• Title/Summary/Keyword: River shape

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Effects of Microtopography on the Development of Riparian Vegetation in Stream Corridors (하천통로에서 미세 지형 발달이 하천 식생에 미치는 영향)

  • 정경진;김동엽
    • 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.

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CFD Analysis on a Tall Building Augmented Wind Turbine (풍력발전기가 설치된 고층빌딜에 대한 전산유체역학적 고찰)

  • Jeon, Wan-Ho;Yoon, Seong-Wook;Kim, Wook;Cho, Jang-Hyung
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.418-421
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    • 2009
  • Renewable energy or green energy is a hot issue in theses days. Since wind resource can be endlessly supplied by nature, researchers and common people are interested in study how to use that resource at home or company. Especially, many architects have tried to integrate wind power generator for a part of building. So in this paper, three buildings installed wind power turbine are targed to CFD analysis and these buildings are Bahrain trade center, Discovery tower, and Pearl river tower. Bahrain trade center is the first builidng installed real wind turbine, Discovery tower is constructing at Texas, and Pearl river tower is designed and proved by china researchers. These buildings have very different type of wind power turbine and each turbine has different conditions for best power generation. Therefor this paper will focus on characteristic shape of buildings, wind power turbine type, and expected purpose of construction. Moreover, CFD analysis will show wind flow pattern and wind speed while wind is passing through wind turbine of three tall buildings. CFD analysis for three buildings make comparison the wind flow patterns with experimental result.

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Echinostomu hortense Metacercariae Naturally Encysted in Odontobutis obscura interrupta (a Freshwater Fibh) and Experimental Infection to Rats (얼룩동사리(Odontobutis sp.)에 피낭한 Echinostoma hortense 및 백에의 감염실험)

  • 안영겸;량영석
    • Parasites, Hosts and Diseases
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    • v.23 no.2
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    • pp.230-235
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    • 1985
  • The metacercariae of an echinostomatid fluke were detected from a freshwater 6sh, Odontobutis obscura interrupta caught from the Seom river system, Wonseong-gun, Kangwon-do, and experimentally infected into rats to obtain the adult worms for the species identification. A total of 32 metacercariae was detected from 10 fishes (27.8%) out of 36 O. obscura interrupta caught from the river. The average size of metacercariae was $153.4{\times}149.0{\;}{\mu}{\textrm{m}}$. Also, it was uniquely specific that thickened membrane was formed around the metacercarial cyst wall. The rats orally infected with those metacercariae were sacrificed 20 days after infection to get the adult worms. The mean length and width of the adult worms were 0.75 cm and 0.13 cm, respectively. The number of collar spines on circumoral disk was 26 to 28, and the end group spines at lateral sides of the oral sucker were 4 on each side. The echinostomatid flukes observed in this study were all identified as Echinostoma hortense according to the morphologies of the cirrus sac, ovary, vitellaria and testes of the adult worms and the shape of eggs. On the other hand, O. obscura interrupta is one of the fresh-water fish that are preferably eaten raw by the rural inhabitants. Although no human case of 5. hortense infection by eating O. obscura interrupta has been experienced yet, the possibility is strongly suggested in this study.

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An Unrecorded Species from Korean Flora: Vallisneria spinulosa (Hydrocharitaceae) (한국산 미기록 식물: 낙동나사말(자라풀과))

  • Na, Hye Ryun;Shin, Hyunchur;Choi, Hong-Keun
    • Korean Journal of Plant Taxonomy
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    • v.38 no.1
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    • pp.69-77
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    • 2008
  • We report Vallisneria spinulosa S. Z. Yan (Hydrocharitaceae) as an unrecorded species from the flora of Korea. This aquatic vascular plant occurs in reservoirs, streams, and ditches at Changnyeong, Changwon, and Gimhae which belong to Nakdong river basin. Vallisneria spinulosa is distinguishable from V. natans (Lour.) Hara already known to Korean flora by the presence of turion and hairs at base of stamen, adnation between pistil and staminodia, the number of stamen, and shape of fruit and seed. V. spinulosa is similar to V. desnseserrulata Makino in the viewpoint of distribution (Japan and southern China), but V. spinulosa has three to five epidermal wings on the surface of seed.

A Study on the Characteristics of Bathroom Design in Apartment Model House - Focused on the south area of the Han river and new town area(Boon-dang) - (아파트 모델하우스 욕실에 나타난 디자인 특성 연구 - 서울 강남 및 신도시(분당)를 중심으로 -)

  • 송윤경;박영순
    • Korean Institute of Interior Design Journal
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    • no.32
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    • pp.36-46
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    • 2002
  • The purpose of this study is to find the characteristics of bathroom through the latest apartment model house, and to investigate the types of design element in bathroom space, that is equipment material, measurement, and shape. Also, this study compare the changes in bathroom investigated through the theoretical study and understand the general design characteristics of modern bathroom. Design characteristics of bathrooms of 19 apartment model houses that are 30pyong to 60pyong model in the south area of the Han river and new city area, Boon-dang were analyzed based on previous studies. The result of the study is as follows. 1) The most remarkable change of bathroom can be found in equipment. The type of bathroom equipment, materials, forms, size have been changing diversely. 2) In addition, the function of bathroom has been changing. Bathroom is not only sanitary place but also place for rest, health-care, beauty-care, storage, and it is possible to add health improving function. 3) On the other hand, $\ulcorner$washstand + toilet + shower booth$\lrcorner$ type is common for family-bathroom, and separate type of $\ulcorner$washstand + toilet + bathtub + shower booth + Powder room + dress room$\lrcorner$type is most common for master-bathroom.

Analysis of Flood Flow Characteristics of the Han River using 1-Dimensional St. Venant Equations (1차원 St. Venant 방정식을 이용한 한강 하류부 하도의 홍수류 특성 분석)

  • Kim, Won;Woo, Hyo-Seop;Kim, Yang-Su
    • Water for future
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    • v.29 no.1
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    • pp.163-179
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    • 1996
  • Flood flow characteristics of the Han River (from Goan to Indo Bridge) are analyzed using 1-dimensional St. Venant equations. NETWORK, a finite difference model, is used to calculate each term (local acceleration term, convective acceleration term, pressure force term, gravity force term, and friction force term) of the momentum equation and to analyze the flow characteristics. By the result of the study, as the general characteristics of flow in a channel that acceleration terms are very small and the other three terms are much greater is presented, three terms(pressure force term, gravity force term, friction force term) are to be main terms which decide the characteristics of flow. Specially in this region the acceleration term is noted so large that it cannot be ignored according to the shape of hydrograph and the region.

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Estimation of river discharge using satellite-derived flow signals and artificial neural network model: application to imjin river (Satellite-derived flow 시그널 및 인공신경망 모형을 활용한 임진강 유역 유출량 산정)

  • Li, Li;Kim, Hyunglok;Jun, Kyungsoo;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.49 no.7
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    • pp.589-597
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    • 2016
  • In this study, we investigated the use of satellite-derived flow (SDF) signals and a data-based model for the estimation of outflow for the river reach where in situ measurements are either completely unavailable or are difficult to access for hydraulic and hydrology analysis such as the upper basin of Imjin River. It has been demonstrated by many studies that the SDF signals can be used as the river width estimates and the correlation between SDF signals and river width is related to the shape of cross sections. To extract the nonlinear relationship between SDF signals and river outflow, Artificial Neural Network (ANN) model with SDF signals as its inputs were applied for the computation of flow discharge at Imjin Bridge located in Imjin River. 15 pixels were considered to extract SDF signals and Partial Mutual Information (PMI) algorithm was applied to identify the most relevant input variables among 150 candidate SDF signals (including 0~10 day lagged observations). The estimated discharges by ANN model were compared with the measured ones at Imjin Bridge gauging station and correlation coefficients of the training and validation were 0.86 and 0.72, respectively. It was found that if the 1 day previous discharge at Imjin bridge is considered as an input variable for ANN model, the correlation coefficients were improved to 0.90 and 0.83, respectively. Based on the results in this study, SDF signals along with some local measured data can play an useful role in river flow estimation and especially in flood forecasting for data-scarce regions as it can simulate the peak discharge and peak time of flood events with satisfactory accuracy.

Geochemical Exploration for the Stream Sediments of the Tumbang Mirih in the Middle Kalimantan, Indonesia (인도네시아 중부 칼리만탄 뚬방미리지역의 하상퇴적물에 대한 지화학탐사)

  • Kim In-Joon;Lee Jae-Ho
    • Economic and Environmental Geology
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    • v.39 no.3 s.178
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    • pp.301-328
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    • 2006
  • The geology of the Tumbang Mirih area in the Middle Kalimantan, Indonesia comprises Permian to Carboniferous Pinoh Metamorphic Rocks and Cretaceous Sepauk Plutonics of the Sunda Shield, late Eocene Tanjung Formation, Oligocene Malasan Volcanics, Oligocene to early Miocene Sintang Intrusives and Quaternary alluvium. Results of geochemical exploration and geological mapping exposed obviously that large amounts of gold-bearing quartz veins were found in the whole Tumbang Mirih areas. In many places, gold grains were megascopically detectable from panning products of stream sediments and conglomerate as Quaternary sediments. Even though no remnants of quartz veins are revealed in the most of survey area except Taran region, association of fold grains with layers of quartz pebbles and clays which correspond to the horizon of unconformity or previous river bottom indicates that the gold grains were separated from quartz veins. Along rivers often pebbles and clay layers just over or 10 to 20cm above the current waterlevel are recognized. The occurrence of gold in the conglomeratic layer was frequently confirmed during geochemical exploration. Since the conglomeratic layer was old stream sediments of Quaternary, it can be assumed that deposition of golds was controlled by shape of river floor, speed and shape of river flow, and distance from the source rock. Taran area and northern Takaoi area based on the all data are recommended as the promising areas.

Influence of the Type of Fine Aggregate on Concrete Properties (잔골재 종류가 콘크리트의 물성에 미치는 영향)

  • Koh, Kyung-Taek;Ryu, Gum-Sung;Yoon, Gi-Won;Han, Cheon-Goo;Lee, Jang-Hwa
    • Journal of the Korea Concrete Institute
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    • v.18 no.4 s.94
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    • pp.459-467
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    • 2006
  • Recently, interest grew on the quality of aggregates following the diminution of primary resources from river as to grow construction demand and the low grade of nature sand like sea sand. Following, need is to diversify the supply sources of fine aggregates which are excessively relying on sea sand and urgency is to find as soon as possible aggregate resources that can substitute sea sand. On the other hand, various fine aggregates are utilized to produce concrete in the domestic construction fields. However, few studies have been systematically investigated on the effects of such fine aggregates on concrete properties. Therefore, this study examined the effects of comparatively widely used fine aggregates in the domestic construction fields on the quality of concrete through the analysis of the effects of such fine aggregates on the physical properties of fresh concrete and strength of hardened concrete. Results revealed that crushed sand degraded the fluidity and air entraining of concrete compared to natural aggregates like sea sand and river sand. Especially, the use of crushed sand exhibiting bad grain shape and grade was larger adverse effect on the physical properties of concrete. The type of fine aggregates appeared to have negligible influence on the strength for W/C of 55%, 45% while crushed sand decreased the strength for W/C of 35% compared to natural aggregates. It analyzed that the combination of crushed sand exhibiting bad grain shape and grade with natural aggregates improved the characteristics of fresh concrete and had negligible influence on the strength.

Effect of Light Intensity on Growth, Caudal Fin Shape, Body Composition and Skin Color of River Puffer, Takifugu obscurus (황복 Takifugu obscurus의 성장, 꼬리지느러미 형태, 체조성과 체색에 미치는 조도의 영향)

  • Kang, Hee Woong;Kang, Duk Young;Jo, Ki Chae;Lee, Jin Ho;Park, Kwang Jae;Lim, Chi Won;Kim, Gyu Hee
    • Korean Journal of Ichthyology
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    • v.19 no.3
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    • pp.185-192
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    • 2007
  • The present experiment was carried out to study the effects of light intensity on growth, survival, caudal fin shape, body composition, skin color and blood component of river puffer, Takifugu obscurus. Four light intensities (0, 500, 1,000, 2,000 lx) were tested in duplicates for 60 days. Specific growth rate (SGR), daily feeding rate (FR) and food coefficient (FC) were reduced following to the decrease of light intensity. However in survival rate there was not significantly different among groups. The damage extent of caudal fin was increased in more strong light intensity. In body composition, moisture and crude protein were only significantly difference according to light intensity. In body color, L and a were the highest in 0 lx. In blood analysis, the content of AST, ALT, GLU significantly increased in more powerful the intensity groups. It is concluded that the supplement of low light intensity (e.g. 0 lx) recommended for the commercial scale aquaculture of river puffer in land-based tank without growth and survival retardation.