• Title/Summary/Keyword: East River

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Younger Dryas Type Climatic Oscillation in the East Sea

  • Kim, Gil-Young;Kim, Dae-Choul;Shin, Im-Chul
    • Journal of the korean society of oceanography
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    • v.34 no.1
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    • pp.43-48
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    • 1999
  • The latest-Quaternary paleoceanographic history of the Ulleung Basin, the East Sea (the Sea of Japan) is reconstructed on the base of planktonic foraminifera, oxygen and carbon isotopes, and accelerator mass spectrometer radiocarbon (AMS-$^{14}$C) data from two cores. Sinistral populations of Neogloboquadrina pachyderma are dominant during the last glacial period while dextral forms of Neogloboquadrina pachydeyma are abundant in the Holocene. An abrupt increase in ${\delta}^{18}$O values in both cores that began about 11 ka B.P may indicate the Younger Dryas cooling episode. A low-salinity event, marked by light ${\delta}^{18}$O values (0-1 %), is observed before the Younger Dryas event. As previous works suggested, the low-salinity event is probably due to the freshening of surface water caused by fresh water input from Huang Ho river and/or the excess of precipitation over evaporation. The lowest salinity water in the Ulleung Basin was probably continued from approximately 18 ka B.P. to 15 ka B.P. The ${\delta}^{18}$O values have gradually decreased since the Younger Dryas as a result of the continuous inflow of the warm Tsushima Current into the East Sea.

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A Study on Upper-Class House in North Kyeung-Buk Region (경북북부지역의 상류주택에 관한 조사연구)

  • 백영흠
    • Journal of the Korean housing association
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    • v.5 no.1
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    • pp.59-69
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    • 1994
  • This paper was made to examine floor plan and block plan of traditional upper-class houses in the north Kyeungsangbukdo region with consideration into city and country each. The results of this study were as following; First, Munkyung area is latitudinally located in northern area along with the Yechon and Andong. However, Munkyung area has open plot system while Yechon and Andong has not. It is because even if Munkyung area is located in the western of Nak-Dong river and belongs to the northern region, it has belonged to the cultural area which is developed around Sangju area. Second, Youngduk area belongs to the east-coast but it had frequent cultural exchange and marriage with Andong which is located on the road along with Tae-Baek Mountain. Due to the cultural exchange, their housing type is very similar to those of Andong which is close plot plan of "ㅁ" type. Therefore, even if Youngduk is located in the east-coast area, it should belong to the cultural background of Andong area. Regionally, the culture of Kyongsangbukdo has been divided into northern area, southern area, and east-coast area. But, the findings of this study indicate that the analysis of location and floor plan of housing should not be based on the natural environment oand geographic characteristics. Hence, it should be based on the all aspects of environment, including social and cultural nature to find more reliable and accurate results.e results.

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A Study on the Flood Damage Assessment by Typhoon RUSA in the East Coast of Kangwon Prefecture Following the 2000 Large Scale Fire Disaster -Focused on the Watershed of Oship River, Samcheok City (2000년 강원도 동해안지역 대규모 산불화재가 태풍루사 홍수피해에 미친 영향 -삼척시 오십천을 중심으로)

  • 강상혁
    • Fire Science and Engineering
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    • v.17 no.4
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    • pp.70-75
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    • 2003
  • The east coast of Kangwon province has been suffering from natural disaster like wildfire and flooding. In April 2000, there has been a great wildfire in this area. Many forest was burnt out, the mountain was bared. Furthermore, on 31st August,2002 typhoon RUSA attacked the area with heavy rainfall of about 315 mm/day, which resulted in 178 deaths and extensive damage to the property, In this regard, our study was focused on the assessment of the factors of flooding damage considering wildfire disaster. Most of results for our study are derived from practical investigation in the east coast of Kangwon province.

The Possibility of Flooding and Human Activities of Gyeongju Area in Ancint Times (고대 경주 지역의 홍수 가능성과 인간 활동)

  • Hwang, Sang-Ill
    • Journal of the Korean Geographical Society
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    • v.42 no.6
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    • pp.879-897
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    • 2007
  • The Royal District in Gyeungju-city was placed in lower surface of alluvial fan that was formed during the Last Glacial Age. During the Holocene, Bukcheon-river was reached in the dynamic equilibrium status and the form of river channel was similar or same to the present. The cases of dying people and carrying houses away by flood for ancient history in Gyeongju were six times, in 131, 160, 350, 496, 657 and 703. Like this big flood was happened at interval of $150{\sim}200$years. A period of big flood appearance in Bukcheon-river was extremely long. Therefore the people who had lived in Gyeongju for ancient history perceived that most part of riverbed of Bukcheon-river was a safety place from flood damages. Not only private houses. In east part of Bunhwangsa temple, that is, west side of Bukcheon-river where the river energy is maximum, a pillow block was built to prevent a lateral erosion but any artificial riverbank was not. In spite of high flood possibility in Bukcheon-river, there was no facility to prevent floods in this section. Also, deposits of flood are not identified. This point is very suggestive that Bukcheon-river did not flood for ancient history.

Dispersal of potential habitat of non-native species tilapia(Oreochromis spp.) inhabiting rivers in Korea (국내 하천에 서식하는 외래종 틸라피아(tilapia)의 잠재적 서식처 확산)

  • Ju Hyoun Wang;Jung Soo Han;Jun Kil Choi;Hwang Goo Lee
    • Korean Journal of Environmental Biology
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    • v.41 no.2
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    • pp.101-108
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    • 2023
  • Recently, in relation to climate change, many studies have been conducted to predict the potential habitat area and distribution range of tilapia and the suitability of habitat for each species. Most tilapia are tropical fish that cannot survive at water temperatures below 10 to 12℃, although some tilapia can survive at 6 to 8℃. This study predicted habitable areas and the possibility of spreading of habitat ranges of tilapia (Oreochromis niloticus and Oreochromis aureus) known to inhabit domestic streams. Due to climate change, it was found that habitats in the Geum River, Mangyeong River, Dongjin River, Seomjin River, Taehwa River, Hyeongsan River, and the flowing in East Sea were possible by 2050. In addition, it was confirmed that tilapia could inhabit the preferred lentic ecosystem such as Tamjin Lake, Naju Lake, Juam Lake, Sangsa Lake, Jinyang Lake, Junam Reservoir, and Hoedong Reservoir. In particular, in the case of tilapia, which lives in tributaries of the Geumho River, Dalseo Stream, and the Nakdong River, its range of habitat is expected to expand to the middle and lower of the Nakdong River system. Therefore, it is judged that it is necessary to prepare physical and institutional management measures to prevent the spread of the local population where tilapia currently inhabits and to prevent introduction to new habitats.

The Tourist Resources' Distribution and Characteristic Around Ondal Cave

  • Jeong, Min-Chae
    • Journal of the speleological society of Korea
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    • v.42 no.2
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    • pp.29-32
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    • 1995
  • The geographical location of Ondal cave is situated between Danyang's cave zone and Yang wol's Kossi cave. The cave is situated at 37$^{\circ}$ 03' North latitude and 128$^{\circ}$ 29' of east longitude and is administratively located in Hari, Yongchun Myen, Danyang Gun, Chung Chong Bug Do. In the light of its natural location, It is situated on the southern side of Nam Han river's water system and in the fort mountain which includes Ondal hill-fort and its mountain range's peak, Nam San.(omitted)

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Scenario Analysis Technology for Flood Risk Management in the Taihu Basin

  • Changwei, Hu
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.140-148
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    • 2010
  • The Taihu Basin is located in the east coast of China, where the threats of frequent floods have induced construction of massive, complex, hierarchical flood defense systems over the interconnected river networks. Digital modeling of flooding processes and quantitative damage assessment still remain challenging due to such complexity. The current research uses an integrated approach to meet this challenge by combining multiple types of models within a GIS platform. A new algorithm is introduced to simulate the impacts of the flood defense systems, especially the large number of polders, on floods distributions and damages.

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Possible Changes of East Asian Summer Monsoon by Time Slice Experiment (Time Slice 실험으로 모의한 동아시아 여름몬순의 변화)

  • Moon, JaYeon;Kim, Moon-Hyun;Choi, Da-Hee;Boo, Kyung-On;Kwon, Won-Tae
    • Atmosphere
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    • v.18 no.1
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    • pp.55-70
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    • 2008
  • The global time slice approach is a transient experiment using high resolution atmosphere-only model with boundary condition from the low resolution globally coupled ocean-atmosphere model. The present study employs this "time slice concept" using ECHAM4 atmosphere-only model at a horizontal resolution of T106 with the lower boundary forcing obtained from a lower-resolution (T42) greenhouse gas + aerosol forcing experiment performed using the ECHO-G/S (ECHAM4/HOPE-G) coupled model. In order to assess the impact of horizontal resolution on simulated East Asian summer monsoon climate, the differences in climate response between the time slice experiments of the present and that of IPCC SRES AR4 participating 21 models including coarser (T30) coupled model are compared. The higher resolution model from time slice experiment in the present climate show successful performance in simulating the northward migration and the location of the maximum rainfall during the rainy season over East Asia, although its rainfall amount was somewhat weak compared to the observation. Based on the present climate simulation, the possible change of East Asian summer monsoon rainfall in the future climate by the IPCC SRES A1B scenario, tends to be increased especially over the eastern part of Japan during July and September. The increase of the precipitation over this region seems to be related with the weakening of northwestern part of North Pacific High and the formation of anticyclonic flow over the south of Yangtze River in the future climate.

Comparison of Atmospheric River Detection Algorithms in East Asia (동아시아 대기의 강 탐지 알고리즘 비교)

  • Gyuri Kim;Seung-Yoon Back;Yeeun Kwon;Seok-Woo Son
    • Atmosphere
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    • v.33 no.4
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    • pp.399-411
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    • 2023
  • This study compares the three detection algorithms of East Asian summer atmospheric rivers (ARs). The algorithms developed by Guan and Waliser (GW15), Park et al. (P21), and Tian et al. (T23) are particularly compared in terms of the AR frequency, the number of AR events, and the AR duration for the period of 2016-2020. All three algorithms show similar spatio-temporal distributions of AR frequency, centered along the edge of the North Pacific high. The maximum AR frequency gradually shifts northward in early summer as the edge of the North Pacific High expands, and retreats in late summer. However, the detailed pattern and the maximum value differ among the algorithms. When the AR frequency is decomposed into the number of AR events and the AR duration, the AR frequencies detected by GW15 and P21 are equally explained by both factors. However, the number of AR events primarily determine the AR frequency in T23. This difference occurs as T23 utilizes the machine learning algorithm applied to moisture field while GW15 and P21 apply the threshold value to moisture transport field. When evaluating AR-related precipitation, the ARs detected by P21 show the closest relationship with total precipitation in East Asia by up to 60%. These results indicate that AR detection in the East Asian summer is sensitive to the choice of the detection algorithm and can be optimized for the target region.

Study on Comparison of Fishes by Trawl Fishery in Nakdong River Estuary, Korea (낙동강 하구 해역의 트롤어구로 채집된 어류의 종조성 비교)

  • Lee, Jong-Hee;Lee, Jae-Bong;Choi, Young-Min;Yeon, In-Ja;Lee, Dong-Woo
    • Korean Journal of Ichthyology
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    • v.24 no.2
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    • pp.84-93
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    • 2012
  • Fish species composition and abundance in the waters of nearby Nakdong River estuary were investigated non-continuously and seasonally by shrimp beam trawl in summer 2007, winter 2009, and from spring 2010 to autumn 2010. During the study period, total fish species were collected 92 species, 36 families in study area. Shannon index was 1.893~2.962, and evenness was 0.050~0.231. Fish species composition was shown interannually and seasonally variations in the waters of nearby Nakdong River estuary. We carryed out cluster analysis to contain the data in previous and current study. Fish species composition was divided 3 groups which were 1987~1988 and 1998, 2001~2002, and 2007~2008 and 2009~2010. Average and minimum length in this study was longer than its in previous studies, and length range in this study was wider than its in previous studies, too. Dominant fish increased individuals and weight per unit area in this study. Especially Lophius litulon, Raja kenojei, Eopsetta grigorjewi, and Zeus faber were much better than past 2002. Liparis tanakai, Repomucenus valenciennei and Leiognathus nuchalis were dominant fish in previous study, but those decreased individuals and weight per unit area in this study.