• 제목/요약/키워드: large river

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초분광수심법 기반 대하천 합류부 하상측정 성능 평가 (Performance evaluation of hyperspectral bathymetry method for morphological mapping in a large river confluence)

  • 김동수;서영철;유호준;권영화
    • 한국수자원학회논문집
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    • 제56권3호
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    • pp.195-210
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    • 2023
  • 국내 대하천은 2010년 대규모 정비사업 이후 자연적 안정화를 위한 추가 재퇴적 및 침식이 진행 중에 있어 정밀 하상 모니터링이 요구되고 있다. 초분광수심법은 저수심의 고해상도 하천 수심측정 측면에서 종래의 접촉식 수심측정 기법을 대체하거나 보완할 수 있는 방법으로 각광을 받기 시작하였다. 본 연구는 초분광수심법에서 대표적인 최적밴드비기법을 소개하고 국내 대하천인 낙동강과 황강 합류부에서 평수기 전형적인 탁도조건에서 초분광수심법을 적용하여 수심맵을 산정하여 국내 하천으로의 적용성을 평가하였다. 이를 위해 수심영역별 최적밴드비기법으로 도출되는 상관도와 평균제곱근오차를 적용하여 최대측정가능수심을 산정하였고 최대추정가능수심 이상은 관계식 구축 시와 수심맵 산정 시 제외시켰다. 그리고 수심과 최적밴드비 관계(d-X)에 비선형성을 검토하여 적용하였다. 국내 대하천인 낙동강-황강 합류부에 적용한 결과는 다음과 같다. 첫째, 초분광수심법은 주로 저수심부에서 정밀한 수심맵을 효율적으로 산정할 수 있음을 보여주었고 최대측정가능수심은 통상적 탁도에서 낙동강의 경우 2.5 m로 나타났고, 탁도가 높은 지류의 경우 1.25 m로 나타났다. 둘째, 최대측정가능수심은 초분광수심법 하상 도출 시 다양한 시나리오의 배제수심을 고려하여 산정 및 적용되어야 하고, 이때 최적밴드비기법 적용 시 평균제곱근오차가 기존의 상관도 방식에 비해 최대측정가능수심 산정에 우수하였다. 셋째, 황강 합류부의 탁도가 높아 측정가능수심이 인근 낙동강에 비해 절반으로 낮아져 초분광수심법은 탁도가 높은 환경일 경우 한계가 있음을 확인하였다.

The diverse species of the genus Hantzschia (Bacillariophyta) in sand flats of the Nakdong River estuary in Korea

  • Joh, Gyeongje
    • Journal of Ecology and Environment
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    • 제37권4호
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    • pp.245-255
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    • 2014
  • To collect the diatom species belonging to the genus Hantzschia, bottom sediments were collected from 32 sampling sites in 23 sand-flat areas in the intertidal zone and river reaches of Nakdong River estuary, Korea. The sand sediments contained a total of 19 species of genus Hantzschia, Hantzschia amphioxys (Ehrenberg) Grunow, H. amphioxys f. capitata O. Muller, H. baltica Simonsen, H. distinctepunctata (Hustedt) Hustedt, H. elegantula (Østrup) Witkowski et al., H. longiareolata Garcia-Baptista, H. marina (Donkin) Grunow, H. pseudomarina Hustedt, H. virgata (Roper) Grunow, H. virgata var. gracilis Hustedt, H. virgata var. kariana Grunow, H. virgata var. leptocephala Østrup and H. weyprechtii Grunow, including six unconfirmed species. Eleven Hantzschia species are reported as new to Korea. Hantzschia virgata, its infraspecies, and neighboring speceis showed large morphological variations within a single species or among the closely related species. Hantzschia amphioxys, H. distinctepunctata, and H. virgata var. leptocephala prefer freshwater habitats in the upper reaches of the river, while others occurred mainly in the sand flats composed of coarse sand in the intertidal area. In the estuarine sediments, the Hantzschia taxa are classified to be typical sand-attached forms.

Simplified Numerical Model of the Wind-driven Circulation with Emphasis on Distribution of the Tuman River Solid Run-off

  • Vanin, N.S.;Moshchenko, A.V.;Feldman, K.L.;Yurasov, G.I.
    • Ocean and Polar Research
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    • 제22권2호
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    • pp.81-90
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    • 2000
  • Supposed construction of a large port in the mouth of Tuman River requires careful examination of possible unfavorable ecological consequences for the Far Eastern Federal Marine Reserve. Since the Tuman River is the largest source of suspended material and possible contaminants flowing into the sea, and in order to understand how this material is allocated in the coastal zone, analyses are needed to check possible pathways of water transport and circulation system in the region. Linearized shallow water equations were used for numerical simulation of the wind-driven circulation to the north off the Tuman River mouth. The model results satisfactorily agreed with in situ data. The model circulation patterns are largely dependent on the wind direction and are conformed by the distribution of bottom sediments, and by the location of organic carbon and some pollutants accumulation zones. The most unfavorable situation for the Marine Reserve is the case of the southwesterly wind; even with quite moderate wind, the waters polluted by the run-off from the Tuman River can attain the south section of the Marine Reserve during the diurnal period.

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하도에서의 홍수추적 -수정 Muskingum-Cunge 방법- (Flood Routing on the River by Revised Muskingum-Cunge Method)

  • 홍종운
    • 한국농공학회지
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    • 제21권1호
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    • pp.13-23
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    • 1979
  • The predictien of a design flood hydrograph at a particular site on a river may be based on the derivation of a discharge or stage hydrograph at an upstream section, together with a method to route this hydrograph along the rest of the river. In order to limit this investigation to cases where the assumption like uniform rainfall may be reasonably valid, the derivation of unit hydrographs has been limited to catchment with an area less than 500 km2. Consequently, flood routing methods provide a useful tool for the analysis of flooding in all but the smaller catchment, particularly where the shape of the hydrograph as well as the peak value is required. The author, therefore, will introduce here a flood routing method on the open channel with a peak discharge of the catchment area concerned. The importance of being able to route floods accurately is also reflected in the large number of flood routing method which have been developed since the year 1900. There are the modified puls method, Steinberg method, Goodrich method, Ekdahl method, Tatum's mean continuously Equation, wisler-Brater method, Muskingum, chung, and Muskingum-cunge (M-C) method and so on. The author will try to introduce a flood routing method which is revised Muskingum-cunge method. In calculating flood routing by the M-C method, whole variable parameters on the river were assumed to almost uniform values from the upstream to the downstream. In the results, the controlled flood rates at the 40km downstream on the river is appeared to decrease 22m$^3$/sec or 12 percent of the peak flood 170m$^3$/sec.

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일제강점기 도시기반시설의 설치를 통해 본 강경의 도시화 과정 (Modern Urbanization Process of Ganggyeong during the Japanese Colonial Period, focused on Installation of Urban Infrastructure)

  • 현태준;김기주;이연경
    • 건축역사연구
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    • 제28권6호
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    • pp.55-65
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    • 2019
  • Ganggyeong, a city which is located at riverside of Geum River, played a role to connect the inland cities and the coastal cities through the Geum river waterway. In Chosun dynasty, Ganggyeong was one of the three major markets in Korea, and at the same time, it was one of the two river docks in Korea. However, after the railway was installed in Korea, railroad was more important than waterway in transporting logistics and in 1911 Honam railroad and Ganggyeong railway station was installed. Thus it was necessary to reorganize urban structure of Ganggyeong city from the traditional river-dock city to modern railroad city. In addition, urban infrastructure to prevent flood damage was needed because Ganggyeong suffered from floods and water shortages every year. Therefore, between 1910s and 1930s large-scale social infrastructures including road, water and sewage system, river bank, floodgate was constructed not only to revitalize the declining city but also to prevent flood damage and water shortages that hinder urban development. The installation of urban infrastructure has enabled the urban expansion and development of Ganggyeong city, and it is still served as a basic urban structure.

낙동가 유역의 지속가능한 이용을 위한 EMERGY 분석 (EMERGY Analysis of Nakdong River Basin for Sustainable Use)

  • 김진이;손지호;김영진;이석모
    • 한국환경과학회지
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    • 제9권1호
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    • pp.49-55
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    • 2000
  • An EMERGY analysis of the main energy flows driving the economy of humans and life support systems consists of environmental energies, fuels, and imports, all expresses as solar emjoules. Total EMERGY use(720.0 E20 sej/yr) of the Nakdong River Basin is 96 per cent from imported sources, fuels and goods and services. EMERGY flows from the environment such as rain and geological uplift flux accounted for only 4 percent of total EMERGY use. Consequently, the ratio of outside investment to attracting natural resources was large, like other industrialized areas. EMERGY use per person in the Nakdong River Basin indicates a moderate EMERGY standard of living, even though the indigenous resources are very poor. Population of 6.66 million people in 1996 is already in excess of carrying capacity of the basin. Carrying capacity for steady state based on its renewable sources in only 0.226 million people. EMERGY yield ratio and environment loading ratio were 1.07 and 28.52, respectively. EMERGY sustainability index, a ratio of EMERGY yield ratio to environment loading ratio, is therefore less than one, which is indicative of highly developed consumer oriented economies. This study suggests that the economic structure of the Nakdong River Basin should be transformed from the present industrial structure to the social-economic structure based on an ecological-recycling concept for the sustainable use of the Nakdong River.

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조절된 하천의 수문지형학적 변화와 식생 피복의 변화에 관한 기초 조사 - 낙동강 안동댐/임하댐 하류 하천 사례 (Basic Investigation about Hydro-Geomorphologic and Vegetation Cover Changes on the Regulated River - A Case of the Downstream River of Andong Dam/Imha Dam on the Nakdong River)

  • 우효섭;이동섭;안홍규;이창석
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2004년도 학술발표회
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    • pp.1335-1339
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    • 2004
  • A hydro-geomorphologic change in a sand bed channel reach and vegetation expansion by changes in the How regime is analyzed in this study. Field and aerial photo surveys, basic hydrological analysis about flow regime change due to two dams, Andong Dam and Imha Dam, on the upstream river and computer modeling are conducted. Two Dams in the study reach have obviously affected downstream channel in many ways including the bed particle coarsening, vegetation expansion on the sandbars and following river channel braiding. The phenomenon of no vegetation on the large point bar in front of Hahwe Village seems due to disturbance of the sandbar surface probably due to the cross flow in the meander reach during the flood. Another reason for no vegetation is that the sandbar on this reach has lower subsurface water lovels, as compared with the others in the up- and downstream of the reach where vegetation expanded, which would hinder vegetation from germinating and growing on the sandbar.

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강우상태에 따른 소수력발전입지의 설계변수 특성 분석 (Analysis on Design Parameters of Small Hydropower Sites with Rainfall Conditions)

  • 이철형;박완순
    • 한국태양에너지학회 논문집
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    • 제32권4호
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    • pp.59-64
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    • 2012
  • The correlation between hydrologic performance design parameters of small hydro power(SHP) sites and rainfall condition have been analyzed for major river systems. The model, which can predict flow duration characteristic of stream, was developed to estimate the inflow caused from rainfall. And another model to predict hydrologic performance for SHP plants is established. Based on the models developed in this study, the hydrologic performance characteristics for SHP sites have been analyzed. The results show that the hydrologic performance characteristics of SHP sites have some difference between the river systems. Especially, the specific design flowrate and specific output of SHP sites located on North Han river and Nakdong river systems have large difference compared with other river systems. It was found that the hydrologic performance design parameters such as specific design flowrate and specific output were affected by rainfall condition in basin area of SHP sites.

비편향 회귀분석모형을 이용한 낙동강 본류 부유사량 산정방법의 신뢰도 향상 (Improvement of Suspended Solid Loads Estimation in Nakdong River Using Minimum Variance Unbiased Estimator)

  • 한수희;강두기;신현석;유재정;김상단
    • 한국물환경학회지
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    • 제23권2호
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    • pp.251-259
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    • 2007
  • In this study three log-transformed linear regression models are compared with the focus of bias correction problem. The models are the traditional simple linear regression estimator (SL), the quasi maximum likelihood estimator (QMLE) and the minimum variance unbiased estimator (MVUE). Using such models, suspended solid loads can be estimated using the discharge - suspended solid data set that has been measured by NIER Nakdong River Water Environment Laboratory. As a result, SL shows negative bias for most values of the measured discharge range. QMLE is nearly unbiased for moderate values of the measured discharge range, but shows increasingly positive bias for either large or small value of the measured discharge range. MVUE is unbiased. It is also analyzed how the estimated regression coefficient and exponent are distributed along Nakdong river main stream.

효율적인 하천정보 서비스를 위한 RIMGIS 개선방안 연구 (A Study on the Improvement of RIMGIS for an Efficient River Information Service)

  • 신형진;채효석;황의호;임광섭
    • 한국지리정보학회지
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    • 제16권1호
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    • pp.15-25
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    • 2013
  • 국가하천에 대한 하천대장, 하천측량도 및 부도 등 관련 정보들을 표준화하여 구축함으로써 관련 업무 활용 및 대국민 서비스 등을 실시하기 위해 국토해양부에서는 지난 2000년도부터 하천관리지리정보시스템(RIMGIS; River Information Management GIS)을 구축하여 운영 중에 있다. RIMGIS는 그 동안 정보환경 변화에 능동적으로 대응하기 위해 여러 차례 개선되었으며, 최근 스마트 리버 하천정보 서비스 및 관련 자료가 방대해짐에 따라 빅데이터를 효율적으로 관리하기 위한 개선이 필요한 실정이다. 본 연구에서는 RIMGIS의 현황 파악, 개선방향 도출, 데이터베이스를 재설계, 배포프로그램 개발 및 하천종합정보시스템 제안을 통해 정보환경 변화에 대응해 향후 스마트 리버 하천정보 서비스를 제공하기 위한 방안을 제시하고자 한다. 따라서, RIMGIS의 활용성을 강화하기 위해 속성정보의 엔터티간 연관관계를 구분할 수 있는 유일키와 외부키 등과 하천표준 데이터베이스 관점에서 테이블간의 위상관계를 정립하여 속성정보 DB의 구성과 정보관리를 위하여 연관관계도도 새롭게 제시하였다. 아울러, 하천관리 패러다임 변화에 대응 가능한 하천관련 정보의 효율적인 관리와 이용 체계 수립을 통해 현재 공급자 중심의 시스템 운영을 수요자 중심으로 확대하기 위한 방안을 도출하였다.