• Title/Summary/Keyword: National River

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Soil Salinity and Vegetation Distribution at Four Tidal Reclamation Project Areas (4개 간척 지구에 분포하는 식생과 토양 염류농도)

  • Lee, Seung-Heon;Ji, Kwang-Jae;An, Yeoul;Ro, Hee-Myong
    • Korean Journal of Environmental Agriculture
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    • v.22 no.2
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    • pp.79-86
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    • 2003
  • This research was conducted to present reference data to be used as newly reclaimed tidal land management. We investigated vegetation succession at 4 reclaimed/reclaiming project areas and discussed relationship with soil and vegetation trhrough investigation and analysis soil chemical characteristics at 2 areas. 14 families 58 kinds were investigated. Vegetation were variou at Dea-Ho conservation polt and Seok-Mun National Industrial Area which are maintaining naturally. Vegetation were simple at Hong-Bo and Dongjin and MinKyong river areas which effected sea water. Common species that were investigated at 9 sites were Suaeda asparagoides, Aster tripolium, Phragmites australis, Suaeda maritima, Suaeda japonica, Carex scabrifolis. As soil desalinization progressing, soil classified at first saline-soidc soil, the nest saline soil and then normal soil. Chenopodiaceae revealed at about 30 dS/m of soil ECe and existed to 10 dS/m of soil ECe. At about 20 dS/m of soil ECe. Aster tripolium, Calamagrostis epigeios, and Sonchus brachyotus revealed and then non-halophytes and common plants at inland revealed at low soil ECe of about 10 dS/m. However it was not to progress vegetation sucdession and soil desalinization at the same time, owing to input of seeds or plants ect from out-ecosystem. So for promotion of vegetation at newly reclaimed tidal land, we proposed that it was very effective to plant artificially halophytes or suitable species through soil test.

Radium Isotope Ratio as a Tracer for Estimating the Influence of Changjiang Outflow to the Northern Part of the East China Sea (라듐 동위원소 방사능비를 추적자로 사용한 동중국해 북부 해역에서 장강 유출수의 영향 추정)

  • Kim, Kee-Hyun;Kim, Seung-Soo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.3
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    • pp.133-142
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    • 2009
  • In order to understand the present environmental condition and future impingement of Changjiang(Yangtze River) outflow upon the adjacent seas after the scheduled completion of the Sanxia (Three Gorges) Dam in 2009, we tried to estimate the mixing ratios among surface waters of three end-members: Changjiang Water (CW), Kuroshio Water (KW), and East China Sea Water (ECSW) using $^{228}Ra/^{226}Ra$ activity ratio and salinity as tracers. Water samples were collected from 32 stations in November 2005 (R/V Tamgu 3), from 20 stations in July 2006 (R/V Ocean 2000) and from 17 stations in August 2006 (R/V Ieodo) in the northern part of the East China Sea. Radium isotopes in ~300 liters of surface seawater were extracted onboard by filtering through manganese impregnated acrylic fibers and following coprecipitation as $Ba(Ra)SO_4$. Activities of radium isotopes were determined by a high purity germanium detector. Results show that the fraction of CW was in the range of 1-23% in the study area, while KW was in the range of 0-30 % and ECSW 58-100 %. The eastward plume of Changjiang outflow, commonly observed in satellite images during summer and also displayed by the eastward-decreasing CW fraction in this study, could be attributed to Ekman transport caused by the SE monsoon prevailing in this region during summer. Results of this study showed that in the drought season, there was a little or no fraction of CW in the study area. Concentration of dissolved inorganic nitrogen (DIN) showed strong positive relationship with the fraction of CW, suggesting Changjiang as the major source of nitrogen. The mixing curve of DIN indicates the removal of nitrate by biological uptake during the mixing of CW with ambient seawater in the study area.

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Analysis of National Vertical Datum Connection Using Tidal Bench Mark (기본수준점을 이용한 국가수직기준연계 분석 연구)

  • Yoon, Ha Su;Chang, Min Chol;Choi, Yun Soo;Huh, Yong
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.3
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    • pp.47-56
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    • 2014
  • Recently, the velocity of sea-level rising has increased due to the global warming and the natural disasters have been occurred many times. Therefore, there are various demands for the integration of vertical reference datums for the ocean and land areas in order to develop a coastal area and prevent a natural disaster. Currently, the vertical datum for the ocean area refers to Local Mean Sea Level(LMSL) and the vertical datum for the land area is based on Incheon Mean Sea Level(IMSL). This study uses 31 points of Tidal Gauge Bench Mark (TGBM) in order to compares and analyzes the geometric heights referring LMSL, IMSL, and the nationally determined geoid surface. 11 points of comparable data are biased more than 10 cm when the geometric heights are compared. It seems to be caused by the inflow of river, the relocation of Tidal Gauge Station, and the topographic change by harbor construction. Also, this study analyze the inclination of sea surface which is the difference between IMSL and LMSL, and it shows the inclination of sea surface increases from the western to southern, and eastern seas. In this study, it is shown that TGBM can be used to integrate vertical datums for the ocean and land areas. In order to integrate the vertical datums, there need more surveying data connecting the ocean to the land area, also cooperation between Korea Hydrographic and Oceanographic Administration and National Geographic Information Institute. It is expected that the integrated vertical datum can be applied to the development of coastal area and the preventative of natural disaster.

Estimation of Total Allowable Pollutant Loads Using Eco-hydrodynamic Modeling for Water Quality Management on the Southern Coast of Korea (생태계 모델에 의한 총허용 오염부하량 산정을 통한 연안해역의 수질관리)

  • Lee, Dae-In;Kim, Jong-Kyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.10 no.1
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    • pp.29-43
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    • 2007
  • For effective management of water quality on the southern coast of korea, a three-dimensional eco-hydrodynamic model is used to predict water quality in summer and to estimate the reduction rate in pollutant loads that would be required to restore water quality. Under the current environmental conditions, in particular, pollutant loadings to the study area were very high, chemical oxygen demand (COD) exceeded seawater quality criteria to comply with current legislation, and water quality was in a eutrophic condition. Therefore, we estimated reduction rates of current pollutant loads by modeling. The model reproduced reasonably the flow field and water quality of the study area. If the terrestrial COD, inorganic nitrogen and phosphorus loads were reduced by 90%, the water quality criteria of Region A were still not satisfied. However, when the nutrient loads from polluted sediment and land were each reduced by 70% simultaneously, COD and $Chl-{\alpha}$ were restored. When we reduced the input COD and nutrient loads from the Nakdong River by 80%, $Chl-{\alpha}$ and COD of Region B decreased below $10\;{\mu}g\;1^{-1}$ and $2\;mg\;1^{-1}$, respectively. The water quality criteria of Region C were satisfied when we reduced the terrestrial COD and nutrient loads by 70%. Total allowable loadings of COD and inorganic nutrients in each region were determined by multiplying the reduction rates by current pollutant loads. Estimated high reduction rates, although difficult to achieve at the present time under the prevailing environmental conditions, suggest that water pollution is very severe in this study area, and pollutant loads must be reduced within total allowable loads by continuous and long-term management. To achieve the reduction in pollutant loads, sustainable countermeasures are necessary, including the expansion of sewage and wastewater facilities, polluted sediment control and limited land use.

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Pollution of Heavy Metals and Sedimentation Rate in the Sediments of Suyeong Bay, Pusan (수영만 퇴적물의 퇴적속도와 중금속 오염)

  • YANG Han-Soeb;KIM Seong-Soo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.5
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    • pp.643-658
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    • 1994
  • The sedimentary records of anthropogenic metal loads in the Suyeong Bay, Pusan were determined by combining the Pb-210 dating technique with the measurements of heavy metals in the sediment cores. The sedimentation rates of sediment particles ranged from $0.12\;to\;0.20\;g/m^2/yr\;or\;2.4{\sim}4.0\;mm/yr$ in accumulation rates. The lowest sedimentation rate was observed at station S3 which was characterized by a bottom with relatively low organic matter contents(e.g. TIL and TOC). Heavy metals showed generally higher concentrations at station S1 and S2 near the mouth of the Suyeong River than at station S3 and the outmost station S4. The contents of copper, lead and zinc in the sediment cores especially from station S1 and S2 began to increase around 1930, and were at their highest levels in the $1960{\sim}1970$ period as a result of increasing industrial activities. Concentrations of these heavy metals have slightly decreased since 1970, probably due to regulation of pollution discharge. The natural background levels of copper, lead and zinc in the sediments of this bay ranged $18{\pm}4ppm,\;28{\pm}6ppm\;and\;74{\pm}9ppm$, respectively, by averaging the contents in the sediment depths corresponding to periods between about 1900 and 1920 at the four stations. The total amounts of anthropogenic loads deposited in the sediments since about 1930 were estimated to be $9{\sim}291{mu}g/cm^2$ for lead, $165{\sim}1122{mu}g/cm^2$ for zinc and $20{\sim}208{mu}g/cm^2$ for copper. These values were remarkably high at stations S1 and S2 relative to the other two stations. At stations S1 and S2, the anthropogenic loads of lead, copper and zinc constituted $29{\sim}30\%,\;32{\sim}42\%\;and\;28{\sim}35\%$ of the total sedimentary inventories at the present day, respectively. These metal contents have a good correlation(r>0.7) with each other and cadmium measurements also show a positive linear relation with nickel or total organic nitrogen.

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Studies on the Life History of Acanthoparyphium tyosenense Yamaguti, 1939 (Acanthoparyphium tyosenense Yamaguti, 1939의 생활사에 관한 연구)

  • KIM Young-Gill;YU Ji-Eun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.6
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    • pp.720-728
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    • 2001
  • Cercaria yamagutii Ito, 1957 (C. yamagutii) was found in Lunatia fortuni (L. fortuni) and Neverita didyma (N. didyma) collected from the tideland of Sim-po located at the estuary of the Mankyong River, Chonbuk. It was finally confirmed that the parasite is Acanthoparyphium tyosenense Yamaguti, 1939 (A. tyosenense) and its life history was clarified in this study. Mactra veneriformis (M. veneriformis) was artificially infected with C. yamagutii isolated from L. fortuni and N. didyma. It began to intrude into M. veneriformis through the inhalent canal. Five hours after infection, the tails of the cercaria began to be separated from the main body and the cercaria started to form cysts. Mature cysts were formed 340 hours (14 days) after infection. The cysts were $300\sim360{\mu}m$ in diameter and the encysted metacercarias were $790\sim800\times300\sim310{\mu}m$ in size. The metacercarias were administered orally to Larus crassiostris (L. crassiostris), and adult worms of $84.5\sim112.5\times55\sim65{\mu}m$ were found full of eggs with $2.20\~3.70$ mm long and $0.40\~0.59$ mm wide after 10 days. In a field study, it was observed that the infection rate of A. tyosenense is $99.5\%$ in M. venerifomis, $76.3\%$ Solen strictus (S. strictus), and $37\%$ Ruditapes philippinarum (R. philippinarum), No difference was found among different host sizes, It was concluded that the first intermediate hosts of A. tyosenense Yamaguti were L. fortuni, N. didyma, Tympanotonus microptera, Cerithidea (Cerithidea) largillierti, Cerithidea (Cerideopsilloa) cingulata, the second intermediate hosts M. venerifomis, S. strictus and R. philippinamn, and the final hosts L. crassiostris and Melanitta fusca stejnegeri.

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Hydrological Feasibility for Heightening Dae-ah Reservoir (대아지 숭상을 위한 수문학적 가능성 평가)

  • Noh, Jae-Kyoung;Lee, Jae-Nam
    • Korean Journal of Agricultural Science
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    • v.35 no.2
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    • pp.225-235
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    • 2008
  • The objective of this study is to evaluate the hydrological feasibility of heightening the Dae-ah reservoir in order to save instream flow at the Bong-dong station situated in the Mankyoung river. The results are summarized as follows. Firstly, from the Dong-sang and Dae-ah cascaded reservoir's water balance analysis, water supply indexes of the Dae-ah reservoir were analyzed to have the rate of water supply divided by watershed area of 1207.4 mm, the rate of water supply divided by rainfall of 95.8%, the rate of water supply divided by inflow of 153.1%, the rate of water supply divided by storage capacity of 236.1%, and the rate of inflow divided by storage capacity of 200.6%. Secondly, from the Dae-ah and Kyoung-cheon paralleled reservoir's water balance analysis, flow durations at the Bong-dong station were analyzed to have the Q95 (the 95th high flow) of $28.95m^3/s$, the Q185 (the 185th high flow) of $2.00m^3/s$, the Q275 (the 275th high flow) of $2.00m^3/s$, and the Q355 (the 355th high flow) of $0.82m^3/s$. Thirdly, in case of heightening the full water level of the Dae-ah reservoir of 10m, from the Dong-sang and Dae-ah cascaded reservoir's water balance analysis, water supply indexes of the Dae-ah reservoir were analyzed to have the rate of water supply divided by watershed area of 1220.7 mm, the rate of water supply divided by rainfall of 96.8%, the rate of water supply divided by inflow of 154.6%, the rate of water supply divided by storage capacity of 160.0%, and the rate of inflow divided by storage capacity of 137.0%. Fourthly, in case of heightening the full water level of the Dae-ah reservoir of 10m, from the Dae-ah and Kyoung-cheon paralleled reservoir's water balance analysis, flow durations at the Bong-dong station were analyzed to have the Q95 of $28.09m^3/s$, the Q185 of $1.79m^3/s$, the Q275 of $1.79m^3/s$, and the Q355 of $0.82m^3/s$. The conclusion appeared not to have the hydrological feasibility of heightening the Dae-ah reservoir from the reason that increased storage capacity does not increase water supply amount any more because of the high rate of the water supply divided by inflow.

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Deformational Phased Structural Characteristics of the Hadong Southern Anorthosite Complex and its Surrounding Area in the Jirisan Province, Yeongnam Massif, Korea (영남육괴 지리산지구에서 하동 남부 회장암복합체와 그 주변지역의 변형단계별 구조적 특성)

  • Lee, Deok-Seon;Kang, Ji-Hoon
    • The Journal of the Petrological Society of Korea
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    • v.22 no.2
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    • pp.179-195
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    • 2013
  • The study area, which is located in the southeastern part of the Jirisan province, Yeongnam massif, Korea, is mainly composed of the Precambrian Hadong southern anorthosite complex (HSAC), the Jirisan metamorphic rock complex (JMRC) and Cretaceous sedimentary rock which unconformably covers them. Lithofacies distribution of the Precambrian constituent rocks mainly shows NS and partly NE trends. This paper researched deformational phased structural characteristics of HSAC and JMRC based on the geometric and kinematic features and the forming sequence of multi-deformed rock structures, and suggests that the geological structures of this area was formed through at least three phases of ductile deformation. The first phase ($D_1$) of deformation happened due to the large-scale top-to-the SE shearing, and formed the sheath or "A"-type fold and the regional tectonic frame of NE trend in the HSAC and JMRC. The second phase ($D_2$) of deformation, like the $D_1$ deformation, regionally occurred under the EW-directed tectonic compression, and most of the NE-trending $D_1$ tectonic frame was reoriented into NS trend by the active and passive folding, and the persistent and extensive ductile shear zone (Hadong shear zone) with no less than 2.3~1.4 km width was formed along the eastern boundary of HSAC and JMRC through the mylonitization process. The third phase ($D_3$) of deformation occurred under the NS-directed tectonic compression, and partially reoriented the pre-$D_3$ structural elements into ENE or WNW direction. It means that the distribution of Precambrian lithofacies showing NE trend locally and NS trend widely in this area is closely associated with the $D_1$ and $D_2$ deformations, respectively, and the NS-trending Hadong shear zone in the eastern part of Hadong northern anorthosite complex, which is located in the north of Deokcheon River, also extends into the HSAC with continuity.

A study on the Meaning Contact of ManChwi Pavilion's Place Transmission and Sense of Prototype Landscape (만취정(晩翠亭)의 장소 전승과 원형경관향유 양상)

  • Lee, Seung-Yeon;Shin, Sang-Sup;Kahng, Byung-Seon
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.34 no.3
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    • pp.38-49
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    • 2016
  • This study is based on the assumption that the documentations, and poetry form a basis for undertone of the location and original landscape explored by inference and enjoyment aspects; the significance has been inferred by investigating the original location, relocated location, and the original landscape of Imsil Manchwi Pavilion. The results of the attempted research for locational value, and preservation of the original landscape before and after the relocation of Imsil Manchwi Pavilion is as follows. Firstly, Manchwi, meaning evergreen, was made a pseudonym of KimWi. The name reflects an image two evergreen pine trees facing one another. The poetry form presents the eternal fidelity. In addition, considering the symbolic plant and the meaning of evergreen pine trees specified on the pavilion, the name is derived from the fidelity, longevity of the family, vitality and so on. Secondly, Manchwi Pavilion was founded in the location, known as the snakehead form, that represents the vitality. Snake faces the swallow form over the river, therefore, it connotes the wishes for fidelity and prosperity of the family. Manchwi Pavillion is prostrate pheasant form which is suitable for those who look for a hiding place or place for their study. It is noticeable that the location infers and hand down the efforts on succession for prosperity of the family and the study. Thirdly, it is estimated that Manchwi Pavilion was established between 1572 and 1582; and the relocation was conducted in the late 1880s. Fourthly, although eternal fidelity was presented in Manchwi Pavillion with locational language, the Manchwi Pavillion after its relocation next to KimWi's grave implies the tendency of the changed value: the commemoration of the ancestors, and prosperity of the family. Fifthly, after the relocation of the pavilion, the proportion of the rooms with Korean heating system, so-called'Ondol'has been increased for its best use in all seasons. And its veranda for extension and its verse couplet implies that this connote the original meaning and pursuit of the study. Sixthly, the way that the poetry portrays pine trees, pond, plants, valleys, and streams shows the aspect of enjoyment of the landscapes and the meaning of fidelity, pure mind, free and easy life, self-examination, the frailty of human life. Lastly, despite the difference between tenth poetic language of three Sipyoung and Wonwoon Sipyeong, exploring the landscape based on the analysis on the poetry can be a basis on the maintenance and restoration of the original landscape as the inspiration and the meaning show that Wonwoon Sipyeong maintains the aspect of the author enjoying original landscape.

Measuring Economic Values of Amenity Services from Urban Greenspaces in the Seoul Metropolitan Area Using Choice Experiments (선택실험을 이용한 서울 도시녹지 어메니티의 경제가치 평가)

  • Choi, Andy S.;Eom, Young Sook
    • Environmental and Resource Economics Review
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    • v.27 no.1
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    • pp.105-138
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    • 2018
  • This paper reports novel empirical results of a choice experiment that elicited the economic values that residents in the Seoul metropolitan area place on the amenity services realized from the landscape views and accessibilities to urban green spaces (i.e., mountains, rivers and urban parks). The 1,000 respondents in the sample were divided into two residential of housing types (apartments vs. houses) and occupancy types (owners vs. tenants). Residents living in apartments are willing to pay an average of 28% (5.0 million KRW per year) above the current housing prices per household for a mountain view, compared to an apartment view from their living room. Their willingness to pay values are about 22% (4.0 million KRW per year) and 10% (1.8 million KRW per year) respectively for a river view and a urban park view. Economic benefits of having access (i.e., a 10 minutes working distance) to mountains, rivers and urban parks are estimated to be an average of 16% (2.9 million KRW per year), 20% (3.6 million KRW per year) and 18% (3.2 million KRW per year), respectively, above the current housing prices per household. On the other hand, access benefits for those residing in houses are 18% (4.7 million KRW per year), 16% (4.1 million KRW per year) and 22% (5.6 million KRW per year) per household, respectively. They are also willing to pay an average of 35% (8.9 million KRW per year) above the current housing prices for keeping or having a garden or vegetation bed. Furthermore, a strong "greenspace premium" is centered around the three Gangnam districts for house-dwellers, whereas it is areas of "new real estate boom" for apartment dwellers.