• Title/Summary/Keyword: 하천 복원

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Development of the GIS-based Stream Hydromorphological Structure Assessment System for Small and Midium-size Streams (GIS 기반 중·소규모 하천의 수문지형 물리적 구조 평가 체계 개발)

  • Kim, Man-Kyu;Kim, Hye-Ju;Park, Jong-Chul
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.2
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    • pp.93-107
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    • 2008
  • Recently, there have been many projects regarding restoration of streams to recover their environmental and ecological functions. For the restoration of streams, it is valuable academically and economically to evaluate the ecological condition of streams and build a plan and an object for restoring streams based on that. On the other hand, one of the methods to figure out the ecological condition of streams is to evaluate the hydromorphological structure of stream. In this study we have developed a field survey system using the stream assessment methode of LAWA (Laenderarbeitsgemeinschaft Wasser in Germany) that can assess the hydromorphological structure of small and medium streams. In addition, we constructed a GIS-based stream assesment system which can support auto mapping system and report writing, using the survey results. These systems are aimed to help people in the area of restoring streams perceive the natural and ecological condition of streams in the process of making plans and managing the projects, and they also try to help in collecting raw data to determine an ideal potential model to which an existing stream should be turned.

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Stream Corridor Ecological Restoration by Small Dam Removal - Removals of Gongreung2 & Gotan Small Dams in Korea - (보 철거를 통한 하천 생물이동통로의 생태적 복원)

  • Ahn, Hong-Kyu;Kim, Si-Nae;Woo, Hyo-Seop
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.171-184
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    • 2012
  • 하천 수위를 유지하거나 농업용수를 취수 할 목적으로 조성되는 크고 작은 보는 용수공급 시설로 이용되고 있으나, 하천 생물이동의 차단, 보 상류부의 수질악화, 수변 생물서식처의 변화, 하천경관 훼손과 같은 환경적 문제를 초래하고 있다. 더욱이 도시화가 진행됨에 따라 토지이용의 변화, 시설의 노후화 등으로 매년 50~150개 정도의 보가 폐기되고 있는 현실이다. 본 연구는 하천에 설치되었으나 용도와 기능이 상실된 보를 철거하여 생태적 연속성을 확보하고 하천 본래의 모습으로 되돌려 주며, 하천의 생태적 건강성을 회복 및 향상 시키고자 하였다. 보 철거 시범사업으로 공릉천에 설치된 길이 76m, 높이 1.5m의 공릉2보와, 한탄강에 설치된 길이 190m, 높이 2.8m의 고탄보를 철거하였고, 각 시범사업 대상지의 물리/화학/생태특성 모니터링 분석을 수행하였다. 그 결과 철거 직후 보의 직 상류부에 전체적으로 침식이 발생하고, 보 하류부는 여울, 하중도, 사주, 침식 등 다양한 지형으로 변모되었다. 본 연구를 통하여 하천복원의 취지에 맞는 하천 본래의 모습에 가까운 하천으로 복원하기 위해서는 기능 및 용도가 상실된 보의 경우는 기존의 보체를 개량하거나 어도를 설치하여 주는 것 보다 구조물 자체의 완전철거를 통한 생물 이동통로 조성이 바람직하다고 판단된다.

Evaluation of River Flood Stability after River Restoration (하천 복원 후의 홍수위 안정성 검토)

  • Kim, Byeong-Chan;Lee, Jong-Seok
    • The Journal of the Korea Contents Association
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    • v.9 no.10
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    • pp.417-426
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    • 2009
  • The eco-friendly river restoration issue has been increased and the importance of the vegetation along the river banks has been understood with its scenery and significant role. However vegetation reduces the stream flow cross section and brings negative effects such as increase of water flow resistance and decreases of river flow velocity. In this study, the method to choose roughness coefficient is studied in the sudden changed hydraulic characteristics by river restoration. Using the HEC-RAS model and the two-dimensional vertical analysis method, Yangjae stream was calculated that the roughness coefficient of the main channel is 0.011~0.159 after river restoration, 0.031 without vegetation on the flood plain, and 0.034~0.506 with vegetation on the flood plain. The level of water in the river is predicted to rise 0.13~0.34m at 30% of vegetation density increase.

An Ecological Restoration of Urban Streams by Supplying Maintenance Water (도시하천의 유지용수 공급에 따른 생태복원)

  • Cho, Hong Je;Lee, Su Ji
    • Journal of Wetlands Research
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    • v.15 no.3
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    • pp.317-328
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    • 2013
  • The aim of this study is to compare the effects of the maintenance water supply methods on the ecological restoration of 5 urban streams such as Mugeo cheon, Yaksa cheon, Yeocheon cheon, Myeongjeong cheon and Cheokgwa cheon in Ulsan metropolitan city. Water quality of the streams have been innovatively improved and the ecosystems have gradually been restored by supplying maintenance water constantly. However, we found that if the maintenance water was in a state of higher salinity or low quality, even enough supply was not helpful and even harmful for ecological restoration. We confirmed that the most important things to create or maintain from the urban stream to the ecological stream are that facilities like a walkway construction should be installed at least, supplying appropriate maintenance water, and a connection with the main stream.

Changes in Riparian Vegetation After Restoration in a Urban Stream, Yangjae Stream (도시 하천 양재천에서 복원후 하안식생의 변화)

  • Cho, Hyung-Jin;Woo, Hyoseop;Lee, Jinwon;Cho, Kang-Hyun
    • Journal of Wetlands Research
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    • v.10 no.3
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    • pp.111-124
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    • 2008
  • The changes in flora and distribution and structure of vegetation were monitored for seven years at a restored reach of an urban stream, the Yangjae Stream, southeast of Seoul, Korea. In the restored reach, diverse kinds of the close-to-nature stream restoration techniques were adapted and implemented in the winter of 1998-1999. The species numbers and diversity indices of riparian plants at the restored reach were higher than those at the unrestored reach seven years after the restoration implementation. But plant diversity was decreased from the early restoration stage of 1999 - 2001 to seven years after the implementation. The dominant species changed from a ruderal annual, Humulus japonicus, to a perennial, Phragmites australis. The floral structure was distinctly different between in the early stage and seven years later on the results of principal component analysis (PCA) because of decreasing in numbers of exotic or ruderal species and planted or introduced plants in newly disturbed habitats. The distribution areas of communities of Humulus japonicus and Erigeron annuus were decreased and those of communities Phragmites australis and Miscanthus sacchariflorus were increased after the restoration implementation. The results of detrended correspondence analysis (DCA) of plant communities revealed that the community structure were changed from the disturbed vegetations to the stable and natural vegetation after the restoration implementation. Total seven species of willows were found at the restored reach, of which two species were planted and the others were naturally introduced. The monitoring results showed that the stream ecosystem of the study reach were successfully recovered in flora and vegetation and could be used as a model site for the stream restoration in urban streams.

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Research on the method used to select an adequate rehabilitation plan for Natural River based on the river's degree of naturalness (하천자연도를 이용한 자연형하천 대안 선정기법)

  • Cho, Hong-Je;Yoon, Jong-Chun
    • Journal of Wetlands Research
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    • v.11 no.3
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    • pp.71-80
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    • 2009
  • Due to the various characteristics of urban river, rehabilitation project for natural river requires distinct alternative approach and selection method for each different types of river. In this study, naturalness of a river was used to establish such alternative for the business and rehabilitation plan for natural river. To assess the naturalness of a river, through AHP, designed to fit the environmental conditions in Korea, was employed. Furthermore, a method that conveniently compares and selects an alternative for rehabilitation plan for natural river by referencing Urban River Basin Enhancement Methods (URBEM) was proposed. After selecting the evaluation items for assessing the naturalness of the river based on the characteristics of the river, multiple alternatives were constructed and the naturalness of river for each of those alternatives were estimated. Comparing the estimated values has made the measurement of the natural recovery effect and the product of river rehabilitation plan for each alternative efficient. In conclusion, selecting the items for evaluating the naturalness of a river with respect to its characteristics was found to be effective for establishing the rehabilitation plan for natural river.

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Vegetation Recruitment and Restoration of a Gravel Bar in Tama River (다마천(多摩川)자갈사주의 식생이입 및 복원 과정)

  • Kim, Jin-Hong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.196-196
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    • 2011
  • 본 연구에서는 일본 다마천 자갈사주의 식생 이입 과정을 조사하고, 과도한 식생 이입에 영향을 미치는 하상토의 특성과 수리적 특성을 분석하여 자갈사주의 복원을 위한 방안에 관하여 조사하였다. 다마천 자갈사주는 넓게 분포하였던 자갈하천(white river)에 버드나무 등의 식생이 과다하게 성장하여(green river), 이를 억제하기 위한 대책을 수립하여 시행하였다. 또한 이곳에 서식하는 고유종(야생 국화)를 복원하기 위한 연구도 진행되었다. 다마천 자갈사주 식생번무의 원인으로, 자갈과 모래 채취, 하천 개수, 상류의 댐과 보의 축조를 들 수 있으며, 자갈사주를 복원하기 위한 종합적인 연구계획이 수립되어 사업이 시행되었다. 복원 대책으로 홍수터를 파고 모래톱 복원, 상류로부터 자갈과 모래 공급, 저수로 확장, 과다 성장한 버드나무나 아카시아 벌목, 표토 제거를 계획하였으며 이를 시행하였다. 모래톱은 성긴 조약돌로 포설하였으며, 다양한 높이로 조성하여 침수 빈도를 다양하게 변화시켰다. 가장 높은 모래톱은 5년 빈도로 하였다. 자갈사주의 복원 및 관리를 위한 모니터링 그룹도 발족하여 현재 자갈사주의 복원 모니터링이 진행 중이며, 이를 바탕으로 체계적이고 계획적인 복원 사업이 진행되고 있다.

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