• Korean Journal of Plant Resources
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• v.22 no.2
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• pp.152-158
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• 2009

We performed RAPD analysis to investigate the inter-/intraspecific relationships and regional variations of Phragmites japonica and P. communis according to the environmental change. One hundred and fourty nine genetic effective polymorphic bands between 300 bp and 1,900 bp were marked from RAPD PCR with nine oligoprimers. From the RAPD analysis by Nei-Li's genetic distance, the dissimilarity indices among the populations of Phragmites japonica were relatively low from 0.012 to 0.061, and Phragmites communis were also low from 0.033 to 0.095. It showed the close genetic relationships among the same species populations, and both species were distinctly independent with relatively high level of dissimilarity indices (0.043 - 0.132). The obvious genetic markers to distinguish two species were confirmed and those profiles were suggested. From the UPGMA phenogram by RAPD analysis, both species showed the water environment related cluster patterns by distributional regions. RAPD analysis was useful to delimit two species taxonomically and to investigate the genetic relationships among inter-/intraspecific populations.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.86-91
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• 2005

We present the results of electrical resistivity surveys carried out to estimate the seasonal variation of the water table level in a large-scale landslide area of Tertiary geology in Japan. One long profile, trending NE-SW, was established perpendicular to the main regional geology of the region. Three boreholes are located very close to the profile. The profile was surveyed twice, once before snowfall and once after snow had melted. The relationship between resistivity and water saturation of pyroclastic materials was clarified through laboratory tests. We did this in order to estimate the water content of the pyroclastic layer from the observed resistivity distribution in the landslide area. The resistivity of the saturated pyroclastic deposit calculated using an empirical formula was found to be $570{\Omega}.m$. Based on this computed resistivity, the groundwater level was deduced by assuming that the pyroclastic deposits were fully saturated beneath the water table. We show that the estimated water table before snowfall is lower than that inferred after snow has melted, by about 1.1 to 4.7 m. This suggests that the water table in the upper part of the pyroclastic layer in the landslide area fluctuates greatly, compared to the lower part. This seasonal groundwater fluctuation is possibly caused by the infiltration of water into the subsurface after snowmelt.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.117-125
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• 2021

According to the character states of nostrils in the Barbatula species comprising 1,366 specimens collected from the major river system in Korea, distribution pattern of the two Korean Barbatula species was reviewed. The taxonomic character related to nostrils in Barbatula was very stable and two character states (widely separated and closely set) were observed in the present materials. B. toni (Dybowski, 1869) with widely separated nostrils distributes in the streams flowing into the East Sea north of Sokcho, Gangwon-do Province; Eogokcheon Stream, a tributary of Namhangang River; and Anseongcheon Stream, Gyeonggi-do Province, whereas B. nuda (Bleeker, 1864) with closely set occurs in most rivers flowing into the Yellow Sea including Nakdonggang River as well as in the Yangyangnamdaecheon Stream, Gangwon-do Province south to Bangyulcheon Stream, Gyeongbukdo Province, flowing into the East Sea as previously reported with some exception. Especially, both Barbatula species were co-occurred in the Yeongokcheon Stream, Gangwon-do Province and Eogokcheon Stream. The present results will provide a useful guide to study the regional fish fauna or fish community analysis as well as to clarify the taxonomical status of the Korean Barbatula species.

• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.463-474
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• 2021

The various external forces can cause inundation in coastal areas. This study is to analyze regional characteristics caused by single or compound external forces that can occur in coastal areas. Storm surge (tide level and wave overtopping) and rainfall were considered as the external forces in this study. The inundation analysis were applied to four coastal areas, located on the west and south coast in Republic of Korea. XP-SWMM was used to simulate rainfall-runoff phenomena and 2D ground surface inundation for watershed. A coupled model of ADCIRC and SWAN (ADCSWAN) was used to analyze tide level by storm surge and the FLOW-3D model was used to estimate wave overtopping. As a result of using a single external force, the inundation influence due to storm surge in most of the coastal areas was greater than rainfall. The results of using compound external forces were quite similar to those combined using one external force independently. However, a case of considering compound external forces sometimes created new inundation areas that didn't appear when considering only a single external force. The analysis considering compound external forces was required to reduce inundation damage in these areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.207-215
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• 2019

This study was conducted to identify key success factors of the Agricultural Cooperative Federation. We classified the divisions of regional agricultural cooperatives into high performers and low performers to investigate differences in environmental stability, resource capacity, resource flexibility, differentiation strategy, and low-cost strategies between high and low performers. Empirical analyses revealed that high performers are superior to low performers in resource capacity, resource flexibility, differentiation, and low-cost, but there was no difference in environmental stability between high performers and low performers. Internal factors including resource and strategy attributes affect business performance, but external factors such as environmental attributes do not. Moreover, resource flexibility generates the broadest gap between high performers and low performers. These results indicate that resource flexibility is the key factor leading to success of organizations with greater competitors because it enables them to overcome their disadvantageous competitive position in size and resources through complete exploitation of resources across divergent business areas owing to its flexibility. Our contribution is that we draw the key success factors of the Agricultural Cooperative Federation through an empirical approach.

• Journal of the Mineralogical Society of Korea
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• v.32 no.2
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• pp.87-102
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• 2019

Pallancata Ag mine is located at the Ayacucho region 520 km southeast of Lima. The geology of mine area consists of mainly Cenozoic volcanic-intrusive rocks, which are composed of tuff, andesitic lava, andesitic tuff, pyroclastic flow, volcano clasts, rhyolite and quartz monzonite. This mine have about 100 quartz veins in tuff filling regional faults orienting NW, NE and EW directions. The Ag grades in quartz veins are from 40 to 1,000 g/t. Quartz veins vary from 0.1 m to 25 m in thickness and extend to about 3,000 m in strike length. Quartz veins show following textures including zonation, cavity, massive, breccia, crustiform, colloform and comb textures. Wallrock alteration features including silicification, sericitization, pyritization, chloritization and argillitization are obvious. The quartz veins contain calcite, chalcedony, adularia, fluorite, rutile, zircon, apatite, Fe oxide, REE mineral, Cr oxide, Al-Si-O mineral, pyrite, sphalerite, chalcopyrite, galena, electrum, proustite-pyrargyrite, pearceite-polybasite and acanthite. The temperature and sulfur fugacity ($f_{s2}$) of the Ag mineralization estimated from the mineral assemblages and mineral compositions are ranging from 118 to $222^{\circ}C$ and from $10^{-20.8}$ to $10^{-13.2}atm$, respectively. The relatively low temperature and sulfur-oxygen fugacities in the hydrothermal fluids during the Ag mineralization in Pallancata might be due to cooling and/or boiling of Ag-bearing fluids by mixing of meteoric water in the relatively shallow hydrothermal environment. The hydrothermal condition may be corresponding to an intermediate sulfidation epithermal mineralization.

• Korean Journal of Plant Taxonomy
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• v.50 no.4
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• pp.427-452
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• 2020

This study of vascular plants was conducted over a period of 33 days from March to October of 2018 in Byeonsanbando National Park, South Korea. Based on voucher specimens and photographs, 829 taxa in total were recorded, including 141 families, 458 genera, 748 species, 16 subspecies, 59 varieties, and 6 forma. Two endangered taxa were identified, Iris koreana Nakai and Saururus chinensis (Lour.) Baill. Five rare taxa were found, including Abeliophyllum distichum Nakai and Hypodematium glanduloso-pilosum (Tagawa) Ohwi. A total of 17 Korean endemic plants were investigated. Examples include Elsholtzia byeonsanensis M. Kim, Eranthis byunsanensis B. Y. Sun, and Lycoris flavescens M. Kim & S. T. Lee. Of floristic regional indicators (third to fifth degree), 52 taxa were identified. Naturalized plants were identified, which included 79 taxa, and 7 species of ecosystem disturbance plants, such as Ambrosia artemisiifolia L., Lactuca serriola L., and Solidago altissima L. were found. We recorded 39 taxa of the plants vulnerable to climate change.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1119-1130
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• 2020

Flood disasters have been recently increasing worldwide due to climate change and extreme weather events. Since flood damage recovery has been conducted as a common coping strategy to flood disasters in the Republic of Korea, it is necessary to predict the regional flood damage costs by rainfall characteristics for a preventative measure to flood damage. Therefore, the purpose of this study is to present the regression functions for human and economic flood damage assessments for the 7 metropolises in the Republic of Korea. A comprehensive regression analysis was performed through the total 48 simple regression models on the two types of flood damage records for human and economic costs over the past two decades from 1998 to 2017 using the four kinds of nonlinear equations with each of the six rainfall variables. The damage assessment functions for each metropolis were finally selected by the evaluation of the regression results with the coefficient of determination and the statistical significance test, and then used for the human and economic flood damage assessments for 100-year rainfall in the 7 metropolises. The results of this study are expected to provide the basic information on flood damage cost assessments for flood damage mitigation measures.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.85-97
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• 2022

In this study, a method for an integrated flood risk mapping was proposed that simultaneously considers the flood inundation map indicating the degree of risk and the disaster vulnerability index. This method creates a new disaster map that can be used in actual situations by providing various and specific information on a single map. In order to consider the human, social and economic factors in the disaster map, the study area was divided into exposure, vulnerability, responsiveness, and recovery factors. Then, 7 indicators for each factor were extracted using the GIS tool. The data extracted by each indicator was classified into grades 1 to 5, and the data was selected as a disaster vulnerability index and used for integrated risk mapping by factor. The risk map for each factor, which overlaps the flood inundatoin map and the disaster vulnerability index factor, was used to establish an evacuation plan by considering regional conditions including population, assets, and buildings. In addition, an integrated risk analysis method that considers risks while converting to a single vulnerability through standardization of the disaster vulnerability index was proposed. This is expected to contribute to the establishment of preparedness, response and recovery plans for providing detailed and diverse information that simultaneously considers the flood risk including social, humanistic, and economic factors.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.999-1009
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• 2021

As the frequency and intensity of extreme weather events due to climate change are increasing in recent years, it is very important to evaluate and analyze climate conditions to manage and respond to the negative effects of climate change in advance. In this study, the trends and characteristics of regional climate change were analyzed by calculating the climate indices for the Chungcheong Province. Annual and monthly UNEP-MP, UNEP-PM and MDM indices were calculated using daily data from 1973-2020 collected from 10 synoptic meteorological stations operated by the Korea Meteorological Administration. The normality of climate data was analyzed through the KS test, and the climate change trend was analyzed by applying the Spearman and Pearson methods. The Chungcheongnam-do region had a relatively humid climate than the Chungcheongbuk-do region, and the annual climate indices showed a dry climate trend in Cheongju and Chungju, while the climate of Seosan and Buyeo was becoming humid. Based on the monthly trend change analysis, a humid climate trend was observed in summer and autumn, while a dry climate trend was observed in spring and winter. Comparison of climate indices during the past (2001-2010) and the recent (2011-2020) years showed a higher decrease in the average climate indices during the last 10 years and a gradually drying climate change trend was recorded.