• Title/Summary/Keyword: large river

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A study on manufacturing technologies of the large-sized jar-coffins exhumed mainly in the Young San river area (대형옹관의 제작기법 연구-영산강유역 출토 옹관을 중심으로)

  • Yang, Pil-Seung;Park, Chul-Won
    • 보존과학연구
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    • s.26
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    • pp.57-75
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    • 2005
  • The burial custom in the Youngsan river area was to build a jar-coffin and lay the body in state, however the methods in building and moulding the massive jar, as well as in which kiln it was made has not been examined precisely. Thus, this research not only investigates previous results related to the manufacturing methods of massive jar-coffins, but also examines samples that were excavated and collected. The clay used to produce jar-coffin consists a large portion of unglazed qualities, which was split-moulded from the bottom up to the mouth area. The interior was finished by applying water, whereas the exterior was decorated by regularly pasting or stamping in parallel with a lattice design. It can be presumed that the finished jar-coffin was not moved, but the ceiling and walls were built around it as a kiln, for the jar-coffin to be oxidized or to reduce the flame condition in a temperature approximately $700~1,200^{\circ}C$The results from the research, however, show limitations to exploit the exact manufacturing method, therefore there is a need for in-depth examinations: mineralogical investigation on a large amount of jar-coffin samples through a polarized light microscope; substance analysis using various equipments; speculation on the temperature in the place of production and the flame inside.

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Environmental Impact Assessment within Regional and Municipal Planning (지역 및 도시계획에서의 환경영향평가)

  • Socher, Wolfgang
    • Journal of Environmental Impact Assessment
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    • v.4 no.3
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    • pp.27-29
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    • 1995
  • Within regional and municipal planning we are using several levels or types of EIA in the city of Dresden. Some of these types, practical aspects and some experiences of our work will be presented in this contribution. Firstly I may introduce you to some general conditions for your better understanding of our principles of work. Surely you know about. the destruction of the political and economical structures in Eastern Germany since 1989. Until today our not quite simple task is to build up new ones. At the same time people were in great expectation of freedom and high standard of living as soon as possible. Economical difficulties increased in association with the breakdown of the market in Eastern Europe. How to rebuild industrial estatements and how to renew the traffic systems? We had to find answers to all these complex question. Should we only repair the former damages or could we reach a really environmental sound production for the future? The demand for a rapid economic growth is an incredible challenge for the application of new environmental ideas. I am truly not sure whether you know the city of Dresden or not. So I would like to give you a short introduction. Dresden is situated in a valley shaped by the river Elbe. There live about 500,000 people. Dresden has a great reputation for arts and sciences. Its also well know as a town of high technology industries such as electronics and optics. We restored the power plant and therefore we don't need any atomic power plants actually we haven't got one. Since 1990 there were founded many official agencies in Dresden because it is the capatal of Saxony. Considering nature and environment we there is a large forest area called "Dresdner Heide". The river Elbe and the meadows are situated on both sides of the river. There are a lot of green and free places in the city area too. Furtheron there is something unusual for a large city: about 50% of the drinking water resources mostly take place within the city itself. The origin is the ground water as well as water from the river Elbe after filtration of course.

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Water Quality Analysis in Nakdong River Tributaries (낙동강 지류·지천 모니터링 결과를 이용한 수질환경 평가)

  • Im, Tae Hyo;Son, Younggyu
    • Journal of Environmental Science International
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    • v.25 no.12
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    • pp.1661-1671
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    • 2016
  • Water quality in Nakdong river was analyzed using 699 monitoring data sets including flow rates and water quality concentrations collected at 195 tributary monitoring stations (the priority management areas: 35 stations, the non-priority management areas: 160 stations) in 2015. The highest average concentrations of all data for BOD, COD, T-N, T-P, SS, and TOC were 30~600 times higher than the lowest concentrations while the highest average loading rates were 800,000~2,700,000 times higher than the lowest loading rates. Because of the very large differences in the concentrations and loading rates, the variation of the concentrations and loading rates in a priority management monitoring station for BOD, T-P, and TOC was analyzed using the coefficient of variation, the ratio of the standard deviation value to the mean value. For BOD, T-P, and TOC, the coefficients of variation for concentration were mostly less than 100%, whereas the coefficients of variation for loading rate ranged from 31.1% to 232.2%. The very big difference in the loading rates was due to the large variation in flow rates. As a result of this, the estimation of water quality at each monitoring station using the average values of the concentrations and loading rates might be not rational in terms of their representativeness. In this study, new water quality analysis methods using all collected monitoring data were suggested and applied according to the water quality standard in medium-sized management areas.

Intraspecific diet shifts of the sesarmid crab, Sesarma dehaani, in three wetlands in the Han River estuary, South Korea

  • Yang, Dongwoo;Han, Donguk;Park, Sangkyu
    • Journal of Ecology and Environment
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    • v.43 no.1
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    • pp.31-42
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    • 2019
  • Background: Han River estuary is a national wetland reserve near the Demilitarized Zone (DMZ) between South Korea and North Korea. This trans-boundary estuary area has been well preserved and shows distinctive plant communities along the salinity gradient. To elucidate energy flows and nutrient cycling in this area, we studied trophic relations between the dominant sesarmid crab, Sesarma dehaani, and food sources in three wetlands with different environments along the estuarine gradients. Results: Stable isotope signatures (${\delta}^{13}C$ and ${\delta}^{15}N$) of the crabs were significantly different among the sites and body size classes. Seasonal changes in ${\delta}^{13}C$ of small crabs were distinct from those of large individuals at all the sites. The isotopic values and fatty acid profiles of the crabs were more different among the sites in September than in May. In May, large-sized crabs utilized more plant materials compared to other dietary sources in contrast to small-sized crabs as revealed by a stable isotope mixing modeling, whereas contributions to diets of crabs were not dominated by a specific diet for different body size in September except at site 1. Based on PCA loadings, fatty acid content of $18:3{\omega}3$, known as a biomarker of plant materials, was the main factor to separate size groups of crabs in May and September. The ${\delta}^{13}C$ value of sediment had high correlation with those of small-sized crabs at site 1 and 2 when 1-month time lag was applied to the value for crabs during the surveyed period. Conclusions: Based on the stable isotope and fatty acid results, the consumption habits of S. dehaani appear to be distinguished by sites and their size. In particular, smaller size of S. dehaani appears to be more dependent on fewer food sources and is influenced more by the diet sources from the sediments in Han River estuary.

The Characteristics of Submarine Groundwater Discharge in the Coastal Area of Nakdong River Basin (낙동강 유역의 연안 해저지하수 유출특성에 관한 연구)

  • Kim, Daesun;Jung, Hahn Chul
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1589-1597
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    • 2021
  • Submarine groundwater discharge (SGD) in coastal areas is gaining importance as a major transport route that bring nutrients and trace metals into the ocean. This paper describes the analysis of the seasonal changes and spatiotemporal characteristicsthrough the modeling monthly SGD for 35 years from 1986 to 2020 for the Nakdong river basin. In this study, we extracted 210 watersheds and SGD estimation points using the SRTM (Shuttle Radar Topography Mission) DEM (Digital Elevation Model). The average annual SGD of the Nakdong River basin was estimated to be 466.7 m2/yr from the FLDAS (Famine Early Warning Systems Network Land Data Assimilation System) recharge data of 10 km which is the highest resolution global model applicable to Korea. There was no significant time-series variation of SGD in the Nakdong river basin, but the concentrated period of SGD was expanded from summer to autumn. In addition, it was confirmed that there is a large amount of SGD regardless of the season in coastal area nearby large rivers, and the trend has slightly increased since the 1980s. The characteristics are considered to be related to the change in the major precipitation period in the study area, and spatially it is due to the high baseflow-groundwater in the vicinity of large rivers. This study is a precedentstudy that presents a modeling technique to explore the characteristics of SGD in Korea, and is expected to be useful as foundational information for coastal management and evaluating the impact of SGD to the ocean.

An Estimation of Quantity of Unused Energy of River Water, Seawater and Treated Sewage as Heat Source and Its Availability in Large Facilities (대규모 시설에서 이용가능한 미활용 에너지의 부존량과 그 이용 가능성에 관한 조사연구-하천수.해수.하수처리수를 중심으로)

  • Heo, Jae-Yeong
    • Journal of National Security and Military Science
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    • s.1
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    • pp.423-446
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    • 2003
  • While the demand for energy has shown a sharp increase recently, the supply seems to be limited by the fact that the conventional fossil fuel energy or nuclear energy has its own environmental problems such as, for example, global warming or nuclear waste disposal. To overcome such limited supply of energy, the utilization of natural thermal energy such as river water and seawater as well as treated sewage can be a substantial supplement. The potential use of the unused energy has become more and more feasible these days as the heat pump technology has been advanced. In the present study, the unused energy resources are estimated on regional and monthly basis for each resource by the method proposed here in order to establish the fundamental data for its utilization. The potential use of the unused energy is a1so discussed.

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A Study on the Runoff Characteristics m Kangwon Watershed (So-yang River Watershed) (강원도 유역의 유출 특성에 관한 연구 (소양강댐 유역 중심으로))

  • Choi, Han-Kyu;Beak, Hyo-Sun;Lee, Min-Seop
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.223-232
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    • 2001
  • This study is finding the most appropriate model of kangwondo watershed. To synthesize each hydrograph, It is found to several parameters which are used in existing hydrographes. then the synthestic hydrograph is compared and investigated with many hydrographes of the rivers in kanwondo. These methods, Nakayasu, Clark, SCS are used to calculate the run-off of this watershed. When the calculated run-off is compared with real rating-curves, then it is found that the SCS method using the Clark's concentrantion time is the best way on this area having large watershed, long river length and gentle water slope, the Nakayasu method is more suitable on this area having small watershed, short river length and steep water slope. Also it is founded from analyzing run-off hydrographes, peak run-off and peak time that the Clark's method applied Kirpich's concentration time way is suitable in the area of kangwondo.

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A Forecasting Model for the Flood Peak Stage and Flood Travel Time by Hydraulic Flood Routing

  • Yoon, Yong-Nam;Park, Moo-Jong
    • Korean Journal of Hydrosciences
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    • v.4
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    • pp.11-19
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    • 1993
  • The peak flood discharge at a downstream station and the flood travel time between a pair of dams due to a specific flood release from the upper reservoir are computed using a hydraulic river channel routing method. The study covered the whole large reservoir system in the Han River, Korea. The computed flood discharges and the travel times between dams were correlated with the duration and the magnitude of flood release rate at the upstream reservoir, and hence a multiple regression model is proposed for each river reach between a pair of dams. The peak flood discharge at a downstream location can be converted to the peak flood stage by a rating curve. Hence, the proposed regression model could be used to forecast the peak flood stage at a downstream location and the flood travel time between dams using the information on the flood travel time, release rate and duration from the upper dam.

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Effects of multiple dam projects on river ecology and climate change: Çoruh River Basin, Turkey

  • Aras, Egemen
    • Advances in environmental research
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    • v.7 no.2
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    • pp.121-138
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    • 2018
  • Depending on the increased energy needs, a large number of dams have been built around the world. These dams have significant impacts on river ecology and climate change. When the climate change scenarios are examined, it is stated that the annual average temperature in Turkey will increase by 2.5-4 degrees in the future years, the south of the country will be opposed to the severe drought threat, and the northern regions will have a flood risk. In particular, it can be predicted that many dams and dam lakes built in the North of Turkey may increase the impact of climate change. In this study, the effects of the dams constructed in Çoruh basin on climate change are examined. Environmental and ecological problems of dam reservoirs have been examined. As a result of the data received from meteorological stations, it was determined that temperature and rainfall changes in the region. In this direction, solution proposal is presented.

Anhui Water Resource Situation and General Plan

  • Yiqun, Hou
    • Proceedings of the Korea Water Resources Association Conference
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    • 2007.05a
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    • pp.67-73
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    • 2007
  • Anhui Province, with a total north-south length of 570km and an east-west width of 450km and a total area of 139.6 thousand km2, accounts for 1.45% of China's total area. The landform and land feature of Anhui Province is diverse, and generally it can be divided into 5 natural regions: (1) Huaibei Plain; (2) Jianghuai Hillocks; (3) Dabie Mountains in the West of Anhui Province; (4) Yanjiang Plain, (5) Mountain Area of southern Anhui Province. Anhui Province is located in the transitional zone of warm and humid zone and subtropical zone, and its mean annual precipitation is 800-1800mm. The province, which has diverse climate, multiple land forms and many rivers and lakes, passes three basins (Huaihe River, Yangtze River and Xin'an River) and has large differences in the time distribution and regional distribution of water resource. Therefore, the development and usage conditions of the water resource in different regions are different.

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