• Title/Summary/Keyword: RESTORED STREAM

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Evaluation of the effects of the river restoration in Hwangji Stream, the upstream reach of the Nakdong River

  • Bong Soon Lim;Jaewon Seol;Chang Seok Lee
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.85-95
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    • 2024
  • Background: In Korea, riparian zones and some floodplains have been converted into agricultural fields and urban areas. However, there are essential for maintaining biodiversity, as they are important ecological spaces. There are also very important spaces for humanity, as they perform various ecosystem services in a changing environment including climate change. Due to the importance of rivers, river restoration projects have been promoted for a long time, but their achievement has been insignificant. Development should be pursued by thoroughly evaluating the success of the restoration project. Ecological restoration is to accelerate succession, a process that a disturbed ecosystem recovers itself, with human assistance. Ecological restoration can be a test bed for testing ecological theories in the field. In this respect, ecological restoration should go beyond a 'simple landscaping exercise' and apply ecological models and theories in restoration practice. Results: The cross-section of the restored stream is far from natural rivers due to its steep slope and artificial material. The vegetation profiles of the restored streams did not reflect the flooding regime of the river. The species composition of the vegetation in the restored stream showed a significant difference from that of the reference stream, and was also different from that of an unrestored urban stream. Although species richness was high and the proportion of exotic species was low in the restored stream, the effect was offset by the high proportion of gardening and landscaping plants or obligate terrestrial plants. Conclusions: Based on both the morphological and ecological characteristics of the river, the restoration effect in the restored stream was evaluated to be very low. In order to solve the problems, a systematic adaptive management plan is urgently required. Furthermore, it is necessary to institutionalize the evaluation of restoration effects for the development of river restoration projects in the future.

Measuring the Economic Value of Restoring Hampyeong Stream Space

  • Lee, Hee-Chan;Leem, Joo-Whan;Kim, Kyu-Ho
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.292-303
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    • 2015
  • The objective of this study is to evaluate the spatial restoration of Hampyeong Stream and to analyze the determinants of demand for the multi-functionalities of the stream. A Contingent Valuation Method (CVM) was used to estimate the multi-functional public benefits of restored stream area, and major determinants were scrutinized by establishing a demand model. The research data was collected by conducting a survey intended for Hampyeong's local residents, resulting in 284 valid samples. In terms of determinants that affect willingness to pay (WTP), 'physical factor of waterfront area' and 'experience factor of stream space' showed a significantly positive influence on WTP. As a result of applying a double-bounded CVM, the willingness to pay for the restored Hampyeong Stream area indicated a potential contribution of 22,523 won (17,362~27,459 won, 95% confidence interval). When multiplying the number of households in Hampyeong-gun, the total annual value of Hampyeong Stream spatial restoration is approximately 302million won.

An Evaluation on Restoration Effect in the Restored Yangjae Stream and the Improvement Plan Based on the Result (복원된 양재천에서 복원 효과 평가 및 평가 결과에 기초한 개선방안)

  • Kim, A Reum;Kim, Dong Uk;Lim, Bong Soon;Seol, Jae Won;Lee, Chang Seok
    • Korean Journal of Ecology and Environment
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    • v.53 no.4
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    • pp.390-407
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    • 2020
  • This study was carried out to evaluate the restoration effect in the restored Yangjae stream and to draw up an adaptive management plan based on the results. As the result of evaluation on the restoration effect, the restored Yangjae stream was evaluated with low naturalness in both terms of the morphology of the stream and the composition and spatial distribution of vegetation. The diverse functional groups were introduced in the vegetation restoration, but the flooding regime, which is significant in the spatial distribution of riparian vegetation, were not correctly reflected. Exotic species or species that were not ecologically suitable for the location were introduced on the embankment and thus a measure to improve those problems is required. As the ecological principle was not reflected in the restoration plan, the stream was constructed as the double terrace structure. Therefore, the width of the waterway was narrowed further, and the waterfront was not designed to accommodate changes from flooding disturbance, making the micro-topography of the stream simpler and the naturalness lower. The adaptive management plan was prepared to improve those problems, and a plan for creating an ecological network was recommended to enhance the restoration effect.

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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Colonization and community changes in benthic macroinvertebrates in Cheonggye Stream, a restored downtown stream in Seoul, Korea

  • Shin, Il-Kwon;Yi, Hoon-Bok;Bae, Yeon-Jae
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.175-191
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    • 2011
  • Colonization patterns and community changes in benthic macroinvertebrates in the Cheonggye Stream, a functionally restored stream in downtown Seoul, Korea, were studied from November 2005 to November 2007. Benthic macroinvertebrates were quantitatively sampled 15 times from five sites in the stream section. Taxa richness (59 species in total) increased gradually over the first year, whereas the density revealed seasonal differences with significantly lower values in the winter season and after flood events. The benthic macroinvertebrate fauna may have drifted from the upstream reaches during floods and from the Han River, arrived aerially, or hitchhiked on artificially planted aquatic plants. Oligochaeta, Chironommidae, Psychodidae, and Hydropsychidae were identified as major community structure contributors in the stream. Swimmers and clingers colonized relatively earlier in the upper and middle reaches, whereas burrowers dominated particularly in the lower reaches. Collector-gatherers colonized at a relatively early period throughout the stream reaches, and collector-filterers, such as the net-spinning caddisfly (Cheumatopyche brevilineata), predominated in the upper and middle reaches after a 1-year time period. Cluster analyses and multi-response permutation procedures demonstrated that the Cheonggye Stream shares more similarities with the Jungnang Stream than with the Gapyeong Stream. Detrended correspondence analysis and nonmetric multidimensional scaling demonstrated that physical environmental factors (depth, current velocity, dissolved oxygen, and pH) as well as nutrients (total nitrogen and total phosphorous), water temperature, and conductivity could affect the distribution of benthic macroinvertebrates in the study streams.

Floral Changes During Three Years After Cheonggyecheon Restoration (청계천 복원 후 3년간 식물상 변화)

  • Kim, Hyeong-Guk;Koo, Bon-Hak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.6
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    • pp.107-115
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    • 2010
  • This study was surveyed to identify changes of flora during three years after restoration in Cheonggyecheon stream. There are four sections in Cheonggyecheon. One and two sections are upper streams and three and four sections are down streams. It was surveyed 328 species in 2006. In 2007 and 2008, 446 and 444 species were found, respectively. This result shows that Cheonggyecheon is unstable initial condition in restored stream ecosystem. Naturalized species were 58 species in 2006 and it was respectively 61 and 63 species in 2007 and 2008. Hazard species of ecosystem were three common species during survey period. In appearance of flora per section, three and four sections constituted by natural sites such as point bars, wide flood plains, riffles and ponds, marshes, etc. were surveyed more species than one and two constructed by concrete materials and narrow flow channel. Recently, as time goes by, introduced species are being increased. And succession has mainly been progressed by one year or binary herbs and perennial herbs. Compared with other restored streams, Cheonggyecheon showed more flora than Yangjaecheon and Anyangcheon. It is judged owing to length of surveyed site, various planted species and area of inhabitation space. To manage restored stream ecosystem, monitoring is essential. Further, because change of vegetation after restoration in Cheonggyecheon is very important, continuous monitoring about Flora and Naturalized species and Hazard species of ecosystem is also very important.

Monitoring of fecal contamination in a partly restored urban stream in Seoul, Korea

  • Seo, Eun-Young;Jung, Dawoon;Yong, Seung-Cheon;Park, Rho Young;Lee, Young-Ok;Ahn, Tae-Seok
    • Environmental Engineering Research
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    • v.21 no.2
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    • pp.211-218
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    • 2016
  • Cheonggye-cheon is a partly restored urban stream located in central Seoul. We monitored fecal contamination using three different fecal indicators, total coliforms (TC), fecal coliforms (FC) and E. coli, to assess differences in each indicator on days of varying weather conditions. Presumptive TC, FC and E. coli colonies were identified by their 16S rRNA sequences. The results showed that enumeration of E. coli provided a better reflection of fecal contamination of the stream than TC and FC. The main sources of contamination were the inflow of fecal-polluted groundwater from the vicinity of a subway line and two inflowing streams. The fecal contamination was worsened on days with heavy rain because untreated sewage from a collecting facility flowed into the stream. Moreover, growth potential of fecal indicator (E. coli) in situ induced by algal exudates was measured. Our results suggest that an appropriate standard based on E. coli rather than TC and FC should be established for improving water quality management strategies of Cheonggye-cheon in the future.

A Proposition on Landscape Restoration of Joseon Dynasty's Palace Gardens (조선시대 궁궐정원의 원형경관 복원을 위한 제안)

  • Ahn, Gye-Bog;Lee, Won-Ho
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.32 no.3
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    • pp.10-20
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    • 2014
  • The purpose of this study is to define criteria for landscape restoration of palace gardens. The case study on Gyeongbokgung and Changdeokgung was used not only to evaluate effectiveness of the criteria, but also to propose solutions to issues of current restoration process of both palace gardens. Following three pairs of different concepts were chosen as criteria to determine on the original form: Diachrony vs. Synchrony, Originality vs. Contemporary Characteristics, and Invariance vs. Deformability. Gyeongbokgung has been restored based on its contemporary characteristics of Year 1888 and the main focus is on its architectural features rather than both architecture and landscape. However, in-depth complementary work on landscape restoration is necessary to restore its originality in Year 1395 such as analyzing photos of Gyeongbokgung taken in modern era. In case of Changdeokgung, we analyzed separately by region or landmark such as Jondeok-Pavilion(尊德亭), Yeonkyung-Hall(演慶堂), and Okryu-Stream(玉流川). Original form of Jondeok-Pavilion Area was changed in 1884. Since diachronic invariance that lasted for 240 years is more important criterion than its contemporary characteristics, it should be restored as how it was painted in Donggwoldo(東闕圖). In Yeonkyung-Hall Area, both original characteristics at the time of Hyomyung Crown Prince and contemporary characteristics of Emperor Kojong Era appear. Therefore, different solution is required for such area to be restored appropriately. Starting from era of King Injo(1636), diachrony and invariance of Okryu-Stream Area were continued throughout the era of King Sukjong and King Jeongjo(1800). It is more than 250 years before Okryu-Stream Area was altered under the rule of Emperor Kojong in 1884. In fact, alterations made to Okryu-Stream Area after 1884 doesn't hold much significance. Therefore, water landscape of Okryu-Stream Area, which was altered in the era of Emperor Kojong, needs to be restored based on Donggwoldo.

A Study on Changing of Flora between Pre and Post of Restoration in Cheonggyechon Stream (청계천 복원 전·후의 식물상 변화 연구)

  • Kang, Soo Hak;Kim, Hyeong Guk;Koo, Bon Hak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.10 no.3
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    • pp.8-13
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    • 2007
  • This study was surveyed to know changing flora between pre and post of restoration in cheonggyechon. As results, it was surveyed families 33, species 94 in 2003 and families 39, species 156 in 2005. In 2006, it was surveyed families 38, species 171. This result shows that cheonggyechon is unstable initial condition in restored stream ecosystem. Also, Naturalized species was 19 species in 2003 and it was respectively 44, 46 species in 2005, 2006. Hazard species of ecosystem was in common 3 species in three surveys. Recently, as time goes by, introduced species are increasing. And succession has mainly been progressed by one year or binary herbs. To administer restored stream ecosystem, monitoring is essential. Therefore, continuous monitoring about Naturalized species and Hazard species of ecosystem is also very important. Further, Because change of vegetation on pre and post of Restoration in Cheonggyechon Stream is very important, Monitoring will have been surveyed continuously.