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Lee S.-B.,Konkuk University | Yoon C.-G.,Konkuk University | Jung K.W.,Korea Water Environment Research Institute | Hwang H.S.,National Institute of Environment Research
Water Science and Technology | Year: 2010

Stormwater pollution is the untreated contaminated water that drains into natural waterways from land uses within an urban catchment. Several studies have demonstrated the deterioration of water quality in receiving bodies of water caused by stormwater runoff. The data have reported that urban runoff play primary roles in degrading water quality in adjacent aquatic systems. The accurate estimation of non-pollutant loads from urban runoff and the prediction of water quality in receiving waters are important. The objective of this paper is to assess the applicability of the watershed scale hydrologic and water quality simulation models SWMM and HSPF to simulate the hydrology of a small watershed in the Han River Basin. Monitoring was performed in small scale watersheds, which is homogeneous land use. The applicability of SWMM and HSPF model was examined for small watersheds using hourly monitoring data. The results of SWMM were reasonably reflected with observed data in small scale urban area. HSPF model was effective at specifying parameters related to runoff and water quality when using hourly monitoring data. The watershed models used in this study adequately simulated watershed characteristics and are recommended to support watershed management. © IWA Publishing 2010. Source

Seo Park S.,Yonsei University | Seo Park S.,Kyushu University | Kim J.,Yonsei University | Lee H.,Yonsei University | And 4 more authors.
Atmospheric Chemistry and Physics | Year: 2016

The sensitivities of oxygen-dimer (O4) slant column densities (SCDs) to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT), and the differential optical absorption spectroscopy (DOAS) technique. The sensitivities of the O4 index (O4I), which is defined as dividing O4 SCD by 1040 molecules2 cm-5, to aerosol types and optical properties are also evaluated and compared. Among the O4 absorption bands at 340, 360, 380, and 477 nm, the O4 absorption band at 477 nm is found to be the most suitable to retrieve the aerosol effective height. However, the O4I at 477 nm is significantly influenced not only by the aerosol layer effective height but also by aerosol vertical profiles, optical properties including single scattering albedo (SSA), aerosol optical depth (AOD), particle size, and surface albedo. Overall, the error of the retrieved aerosol effective height is estimated to be 1276, 846, and 739 m for dust, non-absorbing, and absorbing aerosol, respectively, assuming knowledge on the aerosol vertical distribution shape. Using radiance data from the Ozone Monitoring Instrument (OMI), a new algorithm is developed to derive the aerosol effective height over East Asia after the determination of the aerosol type and AOD from the MODerate resolution Imaging Spectroradiometer (MODIS). About 80 % of retrieved aerosol effective heights are within the error range of 1 km compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements on thick aerosol layer cases. © 2016 Author(s). Source

Lee J.-W.,University of Sheffield | Lee Y.-K.,National Institute of Environment Research | Hatchwell B.J.,University of Sheffield
Animal Behaviour | Year: 2010

Dispersal is a key factor affecting the dynamics and genetic structure of populations. Patterns of natal dispersal vary widely depending on the selection pressures that each species encounters, but the underlying factors determining this variation are poorly understood. We studied the pattern of natal dispersal in a small passerine, the vinous-throated parrotbill, Paradoxornis webbianus, using both direct ringing data and indirect genetic methods. The social structure of this species is characterized by group living without apparent territorial behaviour. The dispersal rate of juveniles from their natal groups was moderate (about 40%) and dispersal distance was short, most individuals moving to neighbouring flocks. Sibling groups that included both sexes usually dispersed or were philopatric together so that they were found in the same winter flock where pairing occurs. Thus, the avoidance of inbreeding or intrasexual competition among siblings appears not to affect natal dispersal in this species. Instead, our results suggest that the benefits of dispersing in groups and/or selection of kin structure within social groups via kin-selected reproductive benefits may promote the observed dispersal pattern: sibling associations without separation of the sexes. This behaviour may have important implications for the kin structure of populations and the evolution of sociality. © 2010 The Association for the Study of Animal Behaviour. Source

An K.-G.,Chungnam National University | Choi J.-W.,Chungnam National University | Lee Y.-J.,National Institute of Environment Research
Animal Cells and Systems | Year: 2013

The objectives of this study were to evaluate how chemical gradients and physical habitats influence trophic dynamics and chemical tolerance in relation to ecological health, based on biological integrity model in the absence of cascading pressures (cascading theory) as a control mechanism of aquatic ecosystems. We conducted physical, chemical, and biological surveys from 76 national streams and rivers of four major watersheds during 2004-2005 along with surveys of 80 reference streams. Maximum species richness lines (MSRLs) in reference sites vs. regular sampling sites indicated that the third- to fifth-order streams were evidently impaired in the metrics of trophic and tolerant components. These trophic modifications were linked with land-use patterns, which resulted in differences of nutrients (N, P), organic matter contents and the N:P ratios on trophic structures. Overall, these trophic factors influenced ecological health, based on multimetric index of biological integrity model in these systems, so that trophic compositions and tolerance were regulated by bottom-up hypothesis. © 2013 Copyright Korean Society for Integrative Biology. Source

Oh H.-R.,Seoul National University | Ho C.-H.,Seoul National University | Kim J.,University of California at Los Angeles | Chen D.,Gothenburg University | And 4 more authors.
Atmospheric Environment | Year: 2015

Massive air pollutants originating in China and their trans-boundary transports are an international concern in East Asia. Despite its importance, details in the trans-boundary transport of air pollutants over East Asia and its impact on regional air quality remain to be clarified. This study presents an evidence which strong support that aerosols emitting in China play a major role in the occurrence of multi-day (≥4 days) severe air pollution episodes in cold seasons (October through March) for 2001-2013 in Seoul, Korea, where the concentration of PM10 (particulates with diameters≤10μm) exceeds 100μgm-3. Observations show that these multi-day severe air pollution episodes occur when a strong high-pressure system resides over the eastern China-Korea region. In such weather conditions, air pollutants emitted in eastern China/southwestern Manchuria are trapped within the atmospheric boundary layer, and gradually spread into neighboring countries by weak lower tropospheric westerlies. Understanding of trans-boundary transports of air pollutants will advance the predictability of local air quality, and will encourage the development of international measures to improve air quality. © 2015 Elsevier Ltd. Source

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