• Title/Summary/Keyword: river basin

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A Stochastic Analysis of the Water Quality with Discharge Variation in Upper Nakdong River Basin (낙동강 상류 유역에서의 유량변동에 따른 수질의 통계학적 분석)

  • Choi, Hyun Gu;Han, Kun Yeun;Choi, Seung Yong
    • Journal of Environmental Impact Assessment
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    • v.20 no.6
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    • pp.833-843
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    • 2011
  • The purpose of this study is to analysis pollutant loading of upper Nakdong River basin according to the variation of discharge. The correlation between discharge and pollutant concentration and between discharge and pollutant loading were analyzed by statistical method, respectively. Regression equation of pollutant loading and discharge was represented as $L=_aQ^b$ in which L = pollutant loading(kg/day), and b = regression coefficients, and Q = discharge($m^3/day$). The correlation coefficient of study area was in range of 0.8428 to 0.9935. The SS was the highest b value 1.2856~1.7730 among water quality parameters because the pollutant loading of SS was much affected by flow. Additionally, the applicability of the regression equations was verified by comparing predicted results with observed value. The correlation coefficient of verification was in range of 0.8983 to 0.9987 and NSEC was in range of 0.7018 to 0.9960. Therefore the pollutant loading was good correlated with discharge. The main result will be used as basic data for water quality management and design of environment fundamental facilities.

The Analysis of Soil Seed Bank at Major Wetlands in Nakdong River Basin and Central Korea (낙동강 일대와 중부 지역 주요 습지의 토양종자은행 분석)

  • Ju, Eun Jeong;Kim, Jae Geun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.77-91
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    • 2009
  • The purpose of this study is to define the species composition of the soil seed banks at major wetlands in Nakdong river basin and central korea and to investigate how soil seed banks relate to aboveground vegetation and soil texture. In 2005, we sampled seed banks at Baksil reservoir, Jillal marsh, Deapyeng marsh, Hwapo marsh, Upo marsh and Junam reservoir in Nakdong river basin and Osan stream and Amsa-dong in Seoul. The soil seeds were estimated with the emergence method from April to October. Total numbers of species at the seed banks were 33 at Baksil, 18 at Daepyeong, 35 at Jillal, 56 at Upo, 32 at Hwapo, 47 at Osan stream, 54 at Amsa waterside, 31 at Amsa meadow. The species diversity in the soil seed banks of Upo marsh was the highest as 0.95. The community overlap index that compares aboveground with underground vegetation is high in the Upo marsh (0.34), Jilla marsh (0.36), and Osan stream (0.27). Soil texture affected distribution of 8 species, Lindernia procumbens, L. attenuata, Arenaria serpyllifolia, Juncus effusus, Persicaria thunbergii, Eragrostis multicaulis, Cyperus nipponicus, Scirpus fluviatilis. Considering the social and cultural values, soils at Amsa meadow, Hwapo marsh and Osan stream have worth to use for wetland restoration.

An improvement on the concrete exothermic models considering self-temperature duration

  • Zhu, Zhenyang;Chen, Weimin;Qiang, Sheng;Zhang, Guoxin;Liu, Youzhi
    • Computers and Concrete
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    • v.19 no.6
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    • pp.659-666
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    • 2017
  • Based on the Arrhenius equations, several hydration exothermic models that precisely calculate the influence of concrete's self-temperature duration on its hydration exothermic rate have been presented. However, the models' convergence is difficult to achieve when applied to engineering projects, especially when the activation energy of the Arrhenius equation is precisely considered. Thus, the models' convergence performance should be improved. To solve this problem and apply the model to engineering projects, the relationship between fast iteration and proper expression forms of the adiabatic temperature rise, the coupling relationship between the pipe-cooling and hydration exothermic models, and the influence of concrete's self-temperature duration on its mechanical properties were studied. Based on these results, the rapid convergence of the hydration exothermic model and its coupling with pipe-cooling models were achieved. The calculation results for a particular engineering project show that the improved concrete hydration exothermic model and the corresponding mechanical model can be suitably applied to engineering projects.

Hydrological Drought Assessment of Agricultural Reservoirs based on SWSI in Geum River Basin (SWSI에 기반한 금강권역 농업용 저수지의 수문학적 가뭄평가)

  • Ahn, So-Ra;Park, Jong-Yoon;Jung, In-Kyun;Na, Sang-Jin;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.51 no.5
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    • pp.35-49
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    • 2009
  • This study proposes a method to evaluate agricultural reservoirs drought by modifying SWSI (Surface Water Supply Index). The method was applied to Geum river basin and the results were represented as spatially distributed information. The SWSI evaluates hydrological drought of watershed unit by selectively applying one or all of the components of snowpack, precipitation, streamflow and reservoir storage. South Korea has 22 % of agricultural area, and rice paddy covers 64 % among them. Usually paddy fields scattered along stream are irrigated by so many small agricultural reservoirs. It is difficult to evaluate agriculture drought by the little information and large number of agricultural reservoirs. In this study, seven agricultural reservoirs over 10 million ton storage capacity were selected in Geum river basin, and the SWSI was evaluated for both upstream and downstream of the reservoirs using 16 years data (1991-2006). Using the results, multiple regression analyses with precipitation and reservoir storage as variables were conducted and the equations were applied to other watersheds. The spatial results by applying regression equations showed that the severe and moderate drought conditions of July and September in 1994, June in 1995, and May in 2001 were well expressed by the watershed unit.

The Outline of Han River Basin Environmental master Plan Project (한강유역 환경보전 종합계획 사업의 개요)

  • 이선환
    • Journal of the Korean Professional Engineers Association
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    • v.15 no.1
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    • pp.46-50
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    • 1982
  • Following rapid industrial development and urbanization in Korea, there is a need for the Government to implement effective control of pollution and to undertake specific schemes in areas where pollution of the environment is severe. In response to this need, Government of Korea prepare Han River Basin Environmental Master Plan Project for water, air, solid waste to cover environmental protection of the Han River Basin. The Project area is approximately 27,000 sq. Km extending over Seoul, Kyunggi, Kwangwon, Chungbuk Province. The total population of Master Plan Project area is approximately 11.6 million, or one-third of the total population of Korea. There are about 8,000 industries, including those located in 16 industrial complexes, in the project area. The scope of work and terms of reference are the following: (1) A Summary of existing land use and forecasts for changes in land use by the year 2,000. (2) Emission inventories for air, waste water, and solid wastes. (3) Forecasts of future population growth patterns and pollution loadings. (4) Identification of specific projects needs to reduce pollution levels and satisfy the environmental quality standards. (5) A Program of enforcement to include (i) self monitoring, and (ii) governmental inspections and surveillance. (6) A program for quality improvement and quality assurance of environmental measurements. (7) Reports summarizing all data collected analyzed during the study. (8) Conceptual design and feasibility studies, including cost estimates, for needed pollution control projects. (9) A financial plan for future detailed design and construction of public facilities, for financial incentives to industry, and for user charges for industrial use of public treatment of disposal works.

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Analysis of the Crop Damage Area Related to Flood by Climate Change Using a Constrained Multiple Linear Regression Model (구속 다중선형회귀 모형을 이용한 기후변화에 따른 농작물 홍수 피해 면적 분석)

  • Kim, Myojeong;Kim, Gwangseob
    • Journal of The Korean Society of Agricultural Engineers
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    • v.62 no.2
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    • pp.1-15
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    • 2020
  • In this study, the characteristics of crop damage area by flooding for 113 middle range watersheds during 2000-2016 were analyzed and future crop damage area by flooding were analyzed using 13 GCM outputs such as hourly maximum rainfall, 10-min maximum rainfall, number of days of 80 mm/day, daily rainfall maximum, annual rainfall amount associated with RCP 4.5 and RCP 8.5 scenarios and watershed characteristic data such as DEM, urbanization ratio, population density, asset density, road improvement ratio, river improvement ratio, drainage system improvement ratio, pumping capacity, detention basin capacity, and crop damage area by flooding. A constrained multiple linear regression model was used to construct the relationships between the crop damage area by flooding and other variables. Future flood index related to crop damage may mainly increase in the Mankyung watershed, Southwest part of Youngsan and Sumjin river basin and Southern part of Nackdong river basin. Results are useful to identify watersheds which need to establish strategies for responding to future flood damage.

A Study on the Flood Quota and Trading System (홍수량 할당과 거래제도에 관한 연구)

  • Kim, Dong Yeub;Choi, Young Jun
    • Environmental and Resource Economics Review
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    • v.15 no.5
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    • pp.939-959
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    • 2006
  • This paper studies the introduction of flood quota system for efficient flood prevention. In the present system where local governments decide its flood prevention independently, the optimal flood prevention in a river basin can not be achieved. Thus, the flood quota system is necessary. In deciding the flood quota for each local government in a river basin, its social and economic characteristics as well as geographical feature of the area should be considered. In order to promote the cooperation among local governments in a river basin, the flood quota is necessary to be accompanied with the trading system of the quota.

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Sustainability Evaluation of Western Nakdong River Basin by the Systems Ecology (시스템 생태학적 접근법에 의한 서낙동강 유역의 지속성 평가)

  • Kim, Jin Lee;Park, Bae Kyung;Lee, Su Woong;Rhew, Doug Hee
    • Journal of Korean Society on Water Environment
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    • v.26 no.3
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    • pp.439-445
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    • 2010
  • An emergy analysis of the main energy flows driving the economy of humans and life support systems consists of environmental energies, fuels, and imports, all expressed as solar emjoules. Total emergy use (371 E20 sej/yr) of the Western Nakdong River Basin is 97 per cent from imported sources, fuels and goods and services. Emergy flows from the environment such as rain and geological uplift flux accounted for only 2.9 percent of total emergy use. Emergy yield ratio and environment loading ratio were 1.03 and 33.27, respectively. Emergy sustainability index, a ratio of emergy yield ratio to environment loading ratio, is therefore less than one, which is indicative of highly developed consumer oriented economies. It is necessary for an efficient management of Western Nakdong River Basin to reduce pollution load basically and to restructure economic activities into an environmental friendly industrial structure depending on renewable energy and resources.

Quantification of Storm Direction for a River Basin (하천유역에 대한 호우 방향성의 정량화)

  • Park, Chang-Yeol;Yoo, Chul-Sang
    • Journal of the Korean Society of Hazard Mitigation
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    • v.10 no.6
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    • pp.109-117
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    • 2010
  • This study quantified the storm direction for a river basin by applying the von Mises distribution, also determined the representative storm direction. Additionally, the whole procedure was repeated for several storm types such as frontal, typhoon and convective storms for their comparison. From the results derived by analyzing a total of 101 storm events for the Naesung river basin, the von Mises distribution was found to explain the directional characteristics of storms. The representative moving directions derived for three different storm types were significantly different each other, which is coincident with the climate of Korea. The results derived in this study could be helpful to estimate more quantitatively the difference in the runoff response with respect to the moving direction of a storm.

The Characteristics of the Cultural Tourism Resources Distribution along the Nakdong River Basin

  • Yhang, Wii-Joo
    • Journal of Environmental Science International
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    • v.12 no.8
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    • pp.835-840
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    • 2003
  • Many various kinds of tourism resources have been distributed along the Nakdong river basin. Previous researches have focused mainly on environmental studies, including water quality control, industrial use of water, biodiversity, etc, with little research done in the field of tourism studies. Central to this study, therefore, is the identification and analysis, from the perspective of cultural tourism, of the area's distribution and characteristics of cultural properties registered by the MOCT. Review of related literature reveals : 1) spatial range bound with the jurisdiction of the river basin like DREO and NRBEO ; 2) analytical subjects limited to cultural properties designated by the three different administrative units of government, city and province. Along with the DREO's predominance over the NRBEO in the total number of cultural properties, the result finds that two cities, Andong and Gyeongju of Gyeongbuk are assigned ownership of most of the cultural properties under the jurisdiction of DREO, while Gyeongnam that of most of the ones under the NRBEO. However, those findings suggest the simple number of cultural properties with no significant level of importance and rarity value reflected. Therefore, future studies need to develop quantified modelling keeping cultural variables in mind and create cultural indices of the competitiveness of the local governments.