• Title/Summary/Keyword: Geographic Displacement

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A Study on the Roughness Length Spatial Distribution in Relation to the Seoul Building Morphology (서울시 건물형태에 따른 거칠기길이 분포특성 연구)

  • Yi, Chaeyeon;Kwon, Tae Heon;Park, Moon-Soo;Choi, Young Jean;An, Seung Man
    • Atmosphere
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    • v.25 no.2
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    • pp.339-351
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    • 2015
  • The purpose of this study is for the fundamental understandings about building morphological parameters and aerodynamic roughness parameters of Seoul, Korea using the detailed urban geographic information datasets. Applied roughness parameter calculations are based on a digital map of buildings with lot area polygons. The quality of the developed roughness length ($z_0$) of Seoul was evaluated with densely installed 107 automatic weather stations. The correlation coefficient results between averaged wind speeds of AWS data and averaged $z_0$ is -0.303 in night and -0.398 in day (200 m radii circles case). Further $z_0$ enhancement should follow by considering other surface features such as high tree and orography of Seoul. However, this study would meet the needs to for local- or meso-scale meteorological modeling applications of Seoul. However, further studies would require for enhancing the $z_0$ applications of Seoul.

Analysis of Crustal Deformation on the Korea Peninsula after the 2011 Tohoku Earthquake (한반도 지각의 2011 도호쿠 대지진 영향 분석)

  • Kim, Su-Kyung;Bae, Tae-Suk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.1
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    • pp.87-96
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    • 2012
  • The U.S. Geological Survey (USGS) announced that an earthquake of 9.0 magnitude had occurred near the east coast of Japan on March 11, 2011, resulting in a displacement of the crust of about 2.4 meters. The Korean peninsula is located on the Eurasian tectonic plate that stretches out to Japan; therefore, there is a high possibility of being affected by an earthquake. The Korean GPS CORS network operated by the National Geographic Information Institute (NGII) was processed for ten days before and after the earthquake. Both static and kinematic baseline processing were tested for the determination of crustal deformation. The static baseline processing was performed in two scenarios: 1) fixing three IGS stations in China, Mongolia and Russia; 2) fixing SUWN, one of the CORS networks in Korea, in order to effectively verify crustal deformation. All data processing was carried out using Bernese V5.0. The test results show that most of the parts of the Korean peninsula have moved to the east, ranging 1.2 to 5.6 cm, compared to the final solution of the day before the earthquake. The stations, such as DOKD and ULLE that are established on the islands closer to the epicenter, have clearly moved the largest amounts. Furthermore, the station CHJU, located on the southwestern part of Korea, presents relatively small changes. The relative positioning between CORS confirms the fact that there were internal distortions of the Korean peninsula to some extent. In addition, the 30-second interval kinematic processing of CORS data gives an indication of earthquake signals with some delays depending on the distance from the epicenter.

Variations of catch of Anchovy and Saury due to oceanic climate change in the Korean seas (해양기후변화에 의한 한국주변 해역에서 멸치와 꽁치의 어장 변화 연구)

  • Oh, Seung-Yeol;Jang, Sun-Woong;Yoon, Hong-Joo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.3
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    • pp.740-746
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    • 2011
  • The variations of catch of anchovy and saury due to oceanic climate change in the Korean Seas were studied. This study area was $31^{\circ}{\sim}38^{\circ}$ N and $124^{\circ}{\sim}132^{\circ}$ E. And data (seawater temperature, salinity, dissolved oxygen) is used from NFRDI (National Fisheries Research and Development Institute) and SST (Sea Surface temperature) obtained to satellite images (NOAA/AVHRR) during 2000 to 2009. The spatial characteristics are analyzed by GIS (Geographic Information System). The results showed that the average of seawater temperature in the depth of 20m increased $1.45^{\circ}C$ in the South Sea and $0.83^{\circ}C$ in the East Sea, respectively. The maximal catch of anchovy was highest in summer (July~September) and winter (December~March), respectively, in compared with spring (April~June). Catch of anchovy has increased since 2000. The maximal catch of saury was highest in spring (May~June), in compared with spring (August~September). The increment of seawater temperature contributed to increase the catch of anchovy, but catch of saury was decrease in the same times.