• Title/Summary/Keyword: riffle

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A Study on the Analysis of Project Implementations at Public Design - Improving Project for Public Design in Daegu, Dongseong Street - (공공디자인 개선사업의 추진실태 분석에 관한 연구 - 대구시 동성로 공공디자인 개선사업을 중심으로 -)

  • Lee, Jong-Kuk
    • Journal of the Korean housing association
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    • v.25 no.6
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    • pp.67-74
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    • 2014
  • Dongseong-ro public design was reformed for a short time to be short of connection and riffle effect of another project and to have limitation on long term and integrated development, so that systematic plan from beginning of the project was needed to produce synergy effects. The purpose of the study was to investigate reformation of Dongseong-ro public design and to check on existing development project again and to take actions against future projects in advance and to reexamine and make long term plan from point of view of development of downtown. This study investigated reformation of Dongseong-ro public design of Junggucheong office of Daegu that was done from May 2007 to December 2010. The study consisted of purpose of the project, scope, time, the committee of promotion, questionnaire survey, residents' participation and follow up to suggest reformation based on questionnaire survey. This study had limitation of investigation into internal materials of 'Dongseong-ro public design reformation's master planning service' of Junggucheong office of Daegu. Further studies were needed to investigate empirically.

Analysis of Economic Effects for Surion Research and Development Program (수리온 연구개발 사업의 경제적 파급효과 분석)

  • Lee, Ki Young;Kim, Sung Geun;Shim, Dai Sung;Kim, Mi Joung;Kwon, Ki Jung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.2
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    • pp.189-194
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    • 2016
  • This paper deals with the economic effects for the Surion(KUH-1) research and development program. The economic effects was measured by Inter-industry analysis method for production-inducing effects, value-added inducement effects, and job-creation effects and by estimating actual domestic input cost. In addition, technical riffle effects was analyzed for aerospace industry, defense industry and commercial industry market through similarity and contribution of technology.

Changes in Benthic Macroinvertebrate Communities in Response to Natural Disturbances in a Stream

  • Bae, Mi-Jung;Park, Young-Seuk
    • Journal of Ecology and Environment
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    • v.32 no.3
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    • pp.197-206
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    • 2009
  • Benthic macroinvertebrate communities were collected from six different sites in the Dobong Stream in Seoul, Korea to investigate spatial and temporal changes in benthic macroinvertebrate communities in response to natural disturbances such as floods and droughts. We collected samples monthly or semimonthly with a Surber net ($30cm{\times}30cm$), and measured environmental factors, including stream temperature, discharge, width, conductivity, dissolved oxygen and pH at each sampling site. Benthic macro invertebrates were strongly affected by floods as well as droughts. In addition, benthic macroinvertebrate communities displayed different responses to the onset of the rainy season in summer 2006 and 2007, apparently due to differences in the intensity and amount of precipitation. Chironomids were particularly sensitive to heavy rain. Floods and droughts also affected the proportions of functional feeding groups during the survey period: the proportion of scrapers was high right after heavy rains, while the proportion of predators tended to increase in intermittent-type streams as the riffle zone decreased. Finally, although species richness and abundance were strongly influenced by heavy rain, they recovered to background levels for within one month, and varied consistently among stream types, indicating habitat stability.

Extraction of Watershed Information using GIS and Diurnal Flow Change in the Rapids and Pool by the Nature-Friendly River Work (GIS를 이용한 유역정보 추출 및 여울과 소의 치수적 복원을 위한 일중 수치해석)

  • Kang, Sang-Hyeok
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.5
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    • pp.517-522
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    • 2010
  • The riffle and pool play an important role for composing river front, but very little information was used for river restoration considering flood control. In this paper extensive field investigation was carried out to estimate hydraulic processes in the pool. Furthermore diurnal stratification model was developed and applied to assess flow change in pool. The physical mechanism of water flow including diurnal processes was well simulated, the results show that diurnal variation of water flow in the pool about 2 m depth is governed by the level of mixing due to density flow. These effort will be useful to guide field data collection work and to understand primary production.

A Study on the Location Characteristics of Rural Village along a Dalchon River in Geosan of Chungbuk Province (충북 괴산군 달천 유역 농촌마을의 입지특성에 관한 연구)

  • Roh, Seon-Hwa;Kim, Sung-Jung;Kim, Tai-Young
    • Journal of the Korean Institute of Rural Architecture
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    • v.7 no.1
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    • pp.19-30
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    • 2005
  • This study is carried out to understand the characteristic of location in vernacular agricultural villages by judging from natural environment around the village. For this purpose, there were selected 17 villages of the riverside villages in Geosan Area which lean against Dalchoen River. After classifying these samples by the morphorogical approach, according to compare them with pre-researched villages, the methodology of spatial structure was investigated in agricultural villages. As a result of the study, the relationship between the agricultural villages and the shape of Dalcheon River can be classified by 3 types that are twisted around villages, attacked villages, and paralleled with villages. First of all, twisted type is located in river terraces, river safety zone and taken a image of the riverside agricultural village. Secondary, attacked type is located in beside riffle, and taken a image of a fishing village. Finally, paralleled type is located in straightly flowing river.

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Modeling Dynamics of Nonconservative Pollutants in Streams with Pools and Riffles

  • Seo, Il-Won;Yu, Dae-Young
    • Proceedings of the Korea Water Resources Association Conference
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    • 1993.07a
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    • pp.175-182
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    • 1993
  • The complex nature of low flow transport and tranformation of nonconservative pollutants in natural streams with pools and riffles has been investigated using a numerical solution of a proposed mathematical model that is based on a set of mass balance equations describing hydrodynamic processes (advection, dispersion, and mass exchange mechanicms in streams and in storage zones) and chemical processes (reaction or decay). In this study, a mathematical model (named "Storage-Transformation Model") has been developed to predict adequately the non-Fickian nature of mixing and transformation mechanisms for decaying substances in natural streams under low flow conditions. Comparisons between the concentration-time curves predicted usingthe proposed model and the measured stream data shows that the Storage-Transformation Model yields better agreements in the goneral shape, peak concentration and time to peak than the 1-D dispersion model. The result of this study also demonstrates the differences between transport in pool-and-riffle streams versus transport in more uniform channels. The proposed model shows significant improvement over the conventional 1-D disperision model in predicting natural mixing and stroage processes in streams through pools and riffles.

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A Study on Application & Evaluation of Riverbed Techniques for the Formation of Hyporheic Zone (하상간극수역의 형성을 위한 하상공법의 적용과 평가)

  • Choi, Jungkwon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.6
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    • pp.119-133
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    • 2013
  • The purpose of this study is to develop riverbed techniques to activating ecological function of hyporheic zone. Hyporheic zone maybe simply defined as an active eco-tone between surface water and groundwater, which facilitates to exchange water, nutrients and aquatic habitat occur in response to variation in discharge and bed geomorphology. The aim of this study is to evaluate the effectiveness of an applied riverbed technique for two years since its installation in the hyporheic zone. The experimental riverbed technique has been implemented on Anyang stream penetrating Anyang city in Gyunggi province. The dimension of the installed structure is 5.0 m in width, 46 m in length. Bottom layer is filled with rip-rap covered with gabion. After the implementation of the technique, the study conducts follow-up monitoring in two years of between 2011 and 2012. The results of follow-up monitoring for two years are as follows:1) In Hydro geomorphic process, the riverbed technique maintains hydraulic stability despite of several flood events in 2011, 2012. 2) After transformation to form pool-and-riffle habitat, for aquatic community composed of freshwater fish, macro invertebrate, and attached algae, the species diversity and population gradually increased. 3) The riverbed technique achieved desired effect on enhancement of ecological function in hyporheic zone.

An Ecological Study on the Aquatic Animal Community in Tan Stream, Seoul (서울 탄천의 수서동물 군집에 관한 생태학적 연구)

  • 배경석;구본관;한선규;신재영;박성배
    • Journal of Environmental Health Sciences
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    • v.23 no.4
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    • pp.1-8
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    • 1997
  • The aquatic animals of Tan stream were composed of 46 species, 28 families, 11 orders, 6 classes in 4 phyla during the survey period of April, 1996 to December, 1996. They were composed of 31 species in aquatic insecta, 6 species in annelida, 3 species in mollusca, 1 species in crustacea, and 5 species in fishes, respectively. Major dominant species in Tan stream were Chironomidae sp.1, Chironomidae sp.2, Chironomidae sp.3, Tubufucidae sp.1, Physa acuta and hirudo niponica. Dominance indices of benthic macroinvertebrates ranged highly from 95.74 to 100.00% at lower stream(site 4), but ranged 50.00 to 95.85% at site 1 through site 3. The aquatic animals ranged from 25 to 32 species at site 1 through site 3, but they were only 3 species at site 4 for survey period. Tan stream in the light of urban stream ecosystem has a little less riffle areas and hydrophyte areas by cementation of riparian area and channel type of water course. Therefore, the species of aquatic animals in Tan stream decreased because of deterioration of water quality according to reduction of self-purifcation ability and loss of microhabitat according to reduction of hydrophyte areas and riparian areas. The tendency of decreasing species of aquatic animals appeared seriously at lower stream From drive licence test authority at Kangnam-ku, Seoul to conjunction point of the Han river.

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Introduction of Hydraulic Field Investigation Method to Utilize on the Inhabitation Environment Definition at a River

  • Lee, Hyun-Seok;Kim, Young-Sung;Lee, Geun-Sang;Seo, Jin-Won;Yang, Jae-Rheen;Kwon, Hyung-Joong
    • Korean Journal of Ecology and Environment
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    • v.41 no.4
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    • pp.547-553
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    • 2008
  • In recent years, attention on the inhabitation environments of animals and plants which coexist with humans is growing more and more, and relevant research is being activated. In habitats of rivers, a lot of factors are interacting, even among them, some elements especially such hydraulic factors as water velocity and water depth, and such geological shapes as gravels, sand and mud are being considered as primary elements. In this study, various field investigations are carried out to determine the relationship between the river habitats of fishes and hydraulic primary elements using high-tech equipments. Furthermore numerical experiments to classify such habitats according to topographical spaces are carried out. In detail, hydraulic field investigations performed in this study can be summarized as topographical survey, discharge measurement, water level fluctuation monitoring and so on. In numerical experiments, the RMA2 model of the commercial program, Surface-Water Modeling System (SMS), which is widely used in conducting a two-dimensional analysis of the flow behavior of a river is utilized. In conclusion, as a result of field investigation, the relationship between water velocity and water depth is obtained. And the relationship between water velocity and water temperature is identified, too. Finally, using above obtained results, the inhabitation environment was classified into Riffle, Glide, Run, Pool, and E.D.Z according to the relationship between water velocity and water depth.

A biota research and analysis for Close-to-nature stream restoration planning (자연형 하천복원계획 수립을 위한 생물상 조사 및 분석)

  • SaGong, Jung-Hee;Ryu, Yeon-Su;Ra, Jung-Hwa
    • Current Research on Agriculture and Life Sciences
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    • v.24
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    • pp.37-42
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    • 2006
  • The purpose of this study was a biota research and analysis for Close-to-nature stream restoration planning of Shinchun. The summary of this study is as follows; 1) The vascular plants in research area recorded of 45 species and insect fauna recorded of 34 species of 8 orders. As a result of table of community classification, the communities were two group; Quercus variabilis community(I), Pinus densiflora-Quercus variabilis-Quercus dentata community(II). 2) As a result of analysis on correlation of tree species, the level of significance in positive correlation between Quercus dentata and Corylus heterophyll aindicated 1% and between Pinus densiflora and Lespedeza bicolor also indicated 1%. 3) As a result of DBH analysis, it is expected that Quercus variabilis and Quercus dentata will dominateover other species in competition and its succession continuously maintains from now on in community I. In community II, it is assumed that there is a high possibility of changing into community of Quercus such as Quercus mongolica, Quercus dentata, and Quercus variabilis. 4) As a result of analysis on insect fauna, insect fauna consists of 94% of whole species as 32 species, 23 families, 8 orders. And 7 species, 7 families 4 orders was found in highly urbanized area, the vicinity of Sang-Dong bridge. 5) As mentioned above, Based on A biota fundamental research, Close-to-nature stream restoration planning were full of suggestions: i) Designating ecosystem preservation area, ii) Making Close-to-nature stream revetments, iii) Making pool-and-riffle, vi) Making decks for observation and walks for nature experience, v) Creating wetland biotope. Through these methods, it is necessary to promote bio-diversity and lead people to the space for eco-learning.

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