• Title/Summary/Keyword: 남서해안

Search Result 135, Processing Time 0.025 seconds

The Fluctuation of Aerosol Number Concentration by Wind Field Variation during Snowfall at the Southwestern Coastal Area (남서해안지역 강설시 바람장 변화에 따른 에어로솔 수 농도 변동)

  • Lee, Dong-In;Kang, Mi-Young;Seo, Kil-Jong;You, Cheol-Hwan;Park, Sung-Hwa;Kim, Poo-Kyoung;Park, Nam-Sik
    • Journal of Environmental Science International
    • /
    • v.17 no.6
    • /
    • pp.699-709
    • /
    • 2008
  • To understand the development mechanism of the aerosols in the surface boundary layer, the variation in the aerosol number concentration due to the divergence and convergence of the wind fields was investigated. The aerosol number concentration was measured in the size ranges of $0.3{\sim}10.0{\mu}m$ using a laser particle counter(LPC) from 0000 LST on 03 Feb. to 0600 LST on 07 Feb. 2004 at Mokpo in Korea during snowfall. The Velocity Azimuth Display(VAD) technique was used to retrieve the radar wind fields such as the horizontal wind field, divergence, and deformations including the vertical air velocity from a single Doppler radar. As a result, the distribution of the aerosol number concentration is apparently different for particles larger than $1{\mu}m$ during snowfall, and it has a tendency to increase at the beginning of the snowfall. The increase and decrease in the aerosol concentration due to the convergence and divergence of the wind fields corresponded to the particles with diameters greater than $1{\mu}m$. It is found that the fluctuations in the aerosol number concentration are well correlated with the development and dissipation of snowfall radar echoes due to the convergence and divergence of horizontal wind fields near the surface boundary layer in the inland during the snowfall.

Pathotypes of Xanthomonas campestris pv. oryzae in Honam District, Korea (호남지역에 분포하는 벼흰빛잎마름병균의 균형)

  • Lee D. K.;Seo J. H.;Choi J. E.;Park K. H.;Bae S. H.
    • Korean Journal Plant Pathology
    • /
    • v.2 no.2
    • /
    • pp.102-106
    • /
    • 1986
  • The 719 isolates of Xanthomonas campestris pv. oryzae collected in Honam district during 1980-1984 were classified with new differential cultivars: 466($64-.8\%$) were pathotype K1, 116$(16.1\%)$ pathotype K2, 130$(18.1\%)$ pathotyps K3, and 7$(1.0\%)$ pathotype K4. No isolate for pathotype K5 was found. The isolates of pathotypes K1, K2 and K3 were distributed in the geographic regions, Haenam, Gwangyang, Gangjin, Wando, Igsan, and Buan. The isolates of all pathotypes were obtained from Milyang 23, Nagdong, and Dongjin which were susceptible to all the pathotypestested, while most of the isolates belonging to pathotype K3 and K4 were obtained from pungsan, Baegyang, Samgwang and Milyang 30.

  • PDF

Time series Analysis of the Summer Rainfall in South korea (남한의 하계강우량의 시계열분석)

  • Ryoo, Sang-Boom;Moon, Sung-Euii;Lee, Bu-Yong
    • Journal of the Korean Geographical Society
    • /
    • v.28 no.3
    • /
    • pp.193-199
    • /
    • 1993
  • The interannual fluctuation, trends and perio-dicties in summer rainfall of South Korea were analyzed primarily by using Mann-Kendall rank method and Power Spectrum analysis for the period from 1920 to 1985. Their relations to Indian summer monsoon rainfall have also been examined. Increasing or decreasing rainfall tendencies are not found in South Korea. In Power Spectrum alalysis, 2.5 years periods are predominent at the 95 per cent confidence level in south Korea as a whole and Pusan. Also the period of 11.0 years is found in Seou. There are another prominent spectral peaks at 2.4, 3.1, 6.2 and 7.3 years period, which are significant at 90 per cent confidence level.

  • PDF

Heavy Metal Concentrations of Marine Surface Sediments and Benthic Foraminifera in Southern and Southwestern Coastal Areas of Korea (국내 남해 및 남서해안지역 해양퇴적물과 저서성 유공충 골격내 중금속함량)

  • Kim, Kyoung-Woong;Yun, Hye Su;Yi, Song Suk;Jung, Kyu-Kui
    • Economic and Environmental Geology
    • /
    • v.30 no.3
    • /
    • pp.223-230
    • /
    • 1997
  • The skeletal chemistry of calcareous microfossils may contribute to the classification of various biological processes and be used as an environmental indicator for future pollution. In order to examine the degree of heavy metal pollutions in marine environments, samples of sediment and benthonic foraminifera were taken from 5 study areas from 3 different stations in coastal offshore regions of Korea. After sieving, cleaning and acid digestion, sample were analyzed for heavy metals by ICP-MS, ICP-AES and AAS. Concentrations of Cd, Cu, Pb and Zn in most of marine sediments from 5 study areas are not higher than those in sediments from unpolluted marine environment in the U.K.. However, pollution indices are up to 0.96~0.99 in the Gwangyang and Yulchon areas which are classified as the special control distric along the coast for pollution. The pollution indices decrease in order of Yulchon > Gwangyang > Mokpo > Gamak = Yoja > Yonggwang areas. Concentrations of Mg, Pb, Sr and Zn in Ammonia beccarii Pseudorotalia gaimardii, Quinqueloculina lamarckiana are reduced after pre-treatment of samples. From the result of bioconcentration index, Mg is easily accumulated in microfossils and Quinqueloculina lamarckiana may be used as the best indicator for future pollution.

  • PDF

On the primary productivity in the southern sea of korea (한국남해역(韓國南海域)의 일차생산력(一次生産力))

  • CHUNG, CHANG-SOO;YANG, DONG-BEOM
    • 한국해양학회지
    • /
    • v.26 no.3
    • /
    • pp.242-254
    • /
    • 1991
  • Southern sea of Korea was investigated for primary productivity during four scientific cruises of Korea Ocean research and Development Institute. Frontal structure appeared to be an important physical characteristic in enhancing the phytoplankton production in the study area. Relatively high productivity was occurred near the front between Tsushima Warm Current Water and Coastal Waters of China continent in March 1990 and in November 1989, and near the front between Tsushima Warm Current Water and Korean coastal Water in April 1989. In August 1988 high productive zone was limited to the tidal front off the southwestern coast of Korea. Nutrient supply related to the frontal structure might play a dominant role in increasing the primary productivity but mechanisms of nutrient enrichment are not clear. Average column productivity showed its maximum in April 1989 (1727 mgC/m$^2$/day). In the costal Waters of the china Continent incident light may be an important factor in regulating the regulating the phytoplankton production because of low light penetration rate resulting from high turbidity.

  • PDF

Some Applications of SAR Imagery to the Coastal Waters of Korea (한국 주변 해역에서의 SAR 영상 응용예)

  • 김태림
    • Korean Journal of Remote Sensing
    • /
    • v.15 no.1
    • /
    • pp.61-71
    • /
    • 1999
  • Several physical phenomena on the sea surface are analyzed from SAR images of South Sea areas, Korea. Strong wave patterns propagating in southerly direction are seen in ERS-1 SAR image on October 11, 1994, and a wave directional spectrum is calculated from this image using the SAR modulation transfer function. RADARSAT SAR image of August 15, 1996 reveals internal waves in northern coastal waters of Cheju Island. Analysis indicates that the internal waves may have been generated by the tidal currents traveling over the shallow bottom of the stratified water in the summer during the tidal changeovers fro ebb to flood and shows patterns of trains of solitons. RADARSAT SAR image taken 3 days after the oil spill accident near Goeje Isalnd on April 3, 1997 detects distinct oil slicks from the accident area but also shows slicks near the coast caused by wind sheltering of coastal mountains and chemical-biological activities.

Wintertime Extreme Storm Waves in the East Sea: Estimation of Extreme Storm Waves and Wave-Structure Interaction Study in the Fushiki Port, Toyama Bay (동해의 동계 극한 폭풍파랑: 토야마만 후시키항의 극한 폭풍파랑 추산 및 파랑 · 구조물 상호작용 연구)

  • Lee, Han Soo;Komaguchi, Tomoaki;Yamamoto, Atsushi;Hara, Masanori
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.25 no.5
    • /
    • pp.335-347
    • /
    • 2013
  • In February 2008, high storm waves due to a developed atmospheric low pressure system propagating from the west off Hokkaido, Japan, to the south and southwest throughout the East Sea (ES) caused extensive damages along the central coast of Japan and along the east coast of Korea. This study consists of two parts. In the first part, we estimate extreme storm wave characteristics in the Toyama Bay where heavy coastal damages occurred, using a non-hydrostatic meteorological model and a spectral wave model by considering the extreme conditions for two factors for wind wave growth, such as wind intensity and duration. The estimated extreme significant wave height and corresponding wave period were 6.78 m and 18.28 sec, respectively, at the Fushiki Toyama. In the second part, we perform numerical experiments on wave-structure interaction in the Fushiki Port, Toyama Bay, where the long North-Breakwater was heavily damaged by the storm waves in February 2008. The experiments are conducted using a non-linear shallow-water equation model with adaptive mesh refinement (AMR) and wet-dry scheme. The estimated extreme storm waves of 6.78 m and 18.28 sec are used for incident wave profile. The results show that the Fushiki Port would be overtopped and flooded by extreme storm waves if the North-Breakwater does not function properly after being damaged. Also the storm waves would overtop seawalls and sidewalls of the Manyou Pier behind the North-Breakwater. The results also depict that refined meshes by AMR method with wet-dry scheme applied capture the coastline and coastal structure well while keeping the computational load efficiently.

Estimation of potential distribution of sweet potato weevil (Cylas formicarius) and climate change impact using MaxEnt (MaxEnt를 활용한 개미바구미(Cylas formicarius)의 잠재 분포와 기후변화 영향 모의)

  • Jinsol Hong;Heewon Hong;Sumin Pi;Soohyun Lee;Jae Ha Shin;Yongeun Kim;Kijong Cho
    • Korean Journal of Environmental Biology
    • /
    • v.41 no.4
    • /
    • pp.505-518
    • /
    • 2023
  • The key to invasive pest management lies in preemptive action. However, most current research using species distribution models is conducted after an invasion has occurred. This study modeled the potential distribution of the globally notorious sweet potato pest, the sweet potato weevil(Cylas formicarius), that has not yet invaded Korea using MaxEnt. Using global occurrence data, bioclimatic variables, and topsoil characteristics, MaxEnt showed high explanatory power as both the training and test areas under the curve exceeded 0.9. Among the environmental variables used in this study, minimum temperature in the coldest month (BIO06), precipitation in the driest month (BIO14), mean diurnal range (BIO02), and bulk density (BDOD) were identified as key variables. The predicted global distribution showed high values in most countries where the species is currently present, with a significant potential invasion risk in most South American countries where C. formicarius is not yet present. In Korea, Jeju Island and the southwestern coasts of Jeollanam-do showed very high probabilities. The impact of climate change under shared socioeconomic pathway (SSP) scenarios indicated an expansion along coasts as climate change progresses. By applying the 10th percentile minimum training presence rule, the potential area of occurrence was estimated at 1,439 km2 under current climate conditions and could expand up to 9,485 km2 under the SSP585 scenario. However, the model predicted that an inland invasion would not be serious. The results of this study suggest a need to focus on the risk of invasion in islands and coastal areas.

Nutrient Contents of Bracken (Pteridium aquilinum L.) and Soil Chemical Properties of Its Habitat in the Coastal Area (남서해안 고사리 생육지의 토양화학적 특성과 고사리식물체의 무기성분 함량)

  • Lee, Soo-Young;Park, Kang-Yong;Park, Yang-Ho
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.43 no.5
    • /
    • pp.631-636
    • /
    • 2010
  • One experiment was carried out to investigate the soil chemical properties of bracken growth and the inorganic element contents of plant. To the results of soil analysis in native bracken (Pteridium aquilinum L.) growth, soil pH was 5.2, organic matter was 19 g $kg^{-1}$ and available phosphate was 20 mg $kg^{-1}$, and exchangeable potassium, calcium, magnesium were 0.32, 2.0 and 1.3 $cmol_c\;kg^{-1}$, respectively. In the bracken cultivation soil, pH was 5.7, organic matter was 13 g $kg^{-1}$ and available phosphate 367 mg $kg^{-1}$, and exchangeable potassium, calcium and magnesium were 0.81, 4.0 and 1.4 $cmol_c\;kg^{-1}$, respectively. The soil pH, available phosphate and exchangeable calcium were much lower in bracken native soil than those of cultivation soil, while organic matter was a little higher in native soil than that of cultivation soil. In native bracken plants, three major elements of nitrogen, phosphorus and potassium, were 4.40, 0.55 and 3.40%, calcium and magnesium were 0.22 and 0.32%, and microelements of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron were 126, 210, 23, 75 and 11 mg $kg^{-1}$, respectively. In cultivation bracken, three major elements of nitrogen, phosphorus and potassium, were 5.50, 0.73 and 3.55%, calcium and magnesium were 0.17 and 0.28%, and microelement contents of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron (B) were 120, 252, 19, 72 and 20 mg $kg^{-1}$, respectively.

Regional Differentials in Elderly Suicide Rate: The Focusing on Effects of Family Instability, 1995-2005 (노인자살률의 지역별 편차: 가족불안정의 영향을 중심으로, 1995-2005)

  • Ryu, Jung-Kyun
    • Korea journal of population studies
    • /
    • v.31 no.2
    • /
    • pp.21-44
    • /
    • 2008
  • The main purpose of this study is to examine the effect of the family instability on the elderly suicide and to examine the change over time. An analytical model of causal structure was set up with residence, family instability and socioeconomic level as explanation variables for this study. The cause of death statistics and micro-data from the vital statistics for 1995, 2000 and 2005 were used. Family instability was measured through divorce, and the rate of elderly(male and female) suicide as well as the suicide rate of the elderly and those in their 20-50's was used for this analysis to examine the effect of divorce. This study hypothesized about family instability and elderly suicide through a literature review. This paper presents maps of the suicide rate by using GIS, and then ANOVA and regression analysis are carried out to verify a difference in the elderly suicide rate affected by residence and divorce. Divorce rate appears in most areas with a high level centering around metropolises except the central inland area. The rate of elderly suicide which stayed in only specific regions with a high level has increased as time went by, and the graph leveled high in most regions except the southwestern coast. In addition, the elderly suicide rate was increased rapidly in rural areas for the most recent 10 years. This shows the seriousness of problems of the aged in rural areas. Through the periods of economic crisis, a sudden increase in divorce causes family instability, which increase the suicide rate increasing. Divorce affects the elderly suicide rate and the 20-50s' suicide rate in the same way, and the stronger effect goes to the elderly rather than those in their 20-50s'. Regarding elderly suicide, the divorce has a different effect by gender, affecting males more than females. With these facts, we can draw the conclusion that family instability has the most significant effect on elderly males' suicide.