• Journal of Wetlands Research
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• v.20 no.1
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• pp.1-13
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• 2018

Glaux maritima var. obtusifolia is distributed in very limited areas in South Korea and thus designated and protected as an endangered species. This study aimed to identify the diversity of vegetation in the Dangsa coast wetlands, the southern limit of G. maritima var. obtusifolia and to assess determinants of the vegetation and the importance of habitats. The phytosociological method of the $Z{\ddot{u}}rich-Montpellier$ School was used for vegetation classification and mathematical and statistical analyses were also conducted to analyze environmental factors and their relationship with the vegetation. The results of this study showed that there were 4 vegetation units in the Dangsa coast wetlands: Glaux maritima var. obtusifolia-Triglochin maritimum community (included three subcommunities), Puccinellia nipponica s.l. community, Beckmannia syzigachne-Isachne globosa community and Typha laxmannii-Phragmites communis community. It was also found that major determinants of the vegetation include moisture environment, soil depth, water level disturbance, vegetation height, community structure, etc. Glaux maritima was identified to grow most dominantly in the typicum subassociation of Glaux. maritima var. obtusifolia-Triglochin maritimum community, and the species compositions and dominant situations were observed to be similar to those in the southern limit in Japan, adjacent to South Korea. The assessment results indicated that the Dangsa coastal wetlands have a significant meaning from phytogeographical and syngeographical aspects, and contribute as a shelter for diverse species. It is required to establish conservation strategies to accurately determine the value of the wetlands of the Dangsa coast from various perspectives, and to protect and manage them.

• Journal of Korea Water Resources Association
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• v.40 no.1 s.174
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• pp.73-88
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• 2007

The goal of this research is to develop and apply the generalized regression neural networks model(GRNNM) embedding genetic algorithm(GA) for the estimation and calculation of the pan evaporation(PE), which is missed or ungaged and of the alfalfa reference evapotranspiration ($ET_r$), which is not measured in South Korea. Since the observed data of the alfalfa 37. using Iysimeter have not been measured for a long time in South Korea, the Penman-Monteith(PM) method is used to estimate the observed alfalfa $ET_r$. In this research, we develop the COMBINE-GRNNM-GA(Type-1) model for the calculation of the optimal PE and the alfalfa $ET_r$. The suggested COMBINE-GRNNM-GA(Type-1) model is evaluated through training, testing, and reproduction processes. The COMBINE-GRNNM-GA(Type-1) model can evaluate the suggested climatic variables and also construct the reliable data for the PE and the alfalfa $ET_r$. We think that the constructive data could be used as the reference data for irrigation and drainage networks system in South Korea.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.344-347
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• 2008

"Nunbora" is a new japonica rice cultivar developed from a cross between Iksan433 resistant to bacterial blight and Miyadamamochi, a waxy line. at Honam Agricultural Research Institute, NICS, RDA, in 2006. This cultivar is a short grain shape and about 118 days of growth duration from transplanting "Nunbora" to harvesting under Korean climatic conditions. The milled rice are snow white and glutinuous. This cultivar shows high resistant reactions to the bacterial blight pathogen race $K_1{\sim}K_3$ and blast respectively. The milled rice yield of "Nunbora" is about 5.34 MT/ha under the standard fertilizer level of the ordinary transplanting cultivation. "Nunbora" would be adaptable for in the middle plain, north middle-mountin plain and Honam plain, and Youngnam plain areas of Korea.

• Korean Journal of Remote Sensing
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• v.11 no.3
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• pp.23-31
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• 1995

The International TOVS(TIROS Operational Vertical Sounders) Process Package(ITPP-VI), which has been installed at Korea Meteorological Administration(KMA), is only for a global usage to need a surface data to generate atmospheric soundings and total ozone amount. If the initial input process in the ITTP-VI is not modified, it takes climatic surface data for producing sounding data and total ozone amount in general. KMA is trying to improve the quality of TOVS total ozone amount using real-time synoptoc observation in various ways instead of climatological data because this retrieved data in the new scheme for total ozone presently used at the KMA may critically provide to analyze the long-term trend of ozone structure over the Korean peninsula. Two cases in this study show that TOVS retrieved total ozone amounts used by synoptic surface observations can delineate more detailed ozone structures rather than those used by climate surface data. The distribution of TOVS retrieved ozone amount fields with the synoptic surface analyzed data(TOVS-GPV) show more in detail relatively than those with the climate data(TOVS-CLIMAT) as expected. In addition, the collocated inter-comparisons of TOVS-GPV with TOVS-CLIMAT, TOMS observations and Dobsometer observations are performed statistically. TOVS-GPV fields with TOMS observations show smaller bias relatively than TOVS-CLIMAT and also reduce the differences.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.81-98
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• 2012

This research aims 1) to analyse the spatial occurrence of red soils, in Korea 2) to predict their spatial distribution using terrain analyses, and 3) to interpret results from the perspective of pedogeomorphological processes. Red soils (often called red-yellow soils) in Korea are frequently found on welldrained plains and gently sloping areas. These soils are widely believed paleo-soils that were formed under hot and humid climatic conditions in the past. The spatial distribution of red soils was derived from the soil map of Korea, and a DEM based soil prediction was developed, based on a continuity equation to depict water and material flows over the landscape. About 64.5% of the red soil occurrence can be explained by the prediction. Close examinations between surveyed and predicted red soil maps show few distinctive spatial features. Granitic erosional plains at the inland of Korea show comparatively low occurrence of red soils, which might indicate active geomorphological processes within the basins. The occurrence of red soils at limestone areas is more abundant than that of the predicted, indicating the influence of parent materials on the formation of red soils. At and around lava plateau at Cheulwon and Youncheon, the occurrence of red soils is underestimated, which might partly be explained by the existence of loess-like surface deposits. There are also distinctive difference of prediction results between northern and southern parts of Korea (divided by a line between Seosan and Pohang). The results of this research calls for more detailed field-based investigations to understand forming processes of red soils, focusing on the spatial heterogeneity of pedological processes, the influence of parent materials, and difference in uplift patterns of the Korean peninsula.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.367-371
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• 2019

In this study, we proposed the sacrificial anode cathodic protection method as a countermeasure to reduce the corrosion of railway rails under oceanic climatic conditions and proved the anticorrosive effect experimentally. In addition, the proposed sacrificial anode cathodic protection method were tested on site to examine long-term rail corrosion monitoring and field applicability for more than 26 months and to prove the effectiveness of rail corrosion. As a result of monitoring the corrosion state using the cellophane tape method, the appearance of the applied sections with sacrificial anode cathodic protection method was good at the present time about 26 months after the field test laying, and no abnormalities and other abnormalities of the rail welded section and the rail web were found. Hence, in places where no sacrificial anodes were installed, rust progressed rapidly. In addition, the proper spacing of sacrificial anodes was found to form the most stable corrosion coating at 1.0 ~ 1.5m. After about 26 months of monitoring, the installation of sacrificial anodes could help stabilize the overall rail corrosion level, even if the spacing was somewhat wider.

• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.411-419
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• 2019

A comprehensive comparison of fatty acid and metabolite profiles in 8 species of perilla seeds harvested from Korea and China was carried out to understand the correlation between cultivation conditions and the quality of perilla seeds. Metabolomic studies revealed that the perilla seeds were distinct from each other, based on the partial least squares -discriminant analysis (PLS-DA) score plots; 23 compounds including metabolites, fatty acids, and phytosterols that predominantly contributed to this interspecies difference were identified. Changes in the growth environment affected these compounds. In particular, phenolic compounds were affected by rainfall and temperature. Moreover, temperature and altitude showed negative and positive correlations, respectively, to oleic acid. Although more studies on the effect of various environmental factors on cultivation of perilla plants as well as their seeds are needed, the present results provide information that would be useful in identifying perilla seeds produced in specific regions and in the cultivation of good quality perilla.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.234-245
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• 2019

In order to select the best varieties and cultivation methods for the production of domestic wheat for Hodugwaja(a walnut shaped confection), we carried out a 3-year experiment (2015~2017) to investigate the effect of different factors (crop variety, planting date, nitrogen fertilization) in a double cropping system (wheat then rice) on crop yields in the Cheonan area. Rice is the second crop in the system, and requires an accumulated temperature for 40 days of about $840{\sim}930^{\circ}C$ to ensure ripening. Transplanting dates for rice between June 29 and July 6 were suitable; transplanting on or after July 13 does not ensure ripening. The daily hours of sunshine ranged from 6.3 to 6.5 hours, which were slightly higher than the optimum of 6.0 to 6.1 hours. The higher the nitrogen fertilizer treatment, the higher culm length, and spike length of wheat. The yield of wheat per 10a tended to increase as the amount of nitrogen fertilizer increased. Wheat yields were highest for the Sooan variety, followed by Goso, followed by Keumgang. The number of days from transplanting to heading of rice were shortest for the Jopyeong variety followed by Unkwang, followed by Haedam. The yield of milled rice per 10a increased as the transplanting date was earlier and the transplanting date of June 9 showed the average yield of more than 500 kg in three varieties. From the results of the experiment, we recommend the Goso wheat variety and the Haedam rice variety for growing in a double cropping system under the climatic conditions of the Cheonan area.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.355-368
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• 2021

This study aims to identify appropriate tree species and crops for agroforestry target sites in North Korea based on ecological geography and site properties. To this end, an ecological geographic map (13 regions and 4 zones) of North Korea was made using satellite images and North Korean academic journal articles. The target agroforestry sites were selected and mapped according to 18 site conditions depending on 3 site characteristics, and the sites were divided into short-term and long-term target sites depending on the agroforestry management period. Finally, optimal combinations of 30 tree species and 19 crops were selected by overlapping the ecological geographic map and agroforestry target site map. For regions within the same zone, tree species and crops were almost similar; however, compared to regions in other zones, they differed. This is likely because the geographical climatic characteristics reflected in the ecological geographic map vary greatly from zone to zone. These results will be used to propose a combination of suitable tree species and crops that takes into account both management purposes and management types for inter-Korean forest cooperation in the agroforestry sector.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.833-845
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• 2021

Quantification of carbon absorption and understanding the human induced land use changes forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by land use changes through remote sensing technology. However, it focused on past carbon absorption changes. So prediction of future carbon absorption changes is insufficient. This study simulated land use change using the Conversion of Land Use and its Effects at Small regional extent (CLUE-S) model and predicted future changes in carbon absorption considering climate change scenarios 4.5 and 8.5 of the Representative Concentration Pathways (RCP). Results of this study, in the RCP 4.5 scenarios there predicted to be loss of 7.92% of carbon absorption, but in the RCP 8.5 scenarios was 13.02%. Therefore, the approach used in this study is expected to enable exploration of future carbon absorption change considering other climate change scenarios.