• Title/Summary/Keyword: Stream ecology

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Strategic Prospects of Environmental Restoration of Stream Side in Japan(III) - With a Special Reference to the Forest Road, Forest Conservation and Erosion Control - (일본(日本)에서 계류변(溪流邊)의 환경복원(環境復元) 발전전략(發展戰略)(III) - 임도(林道) 및 치산(治山)·사방(砂防)을 중심(中心)으로 -)

  • Park, Jae-Hyeon;Woo, Bo-Myeong;Lee, Heon-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.3 no.3
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    • pp.113-125
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    • 2000
  • This study was carried out to introduce current status and development strategy for an environmental restoration of stream side in Japan, and to consider a methodology which could be effectively applied for the environmental restoration of stream side in Korea. The strategy prospects of environmental restoration in Japan were summarized as follows : 1. When we establish the long term erosion control planning, we should make detail planning after considering of a certain block of watershed units. Because most of the disaster is caused by soil movement which was occurred by water contents. 2. Nowadays, the general torrent erosion control planning system in Japan focused on reducing the sediment such as by placement of erosion control facility and by restoration of afforestation, after calculation of several factors including expected amount of sediment, and the different amount of planned sediment and allowable sediment. 3. In the past, the goal of forest conservation and erosion control planing was to fix the amount of soil movement by construction of permanent facilities. While, the goal of forest conservation and erosion control planning in the future needs to change the techniques to a small and middle scale's soil movement which could prevent soil movement from large scale of soil disasters, but allow soil movement effectively. Also, it is considered to change erosion control dams from non passing type to passing type. 4. Restoration of stream-side ecology, erosion control for the conservation of ecology should be planned and conducted cautiously based on concepts of ecology conservation and development of environmentally sound techniques.

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Analysis of the Changes of the Vegetated Area in an Unregulated River and Their Underlying Causes: A Case Study on the Naeseong Stream

  • Lee, Chanjoo;Kim, Donggu
    • Ecology and Resilient Infrastructure
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    • v.5 no.4
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    • pp.229-245
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    • 2018
  • This study aims to investigate the changes in the riparian vegetated area in the Naeseong stream, an unregulated river, in order to analyze the main factors leading to these changes. For this purpose, the land surface cover in the channel area of the Naeseong stream was classified into 9 categories using past aerial photographs collected between 1970 and 2016, which recorded the long-term changes of the Naeseong stream. The increase or decrease in the vegetated area was calculated for each category using a pair of before and after images. The changes in the vegetated area were divided into 6 periods: the unvegetated channel period (1970 - 1980), the first rapid increase (1980 - 1986), the period of decrease due to flood (1986 - 1988), the period of repetitive man-induced disturbance and vegetation increase (1988 - 2008), the period of gradual vegetation increase (2008 - 2013), and the period of second rapid increase (2013 - 2016). Multiple regression analysis was performed using independent variables representing hydrology, climate, and geomorphology. The major variables found to be involved in the changes in the vegetated area of the Naeseong stream were the discharge during June - July, channel width, and temperature during April - June. Among the three variables, discharge and temperature were respectively the main independent variables in the downstream and the upstream reaches as per a single variable model. Channel width was the variable that distinguished the upstream and downstream reaches of the stream. The implication of the long-term increase in the vegetated area in the Naeseong stream was discussed based on the result of this study.

Characteristics of Spatiotemporal Patterns in Benthic Macroinvertebrate Communities in Two Adjacent Headwater Streams (두 인접한 산림 하천에서 저서성 대형무척추동물 군집의 시공간적 특성 분석)

  • Lee, Da-Yeong;Bae, Mi-Jung;Kwon, Yong-Su;Park, Chan-Woo;Yang, Hee Moon;Shin, Yujin;Kwon, Tae-Sung;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.51 no.2
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    • pp.192-203
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    • 2018
  • Headwater streams provide various microhabitats, resulting in high diversity of macroinvertebrate community. In this study, we compared the differences of communities between two adjacent headwater streams (Jangjeon stream (GRJ; GRJ1-GRJ5) and Haanmi stream (GRH; GRH1-GRH3)) in Jungwang and Gariwang mountains, Gangwon-do and evaluated the effects of habitat condition to the macroinvertebrates community composition. In order to characterize the macroinvertebrate communities and extract influential environmental factors, we applied to Cluster analysis (CA), Indicator species analysis and Non-metric multidimensional scaling (NMDS). Total 33,613 individuals in 3 phyla, 5 classes, 13 orders, 51 families, and 114 taxa (genera or species) were collected. Gammarus sp. was dominant at the upper stream of GRJ, whereas Chironomidae spp. was abundant at GRH and the downstream of GRJ. The CA classified samples into six clusters (1-6) reflecting spatial and temporal variation of benthic macroinvertebrate communities. Benthic macroinvertebrate community composition was significantly different between two adjacent streams. Sweltsa sp. 1, Psilotreta kisoensis, Rhyacophila shikotsuensis and Serratella setigera were identified as representative indicator species for clusters 1, 2, 3 and 5, respectively. Similar to CA results, NMDS revealed the spatial and temporal differences of benthic macroinvertebrate communities, indicating the difference of community composition as well as microhabitat condition. Forest composition, proportion of boulders (>256 mm), and water velocity were main factors affecting the macroinvertebrate community composition.

The Stockpiling and Spreading of Topsoil for the Ecological Restoration of Floodplains and the Levee Slope of a Stream (하천 고수부와 제방 비탈면의 생태적 복원을 위한 표토의 집토와 부설)

  • Han, Seung-Wan;Kim, Hyoung-Joon;Chae, Byoung-Koo;Kim, Jeong-Goo
    • Ecology and Resilient Infrastructure
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    • v.2 no.1
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    • pp.99-104
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    • 2015
  • Topsoil including numerous soil seedbanks has been known to be a valuable material for ecological restoration. There is a lack of specific study for its utilization in the field of stream restoration. This study conducted a revaluation of the value of topsoil as a material for stream restoration. Furthermore, an ecological technique using topsoil was applied in an improvement project of a stream environment at the Hwanggujicheon Stream in Korea. Stockpiling and spreading topsoil was specifically applied to the revegetation of a low slope revetment and a high flow plain. The result of this application showed that topsoil played an integral role in eco-friendly restoration in terms of ecological, flood control, economic, and constructional aspects. In conclusion, this study's findings suggest that topsoil is a suitable candidate material for stream restoration.