• The Korean Journal of Ecology
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• 제21권6호
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• pp.809-814
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• 1998

Changes of annual seed production related to climate change were studied for 12 years in Piagol, a riparian valley in Mt. Jiri. Sixty-four seed traps (sized 0.5 ${\times}$ 0.5 $m^{2}$) were set up on the forest floor of surveyed area. Seeds were collected from these traps at an interval of 15 days from September to November since 1984. Vegetation of the study area was mainly consisted of the naturally regenerated Carpinus tschonoskii in the tree layer. Acer mono, Quercus serrata, Carpinus laxiflora and Symplocos chinensis also appeared in the same layer. Maximum production occurred in 1984 and 1994. As a result of comparing seed production with local climate factors for 12 years, seed productivity and the year of maximum production of Carpinus forest were merely related with precipitation, air temperature and duration of sunshine among local climate factors. Duration of sunshine was, however, not contributed to periodically high productivity of seed of riparian valley carpinus forest.

• Journal of Plant Biology
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• 제14권1호
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• pp.5-13
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• 1971

Accumulation of soil organic matter and its vertical distribution at different latitudes in peninsular Korea were studied in the soil of four different forest types viz. Pinus densiflora forest, Castanea forest, Quercus acutissima forest and Carpinus laxiflora forest. Among them, accumulation of soil organic matter in Cheju sites, with a mean annual temperature of 15$^{\circ}C$, was maximum with increasing latitude, soil organic matter concentration decreased. Considering the relationship between concentration of soil organic matter and some climatic conditiions, it seems that concentrations of soil organic matter is a function of annual temperature, especially warmth index or cold index.

• 한국관개배수논문집
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• 제16권1호
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• pp.94-99
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• 2009

• 한국방재학회:학술대회논문집
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• 한국방재학회 2009년도 정기 학술발표대회
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• pp.153.2-153.2
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• 2009

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1996년도 학술발표회 논문집
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• pp.199-204
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• 1996

• 한국초지조사료학회지
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• 제12권3호
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• pp.145-152
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• 1992

Phosphorus(P) cycle of Miscanthus sinensis, Sasa palmata and Artemicia princeps for perennial plants and Polygonwn thunbergii for annual plant were investigated in natural plant communities established in Andosol region. 1. Perennial plants contained about 50-80 % P of the maximum accumulated in whole plant in under ground parts as reserve P before wintering. On the other hand, annual plant returned the most part of P in plant tissues to soil and wintered with a small amount of P in only seed. 2. The storage percentage of K was low compared to P in both perennial and annual plants. And the return of K from litter to soil proceeded rapidly because of easy leaching of K. 3. Perennial plants stored a large amount of P in reserve organs before wintering and carry it over next generation, and P holded in an individual showed a yearly increase. Consequently, P was less susceptible to depressive factor for growth of perennial plants even in poor P circumstances like Andosol region, compared to annual plant.

• KIEAE Journal
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• 제3권1호
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• pp.5-12
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• 2003

Using the wind, we can get a thermal comfort in summer. In winter we must shut out the wind. To achieve sustainable environmental building design, especially wind data is very important. The wind direction and wind velocity of 32 cities were analyzed to suggest the wind map of Korea. The weather data which was used in this paper was from National Weather Service(19711.1~2000.12.31). The results of this study are 1) The monthly wind velocity of Seoul is 1.1m/s-3.8m/s. 2) The maximum wind velocity could be estimated from the annual average wind velocity. The regression curve is Y(The maximum wind velocity)=6.369732 X(annual average wind velocity) + 6.391668 (P< 9.66E-12). 3) The wind velocity at the inland area which is far from 25km sea side is smaller than coastal area. The distance from the sea is major index of wind velocity. 4) The monthly wind direction was compared inland area with coastal area. 5) The uniform-velocity line on the Korean map was obtained.

• Wind and Structures
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• 제34권6호
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• pp.469-482
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• 2022

The generalized extreme value distribution (GEVD) is frequently used to fit the block maximum of environmental parameters such as the annual maximum wind speed. There are several methods for estimating the parameters of the GEV distribution, including the least-squares method (LSM). However, the application of the LSM with the expected order statistics has not been reported. This study fills this gap by proposing a fitting method based on the expected order statistics. The study also proposes a plotting position to approximate the expected order statistics; the proposed plotting position depends on the distribution shape parameter. The use of this approximation for distribution fitting is carried out. Simulation analysis results indicate that the developed fitting procedure based on the expected order statistics or its approximation for GEVD is effective for estimating the distribution parameters and quantiles. The values of the probability plotting correlation coefficient that may be used to test the distributional hypothesis are calculated and presented. The developed fitting method is applied to extreme thunderstorm and non-thunderstorm winds for several major cities in Canada. Also, the implication of using the GEVD and Gumbel distribution to model the extreme wind speed on the structural reliability is presented and elaborated.

• 대한토목학회논문집
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• 제13권3호
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• pp.139-154
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• 1993

본 연구는 자연하천 유역에서의 수위관측점들을 대상으로 지점 홍수빈도해석을 실시하고 하천홍수량의 지역빈도해석에 의한 지역화 회귀모형을 개발한 것이다. 홍수빈도해석은 국내 주요 5대 하천유역인 한강, 금강, 영산강, 섬진강 및 낙동강 유역내에 있는 자연하천관측점들을 대상으로 홍수빈도모형을 이용하여 지점별 홍수량의 크기 및 빈도를 추정하였으며, 이를 바탕으로 홍수빈도예측을 위한 모형의 적용성과 효용성을 비교, 검토하였다. 그 결과 단기간 기록년수의 자료에서는 부분기간치계열 방법의 POT(Peaks Over a Threshold)모형이 연최대치계열 방법의 ANNMAX(ANNual MAXimum) 모형보다 효과적이고 합리적임이 판명되었다. 지역 홍수빈도해석에서 홍수빈도모형에 의한 지점별 홍수추정량과 홍수유출에 영향을 미치는 지형학적 유역 특성인자들간의 상관분석법에 의해 미계측 지점에서의 설계홍수량 추정이 용이한 지역화 회귀모형을 개발하고, 첨두홍수량과 유역 특성인자들간의 상관도를 재현기간별로 작성 제시하였다.

• 대한지리학회지
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• 제39권5호
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• pp.711-721
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• 2004

기상과 관련된 재해의 직접 원인이 되는 극한 기후 사상의 발생 빈도 및 강도의 변화 경향을 파악하는 것이 된 연구의 목적이다. 일최저기온, 일최고기온, 일강수량 자료를 이용하여, 10개 기후 변화 지시자를 산출하였다. 그 변화 경향의 공간 분포를 파악하였다. 일최저기온을 이용하여 산출된 온난야의 발생 빈도는 한반도에서 증가하는 추세를 나타냈고. 최저기온의 증가로 인하여 서리일수는 감소하고 생장기간은 증가하였다. 매해의 일최저기온과 일최고기온의 차로 산출되는 연극한기온교차는 최고기온은 변화하지 않았지만. 최저기온의 증가로 인하여 감소하고 있다. 강수와 관련된 지시자들은 기온 관련 지시자에 비하여 변화 경향이 뚜렷하지 않지만, 무강수일수의 한반도 시계열은 감소하는 경향이 나타났고, 호우지수로 분류될 수 있는 강수강도는 증가하고 있다.