastern side of Soback Mountains. 3. The characteristics of annual variation pattern of the second principal component shows that the entropy is more smaller in summer than national average and the rest of seasons shows larger, especially in January, May and September. This weather entropy's quantity(Rs2) is positive in most Honam Inland area to the western side of Soback Mountains and negative in most Youngnam Inland area to the eastern side of Soback Mountains. 4. Eight type regions (S1-S11) are classified based on the occurrences of minimum weather entropy in South Korea, and annual variation pattern of weather entropy by principal component analysis may be classified into sixteen type regions (Rs1-Rs9). Putting these things together, South Korea can be classifieed into thirty one type regions (Rs1S7-Rs9S10).

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Assessment of Productive Areas for Quercus acutissima by Ecoprovince in Korea Using Environmental Factors (환경요인을 이용한 생태권역별 상수리나무의 적지판정)

  • Kim, Tae U;Sung, Joo Han;Kwon, Tae-Sung;Chun, Jung Hwa;Shin, Man Yong
    • Journal of Korean Society of Forest Science
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    • v.102 no.3
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    • pp.437-445
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    • 2013
  • This study was conducted to develop site index equations and to estimate productive areas of Quercus acutissima by ecoprovince in Korea using environmental factors. Using the large data set from both a digital forest site map and a climatic map, a total of 48 environmental factors including 19 climatic variables were regressed on site index to develop site index equations. Four to six environmental factors for Quercus acutissima by ecoprovince were selected as independent variables in the final site index equations. The result showed that the coefficients of determination for site index equations were ranged from 0.30 to 0.41, which seem to be relatively low but good enough for the estimation of forest stand productivity. The site index equations developed in this study were also verified by three evaluation statistics such as the estimation bias of model, precision of model, and mean square error of measurement. According to the evaluation statistics, it was found that the site index equations fitted well to the test data sets with relatively low bias and variation. As a result, it was concluded that the site index equations were well capable of estimating site quality. Based on the site index equations of Quercus acutissima by ecoprovince, the productive areas by ecoprovince were estimated by applying GIS technique to the digital forest site map and climate map. In addition, the distribution of productive areas by ecoprovince was illustrated by using GIS technique.