• Journal of Environmental Science International
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• v.22 no.12
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• pp.1551-1559
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• 2013

This study was conducted to compare benthic macroinvertebrate communities of urban stream and nature stream in Daegu-si, Gyeongju-si, Gyeongsan-si, Andong-si, and Cheongsong-gun. The survey was carried out with 12 points in total six points for urban stream, six points for nature stream from Sept. 2011 to July 2012. In the urban stream were 33 species belonged to 24 families, 11 orders, 7 classes and 4 phyla while in the nature stream were 73 species belonged to 38 families, 12 orders, 5 classes and 4 phyla. In general, species diversity indices and species richness indices appeared low in urban stream but dominance indices was high. Functional feeding groups and Habitat Oriented Groups appeared comparatively simple in urban stream rather than nature stream. As a result of analysis of community stability, species included to area I and area III equally appeared in nature stream while species included to area I mostly appeared in urban stream. An analysis of the correlation between the population density and the number of species, the population number and biological indicators such as DI, H', RI, and ESB revealed that there was a significant correlativity with the diversity index and a very high correlativity with the number of species, abundance index and the ESB. On the other hand, the population number and the dominance index did not reveal any correlativity. For indicator species, Hydroptila KUa, Physa acuta appeared in urban stream while Paraleptophlebia chocolata, Epeorus pellucidus appeared in nature stream.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.2
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• pp.76-88
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• 1982

The stream morphological characteristics of a basin have important influence upon the analysis of runoff. In this study, the laws of stream morphology-the law of average stream fall and the law of least rate of potential energy expenditure-which were derived based on the analogy of entropy in thermodynamics are introduced and their validity is analysised with the data taken from the topographic maps covering the whole Geum River system. The first law is the Law of Average Stream Fall which states that under the dynamic equilibrium condition the ratio of average fall between any two different order stream in the same river basin in unity. The second law is the law of least rate of energy expenditure which states that all natural streams are intended to choose their own course of flow such that the rate of potential energy loss per unit mass of water this course is a minimum. The parameters representing the morphological characteristics of 13 tributaries in the Geum River system such as stream bifurcation ratio and stream concavity were Computed from the Horton-Strahler's laws and are used to check the law of average stream fall. The result showed that the law of average stream fall agrees reasonably well with law of Horton-Strahler. Concavity of a river basin is shown to be the determinative factor to the formation of a stream system. Concavity of a river basin is shown to be the determinative factor to the formation of a stream system. Based on Horton's Law and the law of average stream fall, longitudinal stream profiles can be calculated.

• Journal of the Korean Society of Hazard Mitigation
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• v.3 no.4 s.11
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• pp.131-143
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• 2003

The purpose of this study was to develop a new method for evaluation of stream naturalness in order to promote stream managers' understanding on importance of improving stream naturalness, and in order to appraise and prescribe for streams effectively in the process of ecological restoration of stream corridors. In order to analyze the evaluation method of stream naturalness and its applicability to streams, stream naturalness index(SNI) which has seven factors such as channel development, longitudinal profile, lateral section, stream bed structure, low flow channel structure, stream surroundings and water quality was suggested in this paper. For case studies, Bokha stream was selected for the evaluation of stream naturalness. At the Bokha stream, the scores of SNI factors were in range of $2.2{\sim}3.8$, and the average of SNI was 3.1, and the most frequent grade of SNI factors was grade 3. Among the 7 factors, the best was lateral section, and the worst was channel development. In this study, SNI grade can represent the characteristics of stream naturalness well and select the streams which will be restored, and can also decide the segment and the method of restoration for deteriorated streams.

• Journal of environmental and Sanitary engineering
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• v.19 no.3 s.53
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• pp.40-51
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• 2004

Community structure of benthic macroinvertebrates in the water system of Anyang Stream was analyzed from August, 2002 to April, 2003. Species number of benthic macroinvertebrates was 78 species, 33 families, 11 orders, 5 classes in 3 phyla. They were collected 49 species at 1st survey, 51 species at End survey and 53 species at 3rd survey, respectively. Species numbers at each tributary were 43 species at the Wanggok Stream, 44 species at the Mokgam Stream, 33 species at the Ohjeon Stream and 26 species at the Hakeu Stream, while it was only 9 species at the Dangjeong Stream. Species number of the main course of Anyang Stream was 24 species. Dominant species of benthic macroinvertebrates at the Wanggok, Ohjeon and Hakeu Stream were Baetis fuscatus, Alainites muticus, Physa acuta and chironominae sp. They were mainly intermediate and tolerant species. Dominant species and subdominant species of the Dangjeong Stream were Limnodrilus socialis, Psychoda KUa and Telmatoscopus KUa as indicator species for severe sewage pollution. Dominant species at Geumjeong-dong and KUa bridge in the main course of Anyang Stream were Physa acuta, Limodrilus gotoi, Chironominae sp., Species diversity indices at the Mokgam Stream were $high(3.53\~4.28\;range)$ and those of the Hakeu, Wanggok and Ohjeon Stream were some what high$(2.00\~3.13\;and\;2.34\~3.10\;range)$. But, species diversity indices in the Dangjeon Stream were low$(1.36\~1.70\;range)$ too. and those of the main course of Anyang Stream were low$(0.86\~1.79\;range)$ too. Species richness indices in the Wanggok and Mokgam Stream were very high$(3.55\~4.02\;and\;2.96\~5.31\;range)$ and those of Geumjeong-dong and Kia bridge in the main course of Anyang Stream were low$(0.89\~1.98\;range)$. Stream bed and riparian bank of middle reach in the Wanggok Stream were good condition and water was clean. The Mokgam Stream had various microhabitats, good water weed area, hetero geneous substrates and etc.. And, stream bed in the Hakeu Stream was in good condition. So, above streams should be continuously in good ecological condition and useful area for citizens.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.67-70
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• 2003

This study is to trace the change of stream shape using the past series of aerial photographs and compare the land use changes of inland along the stream. For the Gyeong-an national stream, aerial photographs of 1966, 1981 and 2000 was selected and ortho photograph was made with RMSE of 1.25, 0.54, 0.72 pixels, respectively. As apparent changes of the stream, the consolidated reaches of stream with levee construction were straightened and their stream width widened. Especially the stream width of inlet part of Paldang lake was widened almost twice because of the rise of water level by dam construction in 1974.

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.1
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• pp.64-74
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• 1981

The stream morphological characteristics of watershed have important influence upon the analysis of runoff. In this study, the effect of the map scale on the stream morphological characteristics was used on the data taken from 15'(1:50, 000) and 7'30"(1 :25,000) topographic maps which could cover the whole Miho River basin This basin are the first tributary of the Geum. River. Otherwise, the longitudinal stream bed profile was calculated by Yang's theoretical stream bed profile, equilibrium profile and actual profile. In the result of this investigation the conclusion is that the resultant relationship obtained from different topographic maps in the scale on the same stream system has come upon the same result as the stream morphological characteristics. Therefore, the great amount of time and effort can be saved in studing the stream morphological charecteristics by using the 15' instead of the 7'30"map system excluding the first order streams.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.566-569
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• 2004

This study is to trace the change of stream shape using the past series of aerial photographs, and to compare the land use changes of riparian area along the stream. For the Gyeongan national stream, aerial photographs of 1966, 1981 and 2000 were selected and ortho photographs were made with interior orientation and exterior orientation, respectively. As apparent changes of the stream, the consolidated reaches of stream with levee construction were straightened and their stream widths were widened. Especially the stream width of inlet part of Paldang lake was widened almost twice because of the rise of water level by dam construction in 1974. The land use maps (1966, 1981,2000) of riparian areas were also made, respectively and classified into 6 categories (water, forest, agricultural land, urban area, road, sandbar) by digitizing. The area of forest and agricultural land decreased and urban area increased as the stream maintenance was performed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.5
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• pp.67-75
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• 2002

This study was carried out to introduce current status to discuss erosion control strategy for the conservation of stream valley ecosystem. To restore stream valley ecosystem, we should establish restoration plans to keep the original shape of stream. It is necessary to use environmentally sound materials with conservation of valley stability. Valley construction for erosion control works should be evaluated continuously based on concepts of conservation and development of stream valley ecology. It is categorized in point of the important of class of stream valley conservation ahead planning and constructure. We suggest that the development of stream valley construction needs to prevent mass movement of soil sediments. In addition, it is established the basal strategy to protect macro and micro aquatic organisms in stream valley ecosystem.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.45-64
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• 2014

This study was carried out to offer the ecological data for restoring and maintaining a local stream by analyzing the vegetation and flora in Geumsan Stream and Gisa Stream, Geumsan-gun, Chungcheongnam-do, Korea. As a result of comparison of realities of land use near Geumsan Stream and Gisa Stream, in Geumsan Stream, the ratio of residential areas, commercial and business places, and places of transportation facilities was high. With these types of land use aggregating densely in the center, farmlands were formed on both sides. On the other hand, in Gisa Stream, farmlands were distributed evenly in all sections. As a result of comparison of flora of the two streams, Geumsan Stream had a total of 166 taxons including 53 families, 131 genuses, 139 species, 23 varieties, and 4 forms, and Gisa Stream had a total of 142 taxons including 42 families, 111 genuses, 116 species, 21 varieties, and 5 forms. As a result of calculation of the Naturalization Index and Urbanization Index, the indices were analyzed to be 23.5% and 12.1% in Geumsan Stream and to be 21.8% and 9.7% in Gisa Stream, respectively. Hence, Geumsan Stream showed higher figures in both evaluation indices than those of Gisa Stream. In addition, as a result of calculation of the Actual Urbanization Index, which is the index supplemented by considering the species pool and area, it could be known that Geumsan Stream (0.0285) was urbanized more than Gisa Stream (0.0107) by about 2.7 times. A total of 18 plant communities were classified in Geumsan Stream and Gisa Stream. In Geumsan Stream, 14 vegetation types were identified, and it was analyzed that there are various vegetation types including Phalaris arundinacea community, Zoysia japonica community, Phragmites japonica-Phalaris arundinacea community, etc. evenly distributed. 11 vegetation types were identified in Gisa Stream, and it was examined that Phragmites japonica community is widely distributed in all sections.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.39-49
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• 1999

Urban streams have, recently, been straightened and widened to alleviate flooding problem. As a result, the stream have been modified inadvertently for ecological functions and microtopography. In this study, we investigated riparian vegetation and microtopography of the tributaries of Han River before and after the monsoon rain in summer. The purpose of this study was to relate the stream microtopography to the distribution of riparian vegetation. The stream microtopography was investigated for its scale and pattern. Vegetation was investigated from 131 plots by Braun-Blanquet method. The distribution of riparian vegetation was significantly correlated with the stream microtopography. Various herbaceous species occurred at stream bank slop, high terrace and channel side. However, at channel side and concave part of terrace where soils were in high moisture level, only a few wetland species were dominated. The complexity of the microtopography in the stream corridors led to heterogeneous riparian vegetation. The vegetation showed more stability against flooding at the stream corridors with natural and complex microtopography than at the urban-type stream corridors with simple topographical features. The results showed that the development of riparian vegetation was influenced by the changes in microtopography, which was primarily determined by the shape and characteristics of channel. It seemed that a close-to-nature river system would be restored more readily with an understanding of microtopographical features affecting the distribution of riparian vegetation.