• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.385-393
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• 2007

Benthic macroinvertebrate communities were studied after a small dam removal from the mid-section of the Gyeongan stream in Gyeonggi-do, Korea. Quantitative sampling was conducted at immediately upstream (upper) and downstream (lower) sites from the dam as well as at the site where the dam was located (dam site: middle) using a Surber sampler (50$\times$50 cm, mesh 0.25 mm), four times (November 2004, May 2005, January 2006, and May 2006) after the dam removal. As a result, 46 species of benthic macroinvertebtates, belonged in 35 genera, 27 families, 11 orders, 5 classes, and 4 phyla, were sampled from the stream sites, but the number of species that occurred at each sampling trial was different (ranged 3$\sim$17 spp.) according to the seasons and sites. Approximately one year after the dam removal, the species number has in-creased and taxa composition has changed as the microhabitat became more heterogeneously due to a riffle formation in the upstream site. Chironomid larvae and tubificid worms, which are common in Korean urban streams, were the dominant species, while Hydropsyche kozhantschikovi was the 2nd dominant species at some sampling trials. In general, McNaughton's dominance indices decreased and Shannon species diversity indices increased approximately one year after the dam removal. Compositions of collector-filterers, clingers, and swimmers increased as hydropsychid caddisflies, heptageniid mayflies, and baetid mayflies increased, respectively, in the upstream site. The group pollution index and the ecological score using benthic macroinvertebrates both indicated that water environment has been improved in the upstream site after the dam removal.

• 한국해양학회지
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• v.18 no.1
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• pp.29-42
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• 1983

This stidy was intended to investigate the heavy metal contents in the bottom sediments of the continental shelt around the Jeju Island and ot the southern coastal area of the Korean Peninsula. For this study 39 bottom sedinent samples were taken from the study area using Phleger gramity corer and Snapper. The average contents of heavy metals were 59.1 ppm Zn, 362.6 ppm Mn, 63.8 ppm Cr, 15.7 ppm Pb, 10.0 ppm Co, 28.9 ppm Ni, 10.5 ppm Cu, and 2.7% Fe in the surficial sediments around the Jejr Island; and 79.ppm Zn, 384 ppm Mn, 8.6 ppm Pb, 17.8 ppm Ni, 23.2 ppm Cu, and 1.59 % fe in those of nearsgore of the southern coastal area respectively. The heavy metal contents were higher in the northwestern part around the Jeju Island compared to those in other region. However, these tendencies were not the result of pollution, but of the differences of grain size of the sedimenrs. In the nearshore of the southern coast, the heavy metal contents did not show any geographical tendency. However, those of Masan and Jinhae Bays wew higher than those of the other region. These seemed to be caused by waste disposal from the industrial compsex located at the adjacent land. Nevertheless these values of heavy metal content except for Zn and Cu in Masan Bay and inner bay of Jinhae are lower than the average values of the each world-wide data of the nearshore sedimentl. The pair correlations of the cach heavy metal elements were calculated by regressino analysis using VAX 780 computer. the following pair elements, such as Zn-Cu, Ni-Cu, Fe-cu, Cr-Cu, Co-Zn, Ni-Zn, Cr-Zn, Ni-Co, Fe-Co, Cr-Co, Fe-Ni, Cr-Ni and Cr-Fe show closely posetive linear correlations in the sediments around the Jeju Island. In general, the heavy metal content increases in proportion to the increase of the mean values of the grain size of the sediments around the Jeju Island. In the southern coastal area, in gineral, thepair correlations of each heavy metal elements did not southern coastal area, in general, the pair correlatttttions of rach heavy metal elements did not show any positive correlation except for the positive linear correlations of Cu-Zn, Cu-ni and Ni-Mn. It is interpreted as a result of the differences of the physecochemical environment of the sampling sites and also of the influences of the ondustrial wastes from the manufacturing factores located at the coastal zone of the study area.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.73-86
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• 2018

Agricultural or rural landscape provides various ecosystem services. However, the ecosystem services function is declining due to various environmental problems such as climate change, land use change, stream intensification, non-point pollution and garbage. The A1B scenario predicts that the mean air temperature of South Korea will rise $3.8^{\circ}C$ degrees celsius in 2100. Agricultural sector is very vulnerable to climate change, so it must be thoroughly predicted and managed. In Korea, the facility horticulture complex is 54,051ha in 2016 and is the 3rd largest in the world(MAFRA, 2014). Facilities of horticultural complexes are reported to cause problems such as groundwater decrease, vegetation and insects diversity reduction, landscapes damage and garbage increase, compared with the existing land use paddy fields. Heat island phenomenon associated with climate change is also accelerated by the high heat absorption of horticultural sites. Therefore, we analyzed the heat island phenomenon occurring in the facility of horticultural complex in Korea. As an improvement measurement, I examined how much air temperature is reduced by putting the channel and the open space. In the case of the Buyeo area, the Computational Fluid Dynamics (CFD) simulation was analyzed for the average summer temperature distribution in the current land use mode at $38.9^{\circ}C$. As an improvement measurement, CFD simulation after 10% of 6m water channel was found to have an effect of lowering the summer temperature of about $2.7^{\circ}C$ compared with the present average of $36.2^{\circ}C$. In addition, CFD simulations after analyzing 10% of the open space were analyzed at $34.7^{\circ}C$, which is $4.2^{\circ}C$ lower than the present. For the Jinju area, CFD simulations were analyzed for the average temperature of summer at $37.8^{\circ}C$ in the present land use pattern. As an improvement measure, CFD simulations after 10% of 6m water channel were found to have an effect of lowering the summer temperature of about $2.6^{\circ}C$ compared to the current average of $35.2^{\circ}C$. In addition, CFD simulations after analyzing 10% of the open space were analyzed at $33.9^{\circ}C$, which is $3.9^{\circ}C$ lower than the present. It can be said that the effect of summer temperature drop in open space and waterway has been proven. The results of this study are expected to be reflected in sustainable agriculture land use and used as basic data for government - level policy in land use planning for climate change.

• Journal of the Korean association of regional geographers
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• v.2 no.2
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• pp.205-217
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• 1996

Today in the industrial society, the urban park is the place for citizens' health, recreation, exercise, and education. This is a very important place as a fine sight and maintenance of public security. As the results of rapid economic growth during the last thirty years, citizens are in the age of material civilization and are challenged with many serious urban problems such as pollution, noise, traffic congestion, human alienation, etc. Rapid material civilization brought to citizens' mental and physical diseases. To some of the problems, it is necessary that we should have proper leisure and recreation facilities, and that we should have the active, positive posture to them. Especially we need the out door recreational spaces and facilities. But nowadays the urban parks are given little thought in spites of the necessity of parks which should be used as a recreational spaces in the urban areas. So, This study attempt to comprehend the function, quantity and quality of the urban park system in Taegu. It is clear that the quantity is inappropriate. Because of inappropriate disposition and management, its coefficiency of utilization is low. In view of the population and park ratio, Dong Gu, Nam Gu, Suseong Gu and Dalseong Gun have comparative good, environments. However, Dalseo Qu, Seo Gu and Jung Gu have less geographical features. There are some methods to provide expansion of the aggregate of urban parks. We can use the school-grounds and their facilities. which were moved from C.B.D. to the outskirts of Daegu, or some parts of urban redevelopment, or the riverside of Sincheon river. In the urban park-program, users' satisfaction-factors are analyzed. We must reconsider the efficiency. The above problems are improved. Active administration and inhabitants' Positive participation are demanded so that the sound development of cities and daily life-surroundings are promoted.

• Korean Journal of Environmental Agriculture
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• v.22 no.2
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• pp.148-152
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• 2003

The phosphorus(P) adsorption capacities of various filter media were investigated in relation to the size and types of fitter media to screen the optimum condition. The objective of this study was to evaluate the constructed wetland longevity by improving P adsorption capacity. The maximum P adsorption capacities of filter media A($4{\sim}10\;mm$), B($2{\sim}4\;mm$) and C($0.1{\sim}2\;mm$) were 8, 10 and 22 mg/kg, respectively, showing those increased as the filter media size decreased. Among the experimental media, the optimum filter media size was $0.1{\sim}2\;mm$. When the filter Medium was supplemented with organic materials which were piled up and decayed in the constructed wetland, the P adsorption capacity was significantly enhanced Under the conditions of optimum fitter media size, the respective Maximum P adsorption capacities of filter media C when supplemented with Ca, Mg, Al and Fe were higher than that of filter media C. However the addition of Ca, Mg, Al and Fe to constructed wetland were not recommended because of the possibility of their secondary pollution. The maximum P adsorption capacity of filter media C was 22 mg/kg, but this was increased to 36 mg/kg when filter media C was supplemented with 2% oyster shell.

• Korean Journal of Ecology and Environment
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• v.38 no.1 s.110
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• pp.83-94
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• 2005

The objective of the study was to elucidate early life history of Rhinogobius brunneus, based on laboratory observations and field works, along with its courtship and spawning behaviors. The male and female fish matured were sampled for the lab experiments from Gap-Stream, which is one of the tributaries of Geum-River, Korea. The spawning behaviors and courtship of matured adults had a typical pattern; matured males of Rhinogobius brunneus built up spawning nests and had their own territory before the spawning, and the behavior then triggered the egg spawning of female with active courtship. The females attached elliptic egg mass as a single layer, on the stones below the spawning nest. After the spawning, the egg mass was guarded by males only until the hatching. The size of egg fertilized, measured by microscope was about 1.5${\pm}$0.1mm in length and 0.7${\pm}$0.1 mm in the egg's width. According to the lab experiments conducted under four temperature regime, the lapsed time for the hatching was shortened as temperatures increased in the treatments. On the contrary to the hatching time, the average length of newly hatched larvae showed a reverse relation with water temperature. The larvae, considered a final stage of the early life history was about 3.6 mm in total length for water temperature of $18^{\circ}C$, whereas they were between 3.1 mm and 3.2 mm for over $25^{\circ}C$. This indicates that higher water temperature may decrease the growth rate in the early life history. These results may provide valuable information for the population conservation and ecosystem protection under accelerated water pollution and habitat degradations in Korea.

• Economic and Environmental Geology
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• v.50 no.5
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• pp.341-352
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• 2017

Along with Cs-137 (half-life: 30.17 years), Sr-90 (half-life: 28.8 years) is one of the most important environmental monitoring radioactive elements. Rapid and easy monitoring method for Sr-90 using Laser-Induced Breakdown Spectroscopy (LIBS) has been studied. Strontium belongs to a bivalent alkaline earth metal such as calcium and has similar electron arrangement and size. Due to these similar chemical properties, it can easily enter into the human body through the food chain via water, soil, and crops when leaked into the environment. In addition, it is immersed into the bone at the case of human influx and causes the toxicity for a long time (biological half-life: about 50 years). It is a very reductive and related with the specific reaction that makes wet analysis difficult. In particular, radioactive strontium should be monitored by nuclear power plants but it is very difficult to be analysed from high-cost problems as well as low accuracy of analysis due to complicated analysis procedures, expensive analysis equipment, and a pretreatment process of using massive chemicals. Therefore, we introduce the Laser-Induced Breakdown Spectroscopy (LIBS) analysis method that analyzes the elements in the sample using the inherent spectrum by generating plasma on the sample using pulse energy, and it can be analyzed in a few seconds without preprocessing. A variety of analytical plates for samples were developed to improve the analytical sensitivity by optimizing the laser, wavelength, and time resolution. This can be effectively applied to real-time monitoring of radioactive wastewater discharged from a nuclear power plant, and furthermore, it can be applied as an emergency monitoring means such as possible future accidents at a nuclear power plants.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.251-270
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• 2014

The purpose of this study is to offer the basic data and method for assessing the naturaliness of temple environment by applying the ecological index of plant to quantitatively and objectively assess the flora and to understand the flora distributed in major temple forest. The ecological index of plant was based in the surveyed flora. The whole flora were summarized as 535 taxa including 103 families, 310 genera, 426 species, 5 subspecies, 82 varieties and 22 forms. And, the numbers of taxa in the Beopheungsa were 267 taxa, 314 taxa of the Daeseungsa and 296 taxa of the Seongjusa. The rare plants were 9 taxa including Aristolochia contorta, Viola albida, Arisaema heterophyllumand so forth, and the Korean endemic plants were 11 taxa including Clematis trichotoma, Stewartia pseudocamellia, Vicia chosenensis and so forth. The specific plants by floristic region were 51 taxa including Wistaria floribunda, Celtis aurantiaca, Angelica gigas and so forth, and the pteridophyta were 26 taxa including Osmunda japonica, Polystichum braunii, Onoclea orientalis and so forth. The naturalized plants were 35 taxa including Fallopia dumetorum, Conyza canadensis, Xanthium strumarium and so forth, the invasive alien plants were 3 taxa including Ambrosia artemisiifolia, Aster pilosus and Eupatorium rugosum. In the results of analysing the ecological index of plant in whole temple forests, RI(Rare Index) was 1.7%, 2.1% of EI(Endemic Index), 9.5% of SI(Specific Index), 1.2 of PI(Pteridophyta Index) and 6.5% of NI(Naturalized Index) in narrow sense. In broad sense, FI(Flora Index) was 11.0%, 1.5% of RI, 3.4% of EI, 4.8% of SI, 10.1% of PI, 10.9% of UI(Urbanized Index) and 25.0% of DI(Disturbed Index). The FI of the Daeseungsa was the highest among the three temple forests. In narrow sense, the RI, SI, NI and DI of the Beopheungsa was high, the seongjusa was higher the EI and SI. In broad sense, the RI and SI of the Beopheungsa, the EI, SI and PI of the Seongjusa, the UI is high in the Daeseungsa. In future, if we will analyze ecological index of plant in other temple forests, we will offer the help to establishing the plan of conservation and restoration on ecosystem in whole temple forests.Environmental Specimen Banks (ESBs) are playing pivotal role in monitoring the effect of environmental pollution on the ecosystem based on the retrospective analysis of the representative samples collected regularly and stored in cryogenic condition.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.187-197
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• 2006

A mathematical modeling program called Hydrological Simulation Program-FORTRAN (HSPF) developed by the United States Environmental Protection Agency(EPA) was applied to the Yongdam Watershed to examine its applicability for loading estimates in watershed scale. It was run under BASINS (Better Assessment Science for Integrating point and Nonpoint Sources) program, and the model was validated using monitoring data of 2002 ${\sim}$ 2003. The model efficiency of runoff was high in comparison between simulated and observed data, while it was relatively low in the water quality parameters. But its reliability and performance were within the expectation considering complexity of the watershed and pollutant sources and land uses intermixed in the watershed. The estimated pollutant load from Yongdam watershed for BOD, T-N and T-P was 1,290,804 kg $yr{-1}$, 3,753,750 kg $yr{-1}$ and 77,404 kg $yr{-1}$,respectively. Non-point source (NPS) contribution was high showing BOD 57.2%, T-N 92.0% and T-P 60.2% of the total annual loading in the study area. The NPS loading during the monsoon rainy season (June to September) was about 55 ${\sim}$ 72% of total NPS loading, and runoff volume was also in a similar rate (69%). However, water quality was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. Overall, the BASINS/HSPF was applied to the Yongdam watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading in watershed scale.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.51-63
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• 2013

To assess the effect of environmental factors on the sustainability of cultured production shellfish, we investigated the habitat characteristics of tidal flat (Namhae-po in Taean). We measured the physiochemical parameters (temperature, salanity, pH, dissolved oxygen and nutrients) and the geochemical characteristics (chemical oxygen demand, ignition loss, C/N ratio and C/S ratio). Surface sediments were collected from several site of tidal flat to examine the geochemical characteristics of both the benthic environment and heavy metal pollution. The grain size for research area of tidal flat were similar at the ratio of silt and clay in comparison with the other site of it. The C/N ratio was more than 5.0, reflecting the range arising from the mix of marine organism and organic matter. The C/S ratio (about 2.8) showed that survey area had anoxic or sub-anoxic bottom conditions. The enrichment factor (Ef) and index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. Adult surf clam (Mactra veneriformis) density was highest at St. 2 (middle part of the Namhae-po), on the other hand, surf clam spat density was highest at St. 3 (lower part of the Namhae-po). Heavy rain, terrigenous suspended clay with fresh water from neighboring agricultural land, and severe high air temperature during summer could be thought as detrimental causes of spat and adult mortality in Namhae-po tidal flat. We suggested that the growth of shellfish in the tidal flat was effected by the various environmental conditions, so an improvement in the cultured method was needed.