• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.411-420
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• 2015

This study examined methods for stand density control by using shape ratio (tree height/DBH) and its application for effective management of Pinus thunbergii coastal disaster prevention forests. We analyzed the present conditions (height, DBH, and density) of P. thunbergii coastal disaster prevention forests at 123 study sites on Jeju Island and west, south, and east coasts of South Korea and compared them with results from previous studies. The average shape ratio for P. thunbergii showed positive correlations with stand density and was significantly higher on the west coast (66.32) than on the south (49.57) and east (48.19) coasts and Jeju Island (48.29). Stands with shape ratio higher than 70 accounted for 50% of the total study sites on the west coast, indicating a decrease in their disaster prevention function compared to that of other previous studies. The stand density in most coastal areas, except the east coast, was significantly higher than the standards recommended by the Korea Forest Service and the Forestry and Forest Products Research Institute of Japan, indicating the need for stand density control. According to the growth estimation equation for P. thunbergii in the coastal area of South Korea, density control is required for young stands less than 14 years old, which show drastic increase in the shape ratio, to conserve their disaster prevention function. Particularly, the first thinning of P. thunbergii forests should be implemented before the stand age of 8 years that a shape ratio exceeds 70. For disaster-prone young stands (${\leq}20cm$ DBH) of P. thunbergii, the stand density was higher in the standard of Japan considering shape ratio than in that of Korea aiming timber production. Hence, the standard guidelines employed in Japan, which assign higher importance to disaster prevention function based on field surveys, can be applied effectively for controlling the stand density of P. thunbergii coastal forests in South Korea, to improve their disaster prevention function.

• Journal of fish pathology
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• v.32 no.2
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• pp.69-80
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• 2019

We performed MLSA (multilocus sequence analysis) and phenotypic characterization of Aliivibrio species isolated from walleye pollock (Gadus chalcogrammus) maintained in 3 different facilities of Gangwon Province, the east coast of Korea. Of 38 Aliivibrio species identified by 16S rDNA sequences, 12 strains were randomly selected and MLSA was conducted with 5 house-keeping genes (gapA, gyrB, pyrH, recA and rpoA) and 16S rDNA gene. Phylogenetic analysis and homology of the concatenated sequences (4,580 bp) with other Vibrionaceae genera revealed that 4 strains (GNGc16.1, YYGc16.1, YYGc16.2, GSGc18.1) were identified as Aliivibrio logei and one strain (GSGc16.1) as A. wodanis. One strain (GSGc17.1) was tentatively identified as A. logei, but needs further analysis because it did not belong to the same clade with A. logei type strain. 6 strains (GSGc17.2, GNGc16.2, GSGc16.2, GSGc17.3, GSGc18.2, GSGc17.4) need further investigation as potential novel species. Either phenotypic characterization or 16S rDNA sequence alone did not provide enough information for identification of Aliivibrio strains at the species level. A. logei and A. wodanis are generally known as non-pathogenic bacteria, but also known as opportunistic or secondary pathogens of cold water fishes. Cares should be taken to prevent potential outbreaks due to these bacteria, although there was no outbreaks during the sampling period.

• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.757-769
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• 2009

This paper is intended to forecast the demand for tourism of fishing regions and find the public policies to activate it. The paper focuses on the east coast regions in Gangwon-do. The analysis was conducted through time series analyses and surveys of the tourists in the regions. The results of analyses showed that, while the number of tourists(both domestic and foreign) to the regions has increased, the regions have not been able to accommodate them enough to help improve economies of the regions. It was forecasted that the number of tourists will significantly increase in the future. However, that rates of increase, especially the rates of increase of foreign tourists, cannot be evaluated positively compared to those of the past. These results suggested a few local governmental policies to activate tourism in the regions.

• Atmosphere
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• v.26 no.1
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• pp.159-183
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• 2016

On 31 July 2014, there was a localized torrential rainfall ($58.5mm\;hr^{-1}$) caused by a strong convective cell with thunder showers over Daegwallyeong. In the surface synoptic chart, a typhoon was positioned in the East China Sea and the subtropical high was expanded to the Korean peninsula. A WRF (Weather Research and Forecasting) numerical simulation with a resolution of 1 km was performed for a detailed analysis. The simulation result showed a similar pattern in a reflectivity distribution particularly over the Gangwon-do region, compared with the radar reflectivity. According to the results of the WRF simulation, the process and mechanism of the localized heavy rainfall over Daegwallyeong are as follows: (1) a convective instability over the middle part of the Korean peninsula was enhanced due to the low level advection of warm and humid air from the North Pacific high. (2) There was easterly flow from the coast to the mountainous regions around Daegwallyeong, which was generated by the differential heating of the insolation among Daegwallyeong and the Yeongdong coastal plain, and nearby coastal waters. (3) In addition, westerly flow from the western part of Daegwallyeong caused a strong convergence in this region, generating a strong upward motion combined by an orographic effect. (4) This brought about a new convective cell over Daegwallyeong. And this cell was more developed by the outflow from another thunderstorm cell to the south, and finally these two cells were merged to develop as a strong convective cell with thunder showers, leading to the record breaking maximum rainfall per hour ($58.5mm\;hr^{-1}$) in July.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.3
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• pp.33-43
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• 2022

This study was conducted to monitor the vegetation recovery in the areas damaged by the forest fires on the east coast that occurred in April 2000. The study site was a forest fire-damaged area in Samcheok-si, Gangwon-do, and 21 monitoring areas (12 natural restoration sites, 9 artificial restoration sites) were selected to analyze the vegetation recovery trend since 1998. The vegetation recovery trend was compared by calculating the values according to the year using the difference Normalized Burn Ratio (dNBR) and Normalized Difference Vegetation Index (NDVI) based on satellite images (Landsat TM/ETM+ and Sentinel-2A). As the result of this study, all 21 sites, vegetation was recovered, and both groups showed the greatest recovery in summer. In the case of the dNBR, the artificial restored sites showed higher values than the natural restored sites, and in the case of the NDVI, the natural restored sites were higher than the artificially restored sites in summer and autumn. However, the difference between the two groups of natural and artificial restoration sites was not significant. Therefore, the direction of forest restoration after forest fire damage can be effectively restored if properly implemented for the purpose of restoration of the target site.

• Journal of The Geomorphological Association of Korea
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• v.17 no.4
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• pp.41-52
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• 2010

Coastal lagoons(Ssangho, Gapyeongri wetland, Gunggaeho and Yeomgaeho) distribute densely around Osan-ri, Yangyang-gun. While Ssangho with the representative lagoon group in the East Coast has maintained the lagoon conditions of water surface since it was formed during the Climax of transgression, the others were formed at the swale areas of sand beach. They vary considerably in area reduction rates and position variations during the 20th century, and the causes examined can be divided into natural, human and other factors. They result in the lagoon aggradation stage by geomorphic development, reclamation due to rapid industrialization and urban development during the 20th century, and lacks of understanding on values of small coastal lagoon or errors in mapping and lags of survey techniques. Therefore, the plans for lagoon restorations should be proceeded by the individual properties of lagoons. The restorations of Ssangho are recommended preferentially and it is desirable to restore to the lagoon conditions of 1920s when the influences of human were minimum.

• Parasites, Hosts and Diseases
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• v.56 no.4
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• pp.341-349
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• 2018

The infection status of Centrocestus armatus metacercariae (CaMc) was broadly surveyed in freshwater fishes from major river systems in the Republic of Korea (Korea) during 2008-2017. A total of 14,977 fishes was caught and examined by the artificial digestion method. CaMc were detected in 3,818 (97.1%) (2,114 Z. platypus: 96.1% and 1,704 Z. temminckii: 98.4%) out of 3,932 Zacco spp. examined and their density was 1,867 (2,109 in Z. platypus and 1,567 in Z. temminckii) per fish infected. The prevalences with CaMc were high, 93.7-100%, in Zacco spp. from all surveyed areas. However, their densities were more or less different by the surveyed areas and fish species. They were most high in Nakdong-gang in Gyeongsangnam-do (4,201 in average), and followed by Geum-gang (2,343), Nakdong-gang in Gyeongsangbuk-do (1,623), Han-gang (1,564), Tamjin-gang and Yeongsan-gang (1,540), streams in the east coast (1,028), Seomjin-gang (488) and Mangyeong-gang (170). In another species of rasborinid fish, Opsariichthys uncirostris amurensis, CaMc were detected in 222 (74.8%) out of 297 ones examined and their density was 278 (1-4,480) per fish infected. CaMc were also detected in total 41 fish species except for the rasborinid fish, Z. platypus, Z. temminckii and O. uncirostris amurensis. Conclusively, it was confirmed that among the 3 species of rasborinid fish, Z. platypus and Z. temminckii are highly prevalent and O. uncirostris amurensis is moderately prevalent with CaMc. Additionally, we could know that variety of fish species act as the second intermediate hosts of C. armatus in Korea.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.117-124
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• 2003

Reproductive cycle and sex ratio of the marsh clam Corbicula japonica, a oviparous clam, were investigated monthly by histological observation. Samples were collected in brackish water of Namdae stream on the east coast of Korea from November 2000 to October 2001. It was able to devide the reproductive cycle of this species into five successive stages; early active (April to June), late active (May to June), ripe (June to August), partially spawned (June to September), spent (September to January) and resting stage (February to April). The spawning period was from July to September, and the main spawning occurred between August and September when seawater temperatures reached above 26$^{\circ}C$. Mature eggs of Corbicula japonica were 60-70 ${\mu}m$ in diameter. The sex ratio of individuals over 10.1 mm in shell length was about 1:1 (x$^2$ = 1.22, p > 0.05).

• Journal of Marine Life Science
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• v.5 no.2
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• pp.58-63
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• 2020

The ascidian Halocynthia aurantium (sea peach), which belongs to the phylum Chordata, is thought to be a valuable organism of aquaculture like H. roretzi (sea pineapple), but its biological characteristics such as development and ecology are not well known. In this study, in order to obtain basic data for H. aurantium farming, the development processes of H. aurantium inhabiting the east coast of Gangwon-do were investigated and compared with those of H. roretzi, a related species. As a result, the morphology and developmental stages of the fertilized eggs, embryos and larvae of H. aurantium were very similar to those of H. roretzi. Fertilized eggs of H. aurantium took about 42.1 hours to hatch at 11℃, almost similar to 40.9 hours of H. roretzi. The time required for larvae to metamorphose into juveniles after hatching was very similar between the two species. The hatched larvae of the two species became juveniles with oral and atrial siphons after 23 days at 11℃. Both types of embryos developed slowly in seawater at low temperatures and rapidly developed at high temperatures. Fertilized eggs of H. aurantium hatched in an average of 62.3 hours at 9℃, 42.1 hours at 11℃, and 36.3 hours at 13℃, whereas those of H. roretzi hatched in an average of 60.4 hours, 40.9 hours, and 35.2 hours. Most of H. aurantium embryos did not develop normally above 15℃, so it is thought that attention is needed in the seed production processes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1B
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• pp.23-33
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• 2009

Climate change, abnormal weather, and unprecedented extreme weather events have appeared globally. Interest in their size, frequency, and changes in spatial distribution has been heightened. However, the events do not display regional or regular patterns or cycles. Therefore, it is difficult to carry out quantified evaluation of their frequency and tendency. For more objective evaluation of extreme weather events, this study proposed a rainfall extreme weather index (STARDEX, 2005). To compare the present and future spatio-temporal distribution of extreme weather events, each index was calculated from the past data collected from 66 observation points nationwide operated by Korea Meteorological Administration (KMA). Tendencies up to now have been analyzed. Then, using SRES B2 scenario and 2045s (2031-2050) data from YONU CGCM simulation were used to compute differences among each of future extreme weather event indices and their tendencies were spatially expressed.The results shows increased rainfall tendency in the East-West inland direction during the summer. In autumn, rainfall tendency increased in some parts of Gangwon-do and the south coast. In the meanwhile, the analysis of the duration of prolonged dry period, which can be contrasted with the occurrence of rainfall or its concentration, showed that the dryness tendency was more pronounced in autumn rather than summer. Geographically, the tendency was more remarkable in Jeju-do and areas near coastal areas.