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Sejong, South Korea

Lee M.-J.,Korea Environment Institute KEI | Song W.,Dankook University | Lee S.,Korea Institute of Geoscience and Mineral Resources | Lee S.,Korea University
Sustainability (Switzerland) | Year: 2015

The purpose of this study was to create maps of potentially sustainable leopard cat (Prionailurus bengalensis) habitats for all of South Korea. The leopard cat, which is on the International Union for Conservation of Nature (IUCN) Red List, is the only member of the Felidae family in Korea. To create habitat potential maps, we selected various environmental factors potentially affecting the species' distribution from a spatial database derived from geographic information system (GIS) data: elevation, slope, distance from a forest stand, road, or drainage, timber type, age, and land cover. We analyzed the spatial relationships between the distribution of the leopard cat and the environmental factors using a frequency ratio model and a logistic regression model. We then overlaid these relationships to produce a habitat potential map with a species potential index (SPI) value. Of the total number of known leopard cat locations, we used 50% for mapping and the remaining 50% for model validation. Our models were relatively successful and showed a high level of accuracy during model validation with existing locations (frequency ratio model 82.15%; logistic regression model 81.48%). The maps can be used to manage and monitor the habitat of mammal species and top predators. © 2015 by the authors. Source

Ha J.H.,Korea Environment Institute KEI | Hidaka T.,Kyoto University | Tsuno H.,Kyoto University
Environmental Toxicology | Year: 2011

Chlorophyll-a concentration has been used as an indicator to estimate microcystin levels in water bodies. This study examined the microcystin to chlorophyll-a ratio in a fishpond in Japan. The ratio varied spatially and temporally during the six-month field survey, which is consistent with reports by other researchers. We investigated the causes of the variability of the ratio by quantifying microcystin synthetase (mcy) A gene with real-time PCR, so as to observe the growth of microcystin-producing cyanobacteria and Microcystis strains in natural cyanobacterial blooms. The application of real-time PCR enabled corroboration of the relationship between the toxigenicity and the toxicity of the blooms. The microcystin to chlorophyll-a ratio was influenced by the combined effects of the durability of the toxic bloom, and the quantity of microcystin-producing cyanobacteria carrying the mcy A gene, especially toxic Microcystis strains. Cyanobacterial blooms produced more microcystin when high concentrations of microcystin-producing Microcystis aggregated in a stationary state with low growth rates. The variable toxicity of blooms needs to be reflected in accurate and efficient alert systems for toxic cyanobacteria and cyanotoxins. © 2009 Wiley Periodicals, Inc. Source

Kim H.,Korea Environment Institute KEI | Hong H.-J.,Korea Advanced Institute of Science and Technology | Jung J.,Korea Advanced Institute of Science and Technology | Kim S.-H.,Korea Advanced Institute of Science and Technology | Yang J.-W.,Korea Advanced Institute of Science and Technology
Journal of Hazardous Materials | Year: 2010

Nowadays, many researchers have studied the environmental application of the nanoscale zero-valent iron (nZVI) and several field applications for the groundwater remediation have been reported. Still, there are many concerns on the fate and transport of the nZVI and the corresponding risks. To avoid such concerns, it was investigated to immobilize nZVI in a support and then it was applied to degrade trichloroethylene (TCE). The nZVI and palladium-doped nZVI (Fe(0)- and Fe/Pd-alginate) were immobilized in the alginate bead where ferric and barium ions are used as the cross-linking cations of the bead. According to TEM (transmission electron microscopy), the size of the immobilized ZVI was as small as a few nanometers. From the surface analysis of the Fe/Pd-alginate, it is found that the immobilized nZVI has the core-shell structure. The core is composed of single crystal Fe0, while most of irons on the surface are oxidized to Fe3+. When 50 g/L of Fe/Pd-alginate (3.7 g Fe/L) was introduced to the aqueous solution, >99.8% of TCE was removed and the release of metal from the support was <3% of the loaded iron. The removal of TCE by Fe/Pd-alginate followed pseudo-first-order kinetics. The observed pseudo-first-order reaction constant (kobs) of Fe/Pd-alginate was 6.11 h-1 and the mass normalized rate constant (km) was 1.6 L h-1 g-1. The km is the same order of magnitude with that of iron nanoparticles. In conclusion, it is considered that Fe/Pd-alginate can be used efficiently in the treatment of chlorinated solvent. © 2009 Elsevier B.V. All rights reserved. Source

Park J.C.,Miryang Regional Office | Song Y.-I.,Korea Environment Institute KEI | Jung Y.M.,K water | Song S.J.,K water | Park D.,Konkuk University
International Journal of Water Resources Development | Year: 2014

This study compares the benefits and disadvantages of two options, i.e. dam construction and a water transfer tunnel between two existing dams, with a particular focus on their effects on the natural environment and local communities and their respective economic efficiencies. It is concluded that significant advantages exist for the construction of a water transfer tunnel between two dams in Korea. This option would secure water resources in a manner that minimizes the economic, environmental and social effects of water resource development and which maximizes the utility of existing water resources. © 2014 Taylor & Francis Source

Lee M.J.,Korea Environment Institute KEI | Park I.,University of Seoul | Won J.S.,Yonsei University | Lee S.,Korea Institute of Geoscience and Mineral Resources
Geomatics, Natural Hazards and Risk | Year: 2014

This study evaluated the landslide hazard at Inje, Korea, using a geographic information system (GIS) and rainfall probabilistic data. The locations of landslides were identified in the study area by aerial photograph interpretation and field surveys. Data about rainfall probability, topography, and geology were collected, processed, and compiled in a spatial database using GIS. Then, the probability of landslides in the study area in recurrence interval years in the future was calculated assuming that landslides are triggered by a daily rainfall of 202 mm or a three-day cumulative rainfall of 449 mm. Twelve factors that influence landslide occurrence were chosen from a database of topography, soil, and forest cover. Landslide susceptibilities were analysed and mapped according to these landslide-occurrence factors, employing the frequency ratio method. Of the total landslide locations, 50% were used for hazard analysis and the remaining 50% were used for model validation. Validation results for the daily rainfall of 202 mm and three-day cumulative rainfall of 449 mm for recurrence interval years were from 89.22% to 91.80% and from 89.38% to 93.80%, respectively. This analysis of landslide hazards took rainfall probability into account. Rainfall, including heavy rainfall, is expected to increase in the future. © 2014 © 2014 Taylor & Francis. Source

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