• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.324-332
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• 2014

In order to reveal the long-term variations of water quality in Jinhae Bay, water qualities had been monitored at 9 survey stations of Jinhae Bay during 2000~2012. The surface and bottom waters concentrations of chemical oxygen demand (COD), dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP), and chlorophyll-a (Chl.-a) were higher at the survey stations of Masan Bay than the stations of other Bays. Especially, station 1 which is located at the inner area of Masan Bay had the highest values in the concentrations of COD, DIN, and Chl.-a because there were terrestrial pollutant sources near the station 1 and sea current had not well circulated in the inner area of Masan Bay. In factor analysis, the station 1 also had the highest factor values related to factors which increase organic matters and nutrients in surface and bottom waters of Masan Bay. However, the stations (st.5, st.6, st.7, st.8, and st.9) of other Bays had lower values of the factors. In time series analysis, the COD concentrations of the bottom waters at 8 stations except for station 1 distinctly decreased. However, the COD concentrations of the surface waters showed no distinct decrease trends at all stations. In the concentrations of nutrients (DIN and DIP) of both surface and bottom waters, there were tremendous decrease trends at all stations. Therefore, these distinct decrease trends of the COD in bottom waters and the nutrients in surface and bottom waters of Jinhae Bay could have been associated with water improvement actions such as TPLMS (total pollution load management system).

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.19-29
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• 2006

The first Japanese pilot-scale $CO_2$ sequestration project has been undertaken in an onshore saline aquifer, near Nagaoka in Niigata prefecture, and time-lapse well logs were carried out in observation wells to detect the arrival of injected $CO_2$ and to evaluate $CO_2$ saturation in the reservoir. $CO_2$ was injected into a thin permeable zone at the depth of 1110m at a rate of 20-40 tonnes per day. The total amount of injected $CO_2$ was 10400 tonnes, during the injection period from July 2003 to January 2005. The pilot-scale demonstration allowed an improved understanding of the $CO_2$ movement in a porous sandstone reservoir, by conducting time-lapse geophysical well logs at three observation wells. Comparison between neutron well logging before and after the insertion of fibreglass casing in observation well OB-2 showed good agreement within the target formation, and the higher concentration of shale volume in the reservoir results in a bigger difference between the two well logging results. $CO_2$ breakthrough was identified by induction, sonic, and neutron logs. By sonic logging, we confirmed P-wave velocity reduction that agreed fairly well with a laboratory measurement on drilled core samples from the Nagaoka site. We successfully matched the history changes of sonic P-wave velocity and estimated $CO_2$ saturation a(ter breakthrough in two observation wells out of three. The sonic-velocity history matching result suggested that the sweep efficiency was about 40%. Small effects of $CO_2$ saturation on resistivity resulted in small changes in induction logs when the reservoir was partially saturated. We also found that $CO_2$ saturation in the $CO_2$-bearing zone responded to suspension of $CO_2$ injection.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.134-167
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• 2022

This study conducted monitoring of flora and vegetation in order to utilize basic data for forest wetland conservation targeting outstanding forest wetlands located in the eastern part of Jeonnam Province. The survey was carried out for a total of 54 times from May 2020 to October 2020, 1-2 times each for each season. The vascular plants of outstanding forest wetland in eastern Jeollanam-do were 93 families, 251 genera, 336 species, 5 subspecies, 47 varieties, 7 forma, and a total of 395 taxa. This was about 8.5% of 4,641 species of vascular plants in Korea Peninsula. A total of 8 taxa and 12 taxa were identified Korea endemic plants and rare plants respectively. A total of 68 taxa and 19 taxa of floristic target plants and invasive alien plants were classified each. the naturalized Index was 4.83% and the urbanized Index was 5.90%. As a result of the analysis by wetland type of the forest wetlands, obligate upland plants were the highest in the forest wetlands in the eastern Jeonnam province (61.4%), with unclassified wetland plants 19.1%, facultative wetland plants 8.2%, and obligate wetland plants 4.6%, facultative upland plants 4.5%, and facultative plants 2.3% were confirmed in the order.

• Journal of Navigation and Port Research
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• v.45 no.1
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• pp.9-15
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• 2021

According to IMO, MASS is defined as a vessel operated at various levels independent of human interference. The safety navigation support service for MASS is designed to improve the safety and efficiency of MASS by developing public services on shore for ship arrivals/departures and for cargo handling. The safety navigation support service consists of a total of six types of services: autonomous operation, berthing/unberthing/mooring, cargo handling and ship arrival/departure service, PSC inspection, condition monitoring, and accident response support services. In order to support accident response service, the relative importance of a bridge navigational equipment was assessed by stratifying the navigation system to provide safe and efficient support services by objective judgment through specific and quantitative methods using AHP, one of decision-making methods used by an expert group. The survey was conducted by dividing the bridge navigational equipment into depth, location, and speed information. As a result of applying the AHP method, the importance of depth, location, and speed information was assessed. The relative importance of each equipment for providing location information was also assessed in order of Radar, DGPS, ECDIS, Gyro compass, Autopilot, and AIS. This was similar to survey results on the utilization of each operator's preference and its impact on marine accidents.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.163-174
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• 2020

Particulate matter levels are rapidly increasing daily, and this can affect human health. Therefore, air pollutant emissions from sea vessels require management. This study evaluates the status of air pollutants, focusing on air pollutant emissions from the vessels of the Korea Coast Guard (KCG), and proposes national management measures to reduce emissions. According to a report recently released (2018) by the National Institute of Environmental Research (NIER), emissions from vessels constituted 6.4 % of the total domestic emissions, including 13.1 % NO_x, 10.9 % SO_x, and 9.6 % particulate matter (PM10/PM2.5). Among the rates of pollutant emission from vessels, the emission rates of domestic and overseas cargo vessels were the highest (50.6 %); the ratio of fishing boats was 42.6 %. With respect to jurisdictional sea area, 44.1 % of the emissions are from the south sea, including the Busan and Ulsan ports, and 24.8 % of the emissions are from the west sea, including the Gwangyang and Yeosu ports. The KCG inspects boarding lines to manage emission conditions and regulate air pollutant emissions, but it takes time and effort to operate various discharge devices and measure fuel oil standards. In addition, owing to busy ship schedules, inspection documents are limited in terms of management. Therefore, to reduce the air pollutant emissions of such vessels, regulations will be strengthened to check for air pollutants, and a monitoring system based on actual field data using KCG patrol ships will be established, for each sea area, to manage the emissions of such vessels. Furthermore, there is a need for technological development and institutional support for the introduction of environmentally friendly vessels.

• Economic and Environmental Geology
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• v.47 no.1
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• pp.39-48
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• 2014

In coastal region, estuaries have complex environments where dissolved and particulate matters are mixed with marine water and substances. Suspended sediment (SS) dynamics in coastal water, in particular, plays a major role in erosion/deposition processes, biomass primary production and the transport of nutrients, micropollutants, heavy metals, etc. Temporal variation in suspended sediment concentration (SSC) can be used to explain erosion/sedimentation patterns within coastal zones. Remotely sensed data can be an efficient tool for mapping SS in coastal waters. In this study, we analyzed the variation in SSC in coastal water using the Geostationary Ocean Color Imager (GOCI) and Landsat Enhanced Thematic Mapper Plus (ETM+) in Gyeonggi-bay. Daily variations in GOCI-derived SSC showed low values during ebb time. Current velocity and water level at 9 and 10 am is 37.6, 28.65 $cm{\cdot}s^{-1}$ and -1.23, -0.61 m respectively. Water level has increased to 1.18 m at flood time. In other words, strong current velocity and increased water level affected high SSC value before flood time but SSC decreased after flood time. Also, we compared seasonal SSC with the river discharge from the Han River and the Imjin River. In summer season, river discharge showed high amount, when SSC had high value near the inland. At this time SSC in open sea had low value. In contrast, river discharge amount from inland showed low value in winter season and, consequently, SSC in the open sea had high value because of northwest monsoon.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.30-40
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• 2009

Employing the Numata-type life form, the paper analyzed changes of plants for 4 years at the Human-made Wetlands along Boknaecheon of Juam Lake since its creation. The number of the species planted at the Human-made Wetlands along Boknaecheon of Juam Lake, which was completed in December 2002, were 15 in total including, 10 families, 13 genera, 12 species and 3 varieties. As for the three-featured life forms of the planted species, there were 6 perennial hydatophytes, recording the biggest number of species in dormancy form; species each of $R_5$, $R_3$, $R_{2-3}$ respectively in radicoid from; 20 species of geomantic dissenminule form ($D_1$) in disseminule form and erecred type(e) existed the most in growth form. With regard to the 3 features of life form identified during the final year of the monitoring that lasted 5 years after the completion of the Wetlands, the number of species and individuals was found to have increased but there was no significant change of tendency as against the composition ration(%) of life form. There were 43 species of therophytes (Th) that covered 24.29% in dormancy form, while $R_5$ was prevalent in radicoid form and $D_4$, $D_1$, and $D_{1,4}$ comprosed 77.39% of the whole disseminule form. Growth form was surveyed in the order of erected type (e), bunch type (t), temporal rosette type (pr), branch type (b) and straight rosette type (ps) and these species comprised 64.97% of the whole flora. Consequently, in case of the artificial wetlands along the Boknaecheon of Juam Lake, it turned out that the vegetation type in which pioneer species of succession, or gradually stabilized perennial vegetation favoring Wetlands because the higher dormancy form has its perennial plants' composition ratio getting, the more its succession is progressing. Even though single grained plants ($R_5$) belonging to radicoid in breeding form, succession is predicted to take place considering the fact that they actually belong to ~ plants like Phragmites japonica that form a connection on the surface of the earth. In addition, it is judged that geomantic disseminule form ($D_1$) conveyed by water and gravitational disseminule form favored by the development of waterside woody plants ($D_4$) seem to be better fit to this area in desseminule form. As for growth form, bunch type (t) is judged to become prevalent on the Wetlands while a good variety of phanerophytes will coexist on the earth due to artificial as well as natural disturbances.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.174-184
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• 2009

Evapotranspiration (ET) is one of the major hydrologic processes in terrestrial ecosystems. A reliable estimation of spatially representavtive ET is necessary for deriving regional water budget, primary productivity of vegetation, and feedbacks of land surface to regional climate. Moderate resolution imaging spectroradiometer (MODIS) provides an opportunity to monitor ET for wide area at daily time scale. In this study, we applied a MODIS-based ET algorithm and tested its reliability for nine flux tower sites in East Asia. This is a stand-alone MODIS algorithm based on the Penman-Monteith equation and uses input data derived from MODIS. Instantaneous ET was estimated and scaled up to daily ET. For six flux sites, the MODIS-derived instantaneous ET showed a good agreement with the measured data ($r^2=0.38$ to 0.73, ME = -44 to $+31W\;m^{-2}$, RMSE =48 to $111W\;m^{-2}$). However, for the other three sites, a poor agreement was observed. The predictability of MODIS ET was improved when the up-scaled daily ET was used ($r^2\;=\;0.48$ to 0.89, ME = -0.7 to $-0.6\;mm\;day^{-1}$, $RMSE=\;0.5{\sim}1.1\;mm\;day^{-1}$). Errors in the canopy conductance were identified as a primary factor of uncertainty in MODIS-derived ET and hence, a more reliable estimation of canopy conductance is necessary to increase the accuracy of MODIS ET.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.515-529
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• 2020

Constructed wetlands undergo biological and physical changes such as an increase in the proportion of arid plants due to the natural succession process after formation. It can adversely affect not only the purification function but also the habitat of species. As such, this study aims to identify environmental factors affecting biodiversity and propose management plans based on the monitoring results of physical environmental changes and the emergence of species in seven constructed wetlands selected based on the water depth and surrounding conditions among the lands purchased by the Nakdong River basin. We examined the environmental conditions and emergence of the Odonata, which is a wetland-dependent species, to predict the trend of changes in biodiversity and abundance. The results showed that the open water area decreased as the emergent plants spread to the deep water in 2015 compared to 2012 when they were initially restored to a depth of 0.2 to 1 m. While a total of 54 dragonfly species were observed, the habitat diversity, such as vegetation, water surface, and grassland, remained similar to the initial formation of the wetlands despite the expansion of the emergent plants. On the other hand, the number of Agrionidae species, which prefer areas with fewer aquatic plants, decreased between 2012 and 2015 due to the diminished water surface. The p-values of the differences in the number of species and population between wetlands by year were 2.568e-09 and 1.162e-08, respectively, indicating the statistically significant differences. The decrease in open water surface was found to have the greatest effect on the biodiversity and habitat density of dragonflies. The time-series survey of constructed wetlands confirmed that the spread of Phragmites communis, P. japonica, Typha orientalis, etc., caused a decrease in species diversity. It suggests that environmental management to maintain the open water surface area is necessary.

• Korean Journal of Ecology and Environment
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• v.46 no.1
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• pp.33-40
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• 2013

From March 2012 to January 2013, this study was conducted as a part of the project for making a precise electronic ecological zoning map of vegetation on a highly reduced scale of 1 to 5,000 with a view to improving management efficiency of national parks and enlarging the availability of the data produced from the basic research monitoring the resources of national parks. For the research accuracy and rapidity, a vegetation map was specially created for the on-the-site-vegetation research. To make the map more meticulous, we categorized the vegetation database into five groups: broadleaved forest, coniferous forest, mixed forest, rock vegetation and miscellaneous one. After comparing the results of the data built for the vegetation research and the actual research findings, it was made clear that vegetation of both categories was almost the same in case of broad-leaved forest with 72.20% and 78.45% respectively, and also equivalent in other groups like, for example, coniferous forest (16.70%, 13.41%), mixed forest (9.50%, 7.49%) and rock vegetation (0.60%, 0.15%). According to the precise vegetation map produced from the research, the deciduous broad-leaved forest was the most widely prevalent type in the correlated hierarchical classification of vegetation, occupying 65.78% of the overall vegetation. It was followed by mountain valley forest (15.17%), coniferous forest (10.90%), and plantation forest (7.00%) in order. It is particularly noteworthy that Mt. Deogyusan national park has retained a very stable and versatile forest vegetation in the outstanding state since approximately 20% of the mountain turns out to belong to the I grade vegetation conservation classification which contains climax forests, unique vegetation, subalpine vegetation, matured stands which are older than 50 years and etc.