• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.162-170
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• 2011

In order to assess the inorganic and organic pollutents characteristics in marine water, we investigated COD (Chemical Oxygen Demand), Chlorophyll a and Escherichia coli during four seasons at 20 stations of Gwangyang Bay and at 23 stations of Jinhae Bay, Korea. The bay is divided into three zones in Gwangyang and four zones in Jinhae respectively, based on the pollutent levels. In Gwangyang Bay, the high concentration (mean 4.7 mg $L^{-1)$) of COD was recorded during spring season at Zone I, which can be characterized as a semi-enclosed eutrophic area (St. 1~9). Also, Chl. a concentrations were high at Zone I (mean 14.0 ${\mu}g\;L^{-1}$). The colony of E. coli were detected during summer season at Zone II, which is influenced by Seomjin River water. The E. coli may have been entered from the river water in a large pulse during rainy season. On the other hand, E. coli was kept low levels during four seasons at the Zone III, which is influenced indirectly by surface water currents from offshore of the bay. In Jinhae Bay, the high COD and Chl. a were shown during all seasons at Zone I, which is characteristed by semi-enclosed eutrophic area of Masan and Haengam bays. The Zone I also had been shown relatively high E. coli concentration in all seasons. In constrast, other three zones did not show seasonal characteristics of the E. coli concentrations. The present study suggests that E. coli concentrations can be significantly elevated in eutrophic semi-enclosed area.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.366-379
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• 2015

Objectives: The objective of this study is to assess airborne particulate matter(PM) pollution and its effect on health of residents living near Ansim Briquette Fuel Complex in Daegu metropolitan region. Methods: The California Puff(CALPUFF) dispersion model, version 5.8, which can estimate the dispersion direction and range of airborn $PM_{10}$ was used to determine the possible areas affected by $PM_{10}$ pollutants emitted from Ansim briquette fuel complex. The CALPUFF modeling with 200 m grid-cell resolution was performed based on $PM_{10}$ emissions estimated from the amount of coal consumption in the fuel complex for four months in 2012. The Weather Research and Forecasting(WRF) fields were processed using CALMET to produce CALPUFF-ready meteorological inputs. Also, the distance from Ansim Briquette Fuel Complex to the residence of each environmental pneumoconiosis patient was analyzed. In addition, the affecting region of the pollutants emitted from briquette factories in Ansim Briquette Fuel Complex was determined. Results: CALPUFF modeling results showed that the highest concentrations of $PM_{10}$ were found near around the fuel complex. The modeled $PM_{10}$ distributions were characterized by significant decreases in concentration with distance from the complex. Seasonally, the highest concentration of $45{\mu}g/m^3$ was calculated in October which was mostly due to the distinct variation of amount of emission. Additional modeling with the maximum $PM_{10}$ emission of about 88 tons per year in 1986 showed that the highest concentration in October was nearly increased by 8 times than the concentration modeled with emission of 2010. As a result of medical examination and interviews for the residents in Ansim Briquette Fuel Complex and its surroundings, 8 environmental pneumoconiosis patients were found. These patients do not have occupational exposure and history. These patients have lived 0.3~1.1 km area in Ansim Briquette Fuel Complex and its surroundings. Conclusions: Airborne particles emitted from Ansim Briquette Fuel Complex can contribute to significant increase in $PM_{10}$ concentration in residential areas near around the complex. Especially, the residents near fuel complex may exposed to the pollutants emitted from the factories in Ansim Briquette Fuel Complex.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.3
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• pp.392-404
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• 2015

Objectives: This study measured and analyzed the concentrations of crystalline silica, elemental carbon and the contribution ratio of pollutants which influence environmental and respiratory disease around the Ansim Briquette Fuel Complex in Daegu, Korea. Methods: We analyzed the crystalline silica and elemental carbon in the air according to FTIR(Fourier Transform Infrared Spectroscopy) and NIOSH(National Institute of Occupation Safety and Health) method 5040, respectively. In addition, lead stable isotopes, and carbon and nitrogen stable isotopes were analyzed using MC-ICP/MS(Multi Collector-Inductively Coupled Plasma/Mass Spectrometer), and IRMS(Isotope Ratio Mass Spectrometer), respectively. Results: The concentration of crystalline silica in the direct exposure area around the Ansim Briquette Fuel Complex was found to be $0.0014{\pm}0.0005mg/Sm^3$, but not to exceed the exposure standards of the ACGIH(American Conference of Governmental Industrial Hygienists). In the case of the autumn, the direct exposure area was found to show a level 2.5 times higher than the reference area, and on the whole, the direct exposure area was found to have a level 1.4 times higher than the reference area. The concentration of elemental carbon in the direct exposure area and in the reference area were found to be $0.0014{\pm}0.0006mg/Sm^3$, and $0.0006{\pm}0.0003mg/Sm^3$, respectively. This study confirmed the contribution ratio of coal raw materials to residentially deposited dusts in the area within 500 meters from the Ansim Briquette Fuel Complex and the surrounding area with a stable isotope ratio of 24.0%(0.7-62.7%) on average in the case of carbon and nitrogen, and 33.9%(26.6-54.1%) on average in the case of lead stable isotopes. Conclusions: This study was able to confirm correlations with coal raw materials used by the Ansim Briquette Fuel Complex and the surrounding area. The concentration of some pollutants, crystalline silica, and elemental carbon emitted to the direct-influence area around the Ansim Briquette Fuel Complex were relatively higher than in the reference area. Therefore, we need to impose continuous and substantive reduction countermeasures in the future to prevent particulate matter and coal raw materials in the study area. It is time for the local government and authorities to prepare active administrative methods such as the relocation of Ansim Briquette Fuel Complex.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.223-231
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• 1999

This study was carried out to investigate the factors influencing water quality of the river (Mankyeong River) and groundwater in controlled horticulture region from 1994 to 1998. Water quality of Mankyeong River was monitored at 13 sites along main stream for 6 months from April to September from 1994 to 1997. Monthly average concentrations of $NH_4-N$, $SO{_4}^{2-}$ and $Cl^-$ were highest in April, while that of $NO_3-N$ was highest in August. Monthly average concentrations of COD was highest in September Concentrations of $NH_4-N$ and $SO{_4}^{2-}$ in many sites of Mankyeong River exceeded the water quality criteria of agricultural water for irrigation. Water quality of Mankyeong River was not suitable for the irrigation source excepted the sites such as Hari, Gosan and Soyang stream. The floodgates of Mokcheon, Yocheon, Jeonju and Samcheon streams were rapidly polluted by the municipal sewage, otherwise the Iksan stream was rapidly polluted by the sewage of swine. The sum of inorganic ion concentrations in Mankyeong River was highest at floodgate of Yocheon due to the sewages municipal and industrial. The order of the major anions and canons concentration in Mankyeong River- stream were $SO{_4}^{2-}$ > $Cl^-$ > $NO{_3}^-$ > $PO{_4}^{3-}$ and $Na^+$ > $Ca^{2+}$ > $NH{_4}^+$ > $Mg^{2+}$ > $K^+$, respectively. The geoundwater quality at controlled horticulture region was surveyed 4 sites from 1994 to 1998. Concentrations of $NH_4-N$ and $NO_3-N$ were lower at the deeper groundwater. However there was no difference between the concentrations of $SO{_4}^{2-}$ and $Na^+$, and the groundwater depth below 15m. Contents of $NH_4-N$, $NO_3-N$, $PO{_4}^{3-}$, $SO{_4}^{2-}$, $Na^+$ and $Cl^-$ in groundwater were the highest at dry season. Nitrate-N level, exceeded $20mg\;l^{-1}$, the critical level for agricultural usage, at Yongjinmyeon Wanju and $PO{_4}^{3-}$ concentration were higher at Seogtandong Iksan than the other places.

• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.221-234
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• 2016

In Korea, most industrial parks and major cities are located in coastal areas, which results in serious environmental problems in both coastal land and ocean. In order to effectively manage such problems especially in coastal ocean, water quality should be monitored. As there are many factors that influence water quality, the Korean Government proposed an integrated Water Quality Index (WQI) based on in situmeasurements of ocean parameters(bottom dissolved oxygen, chlorophyll-a concentration, secchi disk depth, dissolved inorganic nitrogen, and dissolved inorganic phosphorus) by ocean division identified based on their ecological characteristics. Field-measured WQI, however, does not provide spatial continuity over vast areas. Satellite remote sensing can be an alternative for identifying WQI for surface water. In this study, two schemes were examined to estimate coastal WQI around Korea peninsula using in situ measurements data and Geostationary Ocean Color Imager (GOCI) satellite imagery from 2011 to 2013 based on machine learning approaches. Scheme 1 calculates WQI using estimated water quality-related factors using GOCI reflectance data, and scheme 2 estimates WQI using GOCI band reflectance data and basic products(chlorophyll-a, suspended sediment, colored dissolved organic matter). Three machine learning approaches including Random Forest (RF), Support Vector Regression (SVR), and a modified regression tree(Cubist) were used. Results show that estimation of secchi disk depth produced the highest accuracy among the ocean parameters, and RF performed best regardless of water quality-related factors. However, the accuracy of WQI from scheme 1 was lower than that from scheme 2 due to the estimation errors inherent from water quality-related factors and the uncertainty of bottom dissolved oxygen. In overall, scheme 2 appears more appropriate for estimating WQI for surface water in coastal areas and chlorophyll-a concentration was identified the most contributing factor to the estimation of WQI.

• Environmental and Resource Economics Review
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• v.27 no.2
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• pp.233-260
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• 2018

The West Coast is known as one of the world's three largest intertidal mudflats but the mudflat ecosystems have been constantly destroyed by various reclamation projects and industrial complexes. This study intends to estimate the economic values of major ecosystem services provided by the Seocheon intertidal flats using a choice modeling method. The benefits of the intertidal flats are categorized as four different attributes: number of migratory birds (related to biodiversity and cultural services), production of fish and shellfish (regulating services and habitats), tourism activities (cultural services), and number of fishing households in local communities (cultural services). Study results show that the general public enjoys the economic benefits of 1.777 trillion won (900 million won/hectare) as of 2015 in order to preserve 1,200ha of Seocheon mudflat. Assuming that future generations continue to enjoy these economic benefits of mudflat conservation, the annual value converted is about 64.7 billion won/year, corresponding to 53.9 million won/hectare per year. Individuals are willing to pay are expected to maintain their entire life in the 1,000 households living in the Seocheon tidal-flat fishing village, with an average of 11,000 won per person and an additional 50,000 tourist activities per year. It was estimated to have the amount of payment of 9,000 won. An individual's marginal willingness to pay was estimated to be about 11,000 won per year for supporting a total of 1,000 fishing households, 6,000 won to provide tourism activities of 50,000 visitors, and 9,000 won to provide the habitats of 90,000 migratory birds. For segmentation analysis, residents of Seocheon did not place significant values for the attributes besides migratory bird conservation. However, those of Gunsan showed relatively low margtinal willingness to pay for conservation of migratory birds and fishing villages but showed similar preferences for the maintenance of tourism activities compared to the general public. The results imply that the introduction of economic incentive system is needed to effectively manage and conserve ecosystem services of specific intertidal flats.

• Korean Journal of Ecology and Environment
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• v.33 no.2 s.90
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• pp.109-118
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• 2000

The dynamics of inorganic nutrients and phytoplankton population were examined at eight stations of Shihwa Reservoir, which situated near the cities newly constructed and the industrial complex of West-sea in Korea, from January to December 1999. Among environmental factors, average concentration of $NH_4$, SRP and SRSi were $522.7\;{\mu}g\;N/l$, $9.8\;{\mu}g\;N/l$ and $0.26\;{\mu}g\;Si/l$, respectively. Water quality was extremely deteriorated by a great amount of pollutants load into inner reservoir after the event of rainfall. Nutrients concentration was suddenly decreased toward the lower part. While $NO_3$ concentration did not much varied among stations, but it was relatively high in winter season. Chlorophyll-a concentration was high at the upper part of the reservoir, with average of $37.2\;{\mu}/l$, and closely related to the fluctuation of $NH_4$, SRP and SRSi concentrations. The phytoplankton development in the water column was dominated by diatom (autumn), prasinoid (winter) and dinoflagellate (summer). Dominant phytoplankton were composed to Skeletonema costatum of diatom, Prorocentrum minimum of dinoflagellate, Chroomonas spp. of cryptomonad, Eutreptiella gymnastica of euglenoid and Pyramimonas spp. of prasinoid. The large bloom of phytoplankton at the upper zone of the Shihwa Reservoir after inflow of a seawater were consistently observed. In consequence, water quality management of the inlet stream was assessed to be very important and urgent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.55-61
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• 2003

This study was conducted to evaluate distribution and behavior characteristics of heavy metals for tidal flat sediments in the Saemankeum area. The value of heavy metal contents in the tidal flat sediments were higher than that surveyed in 1994, but showing that it's lower when compared with the value of Shiwha lake. Enrichment factors in the tidal flat sediments showed below 1 except for Pb and Zn. Metal excesses was appeared that Cu, Cr, Fe, Mn lacked and Pb, Zn were high. The correlation analysis between heavy metals and organic matters was found high positive relationship (r=0.424$\~$0.839), especially correlation coefficient between ignition loss and oxide Al, Fe, Mn showed high positive relationship above 0.7. The correlation analysis between Brain size and hear metals was found that as grain size was small, heavy metals contents were increased. Correlation coefficient between silt and heavy metals except for Cu, Pb showed high positive relationship as 0.552$\~$0.732.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.279-289
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• 2021

BACKGROUND: Recently, the golden apple snail, Pomacea canaliculata has been used as an environmentally-friendly weed-control agent in rice farming. Although effective for this particular style of farming, P. canaliculata can be destructive to other crops. The objective of this study was to identify overwintering as well as regional and seasonal distribution characteristics of P. canaliculata. Notably, winter is typically fatal for P. canaliculata. However, owing to increasing average global temperatures, we assessed the ability of P. canaliculata to survive through uncharacteristically warm winters. METHODS AND RESULTS: To examine the distribution and overwintering regions of P. canaliculata, We conducted a survey from April 2020 to May 2021 on environmentally-friendly rice fields, agricultural waterways, and streams in 23 cities belonging to 8 provinces. In addition, because air temperature may influence the distribution density of P. canaliculata, we analyzed the winter temperature data (http://weather.rda.go.kr). CONCLUSION(S): In 2021, overwintering of P. canaliculata (1-3 individuals/m²) was observed in the Goheung and Yeongam regions in Jeonnam. Overwintering of P. canaliculata was observed in fewer regions in 2021 than in 2020; this fact may be attributed to the lower minimum temperatures measured in 2021 (approximately 8℃ lower) than those in 2020. Our results suggest that overwintering occurs as long as overnight temperatures are ≥ -15℃, but can take place if temperatures are as low as -19℃.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.138-164
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• 2022

The Neolithic shell midden in Daejuk-ri, Seosan, is distributed on the gentle slope of a low hill close to the west coast. The bedrock of the area consists mainly of schist with various mafic minerals, but shows a partial gneiss pattern. The site consists of loamy topsoil and clay loam subsoil, and the degree of siallization is relatively low. Although the pottery excavated from the shell midden shares mostly similar features, a variety of shapes and patterns coexist. The surface colors, thickness and physical properties are slightly different. The pottery can be subdivided into three types (IA, IB and II) according to the composition of the body clay, the temper and the existence of a black core. Types IA and IB are colorless mineral pottery with a non-black or black core respectively. TypeII is colored mineral pottery with a non-black core. Type I pottery also contains non-plastic colored minerals, but type II contains a large amount of biotite, chlorite, talc, amphibole, diopside and tremolite, which include a large amount of Mg and Fe. The studied pottery contains a small amount of organic matter. Considering the grain size and relatively poor sorting and roundness of the non-plastic particles, the pottery appears to be made by adding coarse non-plastic tempers for special purposes to the untreated weathered soil around the site. The three types of pottery seem to have been incompletely fired in general. While type IB has the lowest degree of oxidation, typeII shows the highest degree of redness and oxidation. It can be interpreted that these differences depend on the firing temperature and the ratio of non-plastic particles. Through a synthesis of the minerals, geochemical data and thermal history, it can be determined that the firing temperature ranged from 600 to 700℃. The pottery types of the Daejuk-ri Shell Midden have slightly different production conditions, mineral compositions, and physical properties, but have undergone similar production processes with basically the same clay materials. The clay is almost identical to the composition of the bedrock and weathered soil distributed in the Daejuk-ri area. Currently, there is an industrial complex in the area, so it is difficult to confirm the soil and geological distribution of the site. However, it is highly probable that the area around the site was self-sufficient for the clay and tempers required for the production of the Neolithic pottery. Therefore, it can be interpreted that the group that left the shell midden in Daejuk-ri lived near the site, visited the site for the purpose of collecting and processing shellfish, and discarded the broken pottery along with shells.