• Korean Journal of Agricultural Science
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• v.41 no.1
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• pp.59-63
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• 2014

Precision farming aims at reduced environmental impacts with increased productivity. Soils are multi-functional media in which air, water and biota occur together and form an essential part of the landscape with a fundamental role in the environment. The requirement for herbicides and fertilizers can vary within a field in response to spatial differences in soil properties. Near infrared (NIR) spectroscopy is widely used today as a nondestructive analytical technique which is capable of determining a number of physio-chemical parameters. The objectives of this study were to develop optimal models to predict chemical properties of paddy soils by visible and NIR reflectance spectra. Total of 60 soil samples were collected in spring from 20 paddy fields within central regions in Korea. Reflectance spectra, moisture contents, pH, total nitrogen (N), organic matter, available phosphate ($P_2O_5$) of soil samples were measured. The reflectance spectra were measured in wavelength ranges of 400-2,500 nm with 2 nm interval. The method of partial least square (PLS) analysis was used to determine the soil properties. The PLS analyses showed good correlation between predicted and measured chemical properties of paddy soils in the wavelength range of 1,800-2,400 nm. Especially, it showed better performance than the previous results which used the entire wavelength range of the spectrophotometer, without considering the optimal wavelength of each soil properties.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1997.05a
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• pp.8-11
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• 1997

Current methods of evaluating soil contamination by heavy metals rely on analyzing samples for total contents of metals or quantities recovered in various chemical extracting solutions. Results from these approaches provide only an index for evaluation because these methodologies yield values not directly related to bioavailability of soil-borne metals. In addition, even though concentrations of metals may be less than those required to cause toxic effects to biota, they may cause substantial effects on soil chemical parameters that determine soil quality and sustainable productivity. The objective of this research was to characterize effects of Cu or Cd additions on soil solution chemistry of soil quality indices, such as pH, EC, nutrient cation distribution and quantity/intensity relations (buffer capacity). Metals were added at rates ranging from 0 to 400 mg/kg of soil. Soil solution was sequentially extracted from saturated pastes using vacuum. Concentrations of Cu or Cd remaining in soil solutions were very low as compared to those added to the soils, warranting that most of the added metals were recovered as nonavailable (strongly adsorbed) fractions. Adsorption of the added metals released cations into soil solution causing increases of soluble cation contents and thus ionic strength of soil solution. At metal additions of 200~400 mg/kg, EC of soil solution increased to as much as 2~4 dS/m; salinity levels considered high enough to cause detrimental effects on plant production. More divalent cations (Ca+Mg) than monovalent cations (K+Na) were exchanged by Cu or Cd adsorption. The loss of exchangeable nutrient cations decreased long-term nutrient supplying capacity or each soil. At 100 mg/kg or metal loading, the buffering capacity was decreased by 60%. pH of soil solution decreased linearly with increasing metal loading rates, with a decrement of up to 1.3 units at 400 mg Cu/kg addition. Influences of Cu on each of these soil quality parameters were consistently greater than those of Cd. These effects were of a detrimental nature and large enough in most cases to significantly impact soil productivity. It is clear that new protocols are needed for evaluating potential effects of heavy metal loading of soils.

• Journal of Environmental Science International
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• v.15 no.4
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• pp.293-304
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• 2006

Sea water samples collected in August, 1994 from 20 stations in the Kwangyang Bay were analyzed by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) to investigate persistence and distribution pattern of four organophosphorus pesticides (DDVP, Diazinon, IBP, EDDP). Except for IBP, the contamination by DDVP, Diazinon, and EDDP in marine aquatic environment in Korea has not been reported previously. In this study, however, all these four pesticides were detected in all stations (except DDVP) and their concentrations were in ng/L level. The concentrations ranged from detection limit to 15.3ng/L for DDVP, 1.8-27.7ng/L for Diazinon, 7.3-63.5ng/L for IBP, and 22.2-1100.1ng/L for EDDP. It is noteworthy that the measured concentrations of IBP and EDDP in this study would be much lower than usual, since the use of IBP and EDDP was less than 50% of average annual consumption due to unusually dry and hot weather condition in the summer of 1994. It was very surprising to find that the highest concentrations of organophosphorus pesticides were observed at stations near Daesa Streamlet instead of Seomjin River, which has more point source of the pesticides. This result suggests that the small river discharge during heavy ram period in summer can give harmful effect on marine biota (both wild and aqua-cultured) with its organophosphorus pesticide residue, despite of their short residence time in aquatic environment. In order to protect the marine life properly from acute toxicity of the organophosphorus pesticides, it needs to be emphasized that monitoring the level of agricultural pesticides in river run-off should be done during active consumption period rather at regular intervals.

• Spatial Information Research
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• v.6 no.1
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• pp.77-90
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• 1998

The complex interactions of climate, topography, geology, biota and hwnan activities result in the land cover patterns, which are impacted by natural disturbances such as fire, earthquake and flood. Natural disturbances disrupt ecosystem communities and change the physical environment, thereby generating a new landscape. Community ecologists believe that disturbance is critical in determining how diverse ecological systems function. Fires were once a major agent of disturbance in the North American tall grass prairies, African savannas, and Australian bush. The major focus of this research was to develop stochastic model of spatial process of disturbance or spatial events and simulate the process based on the developed model and it was applied to the fire arrival process in the Great Victoria Desert of Australia, where wildfires generate a mosaic of patches of habitat at various stages of post-fire succession. For this research, Landsat Multi-Spectral Scanner(MSS) data covering the period from 1972 to 1994 were utilized. Fire arrival process is characterized as a spatial point pattern irregularly distributed within a region of space. Here, nonhomogeneous planar Poisson process is proposed as a model for the fire arrival process and rejection sampling thinning the homogeneous Poisson process is used for its simulation.

• Korean Journal of Ecology and Environment
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• v.49 no.2
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• pp.130-141
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• 2016

This study was conducted to elucidate the structure of river ecosystem in the watershed of the Seom River and Hoengseong Reservoir located in Hoengseong of Kangwon Province from February to October 2007. Topics of the survey were mainly rainfall, discharge, water quality in abiotic factors and attached algae, benthic macroinvertebrates, fish, birds and mammals of flora and fauna in a biotic factors, respectively. Specifically, the Seom River could be seen as a typical flow rate of the stream is controlled to the effect of the dam. Basic water qualities were great to seasonal effects, it was relatively clean. Diatom Achnanthes, Cymbella, Gomphonema, and Navicula were distributed predominantly in the periphytic algae. Benthic macroinvertebrates were mostly aquatic insects and freshwater shellfish, the aquatic insects were abundant Ephemeroptera and Trichoptera. Freshwater fish was the dominant Zacco platypus, fish species varied toward the downstream. Birds were mainly observed in four species, and species Egretta garzetta, which was distributed in a wide area of the Seom River. In mammals, Lutra lutra of Mustelidae was identified that the number of inhabit widely. In aspects of the ecological trophic level, the Seom River was maintained at a relatively stable state in the producer and the consumer relationship. The results of this study will expected to be utilized as a useful data for understanding the structure and function of the lotic and lentic ecosystems.

• Asian Journal of Atmospheric Environment
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• v.12 no.1
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• pp.1-16
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• 2018

Ground-level ozone ($O_3$) can be a menace for vegetation, especially in Asia where $O_3$ levels have been dramatically increased over the past decades. To ensure food security and maintain forest ecosystem services, such as nutrient cycling, carbon sequestration and functional diversity of soil biota, in the over-populated Asia, environmental standards are needed. To set proper standards, dose-response relationships should be established from which critical levels are derived. The predictor of the response in the dose-response relationship is an $O_3$ metric that indicates the dose level to which the plant has been exposed. This study aimed to review the relevant scientific literature and summarize the $O_3$ metrics used worldwide to provide insights for Asia. A variety of $O_3$ metrics have been used, for which we discuss their strengths and weaknesses. The most widely used metrics are based only on $O_3$ levels. Such metrics have been adopted by several regulatory agencies in the global. However, they are biologically irrelevant because they ignore the plant physiological capacity. Adopting AOT40 ($O_3$ mixing ratios Accumulated Over the Threshold of $40nmol\;mol^{-1}$) as the default index for setting critical levels in Asia would be a poor policy with severe consequences at national and Pan-Asian level. Asian studies should focus on flux-based $O_3$ metrics to provide relevant bases for developing proper standards. However, given the technical requirements in calculating flux-based $O_3$ metrics, which can be an important limitation in developing countries, no-threshold cumulative exposure indices like AOT0 should always accompany flux-based indices.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.91-93
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• 2003

It has been estimated that the equivalent of approximately $US 50 billion has been spent on research on the behavior and fate of pesticides in the environment since Rachel Carson published “Silent Spring” in 1962. Much of the resulting knowledge has been summarized explicitly in computer algorithms in a variety of empirical, deterministic, and probabilistic simulation models. These models describe and predict the transport, degradation and resultant concentrations of pesticides in various compartments of the environment during and after application. In many cases the known errors of model predictions are large. For this reason they are typically designed to be “conservative”, i.e., err on the side of over-prediction of concentrations in order to err on the side of safety. These predictions are then compared with toxicity data, from tests of the pesticide on a series of standard representative biota, including terrestrial and aquatic indicator species and higher animals (e.g., wildlife and humans). The models' predictions are good enough in some cases to provide screening of those compounds which are very unlikely to do harm, and to indicate those compounds which must be investigated further. If further investigation is indicated a more detailed (and therefore more complicated) model may be employed to give a better estimate, or field experiments may be required. A model may be used to explore “what if” questions leading to possible alternative pesticide usage patterns which give lower potential environmental concentrations and allowable exposures. We are currently at a maturing stage in this research where the knowledge base of pesticide behavior in the environmental is growing more slowly than in the past. However, innovative uses are being made of the explosion in available computer technology to use models to take ever more advantage of the knowledge we have. In this presentation, current developments in the state of the art as practiced in North America and Europe will be presented. Specifically, we will look at the efforts of the ‘Focus’ consortium in the European Union, and the ‘EMWG’ consortium in North America. These groups have been innovative in developing a process and mechanisms for discussion amongst academic, agriculture, industry and regulatory scientists, for consensus adoption of research advances into risk management methodology.

• Analytical Science and Technology
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• v.23 no.5
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• pp.477-484
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• 2010

Personal care products are a diverse group of synthetic organic chemicals such as antimicrobial compounds, UV filters and organo-phosphate flame retardants and derived from individual usages of soaps, toothpaste and cosmetics. It has been detected in municipal sewage effluent and various environmental samples such as surface water, marine, soil, sediment and aquatic biota in many countries. The occurrence of personal care products in environmental samples could negatively impact the health of the ecosystem and humans, due to persistent, long-term chronic exposure of aquatic organisms. In this study, fifteen personal care products in aquatic environmental samples were determined by gas chromatography-mass spectrometry (GC-MS) with liquidliquid extraction (LLE). Method detection limits were in the range of $0.004\sim0.273\;{\mu}g/L$. Two compounds (TCEP, TCPP) were detected in surface waters and seven compounds (triclosan, 4-MBC, EHMC, BP-3, TCEP, TPP, TBEP) were detected in sewage treatment plants (STP) influents or effluents.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.103-112
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• 1998

Nature-friendly river project has became common practice in Japan. In order to make it available for the conservation and rehabilitation of desirable water environment, water criteria for water environmental assessment must be established. Especially, the criteria estimating the effects on ecosystem in and around river should be constructed. In this paper, classification method for water quality has been developed using biological indices and applied to observed data in Honmyo River, Nagasaki, Japan. Modified PI method (BI') has been suggested and those of three most abundant species resulted effective estimate for an overall water quality with comparatively simple procedure. Extensive database management code was prepared for the comprehensive ecological monitoring of river basin, which includes various biota. That system enables easy access of all the ecological data for a dissemination of a sound and sustainable water environment. The result of this study could improve knowledge base, serve making consensus for citizens, and help river management plans. In Japan, citizen's realization and action are the most critical factor for nature-friendly river restoration project.

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.539-546
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• 2010

In nature, the overall effect of heavy metals on the biota can be influenced by a number of environmental factors like soil characteristics and air pollution by elevated $CO_2$. Pillbugs(Isopoda, Armadillium vulgare) take up heavy metals with their food and store them mainly in the vesicles of hepatopancreas. They accumulate certain metals, occuring in relatively large numbers, are easily collected and identified. Therefore, it has been suggested that total body concentration of metals in pillbugs could be positively correlated to the levels of environmental exposure and that pillbugs could be used as biological indicators of metal pollution and global change by $CO_2$. The aim of the study is to determine effects of heavy metal concentrations in soil and elevated $CO_2$ on pillbugs'body accumulation of heavy metal and growth rate. In this study, pillbugs were collected at five sites (N=287) May 2006. Cu and Zn concentrations in pillbugs were higher than in soils (1.39-41.70 times) than in control. The high bioconcentration of lead in Sangam may be partly associated with reclaimed land uses. Pillbugs in low $CO_2$ and Pb condition showed higher growth rate than in elevated $CO_2$ and Pb condition.