• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.189-198
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• 2020

Wetlands, which provide various ecological services, have been regarded as an important nature-based solution for, for example, sustainable water quality improvement and buffering of impacts from climate change. Although the importance of conserving wetlands to reduce the impacts of various perturbations (e.g., changes of land use, climate, and hydrology) has been acknowledged, the possibility of applying these efforts as a nature-based solution in a macro-scale (e.g., landscape) has been insufficient. In this study, we examine the possibility of ecological network analysis that provides an engineering solution as a nature-based solution. Specifically, we analyzed how land use change affects the structural and functional characteristics (connectivity, network efficiency, and clustering coefficient) of the ecological networks by using the ecological networks generated by multiple dispersal models of the hypothetical inhabiting species in wetlandscape. Changes in ecological network characteristics were analyzed through simultaneously removing wetlands, with two initial conditions for surface area, in the zones where land use change occurs. We set a total number of four zones of land use change with different wetland densities. All analyses showed that mean degree and network efficiency were significantly reduced when wetlands in the zones with high wetland density were removed, and this phenomenon was intensified especially when zones contained hubs (nodes with high degree). On the other hand, we observed the clustering coefficient to increase. We suggest our approach for assessing the impacts of land use change on ecological networks, and with additional analysis on betweenness centrality, we expect it can provide a nature-based engineering solution for creating alternative wetlands.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1867-1873
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• 2008

호안은 제방 및 저수로 하안을 강수와 유수에 의한 파괴와 침식작용에 대하여 직접 보호할 목적으로 설치하는 것이다. 최근에는 자연형.생태하천 등 하천의 친수성.경관.생태계의 보전.재생 등이 중요시 되면서 이런 기능을 가진 많은 호안공법들이 개발 및 시공되고 있다. 하지만 이러한 호안공법에 대한 홍수시의 수리적 안정성 검토 등의 기술적인 검토가 충분치 않은 실정이다. 따라서 호안공법이 적용된 호안에 대해 홍수시의 수리적 안정성에 대한 분석이 필요하다. 본 연구에서는 호안 조사결과 우리나라에서 가장 많은 시공사례가 있는 콘크리트 식생블록에 대해서 개수로 수리모형실험을 통하여 호안의 수리적 안정성을 분석하였다. 분석에 이용된 모형은 실제 하천에 많이 적용되고 있는 H형 식생블록을 1/10 축소모형을 제작하여 사용하였다. 호안경사 1:2에 대해 식생이 없는 경우, 식생이 0.08m, 0.04m 간격으로 있는 경우에 대해 유량을 변화시키면서 식생밀도에 따른 유속 저감 및 소류력 저감 효과에 대한 수리적 안정성을 분석하였다. 그 결과 호안경사 및 식생밀도는 호안부에서 흐름의 에너지 및 유속을 감소시키며, 식생이 없는 호안에 비해 식생이 있는 호안에서는 식생밀도가 증가함에 따라 소류력이 최대 62.24%까지 감소하였다. 호안부에서의 식생의 발달은 유속 및 소류력을 감소시켜 호안부의 안정화에 크게 기여하고 있음을 알 수 있었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.1-1
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• 2017

녹조현상은 부영양화된 호수나 유속이 느린 하천에서 부유성의 조류(식물 플랑크톤)가 대량 증식하여 수면에 집적하게 되고 물의 색을 현저하게 녹색으로 변화시킴으로써 발생된다. 최근에는 이러한 녹조 현상이 광역화, 독성화, 장기화의 특성을 띠며 빈번히 발생되고 있다. 녹조현상은 독소를 발생시키는 남조류에 의해 수생식물에 악영향을 주는 것으로 알려져 있다. 예를 들면 독소에 의한 가축에의 영향, 생태계 파괴로 인한 생태학적인 문제, 산소결핍으로 인한 물고기 및 각종 수중생물 폐사 등의 심각한 문제를 야기한다. 또한 조류는 식수에서 맛과 냄새를 유발할 뿐 아니라 Microcystin-LR과 같은 유해한 독소를 배출하여 공중 보건을 위협한다. 이에 식수원으로 사용되는 하천의 조류 번식에 따른 대응방안 마련이 절실히 요구된다. 유입되는 조류로 부터의 정수처리 설비의 처리 부하를 줄이기 위해서는 취수시스템과 연계한 고속 전처리 조류 제거 시스템을 개발이 필요하다. 기존의 전기응집부상공정(Electro-Coagulation and Flotation, ECF)은 화학 약품(응집제) 투여량이 적은 이점이 있지만 비교적 긴 전기 분해 시간이 필요하여 기존 정수처리 시스템과 연계성에 있어 한계가 있다. 이에 본 연구는 전기 분해 시간을 줄여 유입된 조류를 수 초 내에 응집하여 1분 이내에 조류를 분리하는 초고속 조류 전처리 기술을 개발하였다. 개발된 기술의 현장적용 및 실험 결과, 응집과정이 없이도 Chlo-a는 약 45 %의 제거 효율을 나타났다. 또한 응집제의 투입 및 전극에 의한 부상시스템에 의해 Chlo-a가 약 80 %로 제거되는 것으로 나타나 빈번하게 발생되는 조류로부터 안정적인 물 공급을 위한 전처리 공정으로 활용이 가능할 것으로 판단된다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.217-217
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• 2020

인간 물이용 중심의 하천 관리로 하천에 인위적으로 설치되는 횡단구조물은 물의 흐름을 막아 수질환경을 악화시킬 뿐 아니라 하천의 연속성을 단절하여 생물의 이동을 차단하여 생태계에 악영향을 미친다. 이러한 인위적인 구조물로서 약 34000여개의 농업용 보와 약 16000여개로 추정되는 낙차공이 다수 존재하고 있다. 이러한 구조물은 유수에 의하여 하상으로 전달되는 유수에너지를 저감하기 위하여 다양한 형태의 하상보호공을 설치하여 하천횡단구조물을 보호하도록 되어있다. 그러나 하상보호공에 사용되는 기술 중 사석 및 돌망태와 같은 기술은 시공비용이 적고 빠른 시간에 시공 할 수 있지만 급격한 홍수에 쉽게 파괴 및 유실이 되는 단점이 있으며, 콘크리트 소재 공법은 세굴방지에 좋은 효과를 발휘하는 장점을 지니지만, 시간이 지남에 따라 마모/변형되거나 포락/유실되어 하상을 지속적으로 보호하지 못하게 되며 과도한 세굴은 구조물의 안전성에도 영향을 미친다고 할 수 있다. 최근 기후변화로 인하여 돌발호우 및 강우량의 증가로 돌변하는 하천환경에 대한 적용기술은 미비한 실정이기 때문에, 많은 연구자들은 이에 대한 해결책을 찾기 위하여 자연친화적 생태복원 기술을 개발하고 있다. 본 연구에서는 바이오폴리머를 다층다공성 하상보호기술에 대하여 에너지 저감 효율, 고유속에서 한계 소류력, 소재 이탈 실험을 최대유량 10 ㎥/s, 유속 8m/s를 재현할 수 있는 실규모 하천실험장에서 진행하여 과학적인 안전성을 확인하였다.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.40-46
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• 2007

For restoration of disturbed ecosystem in Lake Paro, artificial floating island (AFI) was installed. Even though the lake water was oligo-mesotrophic, the macrophytes, such as Iris ensata, Iris pseudoacorus, Phragmites communis were growing well in the rubberized coconut fiber media. For elucidating this process, total bacterial numbers, active bacterial numbers and exoenzymatic activities of ${\beta}-glucosidase$ and phosphatase of pore water of media and lake water were analyzed. The average of total bacterial numbers, active bacterial numbers and exoenzymatic activities of ${\beta}-glucosidase$ and phosphatase were $28.6{\times}10^{6}\;cells/ml,\;22.7{\times}10^{6}\;cells/ml,\;452.9nM/L/hr,\;and\;16381.9nM/L/hr$ which were 10, 15, 22 and 38 times higher than those of lake water, respectively. Moreover, the total phosphorus and total nitrogen concentration of media showed high values of 0.82 mg/L and 7.0 mg/L, respectively, while those of lake water 0.07 mg/L and 2.3 mg/L. This results suggest that the bacteria was playing an important role for restoration of disturbed ecosystem with newly created microbial ecosystem in media of artificial floating island.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.390-398
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• 2017

In this study, we conducted a questionnaire survey for the purpose of finding a method of mobile sector ecosystem activation targeted at small and medium businesses (SMBs). Through the total of 204 responders consisting of business employees from each mobile sector, we analyzed the factors inhibiting the development of the mobile ecosystem and preventing the activation the mobile market, as well as conducting a diagnosis of the digital potential. This paper presented suggestions for searching for a systematic supporting strategy considering the short-term inhibitory factors (market structure improvement, financial support, etc.) and long-term orientation factors (personnel nurturing, strengthening of supporting role by governmental initiative) for the activation of the domestic mobile market. After measuring the digital potential, we found that domestic mobile SMBs have perceived the importance of the digital potential and have considered and readied themselves for the future market. The present survey found that if suitable digitalization can be accomplished for their firms' products and services, they have the ability and willingness to succeed in the market. However, they have a hard task ahead of them from adigital delivery perspective given the potential for digital disruptions.

• Journal of the Korean association of regional geographers
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• v.4 no.1
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• pp.15-25
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• 1998

A stream plays an important role as the source of drinking water, the ecological space and the living space. But the today's urban stream whose ecosystem is destroyed and water quality become worse in consequence of covering, concrete dyke construction, and the adjustment of high-water-ground[dunchi], is deprived of the function as a stream. Therefore this paper aims to elucidate the role that urban stream plays ecologically and to try to find a improvement to the problem. A stream is the pathway through which several types of the solar radiation energy are transmitted and the place which is always full of life energy. In the periphery of a stream, primary productivity is high and carrying capacity of population is great. Thus ancient cities based on agricultural products grew out of the fertile surroundings of stream. In Korea most cities of the Chosen Dynasty Period based on the agriculture have grown out of the erosional basins where solar energy is concentrated. The role of a stream in this agricultural system is the source of energy and material(water and sediment) and a lifeline. In consequence of the growth of cities and the rapid growing demands of water supply after the Industrial Revolution, a stream has become a more important locational factor of city. However, because cities need the life energy of urban streams no longer, urban streams cannot play role as a lifeline. And As pollutant waste water has poured into urban streams after using external streams' water, urban streams have degraded to the status of a ditch. As the results of the progress of urbanization, the dangerousness of inundation of urban stream increased and its water quality became worse. For the sake of holding back it, local governments constructed concrete dyke, adjusted high-water-ground[dunchi], and covered the channel. But stream ecosystem went to ruin and its water quality became much worse after channelization. These problems of urban stream can be solved by transmitting much energy contained in stream to land ecosystem as like rural stream. We should dissipate most of the energy contained in urban stream by cultivating wetland vegetation from the shore of stream to high-water-ground, and should recover a primitive natural vigorous power by preparation of ecological park.

• Korea journal of population studies
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• v.24 no.2
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• pp.5-45
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• 2001

Population and the environment are the basic elements of a human ecological system having intrinsic links between them. But, research on their relationships is very limited in both quantity and depth. Although the concern on the topic has grown recently, most discussions lack analytical perspectives and are largely descriptive. The tendency is blamed for problems involved in defining the term, the environment, and the paucity of data on environment. In Korea, the limitation is much grater and, therefore, this study sets a moderate aim: That is, to explore, from ecological perspectives, various implications of population change on the environment in 20th century Korea. More specifically, it examines the related theoretical discussions, the major features of population change, and changes in environmental conditions that can be assumed to have direct or indirect links with population size and urbanization. Official statistics and newspaper articles on various environmental issues consist of the major data sources.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.104-123
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• 2002

The flora survey on Chungnyeongsan and Seorisan was conducted 6 times from 1998 to 2000.817 taxa such as 112 families 415 genera 688 species 1 subspecies 116 varieties 12 forma were recorded. Dominant species in investigated areas was Quercus mongozica and some deciduous broad-leaved species, such as Quercus sp., Acer sp., Fraxinus sp., Carpinus sp., etc. were codominant species in these areas. Pinus koraiensis and Larix teptozepis plantations were also found in these areas. The 16 taxa of rare plants protected by Forestry Service were found in these areas and among them 10 taxa were new populations which had not been recorded in these areas. Discovery of Erunthis stellata, Aconitum koreanum, Paeonia japonica, Scopotia japonica and Acunthopanax senticosus populations indicate that these areas could be regarded as very important one in a biogeographical aspect. Endemic plants were listed 35 taxa and among them 22 taxa including Corydalis maculata, Ulmus macrocarpa, Scrophutaria horuiensis, Cirsium setidens, etc. were new one. Naturalized plants were listed 39 taxa and among them 30 taxa were new one. Lower naturalized index(NI) and higher urbanized index(UI) were recorded compared to those of neighbored areas. There were many kinds of threatening factors fur the plant resources in survey areas, so it is necessary to limit the number of visitors and to introduce the natural relaxation system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.4
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• pp.411-420
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• 1999

Coastal development and reclamation work make environment of shore destroy, such as rapid change of land use and destruction of wet-land and ocean ecosystem. Therefore new technique to detect change have been needed. This study designed new change detection method and applied to study area. The change detection image and quantitative change area by each classes are calculated. Also, this study can use the basic idea-determination data for coastal development and city plan as the sense of sight by changed images that changed from any land-cover to any land-cover between two dates.