• Weed & Turfgrass Science
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• v.6 no.2
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• pp.117-123
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• 2017

Invasive alien species (IAS) can affect agricultural ecosystem negatively and critically. The geographical distributions of nine IAS plants in Korean orchards and uplands were investigated. Ambrosia artemisiifolia distributed widely in Korean peninsula and Ambrosia trifida distributed intensively in Gyeonggi-do. Aster pilosus distributed in Gyeonggi-Gangwon region and Lactuca scariola distributed linear region from the north-western to south-eastern part of Korea. Hypochaeris radicata distributed mainly in Jeju-do and Solanum carolinense distributed in eastern Gyeonggi-do. Rumex acetosella and Sicyos angulatus sporadically occurred in Korean croplands and Eupatorium rugosum was found in one region only. The distribution of IAS plants in croplands was very similar to that in non-croplands suggesting that ecological position of arable lands is not different from that of non-arable lands. Therefore, IAS plants in the croplands should be managed for not only prevention of yield reduction, but also protection or maintenance of original ecosystem. Development of management methods apposite to current Korean status are required to control IAS plants in croplands.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.533-540
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• 2017

Schistosoma mansoni is highly endemic in Tanzania and affects all age groups at different degrees. However, its control approach does not include adult individuals who are equally at risk and infected. To justify the inclusion of adult individuals in MDA programs in Tanzania, the present study focused on determining the prevalence of S. mansoni infection and its related morbidities among adult individuals. This was a cross sectional study conducted among 412 adult individuals aged 18-89 years living in selected villages of Rorya and Butiama districts located along the shoreline of the Lake Victoria. A pretested questionnaire was used to collect socio-demographic and socio-economic information of participants. Ultrasonographic examinations were conducted for all study participants using the Niamey protocol. A single stool sample was obtained from all study participants and examined for S. mansoni using the Kato-Katz technique. The study revealed a high prevalence of S. mansoni (56.3%), and the majority of infected individuals had a light intensity of infection. Ultrasonographic findings revealed that 22.4% of adult individuals had periportal fibrosis (PPF) (grade C-F), with 18.4% having grade C and D and 4% having grade E and F. Males had the highest prevalence of PPF (31.7% vs 10.8%, P<0.001). Organomegaly was common with 28.5% and 29.6% having splenomegaly and hepatomegaly, respectively. S. mansoni infection and its related morbidities included PPF, hepatomegaly, and splenomegaly were common among adult individuals. To reduce the level of transmission of S. mansoni infection, planned mass drug administration campaigns should include adult individuals living in these villages.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.255-262
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• 1982

The data of 37 oceanographic stations in the coastal sea of Jeju island are compiled in terms of temperature, salinity, dissolved oxygen, silicate, nitrate and phosphate to analyge the chelnical characteristics in this region. This work was carried out during June, 1951. The concentrations of nutrients in the layer more than 50 m are generally 0.5-3 times larger than the surface layer. Each constituents in this layer are as follows: temperature ranged 11.8 to $15.4^{\circ}C$ and salinity, 33.8 to $34.8\%_{\circ}$; and also dissolved oxygen and slicate are 5.2 to 5.6ml/l and 5.6 to $9.0{\mu}g-at/l$, respectively. And nitrate and phosphate ranged 1.0 to $6.0{\mu}g-at/l$ and 0.1 to $0.5{\mu}g-at/l$, respectively. The coastal sea of Jeju island is divided into two parts in chemical view point : one is the southeastern sea of Jeju island under the influence of the Tsushima Current, md the other is the northeastern sea of Jejo island under the influence of the Yellow Sea Bottom Cold Water and the south coastal water of Korea. The north-western sea of Jeju island had relatively a cold (about $13^{\circ}C$) and low saline water (about $34\%_{\circ}$), and dissolved oxygen was higher than in the neibouring waters. It seems that in the southern area between Moseulpo and Seogwipo of Jeju island, two different Ivater masses are complicately intermixed and a tidal front is formed.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.635-643
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• 2009

In this paper, a Quaternary fault is described, which is developed in the mid-eastern part of Ulsan Fault Zone, near the southern Gaegok-ri, Oedong-eub, Gyeongju, Korea. The Gaegok 6 fault is developed along the contact between Early Tertiary granite and Quaternary gravel deposit overlying unconformably the granite. The fault strikes $N02^{\circ}{\sim}22^{\circ}E$ and dips $45^{\circ}{\sim}80^{\circ}$ to the west. This fault has a 30~50 cm wide cataclastic shear zone with gouge zone, mixed with Quaternary sediments and fault breccia of granite. In the main Quaternary fault plane, the orientation of striation is $17^{\circ}$, $356^{\circ}$, indicating a dextral strike-slip faulting with some normal component. There is another striation ($78^{\circ}$, $278^{\circ}$ and $43^{\circ}$, $270^{\circ}$) with reverse-slip sense, developed on the subsidiary plane which cuts the main Quaternary fault plane. In brief, the fault has been developed between the granite in the western part and the Quaternary gravel deposit in the eastern part. The western block of fault is uplifted. The striations and movement senses of faults indicate multiple compressional stages in this region. The fault has a similar orientation, westward dipping geometric pattern, and reverse sensed kinematic pattern with Gaegok 1 fault developed in the north. Thus, the Gaegok 6 fault is probably a southern extension of Gaegok 1 fault.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.569-578
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• 2009

Aircraft Measurements of gaseous pollutants($SO_2$, NOx and $O_3$) in the Yellow Sea area, were carried out on 1997-2007. Main measurement site in 124$^{\circ}$-127$^{\circ}$E, 35$^{\circ}$-37$^{\circ}$N (in the Yellow Sea), have been done along the paths classified vertically and zonally. To understand how the air stream affects Long-range transboundary pollutants in Northease Asia (LTP), the tracks of pollutants in northeast Asia have been analyzed by dividing into 6 different regions(regions I-V and L). Compared with Korea's local sources and western north Pacific influenced by the Yellow Sea, when the air stream from region II is dominant, the $SO_2$ concentrations are 3-6times higher. In region II and III, $SO_2$ concentrations are represented highest at 25.0 and 14.7 ppb, respectively. However, in other regions, $SO_2$ concentration was recorderd the highest at 1.1-3.8 ppb, which is 7-15% higher then the highest one over the region II and III. During 1997-2007, the mean amount of incoming pollutants is 0.162 $ton/km{\cdot}hr$ exceeding about 5-times mean amount of outgoing pollutants over the West Sea. During the observed period, the amount of incoming and outgoing $SO_2$ over the Yellow Sea is the highest in winter, at 0.224 $ton/(km{\cdot}hr)$ and 0.120 $ton/(km{\cdot}hr)$, respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.1
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• pp.30-43
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• 2003

The geography, circulation pattern, and ecology show that the semi-closed seas of Northwest Pacific be managed as one complete system. Ongoing multilateral cooperative efforts relevant to marine environmental protection in the Northwest Pacific area, include the Working Group for the Western Pacific (WESTPAC) established under the auspices of WNESCO's Intergovernmental Oceanographic Commissions, the UNDP/GEF Programme on Prevention and Management of Marine Pollution in East Asian Seas (PEMSEA), the North Pacific Marine Science Organization(PICES), and the United Nations Environment Programme(WNEP)'s Northwest Pacific Action Plan(NOWPAP). The present report firstly describes the current situations on the existing regional cooperative regimes for marine environmental conservation in the Northwest Pacific region, with a special respect to the Northwest Pacific Action Plan(NOWPAP) which was adopted in 1994 by Japan, People's Republic of China, Republic of Korea and Russian Federation. Then, problems of the existing regimes are also discussed, together with the suggestion of the possible solutions, focusing on NOWPAP. Suggestions include: 1) the Northeast Asian countries should understand the importance of legally-binding regional convention, and should build up any legally-binding instrument which can function as a big umbrella for real regional cooperation without prejudice to the rights of the States, 2) At present stage, it will be possible to make a regional convention flexible without prejudice to the sovereign right of the States or territorial issues; 3) taking into account that the region often faces many generic political problems that often inhibit the effective collective actions on environmental issues, the leadership from UNEP or other international organizations is required; 4) strong institutional and financial framework should be made, and 5) multilateral efforts to respond to the new marine environmental threats should be taken at the regional level in order to protect the coastal and marine environments in the Northwest Pacific.

• Economic and Environmental Geology
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• v.51 no.5
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• pp.463-471
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• 2018

In this paper, we review previous studies on the relative sea-level changes in the Yellow Sea during the Holocene to comprehensive understand the various research results. Currently, it is reported two theories : 1) the Holocene sea-level has never been higher than the present-day level; and 2) sea-level have reached highstand during mid-Holocene, followed by slow lowering to that of the present. The first theory yields a curve that is similar to a climate-change-related eustatic sea-level curve. However, in reality, most of the relative sea-level fluctuation resulted from land uplift or subsidence. The second theory yields a curve that is fairly coincident with a relative sea-level curve indicative of continental margins being located away from the ice sheets(i.e., far-field), and is considered as an effect of GIA(Glacio Isostatic Adjustment) and gravitational attraction. Based on detailed review of previous researches, we realized that they sourced the same papers, but obtained different results because they selectively chose and added the data. The data used to derive the second theory pertain to the northern Gunsan region, which is located within the western area of the Chugaryeong fault. Thus, we believe that the sea-level curve for the second theory is only representative of the area north of Gunsan, which is subject to GIA and tectonic deformation. Although the relative sea-level curve for the west coastal area is comparable to that for the far-field continental margin region, it is necessary to evaluate local tectonic activities as suggested by active seismicity in the west coastal area and the more than 400 faults currently existing in on the Korean Peninsula.

• Journal of Environmental Science International
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• v.23 no.10
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• pp.1719-1729
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• 2014

This study is carried out in order to bridge the gap to understand the relationships between South Asian and East Asian monsoon systems by comparing the summer (June-September) precipitation of Nepal and South Korea. Summer monsoon precipitation data from Nepal and South Korea during 30 years (1981-2010) are used in this research to investigate the association. NCEP/NCAR reanalysis data are also used to see the nature of large scale phenomena. Statistical applications are used to analyze these data. The analyzed results show that summer monsoon precipitation is higher over Nepal ($1513.98{\pm}159.29mm\;y^{-1}$) than that of South Korea ($907.80{\pm}204.71mm\;y^{-1}$) and the wettest period in both the countries is July. However, the coefficient of variation shows that amplitude of interannual variation of summer monsoon over South Korea (22.55%) is larger in comparison to that of Nepal (10.52%). Summer monsoon precipitation of Nepal is found to be significantly correlated to that of South Korea with a correlation coefficient of 0.52 (99% confidence level). Large-scale circulations are studied to further investigate the relationship between the two countries. wind and specific humidity at 850 hPa show a strong westerly from Arabian Sea to BOB and from BOB, wind moves towards Nepal in a northwestward direction during the positive rainfall years. In case of East Asia, strong northward displacement of wind can be observed from Pacific to South Korea and strong anticyclone over the northwestern Pacific Ocean. However, during the negative rainfall years, in the South Asian region we can find weak westerly from the Arabian Sea to BOB, wind is blowing in a southerly direction from Nepal and Bangladesh to BOB.

• Atmosphere
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• v.28 no.3
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• pp.305-315
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• 2018

This study investigates the characteristic spatial patterns and dynamic processes associated with the summertime extreme temperature events in South Korea during the last 20 years (1995~2014) using Self-Organizing Map (SOM). The classified SOM patterns commonly have high temperature and anticyclonic circulation anomalies over South Korea. The two major teleconnection patterns are identified: one is from the subtropical western North Pacific (WNP) affecting to the north and the other is from the North Atlantic (NA) affecting downstream region. The meridional teleconnection pattern is related to the forcing of positive sea surface temperature (SST) anomaly over the WNP. The northward propagating Rossby wave generates the East Asia-Pacific (EAP) pattern to form an anticyclonic circulation anomaly over South Korea. On the other hand, NA SST anomalies generate an eastward Rossby wave train across the Eurasian continent, leading to the development of an anticyclonic circulation anomaly over South Korea. The EAP pattern occurs more frequently in July and August, whereas the midlatitude teleconnection pattern associated with NA SST anomalies develops more frequently in early summer (June).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.3 no.3
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• pp.45-76
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• 2000

The purposes of this study were to investigate and understand the present status of various types of "deserts", such as sand desert, gravel desert, rock desert, earth desert, salt desert, desert, rocky desert, gobi desert, sandy desert, clay desert, etc., and the general countermeasures for the combating "desertification" "desertization", and to develop the technologies on the revegetation and restoration for the combating desertification in China. The methods of this study were mainly composed of field surveys on the several experimental sites and research institutes related to combating desertification in China, and examinations on the various technologies for the combating desertification at the Daxing Experimental Station of Beijing Forestry University. The conclusion from this study may be summarized as follows; 1. Status and tendency of desertification in China : China is one of the countries seriously threatened by desertification. Desertification affected areas in China are mainly distributed in arid, semi-arid and dry sub-humid areas in China, covering the most regions of the Northeast China (eastern region of Inner-Mongolia), the northern part of the North China (middle and western region of Inner-Mongolia, Shaanxi, Ningsha, Gansu) and the western part of the Northwest China (Xinzang, Qinghai, Xizang). The total area affected by desertification in China is approximately 2.622 million $km^2$. It covers 27.3% of the total territory of China. Until recently, it is estimated that the annual spreading ratio of desertification in China is 2,460 $km^2$. Therefore, desertification is mostly serious problems facing to the Chinese people. 2. The causes and environmental effect of desertification : The desertification in China is mainly caused by compound factors, including natural condition and human activities. In China, the desertification is started by the decrease of precipitation, continuous dry and drought, strong wind, wind and water erosion, land degradation and loss of natural vegetation caused by climate variation, and accelerated by the human activities, such as over-cultivating, over-grazing, over-cutting of woods, irrational use of water resources. Because desertification has affected the geographical features, soil nutrients contents, salinity, vegetation coverage and the functions of ecosystem, the environmental deteriorations in the desertification affected areas are very seriously. 3. The fundamental strategies of combating desertification in China are the increase of education and awareness of people through various mass media, the revision of laws to guarantee operation of Desertification Combating Law and to improve many relating laws and regulations, the application of advanced technologies and training of experts, the establishment of discriminative policies, and increasing arrangement of budget-investment, and so on. China, as a signed country in UNCCD, has made efforts for the combating desertification. Korea is also signed country in UNCCD, so we should play an important role in the desertification combating projects of China for the northest asia and global environmental conservation as well as environmental conservation of Korea.