• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.12
• /
• pp.810-820
• /
• 2012

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) contents in marine sediment and edible fish (4 species) from the estuary near the Yongho wharf in Busan were determined to assess their presence and their potential health risk to the local population through fish consumption was also assessed. Levels of ${\Sigma}PCBs$ and ${\Sigma}DDTs$ in marine sediment were 3.22~197.65 and 1.77~20.27 ng/g dw, respectively. HCHs and endosulfan sulfate concentrations in bottom sediment were 1.42~6.08, 0.56~13.89 ng/g dw, respectively. The bottom sediment in the offshore of the Yongho wharf may be characterized as semi-polluted status with potential adverse marine biological effects in terms of sediment quality guidelines of US NOAA. The mean concentrations of ${\Sigma}PCBs$ in the tissues of olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis) were 67.37, 10.20, 48.26, 22.81 ng/g lw, respectively. DDTs and HCHs were also detected in all fish samples. Lifetime cancer risk and target hazard quotient to local residents due to those fish consumption were found to pose negligible cancer and non-cancer risk.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.1
• /
• pp.31-38
• /
• 2020

The characteristics of ship traffic routes and the long term fluctuation in marine traf ic volume of the incoming and outgoing routes of the Yeosu Gwangyang Port were analyzed using vessel traffic data from the past 22 years and a real-time vessel traffic volume survey performed for 72 hours per year, for three years, between 2015 and 2017. As of 2017, the number of vessels passing through Yeosu Gwangyang Port was about 66,000 and the total tonnage of these ships was about 804,564 thousand tons, which is a 400 % increase from the 189,906 thousand tons shipped in 1996. Specifically, the dangerous cargo volume was 140,000 thousand tons, which is a 250 % increase compared to 1996. According to the real-time vessel traffic volume survey, the average daily number of vessels was 357, and traf ic route utilization rates were 28.1 % in the Nakpo sea area, 43.8 % in the specified sea area, and the coastal area traf ic route, Dolsan coastal area, and Kumhodo sea area showed the same rate of 6.8 %. Many routes meet in the Nakpo sea area and, parallel and cross passing were frequent. Many small work vessels entered the specific sea area from the neighboring coastal area traffic route and frequently intersected the path of larger vessels. The anchorage waiting rate for cargo ships was about 24 %, and the nightly passing rate for dangerous cargo ships such as chemical vessels and tankers was about 20 %. Although the vessel traffic volume of Yeosu Gwangyang Port increases every year, the vessel traffic routes remain the same. Therefore, the risk of accidents is constantly increasing. The route conditions must be improved by dredging and expanding the available routes to reduce the high risk of ship accidents due to overlapping routes, by removing reefs, and by reinforcing navigational aids. In addition, the entry and exit time for dangerous cargo ships at high-risk ports must be strictly regulated. Advancements in the VTS system can help to actively manage the traffic of small vessels using the coastal area traffic route.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.22 no.4
• /
• pp.24-38
• /
• 2019

Due to the dramatic spatial changes caused by industrialization, environmental problems such as air pollution and urban heat island phenomenon, etc. are occurring in cities. In this case, the wind corridor, which is a passage through which fresh and cool air generated in forests outside cities move to the downtown, can be used as a spatial planning method for improving urban environmental problems. Cold air is determined by the characteristics of the flow depending on the topography and land use of cities, and based on this, the medium- and long-term plan should be established. Therefore, this study analyzed the flow of cold air at night through the KLAM_21 model in Suwon-si, Gyeonggi-do, to prepare the basic data required to apply the wind corridors. As a result, it turned out that cold air of Suwon-si was mainly generated from Gwanggyo Mountain that is a large mountain area in the north, and flowed into the urbanization promotion area, and about three hours after sunset, cold air flowed into the downtown. By district, the depth, wind speed, and direction of the cold air layer were formed differently according to the characteristics of the topography and land use. In the areas where large forests were adjacent, the flow of cold air was active. There are three main wind corridors where cold air flows to the downtown of Suwon-si, all of which are formed around rivers. Especially, if the connection between rivers and the surrounding green areas is high, the effect of wind corridors is found to be significant. In order to utilize the wind corridors of Suwon-si, based on the results of this study, it is necessary to make climate maps through actual survey and complex analysis of cold air flow and establish mid-to-long-term plans for the conservation and expansion of major wind corridors.

• Journal of Bio-Environment Control
• /
• v.23 no.2
• /
• pp.116-122
• /
• 2014

This study was conducted to find out the appropriate packaging materials to extend the storability and maintain the quality of cherry tomato for modified atmosphere (MA) storage. Tomatoes were grown by hydroponic at a plastic house in Gangwon Province. Light red maturity stage tomatoes were harvested and packed with MA condition (10,000; 20,000; 40,000; 60,000; 80,000; and $100,000cc/m^2.day.atm$ $O_2$ permeability film) and perforated film to store at $5^{\circ}C$, $11^{\circ}C$ and $24^{\circ}C$. The fresh weight loss was less than 0.6% in all non-perforated breathable films at $^5{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$, but perforated film had less than 2.93% at $5^{\circ}C$, 13.29% at $11^{\circ}C$ and 27.24% at $24^{\circ}C$. The 20,000cc at $5^{\circ}C$ and $11^{\circ}C$, and the 40,000cc film at $24^{\circ}C$ balanced optimum carbon dioxide and oxygen concentration in the package to maintain quality. The 10,000cc film was appeared the significantly highest ethylene concentration at $5^{\circ}C$, $11^{\circ}C$, and $24^{\circ}C$, this film had the lowest $O_2$ permeability. Visual quality, firmness, and soluble solids were maintained in 20,000cc films both at $5^{\circ}C$ and $11^{\circ}C$, the 40,000cc film at $24^{\circ}C$. There was no any trend in titratable acidity and vitamin C content of treated packed film types and temperatures at cherry tomatoes packages. Therefore, the appropriate MA condition for $5^{\circ}C$ and $11^{\circ}C$ is $20,000cc/m^2.day.atm$ $O_2$ permeability film; for $24^{\circ}C$ it is $40,000cc/m^2.day.atm$ $O_2$ permeability film because those films extended the storability through the firmness, soluble solids as well as visual quality.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.18 no.5
• /
• pp.398-405
• /
• 2012

PAHs(Polycyclic Aromatic Hydrocarbons) in coastal area and estuary adjacent to urban area and industrial activities region are mainly introduced into marine environment via atmosphere and river. This study which is evaluated the distribution characteristics of PAHs discharge from rivers and sewage disposal water which flowing into Ulsan bay, and were carried out in Jun of dry season and in Auguest of wet season, 2008. The water samples from eight main rivers and Youngyeon WWTP(Wastewater Treatment Plant) flowed into Ulsan bay were taken for analysis of dissolved PAHs. The range and mean values of dissolved PAHs concentrations showed 10.30 to 87.88 ng/L, its mean 36.94 ng/L in dry season and 10.30 to 69.57 ng/L, its mean 24.37 ng/L in wet season. The distribution of dissolved PAHs showd the high concentrations in the Gungcheoncheon which is flowed from urban and industrial area. The ranges and means values of the loading fluxes were estimated with 0.04 to 8.27 g/day, its mean 2.05 g/day in dry season, and 0.03 to 4.77 g/day, its mean 1.61 g/day, in wet season. The loading flux showed the highest value in Taewha river due to the high flow rate and the urban activity. The composition patterns of dissolved PAHs compound showed most of the trend occupying low molecuar weight PAHs than high molecular weight PAHs. These results were due to physical and chemical characteristics of PAHs compound, and were similar to those of other studies. The concentrations of dissolved PAHs in this study are lower than those of other studies, and the level of PAHs pollution appeared to be not serious in reverine waters of Ulsan coast.

• Korea journal of population studies
• /
• v.23 no.2
• /
• pp.79-112
• /
• 2000

This study was focused on the contrasting pattern of part-time employment between Japan and Taiwan where the environments are similar in terms of expanding service industries and increasing flexibility of labor. In Japan, the expansion of part-time employment and its feminization have occurred, whereas they have not at all in Taiwan. The purpose of this study was to examine the reasons behind this phenomena, and to explore what relations they might have with the supply of women\`s labor in each country. Data analysis showed the following results. First, when the phenomena of part-time employment in Japan and Taiwan are summarized as \`active\` and \`inactive\` models, the difference could be explained by a structure-oriented approach rather than an individual-oriented approach. In other words, the difference between the two countries is mainly because of the structural characteristics of the labor market. a combination of capitalism and patriarchy, and an effect of state welfare and family policies rather than a \`voluntaristic choice\` due tn household work and child rearing. In light of this. the labor market segmentation and flexibility of labor theory in particular provided a useful frame for explanation. Second, with regard to the supply of women\`s labor, the difference between Japan and Taiwan could be found in the structure of the labor market and in family response strategies. The large corporation-oriented and strictly divided labor market structure in Japan activated part-time employment and its feminization, whereas, the small family-oriented businesses and less divided labor market in Taiwan supported the continuity of full-time employment of married women. There was also a room for informal employment in Taiwan which made part-time employment unnecessary. This study showed that even within similar environments of expanding service industry and pursuing flexibility of labor different measures and adaptations were possible. The case of Taiwan in particular, showed the significance of an informal labor market which was a part of industrialization process and a strategy of producing various products through a subcontracting network.

• Economic and Environmental Geology
• /
• v.53 no.1
• /
• pp.23-32
• /
• 2020

Geological CO₂ sequestration is a global warming response technology to limit atmospheric emissions by injecting CO₂ captured on a large scale into deep geological formations. The presented results concern mineralogical and hydrogeological investigations (FE-SEM, XRD, XRF, and MICP) of mudstone samples from drilling cores of the Pohang basin, which is the research area for the first demonstration-scale CO₂ storage project in Korea. They aim to identify the mineral properties of the mudstone constituting the caprock and to quantitatively evaluate the hydrogeologic sealing capacity that directly affects the stability and reliability of geological CO₂ storage. Mineralogical analysis showed that the mudstone samples are mainly composed of quartz, K-feldspar, plagioclase and a small amount of pyrite, calcite, clay minerals, etc. Mercury intrusion capillary pressure analysis also showed that the samples generally had uniform particle configurations and pore distribution and there was no distinct correlation between the estimated porosity and air permeability. The allowable CO₂ column heights based on the estimated pore-entry pressures and breakthrough pressures were found to be significantly higher than the thickness of the targeting CO₂ injection layer. These results showed that the mudstone layers in the Yeongil group, Pohang basin, Korea have sufficient sealing capacity to suppress the leakage of CO₂ injected during the demonstration-scale CO₂ storage project. It should be noticed, however, that the applicability of results and analyses in this study is limited by the lack of available samples. For rigorous assessment of the sealing efficiency for geological CO₂ storage operations, significant efforts on collection and multi-aspect evaluation for core samples over entire caprock formations should be accompanied.

• Economic and Environmental Geology
• /
• v.41 no.1
• /
• pp.15-32
• /
• 2008

The hydrochemical and isotopic (stable isotopes and noble gas isotopes) analyses for hot spring waters, cold groundwaters and surface water samples from the Seokmodo hot spring area of the Ganghwa province were carried out to characterize the hydrogeochemical characteristics of thermal waters and to interpret the source of thermal water and noble gases and the geochemical evolution of hot spring waters in the Seokmodo geothermal system. The hot spring waters and groundwaters show a weakly acidic condition with the pH values ranging from 6.42 to 6.77 and 6.01 to 7.71 respectively. The outflow temperature of the Seokmodo hot spring waters ranges from $43.3^{\circ}C\;to\;68.6^{\circ}C$. Relatively high values of the electrical conductivities which fall between 60,200 and $84,300{\mu}S/cm$ indicate that the hot spring waters were mixed with seawater in the subsurface geothermal system. The chemical compositions of the Seokmodo hot spring waters are characterized by Na-Ca-Cl water type. On the other hand, cold groundwaters and surface waters can be grouped into three types such as the Na(Ca)-$HCO_3$, Na(Ca)-$SO_4$ and Ca-$HCO_3$ types. The ${\delta}^{18}O\;and\;{\delta}D$ values of hot spring waters vary from -4.41 to -4.47%o and -32.0 to -33.5%o, respectively. Cold groundwaters range from -7.07 to -8.55%o in ${\delta}^{18}O$ and from -50.24 to -59.6%o in ${\delta}D$. The oxygen and hydrogen isotopic data indicate that the hot spring waters were originated from the local meteoric water source. The enrichments of heavy isotopes ($^{18}O\;and\;^2H$) in the Seokmodo hot spring waters imply that the thermal water was derived from the diffusion Bone between fresh and salt waters. The ${\delta}^{34}S$ values ranging from 23.1 to 23.5%o of dissolved sulfate are very close to the value of sea water sulfate of ${\delta}^{34}$S=20.2%o in this area, indicating the origin of sulfate in hot springs from sea water. The $^3H/^4He$ ratio of hot spring waters varies from $1.243{\times}10^{-6}\;to\;1.299{\times}10^{-6}cm^3STP/g$, which suggests that He gas in hot spring waters was partly originated from a mantle source. Argon isotopic ratio $(^{40}Ar/^{36}Ar=298{\times}10^{-6}cm^3STP/g)$ in hot spring waters corresponds to the atmospheric value.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.4 no.1
• /
• pp.38-48
• /
• 2002

This study examines the relationships between atmospheric influences and grain yields including yield components as well as growth stages. Data used in this study were collected from the long-term field experiment at Suwon for the period between 1974 and 2000. Mean grain yield of barley cultivar, Olbori, for the recent 14 years(1987∼2000) with warm winters was higher by 0.42 ton per hectare than that for 27 years(1974∼2000) at Suwon as a result of the higher numbers of spikes per unit land area and grains per spike. However, the 1000-grain weight decreased by about 0.6 gram. Mean first day of regrowth for the recent 14 years was earlier by five days than that for 27 years. Also, beginning date of regrowth was positively correlated with that of heading and ripening. Mean period of ripening for the years of 1987 through 2000 was similar to that for 27 years, but mean period of overwintering was shorter by nine days than that for 27 years. On the other hand, mean periods of seedling and tillering were longer by three days than those for 27 years. Meteorological elements at various growth stages affecting grain yield of winter barley were air temperature (positive correlation) and sunshine hour (negative correlation) of overwintering stage, precipitation (negative correlation) of tillering stage, and potential evapotranpiration (positive correlation) of tillering stage. The 1000-grain weight was not significantly correlated with the meteorological elements. Culm length was negatively influenced by high temperature and dry weather situations during the ripening period, but spike length was positively influenced. Overall, it was found that grain yield of barley, cultivar Olbori, was iufluenced by meteorological elements of overwintering, tillering, and ripening stages.

• Economic and Environmental Geology
• /
• v.48 no.5
• /
• pp.409-420
• /
• 2015

The Sangdae-ri riverside around Musimcheon stream, flowing through Gadeok-myon of Cheongju City, is one of the representative strawberry fields employing water curtain cultivation (WCC) in Korea. In this area, annual groundwater use for WCC has been calculated by a few methods. On the assumption that all the water flowing through the final ditch may be mostly composed of groundwater, the discharge rate in it can be used as a good proxy for assessing the groundwater use. However, in the study area, the final ditch was set up in an unpaved state near and parallel to Musimcheon stream. Under such circumstances, the drainwater is likely to be influenced by infiltration and/or inflow of nearby stream. Hence, we examined whether or not stream water has influenced water flowing out through the final ditch in respect of ion concentrations or field parameters such as T, pH and electrical conductivity (EC) values. The period of measuring field parameters and sample collection was from February 2012 through February 2015. The drainwater in the final ditch did not show the average quality of groundwater, but similar quality of stream water in respect of pH, EC, ion contents and water type. From this, it is suggested that measuring the flow rate of the final ditch should not be directly used for assessing groundwater use in the study area. In addition, because of its sensitivity to ambient temperature, water temperature proved not to be appropriate for estimating the interaction between ditch and stream. For accuracy, additional methods will be needed to calculate mixing ratios between stream and ground water within drainage system.