• Title/Summary/Keyword: Main stream area

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Habitat Potential Evaluation Using Maxent Model - Focused on Riparian Distance, Stream Order and Land Use - (Maxent 모형을 이용한 서식지 잠재력 평가 - 하천으로부터의 거리, 하천의 차수, 토지이용을 중심으로-)

  • Lee, Dong-Kun;Kim, Ho-Gul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.6
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    • pp.161-172
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    • 2010
  • As the interest on biodiversity has increased around the world, researches about evaluating potential for habitat are also increasing to find and comprehend the valuable habitats. This study focus on comprehending the significance of stream in evaluating habitat's potential. The purpose of this study is to evaluate habitat potential with applying stream as a main variable, and to comprehend the relationship between the variables and habitat potential. Basin is a unit that has hydrological properties and dynamic interaction with ecosystem. Especially, biodiversity and suitability of habitat in basin area has direct correlation with stream. Existing studies also are proposing for habitat potential evaluation in basin unit, they applied forest, slope and road as main variables. Despite stream is considered the most important factor in basin area, researchers haven't applied stream as a main variable. Therefore, in this study, three variables that can demonstrate hydrological properties are selected, which are, riparian distance, stream order and land use disturbance, and evaluate habitat potential. Habitat potential is analyzed by using Maxent (Maximum entropy model), and vertebrate's presence data is used as dependent variables and stream order map and land cover map is used as base data of independent variables. As a result of analysis, habitat potential is higher at riparian and upstream area, and lower at frequently disturbed area. Result indicates that adjacent to stream, upstream, and less disturbed area is the habitat that vertebrate prefer. In particular, mammals prefer adjacent area of stream and forest and reptiles prefer upriver area. Birds prefer adjacent area of stream and midstream and amphibians prefer adjacent area of stream and upriver. The result of this research could help to establish habitat conservation strategy around basin unit in the future.

Analyses of Seasonal Water Quality Pollution for Side Planning (수변계획을 위한 계절별 수질오염 분석)

  • Lee, Yang-Kyoo;Han, Jung-Geun;Hong, Chang-Sun
    • Journal of Korean Society of Water and Wastewater
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    • v.20 no.3
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    • pp.347-355
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    • 2006
  • Anyang Stream including its main branch is the biggest branch stream of Han River in Korea. The geological and geomorphological characteristics were investigated to the affected area of Anyang Stream, in which rainfall characteristic was analyzed. The water quality surveyed that the analysis of water pollution used to biotic index and biological water pollution. The rainfall pattern in this area was like to that of typical Korea, but the rate of trigger and runoff during summer season(June~August) is more higher than mean of Korea. Before 2003, a dried stream is severe status, which was due to abundant runoff, but this status are improved. After 1997, water quality of stream is recovering status such as water pollution of stream steeply decreased. Especially after 2003, this trend is more quickly improved. Although, owing to the increasing of a T-N and SS at upstream wastewater were due to bad collection of industrial factories, livestock's and mans living, the water quality worsted at upstream. Water quality in total section of main stream was severely contaminated that water-quality limit is 5 with polysaprobic by water self-purification. That of main branch was 1~3limits with ${\alpha}$- and ${\beta}$-mesosaprobic in Anyang city area, But water quality in all area about another branch of Anyang stream except Anyang city area was almost under of 3 grades. Though trying of Anyang city for recover movement(completion of 2nd Sewage Treatment Plant and Water supply pipe system) on Anyang stream, water pollution states of upper branch in Anyang stream was not better than its of 2002 because it may be difference of control area on other cities.

Fractal Dimension of Stream Networks and Main Stream Length with Map Scale (지형도(地形圖) 축척(縮尺)에 따르는 하천 수로망(水路網)과 본류(本流) 하천길이에 관한 Fractal Dimension)

  • Jeon, Min Woo;Cho, Won Cheol
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.4_1
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    • pp.97-106
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    • 1992
  • Total length of stream networks and main stream length vary with topographic map scales, and the stream length of drainage basin on topographic map can be viewed as a fractal. Total length of stream network and main stream length are represented as only stream area ratio($R_a$) based on Horton's laws, thereafter the fractal dimensions of stream network and main stream length are derived as a simple function of stream length($R_L$) and stream area ratios($R_a$) respectively. The derived equations of fractal dimension are applied to Sansung basin in Kum River and compared with the equations already existed. The stream network appeared as space filling with fractal dimension near 2 as map scale increases, while main stream length shows near 1. The results of this study are expected to be helpful in the quantitative analysis of drainage network composition with map scale.

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The Changes of Adjacent Residential Area after the Restoration of Covered Urban Streams (도시복개하천의 복원사업 이후 인접 주거지의 물리적 특성 변화)

  • Kim, Jun-Yeong;Yang, Woo-Hyun
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.133-146
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    • 2014
  • This study aims to analyze the changes of adjacent residential area after the restoration of covered urban streams in seoul. The changes of adjacent residential area after restoration were analyzed by changes of land using, urban structure, individual lot of land and architecture to investigate relationship of the urban stream and residential change. The result as follows: the first one is the change of land use and urban structure in adjacent residential area. This change of infrastructure through stream restoration has transformed land use and urban structure in adjacent residential area. Secondly, there is the changes of the individual lot of land. It seemed that new development by combined lots would be concentrated in stream-side blocks. But, the changes of lots such as combining or dividing lots tend to be concentrated in stream-side, main road and main streets. In stream-side, commercial function of land use has changed to residential one which has restored streams landscape by transformation of lots use without changes of ownership-lots. Finally, there is the change of architecture. It turned out new building in adjacent residential area is similar to general development. However, new building in streamside is related to direction of stream. In addition, remodeling and expansion tend to change in commercial buildings on stream-side bridges of corner lots intensively. As a result, it is related to expectation of architectural activation and improvement of sidewalk environment by stream restoration.

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.

A Study on the Waterways in Traditional Urban Area of Late 1960s Cheongju Korea (1960년대 후반 청주 도심 내 물길에 관한 연구)

  • Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.2
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    • pp.27-34
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    • 2015
  • As part of the waterway restoration to renew traditional urban area, this paper is to assume and research Gyoseocheon(Gyoseo waterway) in Late 1960s Cheongju Korea. The main stream of Gyoseocheon flew from Sangjwagol(the head of the valley) of Uam Mt. to the north gate under Cheongju castle at first, and meandering from Sangdang Park, flew through Sudongseongdang and Bangadari Road to Musimcheon since open railroad of 1920s. This waterway, the eco-friendly figure of Gyoseocheon, that flew to inside the downtown with a planted tree and that is open space was so. The sub stream of Gyoseocheon originated in Seoundong and Tapdong were divided into two parts. One was to join the main stream of Gyoseocheon on Sangdang Park via Munhwadong, and the other was to join the sub stream of Musimcheon at northwest corner via south and west gate of Cheongju castle. This waterway as branch sewer were built into the road culvert.

Evaluation of Watershed Stability by the Forest Environmental and Stream Morphological Factors (산림환경 및 하천형태인자에 의한 유역안정성 평가)

  • Jung, Won-Ok;Ma, Ho-Seop
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.4
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    • pp.1-11
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    • 2001
  • This study was carried out to analyze the characteristics of forest environmental and stream morphological factors by using the quantification theory(I) for evaluation of the watershed stability. Present annual mean sediment yield of erosion control dams were investigated in 167 sites of erosion control dam constructed during 1986 to 1999 in Gyeongbuk. The results obtained from this study were summarized as follows; According to the coefficients of partial correlation, each factor affecting to sediment was shown in order of gravel contents, number of first streams order, number of total streams, length of total streams, forest type, length of main stream, parent rock, stand age, soil texture, stream order, slope gradient, soil depth and aspect. Descriptions of class I were as follow; Igneous rock of parent rock, hardwood stands of forest type, less than 20 year of stand age, less than 30cm of soil depth, sandy clay loam of soil texture, more than 41% of gravel contents, south~east of aspect, 2,501~3,500m of length of main stream, 21~25 of number of total streams, 5,501~10,000m of length of total streams, 3 or more than 4 of stream order, more than 16 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class II were as follow; Metamorphic rock of parent rock, coniferous stands of forest type, more than 25 year of stand age, 31~40cm of soil depth, silt loam of soil texture, 11~20% of gravel contents, north~west of aspect, 2,501~3,500m of length of main stream, 16~20 of number of total streams, 3,501~5,500m of length of total streams, 3 of stream order, 11~15 of number of first stream orders and more than $31^{\circ}$ of slope gradient. Descriptions of class III were as follow; Sedimentary rock of parent rock, mixed stands of forest type, more than 25 year of stand age, more than 51cm of soil depth, silty clay loam of soil texture, less than 10% of gravel contents, south~west of aspect, less than 500m of length of main stream, less than 5 of number of total streams, less than 1,000m of length of total streams, less than 1 of stream order, less than 2 of number of first stream orders and less than $25^{\circ}$ of slope gradient. The prediction method of suitable site for erosion control dam divided into class I, II, and III for the convenience of use. The score of class I evaluated as a very unstable area was more than 8.4494. A score of class II was 8.4493 to 6.0452, it was evaluated as a moderate stable area, and class III was less than 6.0541, it was evaluated as a very stable area.

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Community Structure of Benthic Macroinvertebrates in the Water System of Anyang Stream in Korea (안양천 수계의 저서무척추동물 군집구조)

  • Bae Kyung-Seok;Yoon Jong-Cheol;Lee Soon-Hee;Cho Seog-ju
    • 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.

Assessment of Water Quality Based on Ecological Factors in Anyang River (안양천에서의 생태학적 수질오염도 평가)

  • Lee, Yang-Kyoo;Cho, Won Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.3
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    • pp.39-50
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    • 2006
  • In this study, the water quality investigated during 2002s to 2004s for Anyang river and its affluent that was based on biological and chemical methods as well as ecological index of each streams. The improving of water quality and the multiplicity of specious in the most streams except for Anyang, which was due to the improving of water quality and water resource. The seasonal dry states are completely disappeared, but water quality of Anyang main stream was classified as fifth grades water with BIP 8.51~10.00 and BOD 8.16~14.4mg/l in Anyang stream overall. And alpha-mesosaprobic in upper, mid parts and polysaprobic in down parts of Anyang main stream are appeared according to Saprobien system, respectively. The water supply of treated sewage is appeared that upgrading effects of water quality in Anyang main stream and affluents of Anyang city area, but the practical effects of "Saving Anyang River" could not gained because the water quality of other branches in upstream parts than upstream measuring point of Anyang main stream, Wanggok stream Sanbon stream in Gunpo and Eeiwang cities, was not improved.

Appearance Characteristic of Waterbirds in Banseok Ecological Stream (생태하천으로 조성된 반석천의 물새류 출현특성)

  • Park, Seungki;Na, Sangsoo;Park, Daesoon;Han, Jaebong
    • Journal of Korean Society of Rural Planning
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    • v.26 no.1
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    • pp.89-99
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    • 2020
  • This study was conducted as a basic research to create a sound and vital ecological environment in the city compared to the appearance characteristics of Gap stream(G-stream), which are the main stream of Banseok stream(B-stream), by analyzing the characteristics of waterbirds, including Wild Spot-billed Duck (S-Duck), that live in B-stream built as ecological stream. The waterbird survey was conducted by the line census for 3.2km, Jukdong-bridge to Jamiseon-bridge, from January to August 2018. The analysis of the survey was conducted with Relative species density(RD) of the emerging waterbird species, the Species diversity and Density Per Unit area for 100㎡(DPU). The waterbird survey results of B-stream was conducted 65 times. The five types of water birds that appeared during the survey were Spot-billed Duck(Anas poecilorhyncha), Teal(Anas crecca), Little Egret(Egretta garzetta), Great Egret(Egretta alba), and Grey Heron(Ardea cinerea). As a result, for S-Duck at B-stream, RD was 89.9%, monthly species diversity was simple as 0.3801 in January, 0.5943 in February and 0.3501 in August. The DPU of the S-Duck was 0.165/100㎡ in the B-Stream survey section which was 4.9 times higher than the main stream section, G-stream. The non-freezing zone of the city's small stream is expected to play an important role as a winter stop for wild birds such as S-Duck during the freezing period of the huge stream. For this reason, considering the ecological characteristics of wild waterbirds such as S-Duck when creating ecological stream, a: space and linear selection of waterways which can minimize the impact of natural enemy and increasing the number of walkers, b: management water-friendly plants in the low flow channel, c: arrangement walking-bicycle road will be necessary.