• Title/Summary/Keyword: Eastern coast

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The Recent Increase in the Heavy Rainfall Events in August over the Korean Peninsula

  • Cha, Eun-Jeong;Kimoto, Masahide;Lee, Eun-Jeong;Jhun, Jong-Ghap
    • Journal of the Korean earth science society
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    • v.28 no.5
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    • pp.585-597
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    • 2007
  • The characteristics of the rainfall events on the Korean peninsula have been investigated by means of regional and global observational data collected from 1954 to 2004 with an emphasis on extreme cases $80\;mm\;day^{-1}$. According to our analysis, long-term annual rainfall anomalies show an increasing trend. This trend is pronounced in the month of August, when both the amount of monthly rainfall and the frequency of extreme events increase significantly. Composite maps on August during the 8 wet years reveal warm SST anomalies over the eastern Philippine Sea which are associated with enhanced convection and vertical motion and intensified positive SLP over central Eurasia during August. The rainfall pattern suggests that the most significant increase in moisture supply over the southern parts of China and Korea in August is associated with positive SLP changes over Eurasia and negative SLP changes over the subtropical western Pacific off the east coast of south China. The frequent generation of typhoons over the warm eastern Philippine Sea and their tracks appear to influence the extreme rainfall events in Korea during the month of August. The typhoons in August mainly passed the western coast of Korea, resulting in the frequent occurrence of extreme rainfall events in this region. Furthermore, anomalous cyclonic circulations over the eastern Philippine Sea also promoted the generation of tropical cyclones. The position of pressure systems - positive SLP over Eurasia and negative SLP over the subtropical Pacific - in turn provided a pathway for typhoons. The moisture is then effectively transported further north toward Korea and east toward the southern parts of China during the extreme rainfall period.

Potential Impact of Climate Change on Distribution of Hedera rhombea in the Korean Peninsula (기후변화에 따른 송악의 잠재서식지 분포 변화 예측)

  • Park, Seon Uk;Koo, Kyung Ah;Seo, Changwan;Kong, Woo-Seok
    • Journal of Climate Change Research
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    • v.7 no.3
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    • pp.325-334
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    • 2016
  • We projected the distribution of Hedera rhombea, an evergreen broad-leaved climbing plant, under current climate conditions and predicted its future distributions under global warming. Inaddition, weexplained model uncertainty by employing 9 single Species Distribution model (SDM)s to model the distribution of Hedera rhombea. 9 single SDMs were constructed with 736 presence/absence data and 3 temperature and 3 precipitation data. Uncertainty of each SDM was assessed with TSS (Ture Skill Statistics) and AUC (the Area under the curve) value of ROC (receiver operating characteristic) analyses. To reduce model uncertainty, we combined 9 single SDMs weighted by TSS and resulted in an ensemble forecast, a TSS weighted ensemble. We predicted future distributions of Hedera rhombea under future climate conditions for the period of 2050 (2040~2060), which were estimated with HadGEM2-AO. RF (Random Forest), GBM (Generalized Boosted Model) and TSS weighted ensemble model showed higher prediction accuracies (AUC > 0.95, TSS > 0.80) than other SDMs. Based on the projections of TSS weighted ensemble, potential habitats under current climate conditions showed a discrepancy with actual habitats, especially in the northern distribution limit. The observed northern boundary of Hedera rhombea is Ulsan in the eastern Korean Peninsula, but the projected limit was eastern coast of Gangwon province. Geomorphological conditions and the dispersal limitations mediated by birds, the lack of bird habitats at eastern coast of Gangwon Province, account for such discrepancy. In general, potential habitats of Hedera rhombea expanded under future climate conditions, but the extent of expansions depend on RCP scenarios. Potential Habitat of Hedera rhombea expanded into Jeolla-inland area under RCP 4.5, and into Chungnam and Wonsan under RCP 8.5. Our results would be fundamental information for understanding the potential effects of climate change on the distribution of Hedera rhombea.

Relationship between Migratory Timing of Salmon (Oncorhynchus keta) into the Wangpi River and Coastal Environment of the Mid-eastern Coastal Water of Korea (동해 중부 연안에서 연어(Oncorhynchus keta)가 왕피천으로 이동하는 시기와 연안 환경간의 관계)

  • Kim, Beom-Sik;Jung, Yong-Woo;Jung, Hae-Kun;Lee, Chung Il
    • Journal of Environmental Science International
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    • v.30 no.12
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    • pp.1067-1079
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    • 2021
  • The coastal water is a space where salmon (Oncorhynchus keta), critical energy-conveying mediator, stay to adapt to different environments while traveling between ocean and river ecosystems for spawning and growth. The mid-eastern coast of Korea (MECW) is the southern limit of salmon distributed in the North Pacific Ocean. Understanding the distribution and migration characteristics of salmon in the MECW is important for the prediction of changes in the amount and distribution of salmon related to changes in the future marine environment. We analyzed the relationship between the salmon migratory timing ascending the Wangpi river and change in vertical seawater temperature and tidal elevation. Overall results highlight that (1) Salmon began to ascend the river when the sea surface water temperature (SST) decreased below 20℃; (2) The number of salmon ascending the river increased when the temperature difference between the upper and lower layers decreased, but decreased when the temperature difference was higher than 5℃; (3) The number of salmon ascending the river peaked, when the SST was 18℃-19℃ and sea levels rose at high tide. This study provide important insight into predicting changes in the ecosystem energy circulation through climate change at its southern distribution limit.

The Natural Environment during the Last Glacial Maximum Age around Korea and Adjacent Area

  • Yoon, Soon-Ock;Hwang, Sang-Ill
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.33-38
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    • 2003
  • This study is conducted to examine the data of climate or environmental change in the northeastern Asia during the last glacial maximum. A remarkable feature of the 18,000 BP biome reconstructions for China is the mid-latitude extention of steppe and desert biomes to the modem eastern coast. Terrestrial deposits of glacial maximum age from the northern part of Yellow Sea suggest that this region of the continental shelf was occupied by desert and steppe vegetation. And the shift from temperate forest to steppe and desert implies conditions very much drier than present in eastern Asia. Dry conditions might be explained by a strong winter monsoon and/or a weak summer monsoon. A very strong depression of winter temperatures at LGM. has in the center of continent has influenced in northeast Asia similarly. The vegetation of Hokkaido at LGM was subarctic thin forest distributed on the northern area of middle Honshu and cool and temperate mixed forest at southern area of middle Honshu in Japan. The vegetation landscape of mountain- and East coast region of Korea was composed of herbaceous plants with sparse arctic or subarctic trees. The climate of yellow sea surface and west region of Korea was much drier and temperate steppe landscape was extended broadly. It is supposed that a temperate desert appeared on the west coast area of Pyeongan-Do and Cheolla-Do of Korea. The reconstruction of year-round conditions much colder than today right across China, Korea and Japan is consistent with biome reconstruction at the LGM.

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Flora of the Coastal Forests on the Same Latitude of East and West Coast in Korea (우리나라 동위도지역(동해안, 서해안) 해안림의 식물상)

  • Kim, Nam-Young;Choi, Hye-Jin;Kim, Young-Seol;Lee, Hak-Bong;Son, Ho-Jun;Park, Wan-Geun
    • Journal of Forest and Environmental Science
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    • v.28 no.2
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    • pp.118-136
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    • 2012
  • Investigation of flora was performed from March to October of 2008 as Eastern and Western coastal districts located in the same latitude ($36^{\circ}47^{\prime}-37^{\circ}48^{\prime}$), in order to apply this to basic data for effective protection and management of coastal forests also for insurance of biodiversity in coastal forests. As a result of the investigation of floras, both coastal forests recorded product-plants as follows: 98 families, 262 genera, 370 species, 46 varieties, 4 forms, 1 hybrid, 421 taxa in total. The Eastern coastal forests had 85 families, 188 genus, 248 species, 32 varieties, 3 forms, 1 hybrid, 285 taxa in total, whereas Western coastal forest had 96 families, 227 genus, 306 species, 39 varieties, 2 forms, 1 hybrid, 348 taxa in total. Among them, seashore plants accounted for 10.2% of total plants appeared in both coastal, and they are 26 families, 38 genus, 40 species, 3 hybrids and 43 taxa in total. There are special Korea plants in both coastal; 9 families, 9 genus, 8 species, 1 varieties, 1 hybrid, 10 taxa in total. There are rare plants in both coastal; 8 families, 8 genus, 7 species, 1 varieties, 8 taxa in total. Naturalized plants are also existed; 11 families, 24 species, 1 variety, 30 taxa in total.

Distribution of Whales and Dolphins in Korean Waters Based on a Sighting Survey from 2000 to 2010 (목시조사(2000-2010)에 의한 한국 연안 고래류의 종류 및 분포)

  • Sohn, Hawsun;Park, Kyum Joon;An, Yong Rock;Choi, Seok Gwan;Kim, Zang Geun;Kim, Hyun Woo;An, Du Hae;Lee, Young Ran;Park, Tae-Geon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.5
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    • pp.486-492
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    • 2012
  • In the late 1970s, the National Fisheries Research & Development Institute (NFRDI) started cetacean research to submit the Korean whale catch record to the International Whaling Commission. This continued until the moratorium on commercial whaling in 1986. The NFRDI resumed cetacean research with a pilot whale sighting survey in 1999. Subsequently, the NFRDI has conducted 53 cetacean sighting surveys within the Korean exclusive economic zone between 2000 and 2010. The surveys took a total of 760 days and cruising for 23,866 nautical miles. The finless porpoise Neophocaena asiaeorientalis was sighted most frequently (735 times), followed by the minke whale Balaenoptera acutorostrata (396 times), the long-beaked common dolphin Delphinus capensis (102 times), and the Pacific white-sided dolphin Lagenorhynchus obliquidens (27 times). Minke whales were distributed in the Yellow Sea and coastal area of the East Sea from spring to fall. Pacific white-sided dolphin sightings were restricted to the middle and upper coastal areas of the East Sea in summer. Common dolphins were sighted from east of the southern coast to the eastern coast of the Korean Peninsula from spring to fall. Finless porpoise occurred in all Korean coastal areas, except the middle and upper eastern coast.

Water Quality of Agricultural Groundwater in Western Coast Area and Eastern Mountain Area of Jeollabuk-do (전라북도 서부 해안지역과 동부 산악지역 농업용 지하수 수질 평가)

  • Jo, Jae-Yeong
    • Journal of Applied Biological Chemistry
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    • v.54 no.3
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    • pp.218-224
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    • 2011
  • This study was conducted to estimate the water quality of agricultural groundwater well located in Buan-gun, Jinan-gun, Sunchang-gun, and Jangsu-gun of Jeollabuk-do. The groundwater samples were collected at 328 sites (Buan-gun: 158, Jansu-gun: 45, Sunchang-gun: 32, Jinan-gun: 93, respectively). We measured 4 kinds of general contaminants (pH, $NO_3-N$, $Cl^-$, and COD) and 10 kinds of specific contaminants (Cd, As, $CN^-$, Hg, phenol, Pb, $Cr^{+6}$, organophosphorus, trichloroethylene, and tetrachloroethylene). Generally, the level of general contaminants and specific contaminants in the agricultural groundwater was suitable for water quality standard in all sites for agricultural irrigation water. Exceptionally, chloride concentrations were exceeded water quality standard of agricultural groundwater at some sites in western coast area of Jeollabuk-do. Although water quality standards in agricultural groundwater have been suitable, the water contaminants of agricultural groundwater in western coast area were gradually increased than eastern mountain area.

A Numerical Simulation of the 1993 East Sea Tsunami (1993年 동해 쓰나미의 산정)

  • 최병호;우승범;에핌페리높스키
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.6 no.4
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    • pp.404-412
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    • 1994
  • On July 12. 1993 at 22 : 17 local time (-9h. KST). an earthquake of surface magnitude (MS) 7.6 occurred on the west coast of the Hokkaido and small of offshore island of Okushiri in the East Sea. A major tsumani was generated and within 2 to 5 minutes, extremely large tsunami waves engulfed the Okushiri coastal area and the central west roast of the Hokkaido. This tsunami caused tremendous casualities and damage. A giant tsunami runup of more than 30 m in height was recorded. The tsunami crossed the East Sea and feeled at 27 sites of the eastern Korean coast during the survey on 17-19, July, 1993. The observed tsunami runup at southern part of the eastern Korean coast were generally weaker than the 1993 Japan Sea Central Earthquake tsunami and varied from 0.8 m to 2.6 m. The Present Paper intends to understand the propagation on this tsunami with the aid of numerical computation model andd computer graphic aided video animation.

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Dietary Habitats of Spinyhead Sculpin Dasycottus setiger in the Coastal Waters of the East Sea, Korea (동해 연안에 출현하는 고무꺽정이(Dasycottus setiger)의 섭식생태)

  • Park, Joo Myun;Jung, Hae Kun;Kim, Beon Sik;Jung, Young Woo;Lee, Chung Il
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.3
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    • pp.345-352
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    • 2022
  • In this study, the dietary habits of the spinyhead sculpin Dasycottus setiger were investigated based on 156 specimens collected seasonally between May 2018 and February 2019 from the East Sea off the Korean coast. In terms of the weight contribution (%W), the main food items of the spinyhead sculpin were found to be teleosts (33.5%), followed by carid shrimps (13.8%), amphipods (13.3%), cephalopods (12.0%), and polychaetes (7.1%). Dietary analyses based on the weight contribution of different prey taxa in the diet of the spinyhead sculpin revealed considerable variation in the dietary composition in terms of the sampling region and fish size implying intra-specific dietary segregation. The spinyhead sculpin showed a size-related trends in dietary shift from amphipods to carid shrimps and teleosts in northern region, and from carid shrimps and mysids to teleosts and cephalopods in middle eastern coast. Multivariate analyses of dietary changes revealed that the dietary composition of spinyhead sculpin is significantly associated with the sampling site, but not the fish size. Amphipods contributed more to the diets of the northern population, while mysids typified the diets of spinyhead scuplin inhabiting the middle eastern coast, indicating differences in available food resources between the two study regions.

Seasonal Changes in the Marine Algal Community of the Daejin Coast, Mid-eastern Coast of Korea (동해안 중부 대진연안의 해조 군집 계절 변화)

  • Pyo Il Han;Hyun Soo Rho;Joo Myun Park;Jong Won Park;Beom-Sik Kim;Chung Il Lee
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.57 no.3
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    • pp.262-277
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    • 2024
  • The mid-eastern coast of Korea is located at the boundary between cold and warm currents, which causes changes in the distribution and composition of marine organisms in response to fluctuations in the marine environment. To understand the seasonal changes in the seaweed community, we investigated its species composition, biomass, coverage, and frequency from November 2022 to August 2023. A total of 45 species (7 green, 18 brown, and 20 red algae) were found in the study area. In the intertidal zone, the number of species decreased from autumn to summer; the biomass peaked during winter (471.94 g wet weight m-2). Seaweed groups were the dominant functional groups, which were coarsely branched, filamentous, and sheet-like during autumn, winter, spring, and summer. The morpho-functional group was dominated by turf species. In the subtidal zone, the number of species increased during autumn to spring, whereas the biomass peaked during spring (655.27 g wet weight m-2). The functional group was dominated by coarsely branched species throughout all four seasons, whereas the morpho-functional group was dominated by canopy species. Consequently, changes in the biomass of brown and red algae are recognized as key drivers of seasonal changes in seaweed communities.