• Title/Summary/Keyword: Coastal Regions

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A Numerical Simulation Study of a Heavy Rainfall Event over Daegwallyeong on 31 July 2014 (2014년 7월 31일 대관령에서 발생한 집중호우에 관한 수치모의 연구)

  • Choi, Seung-Bo;Lee, Jae Gyoo
    • Atmosphere
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    • v.26 no.1
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    • pp.159-183
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    • 2016
  • On 31 July 2014, there was a localized torrential rainfall ($58.5mm\;hr^{-1}$) caused by a strong convective cell with thunder showers over Daegwallyeong. In the surface synoptic chart, a typhoon was positioned in the East China Sea and the subtropical high was expanded to the Korean peninsula. A WRF (Weather Research and Forecasting) numerical simulation with a resolution of 1 km was performed for a detailed analysis. The simulation result showed a similar pattern in a reflectivity distribution particularly over the Gangwon-do region, compared with the radar reflectivity. According to the results of the WRF simulation, the process and mechanism of the localized heavy rainfall over Daegwallyeong are as follows: (1) a convective instability over the middle part of the Korean peninsula was enhanced due to the low level advection of warm and humid air from the North Pacific high. (2) There was easterly flow from the coast to the mountainous regions around Daegwallyeong, which was generated by the differential heating of the insolation among Daegwallyeong and the Yeongdong coastal plain, and nearby coastal waters. (3) In addition, westerly flow from the western part of Daegwallyeong caused a strong convergence in this region, generating a strong upward motion combined by an orographic effect. (4) This brought about a new convective cell over Daegwallyeong. And this cell was more developed by the outflow from another thunderstorm cell to the south, and finally these two cells were merged to develop as a strong convective cell with thunder showers, leading to the record breaking maximum rainfall per hour ($58.5mm\;hr^{-1}$) in July.

Toxicity of the Puffer fish, Takifugu pardalis (Jolbok) and Takifugu niphobles (Bokseom) from Coastal Area of Korea (한국 연안산 졸복(Takifugu pardalis)과 복섬(Takifugu niphobles)의 독성)

  • Kim, Ji-Hoe;Son, Kwang-Tae;Mok, Jong-Soo;Oh, Eun-Gyoung;Hwang, Hye-Jin;Yu, Hong-Sik;Lee, Hee-Jung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.5
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    • pp.269-275
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    • 2007
  • The toxicity of two species of puffer fish, Takifugu pardalis and T. niphobles, collected from the coastal regions of Korea was determined using a mouse bioassay. In T. pardalis collected at Tongyeong, the proportion of toxic specimens containing ${\geq}10MU/g$ exceeded 90% for the skin, fins, liver, intestine, ovary, and gallbladder, 11.1% for the testis, and 6.9% for the muscle. In each of the organs, the highest toxin levels were several tens (14-39) of mouse units (MU) per gram in the muscle, testis, and eyeball, but thousands (1,444-5,755) of MU per gram in the skin, liver, intestine, ovary, and gallbladder. The organs of T. pardalis exhibited remarkable variation in toxicity. In T. niphobles, the proportion of toxic specimens exceeded 90% for the ovary and skin, 60-80% for the fins, liver, intestine, and gallbladder, and 4.5% for the muscle; no toxicity was detected in the testis or eyeball using the mouse bioassay. The highest toxin levels were thousands (2,291-7,777) of MU per gram in the liver, intestine, ovary, and gallbladder, hundreds(146-328) of MU per gram in the skin and fins, and 18 MU/g in the muscle. Takifugu niphobles toxicity also exhibited remarkable regional variation. The toxicity in the edible muscle of T. pardalis and T. niphobles was at acceptable levels for human consumption, while the toxicity of the skin of both species of puffer fish was very high, so that care must be taken when used for human consumption.

Geographic Variation and Genetic Diversity between Polluted and Unpolluted Sites of Korean Littorina brevicula(Gastropoda, Littorinidae) Based on the Mitochondrial Cytochrome b Gene Sequence (미토콘드리아 Cytochrome b 유전자의 염기서열 분석을 이용한 한국산 총알고둥(복족강, 총앙고둥과)의 지리적 변이 및 오염.비오염지역간의 유전적 다양성)

  • Suh, Jae-Hwa;Kim, Sook-Jung;Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.18 no.1
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    • pp.75-84
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    • 2002
  • MtDNA cyt b gene was used to investigate the geographic variation of 11 populations (106 individuals) of the planktonic developing, periwinkle Littorina brevicula, throughout Eastern, Western, and Southern coastal regions in Korea. The sequence of 500 base pairs and 13 different haplotypes were determined. Haplotype LbA was predominated through the populations studied with frequence of 0.877. Haplotypes were shown different frequencies in each coastal region (0.82, 0.90, and 1.00, respectively). enetic analysis of the 61 individuals of L. brevicula from the polluted and unpolluted sites yielded 8 distinct haplotypes. Haplotype LbA also was most common, and it was shared by 0.872 of frequency among specimens.

Water Quality Modeling for Environmental Management in Chinhae.Masan Bay (진해.마산만의 환경관리를 위한 수질모델링)

  • 조흥연;채장원
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.11 no.1
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    • pp.41-49
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    • 1999
  • The horizontal two-dimensional model which can predict the long-term water quality(WQ) change is setup for the environmental management. For the model calibration and verification, we measured the pollutants load at 22 streams and the WQ at 16 stations monthly and/or seasonally in Chinhae . Masan Bay. The pollutants release rate from the sediment was also measured to consider the regionally different sediment pollution level. From the model application results, it is shown that the WQ concentrations in most of the regions adjacent to land and river inflow are considerably high, but rapidly decrease along the seaward direction. In Masan Bay, the particulate inflow-pollutants were substantially deposited and gradually contaminated the bottom sediment on account of the excessive pollutants load and flow stagnancy. Eutrophication in the effluent discharge region was also being slowly progressed by the inefficiently treated wastewater containing amount of Nand P constituents.

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Marine terrace and its implications to paleoenvironment during the Quaternary at Suje-ri - Suryum-ri of the East coast of Gyeongju, SE Korea (한반도 남동부 경주시 수제리-수렴리의 해안단구와 제4기 환경변화)

  • HWANG, Sangill;SHIN, Jaeryul;YOON, Soon-Ock
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.97-108
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    • 2012
  • During the last few decades, the ever-increasing knowledge of coastal morphogenic processes has made marine terraces the most recognizable, widespread and scientifically reliable records to determine both qualitatively and quantitatively the vertical movements that have affected the tectonically active coastal regions during the Quaternary. This study first aims to address the marine terrace records from Suje-ri to Suryum-ri along the coast of Gyeongju, SE Korea. Eight distinct flights of terraces, including HH YC, elevated up to 160 m above present sea level have been mapped along the coast of the study areas, and are designated $L_{II}$ to HH YC from the youngest to oldest. Based on the elevation of paleo-shoreline and inferred formation age for HH YC uplift rate since the middle Pleistocene has been estimated at 0.23 mm/year. Establishing the nature and timing of the uplift history derived from marine terraces provide a better understanding of neotectonic framework for explain enigmatic, complex landscape evolution in the Korean peninsula.

Mean Field Bias Correction of the Very-Short-Range-Forecast Rainfall using the Kalman Filter (Kalman Filter를 이용한 초단기 예측강우의 편의 보정)

  • Yoo, Chul-Sang;Kim, Jung-Ho;Chung, Jae-Hak;Yang, Dong-Min
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.17-28
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    • 2011
  • This study applied the Kalman Filter for real-time forecasting the G/R (ground rain gauge rainfall/radar rainfall) ratio to correct the mean field bias of the very-short-range-forecast (VSRF) rainfall. The MAPLE-forecasted rainfall was used as the VSRF rainfall, also the methodology for deciding the G/R ratio was improved by evaluating the change of G/R ratio characteristics depending on the threshold and accumulation time. This analysis was done for the inland, mountain, and coastal regions, separately, for their comparison. As the results, more stable G/R ratio could be estimated by applying the threshold and accumulation time, whose forecasting accuracy could also be secured. The accuracy of the corrected rainfall forecasting by the forecasted G/R ratio was the best in the inland region but the worst in the coastal region.

Economic Effect of the Creation Project of Octopus Ochellatus Spawning and Habitat Ground: the Case of Taean County (주꾸미 산란·서식장 조성사업의 경제적 효과 : 태안군의 사례)

  • Kang, Seok-Kyu
    • The Journal of Fisheries Business Administration
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    • v.49 no.4
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    • pp.109-129
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    • 2018
  • This study is to evaluate economic effect of the creation project of Octopus Ochellatu spawning and habitat ground in Taean County. The main results of this study are summarized as follows: first, the creation project cost of Octopus Ochellatus spawning and habitat ground invested in Taean from 2015 to 2017 was 3,400 million won. Second, The creation project of Octopus Ochellatus spawning and habitat ground directly provides fishing benefits, recreational boat fishing benefits, festival benefits, research and development benefits, and employment benefits. Third, on the basis of above benefits, the creation project of Octopus Ochellatus spawning and habitat ground has a net present value of 14,478 million won, internal rate of return 60.8%, and benefit-cost of 5.03 under a 4.5% social discount rate. Also, the creation project creates 47 jobs. This indicates that the creation project of Octopus Ochellatus spawning and habitat ground contributes not only to the increase in the income of coastal fishery, recreational boat fishing business and fishing villages but also to the job making. In conclusion, with all these results, a project for making spawning grounds and habitats in the specified region gives species more numerically abundant and this gives more profits to fishermen in the coastal area. In addition, this project helps to make attractions to visitors or people who came to those specified regions to participate in events or have recreation, which means it improves profits to that fishing village and improve a settlement condition.

A Study on the Impacts of the 1741 Tsunami Recorded in the Annals of Joseon Dynasty (조선왕조실록에 기록된 1741년 쓰나미 영향 연구)

  • Byun, Sang-Shin;Kim, Kyeong Ok
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.1
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    • pp.30-37
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    • 2021
  • The Annals of Joseon Dynasity record a significant damage of tsunami in the east coast of Gangwon Province on August 29, 1741. The tsunami occurred near Oshima-Oshima island off the southwestern coast of Hokkaido, Japan, and this study conducted simulations of a ray-tracing model to analyze the effects of the tsunami on the East coast of Korean Peninsula at that time. Model results were calculated using four different depth dataset (ETOPO2m, ETOPO1m, SKKU1m, and GEBCO15c), and results using the highest resolution GEBCO15c showed the best description of the damage recorded in the Annals of the Joseon Dynasty. Based on such, the travel time and paths of the tsunami that reached the main regions of Gangwon Province are presented in detail.

A Study on the Physicochemical Characteristics and Formation Age of Coastal Sand Dunes in the Okjukdong and Dajindong, Daecheong Island (대청도 옥죽동·대진동 사구의 물리·화학적 특성 및 퇴적시기 고찰)

  • Shin, Won Jeong;Kim, Jong Wook;Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.2
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    • pp.63-80
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    • 2018
  • The purpose of this study was to investigate the physicochemical characteristics and formation age of sand dunes in the Okjukdong and Dajindong, Daecheong Island. As a result, most of the sand deposited in Okjukdong were composed of medium sized sand with moderately well sorted. The $SiO_2$ and $Al_2O_3$ accounted for a very high proportion of these deposits. There were some differences in characteristics between the sands in the dune and beach, whereas similar characteristics were observed among the materials (OJ-B, OJ-C and OJ-D) in the dune. In case of Dajindong, heterogeneous geochemical characteristics were found in the lower point. It was estimated that this was due to the influence of Daejin-dong black beach. Age dating results showed that uncovered dunes in Okjukdong were deposited $0.44{\pm}0.02$ ~ $0.50{\pm}0.02ka$, and sand depositsin Dajindong were formed $0.16{\pm}0.01$ ~ $0.18{\pm}0.01ka$. In both Okjukdong and Dajindong, sand deposits estimated to be formed 70 years ago, therefore it can be estimated that sand movement was active throughout the area from about hundred years ago. In this study area, the growth of sand dunes has been active in recent several decades or hundred years. It seems that there were different regions where deposits predominated over time. The source of dune sand was also different from time to time. Since the windbreak forest was established, the natural growth of sand dunes was limited, and sand nourishment was carried out by period. Therefore, in order to protect and continuously utilize coastalsand dunesin Daecheong Island, it is necessary to prepare conservation plan.

Analysis of the Performance and Change of Resident Consciousness of the Fishing Village Specialization Capacity Enhancement Project through Surveys - Focusing on the Comparative Analysis of Consciousness of Inland Water and Coastal Residents - (어촌특화 역량강화사업의 성과 및 주민의식 변화분석)

  • Yang, Min-Ho;Kim, Ki-Sung;Koh, Jin-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.63 no.2
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    • pp.19-31
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    • 2021
  • The Ministry of Maritime Affairs and Fisheries has been promoting the 'Fishing Village Specialization Capacity Enhancement Project' to pursue sustainable development of villages such as income generation by using local tangible and intangible resources led by local residents at the village level since 2013. For the fishing village-Specialization capacity enhancement project, six training sessions (mainly in the village unit) are selected by the public offering method, and the project (income generating business, village development project, etc.) is developed for the selected village residents. It has a process of establishing a village project plan (a preliminary plan for village development or a sixth preliminary industrialization plan) based on the training of experts 5 times, practice or excursion 1 time). In this study, four villages in Gangwon-do fishing villages (two coastal villages and two inland water villages) were surveyed on the perception and satisfaction of fishing village development projects before and after training. The survey analysis was conducted by dividing the analysis of resident capacity and satisfaction into personal, interpersonal, and social dimensions. The survey was conducted by distributing a survey before and after training, and a 1:1 survey was conducted according to the residents' cognitive status. Based on the survey, factor analysis, reliability analysis, and analysis using the corresponding sample t-test showed an increase of 0.02 for Yangyang Mulchi fishing village, 0.11 for Samcheok Jangho fishing village, and 0.36 for Hongcheon River fishing industry, but Yanggu Jinmok fishing industry was -0.29, unlike other regions. As a result of this analysis, it has been empirically proven that provision of training projects through resident participation is a very important factor for the success of the fishing village project. Therefore, rather than fostering local leaders, training and community activities to strengthen personal capacities of residents participating in the project, it is necessary to operate the software business with a focus.