• Title/Summary/Keyword: climatic variation

검색결과 177건 처리시간 0.029초

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

  • Kang Yong Q.
    • Fisheries and Aquatic Sciences
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    • 제3권3_4호
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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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시공간적 변동성을 고려한 지하수 함양량의 산정방안 (Estimation of Groundwater Recharge with Spatial-Temporal Variability)

  • 김남원;정일문;원유승
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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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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    • 제1권2호
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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
    • 한국자원식물학회지
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    • 제4권1호
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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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    • 제35권4호
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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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    • 제28권3호
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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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    • 제9권2호
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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.

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

  • 유철상;박정훈;김중훈
    • 대한토목학회논문집
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    • 제26권3B호
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    • pp.233-240
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    • 2006
  • 직접유출을 산정하기 위한 SCS Curve Number 방법에서 CN의 값에 영향을 주는 요소 중의 하나는 선행토양함수조건(AMC)이며, 실무에서도 가장 큰 유출량을 산정토록 하는 AMC-III 조건을 주로 사용하고 있다. 본 연구에서는 1961년부터 2002년까지 42년간의 서울 기상청관측소의 우기시(6월~9월) 일강우자료를 이용하여 AMC의 강우량 대비 발생분포를 분석하였다. 그리고 기후변화에 따른 AMC의 변동특성을 분석하기 위하여 대기대순환모형(GCM)의 예측치에 따른 강우량 대비 AMC의 확률질량함수를 분석하였다. 연구 결과, 본 연구에서 사용한 기후변화시나리오에 의하면 AMC-I의 발생비율은 감소하였고, AMC-III의 발생비율은 증가하는 것으로 파악되었다. 반면에 AMC-II는 커다란 변화를 보이지 않는 것으로 파악되었다.

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

  • 박현욱
    • 대한지리학회지
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    • 제30권3호
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    • pp.207-229
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    • 1995
  • 한반도는 중위도의 아시아대륙 동안에 위치하여 있고 지형적으로 복잡하므로 계절 을 통해 다양하게 탁월한 천후가 출현한다. 이러한 탁월천후의 특성은 일기출현율과 그 연 변화상에 잘 반영되고 있을 것으로 생각된다. 따라서 본 논문은 cybernetics의 일부로 있는 정보이론을 이용하여 남한의 탁월일기의 다소와 그 연변화형에 대해 일기의 평균정보량인 일기엔트로피를 구하고, 주성분분석기법을 응용하여 추출된 일기엔트로피의 연변화형과 그 공간 스케일에 따라 객관적인 작업에 의해 계량적으로 기후지역구분을 한 것이다. 주로 소 백, 태백산맥을 경계로 그 이서와 이동은 일기엔트로피의 출현월과 주성분분석 기법을 응용 하여 수량적으로 추출된 일기엔트로피의 연변화형이 각각 다르게 나타난다. 또한 이것은 해 안과 내륙에 위치하느냐에 따라서도 지역별로 그 정도차가 크다. 남한에서는 최소 일기엔트 로피의 출현월에 다라 8개형의 지역이 나타나며, 주성분분석에 의한 일기엔트로피의 연변화 형에 따라서는 16개형 지역으로 분류된다. 이를 종합하면 남한은 31개 지역으로 지역구분 된다.

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

  • 김태우;성주한;권태성;천정화;신만용
    • 한국산림과학회지
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    • 제102권3호
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    • pp.437-445
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    • 2013
  • 본 연구는 환경인자를 이용하여 우리나라에 생태권역별로 분포하는 상수리나무의 지위지수 추정식을 개발하고 적지면적 및 분포를 추정하기 위해 수행하였다. 이를 위해 산림입지도와 전자기후도로부터 산림생산력에 영향을 미칠 것으로 판단되는 19개의 기후변수를 포함한 총 48개 환경인자를 도출한 후, 최적 조합에 의해 지위지수 추정식을 개발하였다. 최종 생태권역별 상수리나무의 지위지수 추정식에는 각각 4~6개의 환경인자가 독립변수로 사용 되었고, 지위지수 추정식의 설명력을 나타내는 결정계수는 0.30~0.41의 범위에 있는 것으로 분석되었다. 또한 모형의 평균편의, 정도(精度), 표준오차의 3가지 평가통계량을 이용하여 검증을 실시한 결과 비교적 지위 추정능력이 높은 것으로 판명되었다. 본 연구에서는 이와 같이 개발된 생태권역별 상수리나무의 지위지수 추정식을 이용하여 적지면적을 산출하고 적지분포를 도해하였다.