• 제목/요약/키워드: natural streams

검색결과 300건 처리시간 0.029초

골채채취 후 수변환경 변화와 사주 내 식생이입 (Riparian Environment Change and Vegetation Immigration in Sandbar after Sand Mining)

  • 공학양;김세미;이재윤;이재안;조형진
    • 한국물환경학회지
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    • 제32권2호
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    • pp.135-141
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    • 2016
  • This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

GIS 기반 중·소규모 하천의 수문지형 물리적 구조 평가 체계 개발 (Development of the GIS-based Stream Hydromorphological Structure Assessment System for Small and Midium-size Streams)

  • 김만규;김혜주;박종철
    • 한국지리정보학회지
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    • 제11권2호
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    • pp.93-107
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    • 2008
  • 최근 한국에서는 하천의 환경적 생태적 기능을 되살리기 위해 하천복원과 관련된 여러 가지 사업이 진행되고 있다. 이러한 하천복원사업에 있어서 사업대상 하천의 생태성에 대해 평가하고, 이를 바탕으로 하천복원사업의 목표와 계획을 수립할 수 있도록 하는 일은 학술적이나 사업적으로나 모두 값진 일이 될 것이다. 한편, 하천의 생태성을 개략적으로 판단할 수 있는 방법의 하나는, 하천의 수문지형 물리적 구조(hydromorphological structure)를 평가하는 것이다. 본 연구에서는 LAWA(물관리 연구 독일 연방 법적공동체)의 하천 평가 기법을 이용하여 중 소규모 하천의 자연 생태성을 평가하기 위한 하천의 수문지형 물리적 구조를 평가하는 현장 조사 체계(field survey system)를 개발하고, 아울러 조사결과를 이용하여 도면자동화 체계(auto mapping system) 및 보고서로 작성하는 과정을 지원하는 GIS 기반의 하천 평가 체계를 개발하였다. 하천복원 및 관리 분야 종사자들이 하천복원 계획 수립과 관리의 단계에서 대상하천의 하천자연도 내지 생태성을 인지하고 분석하는데 도움을 주고, 대상하천의 '도달해야 하는 이상적인 하천모델상'을 결정하기 위한 기초 자료를 수집하는데 도움을 주고자 한다.

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울산시 도심하천의 자연형 하천 조성에 따른 식생 변화 (Change of Vegetation Based on Nature-friendly River of Urban Streams in Ulsan)

  • 강호선;조홍제
    • 한국수자원학회논문집
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    • 제47권7호
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    • pp.657-670
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    • 2014
  • 수질개선과 하천개수를 통한 자연형하천 조성으로 주민들의 친수공간으로 이용되고 있는 울산시의 5개 도시하천에 대해 식생을 조사하였다. 하천의 기하학적 특성이나 수질 및 제내지 및 제외지 등 주변여건과 식생의 활성화 등과의 상관관계를 조사하였다. 각 하천의 자연형하천 조성시기가 다르고 일천한 관계로 뚜렷한 정량적 상관관계를 얻을 수는 없었으나, 식생의 활성화 정도가 현하천의 수질과 제내지 및 제외지 등 주변 여건에 의한 차이점은 어느 정도 확인할 수 있었다. 자연상태에 가까운 척과천은 식생종류가 다양하였고, 수질과 주변 여건이 좋은 무거천과 명정천은 인위적 유지용수 공급과 개수공사에 의한 인공물이 많지만 식생의 활성화 정도가 좋았다. 반면에 수질이 나쁘거나 하폭과 둔치가 좁은 데도 무리하게 산책로 등을 조성하였던 여천천과 약사천은 식생의 종류가 다양하지 못하였고 활성화도 낮은 것으로 나타났다.

도시하천 복원경로 추적방안에 관한 연구 (A Study of Restoration Path Tracking Method for Urban Stream)

  • 임용호;엄정섭
    • 한국공간정보시스템학회 논문지
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    • 제10권2호
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    • pp.25-33
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    • 2008
  • 본 연구의 목적은 도시의 질적 성장에 필요한 수공간 확보방안으로 도시화 과정에서 사라진 소하천을 찾아내고 찾아진 소하천을 복원할 때 도시의 현실에 맞는 적절한 경로를 찾는 방법을 찾는 것이다. 연구결과 GIS를 이용하여 도시내의 사라진 소하천을 발견할 수 있었으며 발견된 소하천을 복원할 경우 영향을 주는 요인으로 고도, 토지이용, 지가를 선정하여 각각의 요인별 최적경로를 분석하였고 3가지 요인을 모두 반영한 최적경로를 분석하였다. 3가지 요인이 하천복원에 미치는 영향이 서로 다르기 때문에 중요도에 따른 최적의 가중치를 찾아내고 최적가중치를 이용하여 최적의 복원경로를 추적하는 방법을 개발하였다. 본 연구의 결과는 친환경도시건설과 도시민의 쾌적한 삶을 위해 사라진 하천을 복원경로를 찾는데 기여할 것이다.

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Aqeous Neutralizer as Reactive Solvents for Odorous Ammonia Removal

  • Park, Young-G.
    • Environmental Engineering Research
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    • 제13권3호
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    • pp.119-124
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    • 2008
  • Ammonia is an inorganic compound that may cause severe odor problem. In this study the effectiveness of applying natural neutralizer to destroy and remove the odor-causing compound from gas streams was studied. Experimental result evaluated with a bench-scale apparatus via the neutralization of gas phase. This indicates that the natural neutralization depends on the gas concentration, gas residence time, temperature and pH. Removal efficiency of ammonia from gas stream was achieved by 95% using theconvection in the packed bed. This study proved the chemical neutralization technology was effective for controlling inorganic odor-causing compound.

영산강 하류권역 하천수의 수질평가 (Water Quality Assesment of the Lower Yeongsan River System)

  • 윤석태;고영구;오강호;문병찬;김해경
    • 환경영향평가
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    • 제12권4호
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    • pp.259-270
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    • 2003
  • To investigate the water quality and the pollution state of lower Yeongsan river system, 38 water samples were taken from the main stream of the Yeongsan river, Gomakwon and Hampyeong streams of the system in dry and flood seasons, May and August, 2001. The Yeongsan river is typically natural in accordance with pH-& diagram. But the chemistry based on Piper's diagram indicates that the river is influenced by seawater. BOD increases as the sampling sites are approaching the downstream in Gomakwon and Hampyeong streams overwhelming WQS V grade of 12.40mg/l. T-N and T-P of the river are mainly loaded not in above branch streams but in the main stream of the river, which are caused by manure for farming, domestic animal discharges and life-sewage, in possible. Meanwhile, heavy metal contents are below WQS or not detect in whole water samples. So, it shows that the above river waters be polluted by not industrial but life/agricultural foul waters.

청계천 복원 후 3년간 식물상 변화 (Floral Changes During Three Years After Cheonggyecheon Restoration)

  • 김형국;구본학
    • 한국환경복원기술학회지
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    • 제13권6호
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    • pp.107-115
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    • 2010
  • This study was surveyed to identify changes of flora during three years after restoration in Cheonggyecheon stream. There are four sections in Cheonggyecheon. One and two sections are upper streams and three and four sections are down streams. It was surveyed 328 species in 2006. In 2007 and 2008, 446 and 444 species were found, respectively. This result shows that Cheonggyecheon is unstable initial condition in restored stream ecosystem. Naturalized species were 58 species in 2006 and it was respectively 61 and 63 species in 2007 and 2008. Hazard species of ecosystem were three common species during survey period. In appearance of flora per section, three and four sections constituted by natural sites such as point bars, wide flood plains, riffles and ponds, marshes, etc. were surveyed more species than one and two constructed by concrete materials and narrow flow channel. Recently, as time goes by, introduced species are being increased. And succession has mainly been progressed by one year or binary herbs and perennial herbs. Compared with other restored streams, Cheonggyecheon showed more flora than Yangjaecheon and Anyangcheon. It is judged owing to length of surveyed site, various planted species and area of inhabitation space. To manage restored stream ecosystem, monitoring is essential. Further, because change of vegetation after restoration in Cheonggyecheon is very important, continuous monitoring about Flora and Naturalized species and Hazard species of ecosystem is also very important.

엔트로피 개념을 이용한 제주도 상시하천의 평균유속분포 추정 (Mean Velocity Distribution of Natural Stream using Entropy Concept in Jeju)

  • 양세창;양성기;김용석
    • 한국환경과학회지
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    • 제28권6호
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    • pp.535-544
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    • 2019
  • We computed parameters that affect velocity distribution by applying Chiu's two-dimensional velocity distribution equation based on the theory of entropy probability and acoustic doppler current profiler (ADCP) of Jungmun-stream, Akgeun-stream, and Yeonoe-stream among the nine streams in Jeju Province between July 2011 and June 2015. In addition, velocity and flow were calculated using a surface image velocimeter to evaluate the parameters estimated in the velocity observation section of the streams. The mean error rate of flow based on ADCP velocity data was 16.01% with flow calculated using the conventional depth-averaged velocity conversion factor (0.85), 6.02% with flow calculated using the surface velocity and mean velocity regression factor, and 4.58% with flow calculated using Chiu's two-dimensional velocity distribution equation. If surface velocity by a non-contact velocimeter is calculated as mean velocity, the error rate increases for large streams in the inland areas of Korea. Therefore, flow can be calculated precisely by utilizing the velocity distribution equation that accounts for stream flow characteristics and velocity distribution, instead of the conventional depth-averaged conversion factor (0.85).

Current Status of Korean Otter and Their Conservation

  • Han, Seung Woo;Han, Sung Yong
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제3권1호
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    • pp.1-6
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    • 2022
  • Among the 13 species of otters in the world, only one Eurasian otter (Lutra lutra) is found in South Korea. In the Korean Peninsula, otter pelts were historically valuable and expensive commodities used for international trade, and otters have long been poached as hunting animals. Recent rapid economic development in South Korea has increased habitat fragmentation and loss, creating a continuing threat to the natural environment. Otters live only in the area of rivers and streams as a family group and are territorial (linear habitat). Due to these limited conditions of otter habitat, the population size of otter is lower than that of onshore mammals. According to recent research, DNA analyses using microsatellite markers have shown that only approximately 7-21 otter individuals inhabit river systems for a length of 50-230 km. Korea's urban streams are associated with many threats that hinder otters from inhabiting them. Many areas around the urban streams are surrounded by high concrete riverbanks, and the risk of roadkill is also high. Nevertheless, ecological restoration projects in the urban rivers will contribute greatly to the stable inhabitation of otters. Detailed otter conservation strategies, such as the elimination of threat factors, improvement of habitat environment, and restoration of food resources and shelter, will provide a positive restoration effect on otter and river ecosystems as well.