• Title/Summary/Keyword: small stream

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A Study on Improvement of the Small Stream Management Project (around Small stream maintenance Act) (소하천 정비사업의 개선방안 -소하천정비법을 중심으로-)

  • KONG, Rakyong
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.3
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    • pp.841-852
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    • 2015
  • The objectives of this study are to amend of the Small Stream Maintenance Act. In general, small streams have diverse ecological and social characteristics because they are extensively formed across watersheds over time. However, small streams in Korea have been significantly degraded primarily because of human disturbances including stream maintenance activities. Especially, covered streams are majority problem in the Small Stream Maintenance. In order to improve this problem, the Small Stream Maintenance Act be amended to the Small Stream Management Act.

An Analytical Study of Foreign Researches and Examples on Ecological Restoration for the Small Stream (샛강 생태복원을 위한 해외 사례 연구의 고찰)

  • Kwon, Tae-Ho;Park, Jae-Hyeon;Kim, Dong-Wook
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.5
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    • pp.26-37
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    • 2004
  • Most domestic small rivers and streams due to industrialization and urbanization have managed by concrete structures. The environmental functions of the river and stream are disappearing and urban streams play only the role of drainage systems. Also, the researches to restore natural streams are something yet to develop and not established the restoration for ecological functions of a small stream. Therefore the researches are required to develop ecological engineering system for watershed management system to handle various pollutants with restoration for ecological functions of a small stream. To develop this, the ecological engineering system for watershed management system could be developed with ecological conservation. In addition, ecological engineering system for watershed management system should be prior to conserve the habitat of biological resources and water conservation and applied to the original shape of streams. Also, it should be designed to restore the micro-topography of stream, the habitat of plant population in watershed. It is needed to develop the integrated researches to restore a small stream ecosystem.

Study on Guideline for the Selection of Small Stream Implementation Projects (소하천정비사업 우선순위 선정기준에 관한 연구)

  • Cheong, Tae-Sung;Kang, Byung-Hwa;Jeong, Sang-Man
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.2
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    • pp.163-170
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    • 2011
  • Natural stream disasters due to a localized torrential and flash flood has occurring in a small stream especially un-implemented small stream. The survey results during ten years from 2001 to 2010 show that the small stream implementation projects (SSIPs) expenses is increasing with the damages is generally decreasing with variableness in which SSIPs is contributing to disaster prevention in a small stream. This study develop guideline for the selection of SSIPs to support high risk stream at first and save the small streams located on the mountainous area, prevention area and agricultural area which streams have no implementation effects. Developed sub items in guideline are evaluated by stream data collected from 212 small streams where it is proved that sub distance of each item are well arranged by normal distribution. This SSIPs is useful for selecting high risk small stream at first to maximize disaster risk reduction with minimum SSIPs expenses. Also, this SSIPs is used for leading to save small stream on the upstream to minimize flood damages on the down stream with selection a SSIP purchasing agricultural land for preparing flood plane.

The development of design-width prediction equation by using 12 local governments data collected from small stream of Korea (국내 12개 시·도 자료를 이용한 소하천 계획하폭 산정식 개발)

  • Choi, Changwon;Cheong, Tae Sung
    • Journal of Korea Water Resources Association
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    • v.56 no.3
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    • pp.185-194
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    • 2023
  • There are more than 22,300 small streams distributed nationwide in Korea, and they have various runoff characteristics depending on basin area, topography and land use. For small stream disaster management, establishing detailed design standards suitable for the small streams is important, but most of the formulas currently proposed in the small stream design standard are based on the river design standard aimed at national and local rivers or foreign river design standards. The design-width is an important factor in determining the size of the stream. It is determined by using design-flood discharges or more variables such as design-flood discharges, basin area, slop, etc in the small stream design standard. This study collected various characteristics information such as the design-flood discharges, basin area, river length and river slop, and design-width values from 4,073 small streams distributed in 12 cities and provinces in Korea to suggest the appropriated design-width formula. This study developed two design-width formulas by using the regression analysis which one is using the design-flood discharges and the other is using various variables such as the design-flood discharges, basin area, river length and river slope collected from the small steams. It is expected that both equations developed in here can be used for small stream disaster management, such as improving small stream design standard or establishing a comprehensive small stream maintenance plan.

Stream Eco-corridor Restoration by Out-aged Small Dam Removal - Focused on Gokreung River Gokreung 2 Small Dam Removal - (기능을 상실한 보 철거를 통한 하천생태통로 복원 - 곡릉천 곡릉2보 철거를 대상으로 -)

  • Ahn, Hong Kyu;Woo, Hyoseop;Rhee, Dong Seop;Kim, Kyu Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.2
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    • pp.40-54
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    • 2008
  • Small and large dams are installed in the course of a stream for maintaining the water level of the stream or obtaining agricultural water. Currently about 18,000 of them are installed in Korea to supply water. However, the environmental problems of small dams are well known : the interruption of stream eco-corridors, deterioration of water quality in the upper reaches of the small dam, changes in the habitats of riparian organisms, damages to the stream scenery. In a very few of these small dams artificial eco-corridors like fishways are installed, but the number is very minimal.Accordingly, to efficiently restore stream eco-corridors by removing these small dams, it will be necessary to closely examine physical impacts, such as changes in the riverbed and changes in the shape of the stream caused by the removal, chemical impacts, such as changes in water quality, and transport and accumulation of contaminated sediments and biological impacts, such as changes in the habitats of organisms, and develop related technologies in advance, and have these technologies verified through demonstration application in the sites. In this study, we analyzed the physical, chemical and ecological impacts of the removal of the above-mentioned small dams, and conducted a research on the demonstration small dam removal project for a spot investigation. As a result, the small dam removal will restore the eco-corridor, there by improving the habitat of fishes and crustaceans. The number of major underwater organisms inhabiting the Gokreungcheon, such as Korean spotted sleepers, Chinese minnows, Microphysogobio yaluensis, Abbottina rivularis, stone morokos, striped shinners, long-nosed barbels, and Chinese mitten crabs, is expected to increase, and the food chain in the ecosystem will improve so that species diversity will improve as well.

Water Quality Management Plan through Mass Balance at Small Urban Stream (중.소 도시하천의 물질수지를 통한 수질관리 방안 도출)

  • Oh, Jong-Min;Shin, Dong-Hwan;Choi, I-Song
    • Journal of the Korean Society of Hazard Mitigation
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    • v.4 no.1 s.12
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    • pp.51-56
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    • 2004
  • In this study, the variation of water quality in Osan stream was investigated through continuous monitoring, and mass balance and metabolism occurred into water body were estimated to set up effective management plan for water quality of small urban stream. From the results of continuos investigation of water quality in Osan stream, the things written as follows must be previously done to improve water quality of main stream. Firstly, it need that effective management plan for tributaries must be set up to improve the water quality in main stream. Secondly, the counter plan for re-eruption of pollutants from sediment in main-stream is required to prevent inner pollution. In this study, we showed that small urban stream can be managed effectively by simple investigation to prevent deterioration of water quality. Therefore continuous monitoring for water quality in stream is important to improve water quality, furthermore matter cycle and mass balance happening in the stream environment must be correctly estimated to make up healthy stream environment.

Vegetation survey in nature-friendly small streams for each protection method (자연형 소하천의 호안공법별 식생분포 조사)

  • Lee, Kang-Suk;Park, Jin-Ki;Yeon, Gyu-Bang;Park, Jong-Hwa
    • Korean Journal of Agricultural Science
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    • v.38 no.2
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    • pp.315-324
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    • 2011
  • Riparian vegetation distribution patterns and diversity relative to various fluvial geomorphic channel patterns, stream bank stabilization methods, and stream flow processes are described and interpreted for selected nature-friendly small stream bank protection of Goesan, central Korea. Idong Stream Pilot Project, which began in May 2003 and finished in December 2003, was selected to develop effective methods which was nature-friendly stream bank protection. The project aim to maintain or increase stream bank stabilization ecosystem goods and services while protecting downstream and stream bank ecosystem. A number of protecting methods which were a Flight of fieldstone, Vegetation block, Green river block, Stone net, Green environment block, Eco friendly cobble, Vegetation mat and Geo-green cell and Firefly block were applied on the bank of Idong stream. The stream sites have been monitored about vegetation conditions each method in 2007. We selected six points to separately investigate in left and right bank. The main purpose of this study was to find out suitable methods and to improve stream restoration techniques for ecosystem. On the stream bank, H environment block method (9.7) was the highest average of vegetation coverage and Firefly block method (3.87) was the lowest average in applied methods.

Temporal and Spatial Analysis of Hydrology and Water Quality in Small Rural Streams for Stream Depletion Investigation (건천화된 농촌소하천의 시·공간적 수문 수질 특성분석)

  • Lee, Ye Eun;Kim, Sang Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.55 no.6
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    • pp.177-186
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    • 2013
  • The purpose of this study was to analyze the temporal and spatial characteristics of the stream flow of small rural streams for investigating the status of stream depletion located downstream of irrigation reservoir. Bonghyun and Hai reservoirs and each downstream were selected for this study. Streamflow was measured for 8 stations downstream from two reservoirs from 2010 to 2012. The water quality samples were collected monthly from the 8 stream stations and 2 reservoir stations from 2011 to 2012. The stream depletion was found in most of the downstream of reservoirs for the non-irrigation period and even in the irrigation period when there were a lot of antecedent precipitation. We found that the stream segments where there were few streamflow, vegetation covers the stream and block the streamflow which makes the stream lost its original function as a stream. Water quality monitoring results of Bonghyun stream indicated that the concentration of SS, Turbidity, TOC, COD were decreased as the stream flows from the reservoir to downstream while the TN and TP were increased. The correlation analysis for water quality data indicated that the correlation between T-N and T-P was high for Bonghyeon and Sukji streams, respectively. Continuous monitoring for rural streams located in downstream of reservoirs are required to quantify the status of stream flow depletion and determine the amount of environmental flows.

Comparison of Water Resources by Kajiyama and SWAT models for an Ungauged Small Watershed (미계측 소유역의 수자원량 산정을 위한 가지야마 공식과 SWAT모형의 비교 분석)

  • Kim, Ki-Cheol;Shin, Min-Hwan;Choi, Yong-Hun;Seo, Ji-Yeon;Choi, Joong-Dae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.2244-2248
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    • 2008
  • This study was focused on estimated Stream Maintenance Flow and performed for simulate securing Stream Maintenance Flow in New town development area. Tributary streams were made of 6 small streams, joined Gong-ji Stream and Eu-am lake finally. For estimate Stream Maintenance Flow used Kajiyama and SWAT models for calculate available flow in study area. As a result the annual average stream flow dry years were $2,300{\sim}136,000\;m^/day3$, the annual average stream flow wet years were $4,800{\sim}136,031\;m^3/day$. The coefficient of determination($R^2$) and Nash-sutcliffe coefficient(EI) for comparison between Kajiyama and SWAT models were 0.88, 0.78 respectively.

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A Study on the Reduction of Viscous Frictional Force with Uniform Pressure Distribution in the Turbulent Boundary Layer (균일(均一) 압력(壓力) 분포(分布)에 의(依)한 난류(亂流) 경계층내(境界層內) 결성(結性) 마찰력(摩擦力)의 감소화(減小化)에 관한 연구(硏究))

  • Sung, Du-Nam;Kim, Si-Young
    • Journal of Fisheries and Marine Sciences Education
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    • v.9 no.1
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    • pp.40-48
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    • 1997
  • In this study, uniform pressure distribution with small hole on the surface of symmetric object were given to reduce the viscous frictional force. The results were as follows : 1. The velocity on upper stream were accelerated by uniform pressure distribution on symmetric objects for reducing the viscous frictional resistances. 2. The effects of the distributed small holes were reduced the viscous frictional resistances in down stream region more than upper stream due to the increasing pressure in reverse flow region. 3. The viscous skin friction on surface of symmetric objects with and without distributed small holes are effect in region of upper stream and much decreased in down stream region due to increasing of boundary layer thickness.

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