• Ecology and Resilient Infrastructure
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• v.10 no.2
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• pp.40-49
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• 2023

To reduce the damage of extreme flooding caused by climate change and to create flood mitigation sections in a nature-friendly riparian area, it is necessary to restore the floodplain area by referring to the past floodplain section of the current inland waterfront area before the levee was built. This study proposed a method of selecting a location for floodplain restoration using old maps of the Geum River study section and analyzed the effect of flood level reduction through unsteady flow numerical simulations using the floodplain as a flood mitigation space. As a result of analyzing changes in the river areas using old maps, the river section was estimated to gradually reduce by 27.8% (1,059,380 m²) in 2020 compared to 1919, and it was found to have an effective storage capacity of 2,200,868 m³ when restored to offline storage. The flood level and discharge control effects analyzed based on HEC-RAS unsteady flow simulation were 16 cm and 219.01 m³/s, respectively, in the downstream cross-section. In the numerical simulation in this paper, the flood mitigation space was applied as an offline reservoir. The effect of reducing the flood level may differ if levee retreat/relocation is applied.

• Korean Journal of Environment and Ecology
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• v.20 no.2
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• pp.235-258
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• 2006

The monitoring of vegetation and water quality before(2003), during(2004) and after(2005) the restoration work of Cheonggye Stream indicated that $BOD_5$ concentration before the project averaged 51.1mg/L and that both the inflow of water from Hang River and the funnel of subway station water into the stream lowered the $BOD_5$ to 3.3mg/L, improving its water quality to the third grade. Species of plants slightly increased from 121 to 132 after the restoration. Specifically, perennial plant comprised 35.6%, an increase from 24.8% recorded before the restoration. Phragmites communis and Zoysia japonica communities were observed as the introduction vegetation. However, Humulus japonicus and Erigeron canadensis communities, which were classified into the first grade according to the vegetation conservation classification, were found to be still prevailing though they were dominant community before the restoration, meaning that the ecological condition of plants had not changed very significantly. An the other hand the water quality of the reference reach was classified into the first grade based on $BOD_5$, which implies the water quality of the section was better than the project reaches. Besides the section had more diverse plant species which numbered 154, and furthermore, the rate of immigrated plants comprised 13% which was lower than 28.8% recorded by the project sections. The project reaches are considered to be inferior to the reference section in terms of ecological condition. The effectiveness of the stream restoration cannot be determined only by such short-term investigation as was conducted in this study, and it is considered that the effectiveness of the restoration of Cheonggye Stream can be determined only if investigations in other major factors are conducted over the long-term period.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.43-54
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• 1999

1. Hanoi city was built up on the wetland landscape of the Red River delta therefore it has a network of many lakes and rivers. 2. The aquatic biodiversity (Macrophytes, Invertebrates, Fishes, Vertebrates) of the 6 main lakes (Ho Tay, Hoan Kiem, Bay Mau, Giang Vo, Dong Da, Thanh Nhan) are rich and diverse. It represents the patterns of Red River delta one's. Many rare and endangered species are found in these lakes Particularly a giant freshwater turtle species in Hoan Kiem lake. 3. All of these lakes are more or less polluted. Their environments are seriously degrading both in water quality and aquatic biodiversity. 4. Based on socio-economical and cultural role of these lakes of Hanoi city, it is very necessary to preserve and to restore their environments and aquatic biodiversity: water Pollution control, landscape planning, making roads around the lakes and erosion control for their banks, legislation measures, rational exploitation of aquatic biodiversity, restoration the artificial wetlands with macrophytes.

• Journal of Environmental Health Sciences
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• v.36 no.1
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• pp.72-75
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• 2010

대한민국의 주요 하천인 한강, 금강, 낙동강, 영산강에서 2009년 11월부터 정부가 추진하는 4대강 살리기 사업(이후 4대강 사업)이 본격적으로 시작됐다. 정부는 기후변화 시대에 홍수와 가뭄에 대비하고 물 부족 시대에 수자원을 확보하며, 하천의 자연 생태계를 살리고 사람이 즐길 수 있는 레저 친수문화 공간을 조성하기 위해서라고 사업 목적을 내세운다. 환경시민단체와 상당수의 학자, 전문가들은 4대강 살리기 사업의 근간인 하도(강줄기)준설과 보 건설은 하천 수질 오염과 자연과 생태 환경 파괴로 끝날 뿐이라며 강하게 반대한다. 22조 2천억 원이라는 막대한 사업비가 들어가는 거대 사업의 시한을 정부는 이명박 대통령 임기 말년인 2012년으로 못 박고 있다. 2010년 지방선거와 2012년 차기 대통령 선거를 앞두고 전국 규모의 대형 토목 개발 사업을 이용한다는 의혹까지 제기되고 있다. 4대강 살리기 사업에 대한 비판과 결과에 대한 논란은 사업 기간은 물론 종료 이후에도 계속될 것으로 전망된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.452-456
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• 2009

무심천에 대한 모니터링은 '무심천 살리기'의 일환으로 이루어진 하천종합조사사업으로써 저수량, 홍수량, 생태계 및 하천공법 등에 대한 조사 및 분석을 수행하고 있다. 모니터링은 5년간에 걸친 사업으로 2007년 5월부터 시작하여 2009년 현재 2차년도 사업을 진행중이다. 본 연구에서는 특히 무심천에 적용된 하천공법에 대한 조사 및 분석에 국한하였다. 여기서 2002년부터 자연형 하천정화사업에서 적용했던 공법과 이로 인한 수리인자의 변화를 관찰하고, 저수로 호안을 포함한 각종 하천환경 시설물의 수리적 대응도를 분석하여 개선 방안을 제시한 것이다. 무심천의 조사구간은 미호천 합류부로부터 청원군과의 경계인 지북동 경계점 까지이며, 조사 및 분석한 하천연장은 무심천 본류 12.0 km이다.

• The Korean Journal of Ecology
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• v.21 no.4
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• pp.373-382
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• 1998

This paper describes the ecological structure and function of riparian zone, and their historical changes with land-use. The riparian zone consists of valley floor landform and riparian vegetation. The functions discussed are attenuation of sunlight energy, input of leaves and needles, contribution of woody debris to streams, and retention of flowing material out of transport. These primary functions directly or indirectly influence water and sediment qualities of streams, bars and floodplains, and thereby aquatic biota. Temporal changes in a hydrological system and riparian ecosystem were examined with reference to land-use conversin in order to understand the linkages between these two systems in Toikanbetsu River. The influences of channelization and land-use on discharge of suspended sediment and wetland vegetation was also investigated in Kushiro Marsh. These two examples suggested that the ecological functions of riparian zone have been degraded as flood control and reclamation works have expanded in the past twenty years The author proposes river restoration planning by preserving or creating landscape elements based on the concepts of sustaining physical and ecological linkages.

• Journal of Species Research
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• v.1 no.1
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• pp.87-99
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• 2012

Before the construction of Hantangang dam, we surveyed vertebrate fauna along the Hantangang River and collected samples. We collected 248 specimens (1,394 individuals) of 41 fish species from 10 families in four orders, including 17 endemic species and 5 endangered species. In our herpetofauna survey, we collected 47 amphibian samples of 10 species from 5 families in 2 orders, and 19 reptile samples of 5 species from 2 families in 1 order. We observed 25 species of bird (6 orders, 14 families) inclulding collection of 51 bird specimens (10 species from 5 families in 1 order). We collected 91 mammals of 6 species, and identified 7 species from field sign and direct observation from a total of 10 families in 5 orders. This collection and list comprise the final vertebrate faunal survey of the Hantangang region, and will provide basic scientific information for future research on conservation and restoration of the region.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.679-685
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• 2005

In Korea, water management policy had been successfully conducted until late 1980's. During the period, fundamental needs of human-being, such as requirements of drinking and irrigation waters and flood protection for living, had been satisfied. However, most of recent water problems occurred after the late 1980's such as water quality management and new water resources development, have been unresolved and accumulated. Because, our water governing institutions have become ineffective as water management issue has been changed gradually from fundamental human needs such as water supply and/or flood protection to complex/integrated issues, for example, river restoration. To solve those water problems accumulated, we needs a new paradigm of water governing institution such as setting up national water management committee and river basin committee, in order to coordinate water-related ministries' policies and establish national water resources planning in an integrated format.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.187-190
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• 2008

The water quality at the Dongbin Harbor at Pohang city, is getting worse due to the sewage and the wastewater from communities. In this syudy, RMA2 and RMA4, which is two-dimensional depth-averaged finite element numerical model, were employed to simulate the improvement of water quality from inflowing water through an inland canal to be planned connecting Dongbin Harbor and the Hyeongsan River. For the comparative result of the numerical model, both the present condition and the restoration condition (after construction of an inland canal) is simulated. The results of these conditions reasonably simulate a real situation at the Dongbin Harbor. After construction of an inland canal, the water quality at the Dongbin Harbor will be compared to the fresh water quality of the Hyeongsan River at the steady state. Futhermore, The result of simulation will be used to decide the most effective dimension of the canal.

• Korean Journal of Ecology and Environment
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• v.52 no.1
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• pp.28-39
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• 2019

This study was conducted to elucidate microplastics detection of freshwater ecosystems in Geum river. Samples are collected at 6 points in freshwater, 5 points in fishes. Freshwater was sampled 100 L per each points and fish species were Opsariichthys uncirostris amurensis, Hemibarbus labeo, Pseudogobio esocinus, Zacco platypus, Micropterus salmoides and Cyprinus carpio. FTIR analyis was adopted to identify microplastic types. Extracted microplastics were PES (polyester), PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PVC(Polyvinyl chloride) in freshwater, and PES, PE, PP, PET, PVC in fishes. Our results were expected to be used basic research information for further study in microplastics of freshwater ecosystems.