• Title/Summary/Keyword: Geographic variation

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Large-Scale Slope Stability Analysis Using Climate Change Scenario (1): Methodologies (기후변화 시나리오를 이용한 광역 사면안정 해석(1): 방법론)

  • Choi, Byoung-Seub;Oh, Sung-Ryul;Lee, Kun-Hyuk;Lee, Gi-Ha;Kwon, Hyun-Han
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.3
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    • pp.193-210
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    • 2013
  • This study aims to assess the slope stability variation of Jeollabuk-do drainage areas by RCM model outputs based on A1B climate change scenario and infinite slope stability model based on the specific catchment area concept. For this objective, we downscaled RCM data in time and space: from watershed scale to rain gauge scale in space and from monthly data to daily data in time and also developed the GIS-based infinite slope stability model based on the concept of specific catchment area to calculate spatially-distributed wetness index. For model parameterization, topographic, geologic, forestry digital map were used and model parameters were set up in format of grid cells($90m{\times}90m$). Finally, we applied the future daily rainfall data to the infinite slope stability model and then assess slope stability variation under the climate change scenario. This research consists of two papers: the first paper focuses on the methodologies of climate change scenario preparation and infinite slope stability model development.

Genetic Diversity and Population Genetic Structure of Exochorda serratifolia in South Korea (가침박달 집단의 유전다양성 및 유전구조 분석)

  • Hong, Kyung Nak;Lee, Jei Wan;Kang, Jin Taek
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.122-128
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    • 2013
  • Genetic diversity and population genetic structure were estimated in nine natural populations of Exochorda serratifolia in South Korea using ISSR marker system. Average of polymorphic loci per primer was 5.8 (S.D.=2.32) and percentage of polymorphic loci per population was 78.7% with total 35 loci from 6 ISSR primers. In AMOVA, 27.8% of total genetic variation came from genetic difference among populations and 72.2% was resulted from difference among individual trees within populations. Genetic differentiations by Bayesian inference were 0.249 of ${\theta}^{11}$ and 0.227 of $G_{ST}$. Inbreeding coefficient for total populations was 0.412. There was significant correlation between genetic distance and geographic distance among populations. On the results of Bayesian cluster analysis, nine populations were assigned into three groups. The first group included 5 populations, and the second and the third had two populations per group, respectively. These three regions could explain 10.0% of total genetic variation from hierarchical AMOVA, and the levels of among-population and among-individual were explained 19.7% and 70.3%, respectively. The geographic distribution of populations following the three Bayesian clusters could be explained with mountain range as Baekdudaegan which is the main chain of mountains in Korea. The mountains as the physical barrier might hamper gene flow in the pearlbush. So when protected areas are designated for conservation of this species, we should consider those three regions into considerations and would better to choose at least one population per region.

GIS Mapping of Coastal Pollution Induced by Hebei Spirit Oil Spill (허베이 스피리트호 유류유출 사고에 따른 해안오염 GIS 지도 제작 연구)

  • Park, Jae-Moon;Choi, Hyun-Woo;Yoon, Hong-Joo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.12 no.3
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    • pp.164-178
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    • 2009
  • This study was aimed to make GIS oiling thematic maps and analyze temporal oiling variation patterns for two months after 'Hebei Spirit' oil spill accident in December 7, 2007 using GIS and oiling status surveyed data. As a basic work for making of oiling thematic maps, geometric corrections were performed with IKONOS images using ground control points data. These corrected images were used to make detailed coastline from digital charts, and then spatial unit of coastline were defined using classified coastline types. And to know the representative parameters which reflect oiling situation, relationship between oiling status parameters extracted from four times oiling assessment reports and total petroleum hydrocarbons (TPHs) data (December 2007 and January 2008) monitored by Korea Ocean Research and Development Institute (KORDI). Using these representative oiling status parameters pollution value were calculated, and they were keyed into spatial unit of coastline as attributive value. GIS oiling status thematic maps made with coastline containing pollution value showed the initial two month's situations somewhat well. Also, to analyze temporal variation pattern of coastline types, about 13.4km length coastline around Malripo beach was defined as detailed study area where is the common spatial zone surveyed oiling status by each organizations. Based on this study results, it could be possible to provide oiling status maps quickly and to support decision making for oiling control action and scientific pollution monitoring.

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Morphological variation and aspects of the geographic distribution of Orobanche coerulescens Stephan ex Willd. (Orobanchaceae) on Ulleung-do and Dok-do Islands (울릉도, 독도 초종용에서 형태 변이와 지리적 분포 양상)

  • Lee, Woong;Jeong, Keum Seon;Choi, Kyung;Kim, Jin Seok;Cho, Seong Ho;Pak, Jae-Hong
    • Korean Journal of Plant Taxonomy
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    • v.46 no.4
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    • pp.405-412
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    • 2016
  • We investigate the intraspecific morphological variations and geographical distributions from twelve populations (28 samples) of Orobanche coerulescens in Korea. Two main morphological types were detected, i.e., glabrous (G-type) and pilose (P-type), in the external morphology (stem, leaf, bract, calyx, and corolla). The G-type was found on Ulleung-do and Dok-do, and the P-type was observed on the coasts of South Korea, Jeju-do and Ulleung-do. The distinct difference in the morphological types and geographical distribution suggested the existence of two putative lineages with different distribution processes. O. coerulescens, distributed in very limited areas, was only identified as the G-type on Dok-do. Hence, conservation efforts should focus on protecting native habitats to conserve native species and the unique biogeographic significance of this species.

Development of Information System based on GIS for Analyzing Basin-Wide Pollutant Washoff (유역오염원 수질거동해석을 위한 GIS기반 정보시스템 개발)

  • Park, Dae-Hee;Ha, Sung-Ryong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.34-44
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    • 2006
  • Simulation models allow researchers to model large hydrological catchment for comprehensive management of the water resources and explication of the diffuse pollution processes, such as land-use changes by development plan of the region. Recently, there have been reported many researches that examine water body quality using Geographic Information System (GIS) and dynamic watershed models such as AGNPS, HSPF, SWAT that necessitate handling large amounts of data. The aim of this study is to develop a watershed based water quality estimation system for the impact assessment on stream water quality. KBASIN-HSPF, proposed in this study, provides easy data compiling for HSPF by facilitating the setup and simulation process. It also assists the spatial interpretation of point and non-point pollutant information and thiessen rainfall creation and pre and post processing for large environmental data An integration methodology of GIS and water quality model for the preprocessing geo-morphologic data was designed by coupling the data model KBASIN-HSPF interface comprises four modules: registration and modification of basic environmental information, watershed delineation generator, watershed geo-morphologic index calculator and model input file processor. KBASIN-HSPF was applied to simulate the water quality impact by variation of subbasin pollution discharge structure.

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Relationship assessment among land use and land cover and land surface temperature over downtown and suburban areas in Yangon City, Myanmar

  • Yee, Khin Mar;Ahn, Hoyong;Shin, Dongyoon;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.32 no.4
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    • pp.353-364
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    • 2016
  • Yangon city is experienced a rapid urban expansion over the last two decades due to accelerate with the socioeconomic development. This research work studied an investigation into the application of the integration of the Remote Sensing (RS) and Geographic Information System (GIS) for observing Land Use and Land Cover (LULC) patterns and evaluate its impact on Land Surface Temperature (LST) of the downtown, suburban 1 and suburban 2 of Yangon city. The main purpose of this paper was to examine and analyze the variation of the spatial distribution property of the LULC of urban spatial information related with the LST and Normalized Difference Vegetation Index (NDVI) using RS and GIS. This paper was observed on image processing of LULC classification, LST and NDVI were extracted from Landsat 8 Operational Land Imager (OLI) image data. Then, LULC pattern was linked with the variation of LST data of the Yangon area for the further connection of the correlation between surface temperature and urban structure. As a result, NDVI values were used to examine the relation between thermal behavior and condition of land cover categories. The spatial distribution of LST has been found mixed pattern and higher LST was located with the scatter pattern, which was related to certain LULC types within downtown, suburban 1 and 2. The result of this paper, LST and NDVI analysis exhibited a strong negative correlation without water bodies for all three portions of Yangon area. The strongest coefficient correlation was found downtown area (-0.8707) and followed suburban 1 (-0.7526) and suburban 2(-0.6923).

Genetic diversity and structure of natural populations of Picea jezoensis in South Korea

  • Lee, Seok Woo;Yang, Byeong Hoon;Hur, Seong Doo;Lee, Jung Joo;Song, Jeong Ho;Moriguchi, Yoshinari
    • Journal of Korean Society of Forest Science
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    • v.97 no.2
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    • pp.187-195
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    • 2008
  • Picea jezoensis (Sieb. et Zucc.) Carriere is one of the major and widespread components of the cold-temperate and boreal forests in Russian Far East, northeast China, Korea, and Japan. However, it is restricted to a highly fragmented range in South Korea with small populations. Mean expected heterozygosity $(H_e)$ based on 22 loci in 11 isozyme systems was 0.077 for four sampled populations that covered the whole distribution range of P. jezoensis in South Korea. This value is within the range reported for conifers, but it is very low compared to that of other spruce species as well as that of P. jezoensis populations in Russian Far East. Most populations had a slight excess of heterozygotes and the Wright's $F_{IS}$ (-0.019) was comparable to that previously reported for other spruce species. In all of the four populations, the Wilcoxon sign-rank test indicated no greater heterozygosity than that expected for populations at mutation-drift equilibrium, suggesting that the populations have not been bottlenecked recently. Despite a fragmented range and isolated populations, population differentiation was not high $(F_{ST}=0.047)$ and the number of migrants per generation was 5.09. Nei's genetic distances were also small $({\bar{D}}=0.005)$ but strongly related to geographic distances between populations, suggesting an Isolation by Distance. The northernmost isolate, Mt. Gyebang population was genetically distinct from the other three populations. Implications for the conservation of genetic variation of P. jezoensis in South Korea were discussed.

Universal Indicators for Oil and Gas Prospecting Based on Bacterial Communities Shaped by Light-Hydrocarbon Microseepage in China

  • Deng, Chunping;Yu, Xuejian;Yang, Jinshui;Li, Baozhen;Sun, Weilin;Yuan, Hongli
    • Journal of Microbiology and Biotechnology
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    • v.26 no.7
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    • pp.1320-1332
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    • 2016
  • Light hydrocarbons accumulated in subsurface soil by long-term microseepage could favor the anomalous growth of indigenous hydrocarbon-oxidizing microorganisms, which could be crucial indicators of underlying petroleum reservoirs. Here, Illumina MiSeq sequencing of the 16S rRNA gene was conducted to determine the bacterial community structures in soil samples collected from three typical oil and gas fields at different locations in China. Incubation with n-butane at the laboratory scale was performed to confirm the presence of "universal microbes" in light-hydrocarbon microseepage ecosystems. The results indicated significantly higher bacterial diversity in next-to-well samples compared with background samples at two of the three sites, which were notably different to oil-contaminated environments. Variation partitioning analysis showed that the bacterial community structures above the oil and gas fields at the scale of the present study were shaped mainly by environmental parameters, and geographic location was able to explain only 7.05% of the variation independently. The linear discriminant analysis effect size method revealed that the oil and gas fields significantly favored the growth of Mycobacterium, Flavobacterium, and Pseudomonas, as well as other related bacteria. The relative abundance of Mycobacterium and Pseudomonas increased notably after n-butane cultivation, which highlighted their potential as biomarkers of underlying oil deposits. This work contributes to a broader perspective on the bacterial community structures shaped by long-term light-hydrocarbon microseepage and proposes relatively universal indicators, providing an additional resource for the improvement of microbial prospecting of oil and gas.

Spatial Analysis of Stomach Cancer Incidence in Iran

  • Pakzad, Reza;Khani, Yousef;Pakzad, Iraj;Momenimovahed, Zohre;Mohammadian-Hashejani, Abdollah;Salehiniya, Hamid;Towhidi, Farhad;Makhsosi, Behnam Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.27-32
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    • 2016
  • Stomach cancer, the fourth most common cancer and the second leading cause of cancer-related death through the world, is very common in parts of Iran. Geographic variation in the incidence of stomach cancer is due to many different factors. The aim of this study was to assess the geographical and spatial distribution of stomach cancer in Iran using data from the cancer registry program in Iran for the year 2009. The reported incidences of stomach cancer for different provinces were standardized to the world population structure. ArcGIS software was used to analyse the data. Hot spots and high risk areas were determined using spatial analysis (Getis-Ord Gi). Hot and cold spots were determined as more than or less than 2 standard deviations from the national average, respectively. A significance level of 0.10 was used for statistical judgment. In 2009, a total of 6,886 cases of stomach cancers were reported of which 4,891 were in men and 1,995 in women (standardized incidence rates of 19.2 and 10.0, respectively, per 100,000 population). The results showed that stomach cancer was concentrated mainly in northwest of the country in both men and women. In women, northwest provinces such as Ardebil, East Azerbaijan, West Azerbaijan, Gilan, and Qazvin were identified as hot spots (p<0.1). In men, all northwest provinces, Ardabil, East Azerbaijan, Gilan, Qazvin, Zanjan and Kurdistan, the incidences were higher than the national average and these were identified as hot spots (P<0.01). As stomach cancer is clustered in the northwest of the country, further epidemiological studies are needed to identify factors contributing to this concentration.

Variation in Cone, Seed, and Bract Morphology of Abies nephrolepis (Trautv.) Maxim. and A. koreana Wilson in Native Forests (분비·구상나무 천연집단(天然集團)의 구과(毬果), 종자(種子), 포침특성(苞針特性) 변이(變異))

  • Song, Jeong-Ho;Lee, Jung-Joo;Kang, Kyu-Suk
    • Journal of Korean Society of Forest Science
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    • v.97 no.6
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    • pp.565-569
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    • 2008
  • Geographic variation of characteristics of cone, seed and bract morphology were examined in 8 populations of rare endemic Abies nephrolepis (Trautv.) Maxim and A. koreana Wilson. Additionally we studied classification index to distinguish between the species by the method of discriminant analysis. Nested ANOVA showed that there were statistically significant differences among populations as well as among individuals within populations in all 13 morphological traits. In the seed length, seed index, bract width, and bract index of A. nephrolepis and the bract width and index of A. koreana, variance components among populations were larger than those among individuals within populations. In discriminant analysis, three traits (cone width, length of seed wing, and bract length) were found to be useful in discriminating A. nephrolepis from A. koreana. The optimal classification results of stepwise selection were discriminated length of seed wing and bract length.