• Title/Summary/Keyword: Jang river region

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Climate Change Assessment on Air Temperature over Han River and Imjin River Watersheds in Korea

  • Jang, S.;Hwang, M.
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.740-741
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    • 2015
  • the downscaled air temperature data over study region for the projected 2001 - 2099 period were then ensemble averaged, and the ensemble averages of 6 realizations were compared against the corresponding historical downscaled data for the 1961 - 2000 period in order to assess the impact of climate change on air temperature over study region by graphical, spatial and statistical methods. In order to evaluate the seasonal trends under future climate change conditions, the simulated annual, annual DJF (December-January-February), and annual JJA (June-July-August) mean air temperature for 5 watersheds during historical and future periods were evaluated. From the results, it is clear that there is a rising trend in the projected air temperature and future air temperature would be warmer by about 3 degrees Celsius toward the end of 21st century if the ensemble projections of air temperature become true. Spatial comparison of 30-year average annual mean air temperature between historical period (1970 - 1999) and ensemble average of 6-realization shows that air temperature is warmer toward end of 21st century compared to historical period.

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Spatial Estimation for Establishing Fireflies Habitat in Daegu City and Gyeongbuk Province

  • Lee, Do-Hun;Kim, Tae-Su;Kim, Jong-Yong;Park, In-Hwan;Jang, Gab-Sue
    • Journal of Forest and Environmental Science
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    • v.35 no.1
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    • pp.61-68
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    • 2019
  • The purpose of this study is to evaluate the natural habitat of Hotaria unmunsana Doi, which was first discovered at Mt. Unmun also represents a landscape indicator species for Daegu and Gyeongbuk provinces, and Luciola lateralis Motschulsky, which is the object of experiential activation at festivals in some cities in the region. The spatial range of this study is limited by Daegu City and Gyeongbuk province, and is used to predict the preference of firefly for altitude, slope, direction, shaded relief, riparian buffer zone, river environment, and farmland to analyze the area that best matches the habitat of fireflies. As a result, fireflies are highly influenced by altitude and there may be no large-scale habitats in some areas through the Nakdong and the Baekdu mountain ranges, which occur at high altitude. In most of the cities, we found major habitats around the streams and wetlands. By region, the sites were widely distributed around the cities focused on Nakdong River, and many habitats emerged around the Nakdong River tributary and gentle slopes. In order to preserve and spread the habitat of fireflies, the physical environment as well as their relationship with food chains and symbiotic organisms should be established, and excessive use of pesticides and herbicides in agricultural areas should be avoided.

Molecular profiling of 18S rRNA reveals seasonal variation and diversity of diatoms community in the Han River, South Korea

  • Muhammad, Buhari Lawan;Lee, Yeon-Su;Ki, Jang-Seu
    • Journal of Species Research
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    • v.10 no.1
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    • pp.46-56
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    • 2021
  • Diatoms have been used in examining water quality and environmental change in freshwater systems. Here, we analyzed molecular profiling of seasonal diatoms in the Han River, Korea, using the hypervariable region of 18S V1-V3 rRNA and pyrosequencing. Physicochemical data, such as temperature, DO, pH, and nutrients showed the typical seasonal pattern in a temperate region. In addition, cell counts and chlorophyll-a, were recorded at high levels in spring compared to other seasons, due to the diatom bloom. Metagenomic analysis showed a seasonal variation in the phytoplankton community composition, with diatoms as the most frequently detected in spring (83.8%) and winter (69.7%). Overall, diatom genera such as Stephanodiscus, Navicula, Cyclotella, and Discostella were the most frequent in the samples. However, a large number of unknown Thalassiosirales diatoms were found in spring (35.5%) and winter (36.3%). Our molecular profiling revealed a high number of diatom taxa compared to morphological observation. This is the first study of diatoms in the Han River using molecular approaches, providing a valuable reference for future study on diatoms-basis environmental molecular monitoring and ecology.

Cause and Process of Place-Name Change by Social Influence : A Case Study of Jin-An Region (사회적 영향에 의한 지명 변화의 원인과 과정 -전북 진안군 지명을 사례로-)

  • Cho, Sung-Wook
    • Journal of the Korean association of regional geographers
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    • v.13 no.5
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    • pp.526-542
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    • 2007
  • This study look into the place-name change by social influence around Jin-An region. The place-names were made through joining natural environment with social condition. The place-names were born as a river name firstly, and it was selected as the artificial administration district name in this region(Ju-Chon, Jeong-Chon, An-Chon). Generally the place-name is reflected by a terrain feature of narrow area but this region's place name was made by wide river drainage area as a system. It is different point to others place-name and the social factor played more important role than natural environment in this process. The displacement process of mountain name which is from Ju-Jul to Un-Jang was through social situation change without the natural conditions change. It was used to the Ju-Jul firstly and coexistent the Ju-Jul with Un-Jang and only use the Un-Jang recently. Formal change period was 1910s in the map, Mt. Un-Jang(雲長山) had the advantage at the pronunciation and written than Mt. Ju-Jul. Mt. Gu-Bong(九峰山) was played important role for new mountain name and Song Ik-Pil(宋翼弼) was appeared for rationalization of Mt. Un-Jang.

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Characteristics of Fish Community in the Seomjin River and Brackish Area (기수역이 존재하는 섬진강의 어류군집 특성)

  • Baek, Seung-Ho;Yoon, Ju-Duk;Kim, Jeong-Hui;Lee, Hae-Jin;Choi, Kee-Ryong;Jang, Min-Ho
    • Korean Journal of Environmental Biology
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    • v.31 no.4
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    • pp.402-410
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    • 2013
  • In this study, to identify ichthyofauna of the Seomjin River, which has no barrage at estuary, and to estimate effect of estuary barrage, fish sampling was conducted at 16 study sites in mainstream of the Seomjin River from 2010 to 2012. A total of 54 species classified into 17 families were collected. Cyprinidae was the dominant family and Zacco platypus (relative abundance, RA: 47.8%) was identified as the dominant species. In total, 17 Korean endemic species (31.5%) were collected, and it is higher than the average endemic rate of Korean peninsula (22.5~25.9%). Although the relative abundance of exotic species (1.1%) was low, it is higher than the past studies (2002: 0.0%, 2009: 0.4%). Dominance index of freshwater region (St.4~St.16) was relatively higher than estuary (St.1~St.3), because Z. platypus showed high relative abundance at freshwater region. But diversity and evenness index showed contradictory results, as estuary was higher than freshwater region. The ratios of sea fish, peripheral freshwater fish and economic fish, and diversity index are higher than the Nakdong River, the Yeongsan River and the Geum River. In conclusion, to conserve the value of the Seomjin River ichthyofauna, continuous monitoring is necessary.

Investigation on Water Quality Variation Characteristics during Dry Season in Namhan River Drainage Basin (남한강수계 저수기 수질변동 특성에 관한 연구)

  • Lee, H.J.;Kong, D.S.;Kim, S.H.;Shin, K.S.;Park, J.H.;Kim, B.I.;Kim, S.M.;Jang, S.H.;Cheon, S.U.
    • Journal of Korean Society on Water Environment
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    • v.23 no.6
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    • pp.889-896
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    • 2007
  • From the direct outflow of Chungju Dam to the junction of water body and watershed in Paldang lake is the scope of this research. This study performed to investigate the main cause of water quality deterioration and the influenced region in the middle field range of the Namhan river Basin with the onsite measurement of water quality and flow rate simultaneously during spring dry season. The purpose of this study is to find out the time-spatial variation characteristics of water quality and flow rate. Following the flow direction $BOD_5$ and $COD_{Mn}$ concentration increased to the highest value of 3.7 mg/L, 5.9 mg/L at Wolgesa respectively. Chl.a concentration increased to $50mg/m^3$ or so at Kangsang, after that it decreased to $37mg/m^3$ at the junction of Paldang lake. Organic matter concentration variation trend showed similar than that of Chl.a. Also $BOD_5$ concentration tendency was similar to Chl.a in every measuring sites except Paldang lake mixing zone. The major factors of water quality deterioration in Namhan river and Paldang lake during dry season were algal bloom and followed internal production. High phosphorus load from Dalcheon and Seom river caused dry season algal bloom and internal production in transitional zone which was stagnant area in downstream of Namhan river.

A Study on Harbor Logistics in China (중국의 항만 물류집중화에 관한 연구 - 상하이항과 장강을 중심으로 -)

  • Lee, Jong- Won
    • Journal of Navigation and Port Research
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    • v.31 no.3 s.119
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    • pp.187-195
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    • 2007
  • China has been the hub of business in Asia' and has developed infra-system and development policy on harbor and logistics. Investment on development of Sanghai port and fang river has been increasing. This development has put importance on logistics in East Asia Additionally, port surrounding of China has been activated Therefore, This paper is going to suggest three measures. First, shipping corporation of Korea will provide different services and network according to the growth of China logistics. Secondly, Korea is to invest with Chinese companies around fang river to freight service industry. Thirdly, it is to construct Yellow sea Rim transport network by Sanghai port and fang river development.

Estimation of te origin through Disposable Lighters Monitoring of the nakdong River Esturary Using GIS (GIS을 활용한 낙동강 하구 해안의 일회용라이터 모니터링을 통한 발생지 추정)

  • Kim, Young-Min;Jang, Seon-Woong;Yoon, Hong-Joo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.6
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    • pp.729-736
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    • 2015
  • In this study, It was analyzed to estimate the origin from the collected disposable lighters with the printed company name and telephone number on the surface. Monitoring was done bimonthly from 2 areas of sandbar Coastline of Nakdong River Estuary(Jinu-do, Shinja-do) and 3 areas(Doomo beach, Heungnam beach, Yeocha beach) of Northeastern coast of Geoje-do. As a result of the monitoring, there were 166 lighters collected. Then, the monthly occurrence amount was concentrated in Jun, August. The origin of Disposable lighters that flowed in study area were mostly cause to the Nakdong River basin region and the coastal area where population densities are high.

Seasonal Variations of Physical Conditions and Currents in the Sea Near Gadeok-Sudo (가덕수도 근해에서 물리적 현상과 해류의 계절 변동)

  • Jang, Sung-Tae;Jeon, Dong-Chull;Shin, Chang-Woong
    • Ocean and Polar Research
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    • v.30 no.1
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    • pp.33-46
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    • 2008
  • In order to investigate seasonal variations of the physical environments in the region of Jinhae Bay-Nakdongpo, we carried out hydrographic surveys from November 2000 to November 2001. Horizontal and vertical distribution of salinity and temperature shows large seasonal variations. Water column is well mixed in winter and stratified in summer. Low-salinity water is distributed in the form of patches because of the drainage control at the Nakdong River. Seasonal variations in the sea near Gadeok-Sudo are affected by topography, river discharge and tidal current. Currents have been measured using a bottom mounted ADCP and DCM12 between November 2000 and August 2001 in the Gadeok-Sudo. The current in the Gadeok-Sudo shows a distinct two-layer structure with reversed current. Low-pass filtered time series of wind, sea elevation and current are coherent for the period of 1-2 days and are attributed to Ekman-like dynamics. Spatial and temporal circulation pattern shows a slight different. The subtidal current in Jinhae Bay goes northward, however is reversed in the Gadeok-Sudo mouth.

Fish Fauna and Community Structure in the Mid-Upper Region of the Seomjin River (섬진강 중.상류 수계의 어류상과 군집구조)

  • Jang, Sung-Hyun;Ryu, Hui-Seong;Lee, Jung-Ho
    • Korean Journal of Ecology and Environment
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    • v.42 no.3
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    • pp.394-403
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    • 2009
  • The fish fauna and community structures were investigated at 15 stations in the midupper region of the Seomjin River watershed from August in 2008 to April in 2009. During the studying period, 42 species belonging to 11 families were collected. Dominant family in the all sites was Cyprinidae (28 species, relative abundance: 66.7%) during the study. Total of 42 species (primary freshwater: 40 species, peripheral freshwater: 2 species) were found with the primary freshwater fishes being the highest. Dominant species was Zacco platypus (22.3%), and subdominant species was Coreoferea herzi (10.8%). Also, Pseudogobio esocinus (9.0%) and Carassius auratus (5.8%) were numerous. There were 17 Korean endemic species (40.5%), including Rhodeus ocellatus, Acheilgnathus koreensis, A. somjinensis, Coreoleuciscus splendidus and Sarcocheillichthys variegatus wakiyae. Among them, Acheilgnathus somjinensis was identified for designation required to protect under a wildlife category. In conclusion, we could define that the Seomjin River watershed has a very good water conditions as habitat of fish.