• Title/Summary/Keyword: Headwater

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Estimated Headwater Stream Temperature Using Environmental Factors with Seasonal Variations in a Forested Catchment (환경인자를 이용한 산지계류의 계절별 수온변화 예측)

  • Nam, Sooyoun;Jang, Su-Jin;Kim, Suk-Woo;Lee, Youn-Tae;Chun, Kun-Woo
    • Korean Journal of Environment and Ecology
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    • v.34 no.1
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    • pp.55-62
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    • 2020
  • To estimate headwater stream temperature with seasonal variations, we analyzed precipitation, runoff and air temperature in experimental forest of Kangwon National University, Gangwon-do (2017~2018 years). The daily mean value of headwater stream temperature for spring was 6.9~17.7℃ and correlated with air temperature, that for summer and fall were 12.2~26.3℃ and 3.6~19.3℃, correlated with air temperature and runoff. Based on seasonal variations, we applied for stepwise multiple linear regression analyses to estimate headwater stream temperature with seasonal variations. The equations were headwater stream temperature(WT)spring=(0.553×Air temperature)+(0.086×Runoff)+4.145 (R2=0.505; p<0.01), WTsummer=(0.756×Air temperature)+(-0.072×Runoff)+2.670 (R2=0.510; p<0.01), and WTfall=(0.738×Air temperature)+(0.028×Precipitation)+2.660 (R2=0.844; p<0.01). The coefficient of determination (R2) was greater than when it was estimated by air temperature in all seasons and progressively increased from spring to winter. Therefore, we indicated difference on estimated magnitude of stepwise multiple linear regression, due to effects on headwater stream temperature of different environmental factors with seasonal variations. Furthermore, temporal factors with spatial characteristics (e.g., river versus headwater stream) could be recommended for estimating headwater stream temperature.

Characteristics on Seasonal Variation of Stream Water Quality on Upland Headwater Streams in Forested Catchments (산림유역의 계류수질 현황 및 계절적 변동 특성)

  • Nam, Sooyoun;Lim, Honggeun;Li, Qiwen;Choi, Hyung Tae;Yang, Hyunje;Kim, Jaehoon
    • Journal of Korean Society on Water Environment
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    • v.38 no.5
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    • pp.220-230
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    • 2022
  • Seasonal variability of water quality in the upland headwater streams in ten forested catchments (37.0~209.0 ha) was examined from April to November 2021. Here, seven physicochemical parameters were analyzed including pH, electrical conductivity (EC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N), total phosphorous (T-P), and BOD/TOC. The parameters were compared with those of lowerland rivers as middle and lower reaches within a watershed. The pH showed was low (6.4~6.9) during all the seasons, however, BOD and BOD/TOC in the fall season were 2-fold higher than in the spring and summer seasons. Based on environmental standards, the water quality level revealed that the upland headwater streams maintained the purity and cleanliness of water except for pH in the summer season. BOD/TOC of all the seasons and BOD of the fall season in the upland headwater streams were higher than that in the lowerland rivers, whereas the rest of the physicochemical parameters in the upland headwater streams were lower than that in the lowerland rivers. Additionally, the water quality level maintained the purity and cleanliness of water as "Good" in two reaches. The unique aspects of our study design enabled us to draw inferences about water quality characteristics with temporal and spatial analysis in upland headwater streams. This design will be useful for the long-term strategy of effective water quality management for integrated upland headwater streams and lowerland rivers within a watershed.

Seasonal Difference in Macroinvertebrate Contribution to the Leaf Litter Breakdown in a Headwater Stream at Mt. Jumbong (점봉산 소하천의 낙엽분쇄에 대한 대형무척추동물 기여도의 계정간 차이)

  • Chung, Keun
    • The Korean Journal of Ecology
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    • v.19 no.6
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    • pp.563-573
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    • 1996
  • Macroinvertebrate contribution to the leaf litter breakdown of Carpinus cordata was estimated at headwater streams at Mt. Jumbong (38°03'N, 128°25'E) during spring and winter spring by using two types of litter bag. Coarse-mesh bags with 10 g of leaf letter were placed in a 1st-order stream in April (the spring experiment) and December 1995 (the winter-spring experiment). Fine-mesh bags with 5 g of leaf letter were placed in a nearby 3ed-order steam. The breakdown of Carpinus in coarse-mesh bags was rapid, and, in terms of season, leaf litter processed rapidly during spring. daily mass loss rates of leaf litter (-k±1 SE) were highest for coarse-mesh bags in the spring experiment (-0.0429±0.0048), followed by coarse-mesh bags in the winter-spring (-0.0146±0.0014), fine-mesh bags in the spring (-0.0078±0.0004), fine-mesh bags in the winter-spring experiment (-0.0054±0.0005). Macroinvertebrate contribution to the litter breakdown was estimated by the difference of % leaf letter remaining between coarse -mesh bage and fine-mesh bags. Although shredders were more abundant during the winter-spring, their contribution was greater during the spring (50%) than the winter-spring (22∼33%). This result appeared to be due to the change in the chemical composition of leaf letter during processing, and to the seasonal growth patterns of major shredder taxa.

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Spatial Distribution and Geomorphological Characteristics of Headwater Stream (Dorang) Catchments in Geum River Basin (금강유역 내 도랑유역 분포 및 지형적 특성 분석)

  • Kim, Haejung;Cho, Hong-Lae;Koo, Bhon Kyoung
    • Journal of Korean Society on Water Environment
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    • v.30 no.3
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    • pp.319-328
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    • 2014
  • Dorang - the Korean term for headwater streams - occupy a large portion of the total stream length in a basin, and contribute significantly towards the quantitative and qualitative characteristics, and the ecosystem, of the main river. The Ministry of Environment of South Korea has supported the investigation of the status of Dorang in the nation's four major basins, since 2007. Without a widely accepted academic or legal definition of Dorang, however, there are limits to understand the distribution of Dorang at the national scale and to systematically compile a Dorang database. This paper, through a review of the stream classification system and Korean legal system delineating streams, defines Dorang as 1st and 2nd order streams according to the Strahler ordering method, in a 1:25,000 geographical scale. Analysis of the Geum River basin, with this definition, reveals that the total length of Dorang is 20,622.4 km (73.6% of total stream length), and the number of Dorang catchments is 23,639 (71.3% of the basin area). Further analysis of the geomorphological characteristics of Dorang catchments shows that the average total stream length is 1.1 km, average catchment length is 1.2 km, average drainage area is $0.4km^2$, and average drainage density is 3.08/km.

A Study on the Conservaion, Rehabilitation and Creation of Naturality of Rivers : Characteristic of Ecological Land Use in the River Basin(1) (하천에 있어서 자연성의 보전, 정비 및 창출에 관한 연구 : 지역하천의 생태학적 토지이용 특성(1))

  • Lee, Haeng-Ryeol;Kim, Hun-Hui;Park, Jeong-Won
    • Proceedings of the Korean Society of Rural Planning Conference
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    • 1998.03a
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    • pp.25-26
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    • 1998
  • This study was aimed to investigate the land use characteristics between urban and rural river systems. The ecological land unit systems was used to the key method for that objectives and the visual analysis was also used. The results were as followings : The won-sung river was characterized by the formal urban river system of which the headwater was covered with the various man-made constructions. Also the pong-se river showed a little simptoms of the urbanization from the headwater that meant the urgent ecological land use evaluation about that region.

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Leaf Litter Processing and Patterns of Shredder Distribution in Headwater Steams in Southeastern Korea (한국 남동지역 상류 하천에서의 낙엽 분해기작과 shredder 분포 유형)

  • Kim Hyun-woo;Gea-Jae Joo;Jong-hoon Choi
    • The Korean Journal of Ecology
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    • v.19 no.6
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    • pp.529-541
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    • 1996
  • During the period of December 1992 (winter-spring) and from February 1995 (winter-spring), the leaf processing rates of oak (Quercus serrata) and tulip (Liriodendron tulipifera) tree was investigated in the headwater streams in southeastern part of Korea in conjunction with the distribution pattern of macroinvertebrate fauna. Using two types of bags ($10\times30cm$ with 5 g of dry leaves; open bag with holes, closed bag without holes), decomposition rates of oak and tulip tree by shredder and/or microbiota at a reatively undisturbed 2nd-order stream were compared, Regardless of leaf type, leaves in the open bage decomposed slightly faster than those in the closed bags. In the 1992 experiment, osk leaves decomposed much slower than tulip leaves (after 138 degree days, osk : closed, 0.006% loss/day ; open, 0.008 ; tulip: closed, 0.021 ; open, 0.023; n=2). The of the first experiment using oak leaves in 1995 were similar to those of the first experiment (after 151 degree days, oak: closed, 0.005% loss / day; open, 0.006; n=6). Over 50% of invertebrates from 122 leaf pack samples collected from 12 streams during the winter period of 1994 were identified as shredders (shredder, 56.2; collector, 32.7; scraper, 8.65; predator, 2.45%). Among shredders, Gammarus sp. and Tipula sp. were dominant species in terms of number and biomass (8.2 ind./g, 1.0 ind./g AFDW of leaves). Among many physico-chemical parameters, the width of stream channel was found to be the most influential factor in the distribution of Gammarus and Tipula (Gammarus: r=-0.34, P<0.001;Tipula:r=0.40, P<0.001). Considering the fact that oak is one the dominant riparian vegetation in the southeastern part of korea, the patterns of oak processing and shredder distribution shown in theis study may well represent some of the important characteristics of headwater steams in southeastern Korea.

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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.