• Korean Journal of Ecology and Environment
• /
• v.50 no.3
• /
• pp.325-336
• /
• 2017

The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were $NH_3-N$, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.23 no.6
• /
• pp.87-107
• /
• 2020

The purpose of this study is to present the basic data for maintenance and management of river ecosystem by surveying and analysing the kinds and their characteristics of vascular plants in Bukcheon stream, Gyeongju-si, South Korea. The numbers of vascular plants were summarized as 428 taxa including 92 families, 265 genera, 3 subspecies, 24 varieties, 6 forms, 5 hybrids and 5 cultivars. Among the identified taxa, there were 90 planted species. The endangered wild species was Cicuta virosa, and the rare plants were 5 taxa including Prunus × yedoensis, Juniperus chinensis L. var. sargentii and so on. The Korean endemic plants were 5 taxa Populus × tomentiglandulosa, Salix koriyanagi, Lespedeza maritima, Forsythia koreana and Aster pseudoglehni. The specific plants by floristic region were 26 taxa including 2 taxa of grade V, 3 taxa of grade IV, 2 taxa of grade III, 8 taxa of grade II and 11 taxa of grade I. The naturalized plants were 81 taxa including Euphorbia maculata, Erigeron strigosus, Vulpia myuros and so on. The invasive alien plants were 7 taxa including Humulus scandens, Rumex acetosella, Ambrosia artemisiifolia, Ambrosia trifida, Lactuca seriola, Symphyotrichum pilosum and Paspalum distichum.

• Animal Systematics, Evolution and Diversity
• /
• v.39 no.4
• /
• pp.264-271
• /
• 2023

The edible jellyfish Rhopilema esculentum occurs in waters throughout northeastern Asia, including in Korea, China, and Japan. In Korean waters, R. esculentum has appeared in two regions (Gangwha and Muan). Based on the appearance of young medusae and coastal distribution records, these two regions may be key R. esculentum breeding sites. In the present study, we investigate and compare the genetic structure of R. esculentum in the two regions using mitochondrial sequences (16S ribosomal RNA and cytochrome c oxidase subunit I). The genetic diversity of the R. esculentum population at Ganghwa exceeded that of the population at Muan. Despite considerable geographic separation (400 km) between the two regions(Gangwha and Muan), our haplotype network suggests that the Gangwha and Muan populations of R. esculentum are related. The simple and monotonous genetic structure of the Muan population shows that R. esculentum emergence is relatively recent. In contrast, the Gangwha population shows evolution. Moreover, jellyfish of the Gangwha population are genetically diverse and remain constant despite environmental fluctuations in the Han River. The Gangwha area is considered to be the old origin of R. esculentum in Korea.

• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• pp.855-865
• /
• 2024

Commercial deployment of nuclear microreactors presents an opportunity for the industry to rethink its approach to manufacturing, siting, operation and maintenance, and fuel cycle management as certain principles used in grid-scale nuclear projects are not applicable to a decentralized microreactor economy. The success of this nascent industry is dependent on its ability to reduce infrastructure, logistical, regulatory and lifecycle costs. A utility-like 'Central Facility' that consolidates the services required and responsibilities borne by vendors into one or a few centralized locations will be necessary to support the deployment of a fleet of microreactors. This paper discusses the requirements for a Central Facility, its implications on the cost structures of owners and suppliers of microreactors, and the impact of the facility for the broader microreactor industry. In addition, this paper discusses the pre-requisites for eligibility as well as the opportunities for a Central Facility host site. While there are many suitable locations for such a capability across the U.S., this paper considers a facility co-located with the Vogtle Nuclear Power Plant and Savannah River Sites to illustrate how a Central Facility can leverage the existing infrastructure and stimulate a local ecosystem.

• Journal of Environmental Impact Assessment
• /
• v.20 no.1
• /
• pp.61-69
• /
• 2011

Integrated stream naturalness based on abiotic and biotic factors were developed. Abiotic factors considered in this study were types of land use in the riparian area, river bank and high water bed streamside, revetment, bed substrate and artificial construction of streamside. Biotic factors included types of vegetation, assemblages of fish, macroinvertebrate, bird and mammal(Otter) in streams. The presence/absence of legal species and biological assessment index were also weighted as important parameters in this study. Scoring criteria selected for each matrix was five rating system; 1=poor, 2=moderate, 3=fair, 4=good, 5=excellent. Numerical ratings for the matrix were then summed. This resulted in a minimum score of 13 if all matrix at a site were poor, and a maximum score of 65 if all matrix were excellent. Five grade system from poor(I) to excellent condition(V) was employed. To verify its validity in natural environment, the evaluation system was applied to the Gapchun stream which is a test bed selected. Our result showed that stream naturalness of each reach was clearly distinguished by biotic and abiotic characteristics. Determination of correlation coefficient between abiotic and biotic factors was also high ($R^2=0.96$, p<0.05). In conclusion, assessment for stream naturalness reflecting abiotic and biotic factors was useful method representing stream integrated.

• Journal of Ocean Engineering and Technology
• /
• v.15 no.4
• /
• pp.28-37
• /
• 2001

The water quality in Yongil Bay is getting worse due to the sewage and the waste water from the surrounding industrial complex. The study aims to simulate the current system that is necessary to build ecosystem model for the optium water quality control and clarify the correlation of current system characteristics with water quality in Yongil Bay. To clarify the characteristics of coastal water movement system and verify the applicability of the 3-D model, the current system was simulated using 3-D model baroclinic model which considers tidal current and density effects. As the results of numerical experiments, it is proved the 3-D model is the most applicable on appearing the current system of the stratificated Yongil Bay difference of density. Form the results of simulation considered tidal current only, it can be clarified that the water body flows in the inner bay through the bottom layer and flows out the outer bay through the surface layer in Yongil Bay. And the fresh water from the Hyongsan river and the thermal discharge form POSCO have a little effect on the current system in Yongil Bay, but the diffusion of heat and salt has an important effect upon the formation of the density stratification of the water quality distribution is closely related with the current structure characteristics as well as the tidal residual current system in Yongil Bay.

• Korean Journal of Environment and Ecology
• /
• v.11 no.2
• /
• pp.210-213
• /
• 1997

This study for development of close-to nature revetment techniques is conducted to rehabilitate disturbed stream ecosystem. For this objective, the experimental reach as on-site dimonstrated research was set up in Hakyoul, the Yangjaech'on from Oct. 1995 to Nov. 1996. Special emphasis on the developing process of the design of revetments was given to geomorphic character of 3 types of low flow channel bank: point bar, attack point and shallow bay. Each revetment was developed with the consideration on revegetation of emergent plants. And designed techniques were applied to the experimental reach, and were evaluated with monitoring for 1 year. As a result of the process, the experiment suggested ecological alternatives to enhance technical feasibility and to replace the conventional river-work.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.2
• /
• pp.85-102
• /
• 2012

The purpose of this study is to offer the raw data for conserving the biodiversity of urban ecosystem by objective surveying and analysing the vascular plants distributed in major sites of Yangsan-si, Gyeongsangnam-do. The results are as follows. The numbers of vascular plants were summarized as 522 taxa including 110 families, 314 genera, 459 species, 4 subspecies, 46 varieties and 13 forms. The rare plants were 5 taxa including Aristolochia contorta, Drosera rotundifolia, Potentilla discolor, Viola albida and Hydrocharis dubia. The endemic plants were 13 taxa including Salix koriyanagi, Carpinus laxiflora, Stewartia pseudocamellia, Weigela subsessilis and so forth. The specific plants by floristic region were 30 taxa including Caltha palustris, Caryopteris incana, Ilex macropoda, Monochoria korsakowii and so forth. The naturalized plants were 44 taxa including Phytolacca americana, Lepidium virginicum, Solanum americanum, Aster subulatus var. sandwicensis, Panicum dichotomiflorum and so forth. The invasive alien plants were 5 taxa including Sicyos angulatus, Ambrosia artemisiifolia, Ambrosia trifida, Aster pilosus and Paspalum distichum.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.24 no.1
• /
• pp.81-96
• /
• 2021

The purpose of this study was conducted in order to provide the necessary basic data, to establish management solutions and to improve biodiversity by calculating similarity index, urbanization index (UI), and disturbed index (DI) to understand current status of naturalized and invasive alien plants in Eulsukdo, Maekdo and Samnak ecological parks in Busan, South Korea. The numbers of naturalized plants identified in these parks were 76 taxa; 20 families, 53 genera, and 76 species. As a result of the similarity index analysis, the most similarity level (83.0%) was obtained at Eulsukdo and Maekdo parks. The numbers of invasive plants identified in the two parks were 11 taxa; Rumex acetosella L., Sicyos angulatus L., Solanum carolinense L., Ambrosia artemisiifolia L., Ambrosia trifida L., Hypochaeris radicata L., Lactuca serriola L., Solidago altissima L., Symphyotrichum pilosum (Willd.) G.L.Nesom, Paspalum distichum L., and Humulus scandens (Lour.) Merr. Overall, UI and DI were 28.6% and 66.7%, respectively, indicating that the ecosystem disruption was serious.

• Journal of Korean Society on Water Environment
• /
• v.26 no.6
• /
• pp.986-993
• /
• 2010

Spatially distributed on-site devices such as bioretentions and bioboxfilters are becoming more common as a means of controlling urban stormwater quality. One approach to modeling the cumulative catchment-scale effects of such devices is to resolve the catchment down to the scale of a land parcel or finer, and then to model each device separately. The focus of this study is to propose a semi-distributed model for simulating urban stormwater quantity and identifying best sites for spatially distributed on-site stormwater control devices in an urban drainage system. A detailed model for urban stormwater improvement conceptualization simulation is set up for a $0.9342km^2$.