• Title/Summary/Keyword: Ecological river

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Analyzing Ecological Soundness Considering the Implicit Weight of the Indicator (지표의 내재적 가중치를 고려한 하천의 생태적 건전성 평가)

  • Kim, Hong-Myung;Ha, Sung-Ryong
    • Journal of Environmental Impact Assessment
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    • v.30 no.4
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    • pp.258-269
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    • 2021
  • The purpose of this study is to establish a system to evaluate the ecological soundness of the Geum river basin. The study target area is 14 sub-watersheds of the Geum river basin. For the selection of indicators to ensure transparency and consistency of the evaluation indicators, the ecological soundness indicators were secured by using the indicator adjustment method derived in consideration of the intrinsic weight change characteristics between indicators. The index with the greatest impact on the final composite index was identified as the index of the aquatic ecology among the water quantity, water quality, aquatic ecology, and habitat-riparian environment dimensions. As a result of analyzing the ecological health index of the river, the watershed upstream of the dam (based on the Daecheong -dam) was evaluated to be in relatively good condition until 2014 compared to the base year(2008), and the watershed downstream of the dam was evaluated to be in a poor condition. The annual trend of changes in the ecological soundness index on an annual basis is as follows. In the case of Yongdamdam, Yongdamdamdownstream, Bocheong-chun, Daechungdam, Daechungdamdownstream, and Nonsancheon, although there are differences by time period, the soundness index is in declining. On the other hand, Mujunamdaecheon, Yeongdongcheon, and Gapcheon were evaluated to have improved soundness, while Chogang, Daechungdamupstream, Mihocheon, Gongjugeumgang, and Geumgangestuary were evaluated to deteriorate again after soundness was improved.

A Basic Study on Connectivity of Urban Parks for the Urban Ecological Network Establishment (도시생태네트워크 구축을 위한 도시공원의 연결성 평가 기초 연구)

  • Sung, Hyun-Chan;Kim, Mi-Ri;Hwang, So-Young;Kim, Su-Ryeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.17 no.2
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    • pp.125-136
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    • 2014
  • Urban Green Area has ecologically deteriorated along with quantitative loss, being developed as a dot itself rather than connected to forests and green networks around the park. The present study aims to propose a connected plan on Urban Ecological Network establishment through 'assessment of the connectivity of the entire urban parks' in accordance with distance of forest and river and 'assessment of trends in connection fragmentation of urban parks' in accordance with the past change of forest and river. According to the result of this study, criteria based on previous research was "directly linked type is less than 300m, conceptually linked type is between 300m to 1km, the isolated type is greater than 1km". And the result of 'assessment of the connectivity of the entire urban parks' is analyzed as the rate of park and green network, 41.7% in Suwon, 80.0% in Seongnam, 88.9% in Namyangju on the basis of office and field investigation. Also, according to the result of 'assessment of trends in connection fragmentation of urban parks', consideration for connection to the original forest is insufficient.

Model development in freshwater ecology with a case study using evolutionary computation

  • Kim, Dong-Kyun;Jeong, Kwang-Seuk;McKay, Robert Ian (Bob);Chon, Tae-Soo;Kim, Hyun-Woo;Joo, Gea-Jae
    • Journal of Ecology and Environment
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    • v.33 no.4
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    • pp.275-288
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    • 2010
  • Ecological modeling faces some unique problems in dealing with complex environment-organism relationships, making it one of the toughest domains that might be encountered by a modeler. Newer technologies and ecosystem modeling paradigms have recently been proposed, all as part of a broader effort to reduce the uncertainty in models arising from qualitative and quantitative imperfections in the ecological data. In this paper, evolutionary computation modeling approaches are introduced and proposed as useful modeling tools for ecosystems. The results of our case study support the applicability of an algal predictive model constructed via genetic programming. In conclusion, we propose that evolutionary computation may constitute a powerful tool for the modeling of highly complex objects, such as river ecosystems.

Effects of Landscape Ecological Characteristics on Bird Appearance - Focused on The Nakdong River Estuary - (경관생태학적 특성이 조류출현에 미치는 영향 - 낙동강 하구를 대상으로 -)

  • Kim, Bum-soo;Yeo, Unsang;Oh, Dongha;Sung, Kijune
    • Journal of Environmental Impact Assessment
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    • v.24 no.3
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    • pp.287-299
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    • 2015
  • If the Nakdong River estuary is to be sustainable, land use management practices need to consider bird habitat requirements, especially given that the area serves as an important migratory bird sanctuary. In this study, bird habitats found in the Nakdong River estuary were classified into 11 different types including Phragmites australiss, mud flat, farmland, open surface in freshwater, sand bar, riparian forest, Scirpus planiculmis, waterway, construction, grasslands, and open surface in sea or brackish water. Taking into consideration the regional characteristics, habitat properties, and landscape indices, a total of 12 study sites were analyzed. Mud flat, construction, farmland, and P. australis account for 80% of the total land area. The high area ratio of construction and farmland to other types of habitat revealed a high amount of historical human activity and intervention in the area. Both patch numbers as well as patch density were high in West Nakdong River, Samrak Waterfront, Maekdo River, and Daejeo Floodgate, with these areas showing the greatest fragmentation as well. Total numbers of species and individuals had a positive correlation with the area and the number of habitat types. Findings suggest that protecting the habitat area, especially in S. planiculmis, is the most important factor for bird habitat management and that future development could result in habitat loss, having a profoundly adverse impact on bird populations. Therefore, it is important that the total area should be carefully protected by land use regulations in order to ensure that the Nakdong River estuary maintains its functional integrity as a migratory bird sanctuary.

Assessment of Water Quality Based on Ecological Factors in Anyang River (안양천에서의 생태학적 수질오염도 평가)

  • Lee, Yang-Kyoo;Cho, Won Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.3
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    • pp.39-50
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    • 2006
  • In this study, the water quality investigated during 2002s to 2004s for Anyang river and its affluent that was based on biological and chemical methods as well as ecological index of each streams. The improving of water quality and the multiplicity of specious in the most streams except for Anyang, which was due to the improving of water quality and water resource. The seasonal dry states are completely disappeared, but water quality of Anyang main stream was classified as fifth grades water with BIP 8.51~10.00 and BOD 8.16~14.4mg/l in Anyang stream overall. And alpha-mesosaprobic in upper, mid parts and polysaprobic in down parts of Anyang main stream are appeared according to Saprobien system, respectively. The water supply of treated sewage is appeared that upgrading effects of water quality in Anyang main stream and affluents of Anyang city area, but the practical effects of "Saving Anyang River" could not gained because the water quality of other branches in upstream parts than upstream measuring point of Anyang main stream, Wanggok stream Sanbon stream in Gunpo and Eeiwang cities, was not improved.

An Integrated Ecological-Economic System Dynamics Model Analysis on the Ecosystem Restoration Policy (II): Extensions and Relaxations of the Model of King Crabs in the Imjin River, Korea (생태계 복원사업의 생태.경제 통합체계 동태분석(II) -임진강 참게 복원사업의 확장모형-)

  • Jeong, Hoi-Seong;Jeon, Dae-Uk
    • Korean System Dynamics Review
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    • v.7 no.2
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    • pp.97-120
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    • 2006
  • This paper deals with the extension of and discussion on the System Dynamics model (Jeong & Jeon, 2005) of river crabs in Korea. The previous model has been elaborated to empirically search for the optimal restoration and harvest rates of crabs in the Imjin River, on the basis of theoretical models of population dynamics in the field of bio-mathematics and environmental economics. In this paper, the authors tries to couple a series of new feedback loops related to density restrictions and cannibalistic behaviors with a stage-structured model of the crab ecosystem, and also to endogenize the parameter of baby crabs' survival that is caused by water quality improvement and income increase. Through these extensions and relaxations, the authors are able to argue about the strategic decision of the optimal rates additional considerations as well as the properties of the integrated system that was not covered in the previous paper.

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