• 환경영향평가
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• 제21권5호
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• pp.631-648
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• 2012

The integrative ecological approaches of chemical assessments, physical habitat modelling, and multi-metric biological health modelling were applied to Gwanpyeong Stream within Gap-Stream watersheds to evaluate environmental impacts on the constructions of residential and commercial complex. For the analysis, the surveys conducted from 45 sites of reference streams within the Gap-Stream watershed and 3 regular sites during 2009 - 2010. Physical habitat health, based on the habitat model of Qualitative Habitat Evaluation Index(QHEI) declined from the headwaters(good - fair condition) to the downstream(poor condition). Chemical water quality, based turbidity and electric conductivity(EC), was degraded toward to the downstream, and especially showed abrupt increases, compared to the values of control streams(CS). Also, concentrations of chlorophyll-a in the downstreams were greater compared to the control stream(CS), indicating an eutrophication. Biological health conditions, based on the Index of Biological Integrity(IBI) using fish assemblages, averaged 19.3 which is judged as a fair condition by the biological criteria of the Ministry of Environment, Korea. The comparisons of model metric values in sensitive species and riffle-benthic species on the Maximum Species Richness Line(MSRL) of 45 reference streams indicated a massive disturbances in all sampling locations. Also, tolerance guild and trophic guild analyses suggest that dominances of tolerant species and omnivores were evident, indicating a biological degradation by habitat disturbances and organic matter pollutions. There was no distinct longitudinal variations of IBI model values from the headwater to the downstream in spite of slight chemical and habitat health gradients among the sampling sites. Overall, integrative ecological health(IEH) scores, based on the chemical, physical, and biological parameters, were low compared to the 45 reference streams due to physical and chemical disturbances of massive constructions of the residential and commercial complex. This stream, thus showed a tendency of typical urban streams which are disturbed in the chemical water quality, habitat structures, and biological integrity. Effective stream management plans and restoration strategies are required in this urban stream for improving integrative stream health.

• 한국지역지리학회지
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• 제4권1호
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• pp.15-25
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• 1998

하천은 식수원 및 생태공간, 그리고 생활공간으로서 중요한 역할을 한다. 하지만 오늘날의 도시하천은 복개, 콘크리트 제방 설치, 둔치 정비로 인하여 생태계가 파괴되고 수질오염이 심하여 하천으로서의 기능을 상실하였다. 따라서 본 논문에서는 도시하천이 생태학적으로 수행하는 역할을 밝히고 그 개선방안을 모색하였다. 하천은 다양한 형태의 태양 복사 에너지를 전달하는 통로이어서 항상 생명력이 충만한 장소이다. 하천 연변은 1차 생산성이 높아 인구의 부양능력도 크기 때문에, 농업을 기초로 한 고대 도시들은 비옥한 하천 연변에서 발달하였다. 우리나라의 경우 농업에 기반을 둔 조선시대의 도시들은 태양 에너지가 결집된 침식분지에서 발달하였다. 이러한 농촌생태계에서 하천의 역할은 에너지와 물질(물과 퇴적물질)의 공급원이자 생명선이다. 산업혁명 이후 도시의 성장과 더불어 물의 수요가 급증함으로써, 하천은 도시의 더욱 중요한 입지요소가 되었다. 그러나 도시에서 더 이상 도시하천의 에너지를 필요로 하지 않으므로써 도시하천은 생명선의 구실을 하지 못하고, 외부하천의 물을 이용한 후 오폐수를 도시하천에 방류함으로써 도시하천은 하수구로 전락하고 말았다. 도시화가 진행됨에 따라 하천의 범람 위험성은 증가하였으며 수질은 악화되었다. 이를 억제하기 위하여 콘크리트 제방을 설치하고 둔치를 정비하였으며 하천을 복개하였다. 그러나 이러한 하천개수 결과 하천의 생태계는 파괴되었고 수질오염은 더욱 심해졌다. 도시하천의 이러한 문제들을 해결하기 위해서는 농촌하천에서처럼 하천내의 많은 에너지를 육상으로 이동시켜야 한다. 이를 위하여 하천 연변에서 둔치에 이르기까지 습지를 가꾸어 하천내의 에너지를 소모시키고, 생태공원을 조성하여 원시적 자연의 생명력을 되찾아야 한다.

• 한국습지학회지
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• 제19권4호
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• pp.491-500
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• 2017

하천수량은 하천의 수질, 생태환경보전에 있어 가장 근원적이고 기본적인 사항으로 매우 중요한 요소이다. 본 연구의 목적은 경기도 도심하천의 불투수면적률에 따른 하천수량 변화 원인 및 영향을 분석하여, 경기도 도심하천의 하천수량 확보 방안 및 하천관리 정책에 반영할 있는 자료를 제시하는 것이다. 이를 위해 안양천유역, 탄천유역, 오산천유역을 표본 도심하천으로 선정하고, 불투수면적률(%ISA)에 따른 하천수량 및 수질의 변화와 직 간접적인 하천수 확보방안을 검토하였다. 그 결과를 정리하면 다음과 같다. 안양천유역, 탄천유역, 오산천유역의 불투수면적률은 2014년을 기준으로 약 10년전 보다 각각 5.32%, 6.32%, 7.22% 증가하였으며, 전반적으로 불투수면적률이 증가할수록 유출계수는 증가하는 경향을 보였다. 하천 재이용수량은 탄천유역에서 하천수 확보에 긍정적 효과가 나타났지만 안양천유역과 오산천유역은 하천수 확보 효과가 미흡하였다. 그러나 하천 재이용수량으로 인해 각 하천 수질등급이 개선되는 것으로 나타났다.

• 한국습지학회지
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• 제21권3호
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• pp.224-235
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• 2019

급격한 도시화는 도시 하천에 크게 세 가지 문제점을 야기하고 있다. 첫 번째 문제는 불투수지역의 증가에 따른 강우의 토양 침투량 감소이다. 토양 침투량 감소는 도시하천의 물순환에 심각한 왜곡을 일으키게 된다. 두 번째 문제는 도시적 토지이용에 따른 비점오염물질의 증가이며, 세 번째 문제는 구도심에서의 합류식 하수관거 월류수이다. 비점오염물질의 증가 및 합류식 하수관거 월류수는 물순환 왜곡과 맞물려서 도시하천 수질오염을 가중시키게 된다. 본 연구에서는 이러한 세 가지 문제점에 대한 해결방안을 제시하고자 부산 온천천 유역을 대상으로 EPA SWMM을 구성하였으며, 미국 뉴욕시에서 실제로 시행중인 사업을 벤치마킹하여 생태저류지 설치 사업을 계획하였다. 사업 시나리오별로 물순환 개선효과와 비점오염 및 합류식 하수관거 월류수의 저감량이 요구되는 예산과 함께 분석되었다.

• Korean Journal of Hydrosciences
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• 제8권
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• pp.19-30
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• 1997

The hydraulics of flow within the covered reach of urban streams is very complicated due to the accumulation and interference effect of eddies around the multipli piers supporting the covering slab. An extensive experimental study is done to quantitatively estimate the backwater rise effect caused by various arrays of multiple piers. The factors governing the backwater rise are found out to be the contraction ratio due to the piers. Foude number of the flow, longitudinal pier spacing, and the length of the covered reach. For a single section of lateral pier arralyzed and a multiple regression equation derived. The effect of multiple piers, arrayed in both lateral and longitudinal directions. on the backwater rise is analyzed in terms of the contraction ratio. Froude number, longitudinal pier spacing and the total length of the covered reach. A multiple regression equation for the backwater rise estimation is proposed based on the experimental data collected in this study.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2004년도 학술대회
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• pp.68-69
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• 2004

• 한국환경생태학회:학술대회논문집
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• 한국환경생태학회 2003년도 추계학술논문발표회 논문집
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• pp.205-207
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• 2003

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.115-123
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• 2012

A video analysis system used to detect events in video streams generally has several processes, including object detection, object trajectories analysis, and recognition of the trajectories by comparison with an a priori trained model. However, these processes do not work well in a complex environment that has many occlusions, mirror effects, and/or shadow effects. We propose a new approach to a context-aware video surveillance system to detect predefined contexts in video streams. The proposed system consists of two modules: a feature extractor and a context recognizer. The feature extractor calculates the moving energy that represents the amount of moving objects in a video stream and the stationary energy that represents the amount of still objects in a video stream. We represent situations and events as motion changes and stationary energy in video streams. The context recognizer determines whether predefined contexts are included in video streams using the extracted moving and stationary energies from a feature extractor. To train each context model and recognize predefined contexts in video streams, we propose and use a new ensemble classifier based on the AdaBoost algorithm, DAdaBoost, which is one of the most famous ensemble classifier algorithms. Our proposed approach is expected to be a robust method in more complex environments that have a mirror effect and/or a shadow effect.

• 한국환경과학회지
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• 제18권1호
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• pp.113-127
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• 2009

This study was designed to present a river model with an aim at restoring the ecosystem and improving the landscape along the urban rivers on the basin of the Namhan river, a core life channel for the National Capital region. The revelation of botanical status, transition trend and correlation of plants might lead to providing the urban river restoration projects and ecological river formation projects with basic data for a model of ideal aquatic ecology and landscape. The outcomes of this study could be summed up as follows: 1. Communities of Juglans mandshurica, Cornus controversa and Fraxinus mandshurica constitute the main portion of flora at or around uppermost branch streams of the River Namhanis harbored mainly in and around small brooks 2. Typical terrestrial forest communities formed around the River Namhan are composed mainly of Larix leptolepis, Pinus rigida, planned forestation of Pinus koraiensis, Quercus acutissima, Quercus variabilis and Pinus densiflora. 3. The analysis into terrestrial environment of plant communities showed a high content of $P_2O_5$, typical communities found in the artificially disturbed land Finally, it seems also desirable to continue to make every exertion to explore the relationship between fluvial and terrestrial ecologies with a purport of building up a model of natural streams in urban area based on the surveyed factors for plant life, forest communities, soil and landscape and, moreover, on the forecasting for overall influences derived from the relation upon the ecosystem.

• Environmental Engineering Research
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• 제19권2호
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• pp.175-184
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• 2014

Weirs are conventional structures that control water level and velocity in streams to facilitate water resource management. Despite many weirs built in streams, there is little information how weirs change hydrology regime and how that translates to sediment and phosphorus (P) responses. This study evaluated the influence of weirs on P retention and mobilization in an urban tributary of the Han River in Korea. Total P concentrations in sediments upstream of weirs were higher than the downstream site, mainly due to the increase of potentially available fractions (labile P and aluminum- and iron-bound P) (p < 0.05). Equilibrium phosphorus concentrations ($EPC_o$) were lower than soluble reactive phosphorus (SRP) concentrations of stream waters, but there was an increasing trend of sediment $EPC_o$ upstream of weirs compared to the downstream site (p < 0.001) indicating a greater potential for P release upstream of weirs. Sediment core incubation showed that SRP release rates upstream of weirs were higher than the downstream site under anoxic conditions of the water column (p < 0.01), but not under oxic conditions. SRP release rates under anoxic conditions were greater than that measured under oxic conditions. Un-neutral pH and increased temperature could also enhance SRP release rates upstream of weirs. We conclude that weirs can increase P retention within stream sediments and potentially promote significant P releases into waters, which in turn cause eutrophication.