• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.537-549
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• 2023

The distribution characteristics of tidal flat sediment components are used as an essential data for coastal environment analysis and environmental impact assessment. Therefore, a reliable classification map of surface sedimentary facies is essential. This study evaluated the applicability of regression kriging to generate a classification map of the sedimentary facies of tidal flats. For this aim, various factors such as the number of field survey data and remote sensing-based auxiliary data, the effect of regression models on regression kriging, and the comparison with other prediction methods (univariate kriging and regression analysis) on surface sedimentary facies classification were investigated. To evaluate the applicability of regression kriging, a case study using unmanned aerial vehicle (UAV) data was conducted on the Hwang-do tidal flat located at Anmyeon-do, Taean-gun, Korea. As a result of the case study, it was most important to secure an appropriate amount of field survey data and to use topographic elevation and channel density as auxiliary data to produce a reliable tidal flat surface sediment facies classification map. In addition, regression kriging, which can consider detailed characteristics of the sediment distributions using ultra-high resolution UAV data, had the best prediction performance compared to other prediction methods. It is expected that this result can be used as a guideline to produce the tidal flat surface sedimentary facies classification map.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.4
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• pp.140-155
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• 2020

This study was conducted to identify the location characteristics of infected farms in the areas where livestock diseases were clustered(southern Gyeonggi-do and Chungcheong-do), analyze the probability of disease occurrence in poultry farms, find out the areas corresponding to the conditions, and use them as the basis for prevention of livestock diseases, selection of discriminatory prevention zones, and establishment of prevention strategies and as the basic data for complementary measures. The increase of one poultry farm within a radius of 3-kilometers increases the risk of HPAI infection by 10.9% compared to the previous situation. The increase of 1m in distance from major roads with two lanes or more reduces the probability of HPAI infection by 0.001% compared to the previous situation. If the distance of the poultry farm located with 15 kilometers from a major migratory bird habitat increases by 15 to 30 kilometers, the chance of infection with HPAI is reduced by 46.0%. And if the distance of the same poultry farm increase by more than 30 kilometers, the chances of HPAI infection are reduced by 88.5%. Based on the results of logistic regression, the predicted probability was generated and the actual area of the location condition with 'more than 15 poultry farms within 3km a radius of, within 1km distance from major roads, and within 30km distance from major migratory birds habitat was determined and the infection rate was measured. It is expected that the results of this study will be used as basic data for preparing the data and supplementary measures when the quarantine authorities establish discriminatory quarantine areas and prevention strategies, such as preventive measures for the target areas and farms, or control of vehicles, by identifying the areas where livestock diseases are likely to occur in the region.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.3
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• pp.295-303
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• 2000

The purpose of this research is to enhance efficiency and tide measurement of the bathymetry survey based on the DGPS techniques which is becoming popular today due to a lot of benefits using the GPS. And according to the result of this research, choice and interpolation were possible with the most optimum method according to the various mathematical regressive equations as linear, parabolic, polynomic, reciprocal, hyperbolic, logarithmic and Gaussian functions. And the height of ground surface is easily calculated by 2D+1D transformation of coordinate of WGS84 in Cm-level based on the real time, even though the GPS time and tide were used to be synchronized through step-wised processing before. And because of the synchronization of time, the real time DGPS can cope with the loss of local current and changes of the tide.

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.203-216
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• 2003

The process of constructing coastal digital elevation model(DEM), for the 3 dimensional analysis, is composed by abstracting land layers for land elevation and water depth, reprojecting UTM, relocating geographical grid, and interpolating works. The geomorphic set of shallow sea, including tidal current, tidal zone deposition, and water depth distribution, was analyzed by eye search of Landsat TM image, masking of land zone, band combination and regression analysis. Some horizontal differences, between combined DEM and surveyed data of shallow sea, was corrected for analysis. Analyzed geomorphic elements are stream channel, alluvial fan, coastal terrace, tidal current. and shallow sea bank. Results of analysis present that transported fluvial materials influence tidal sedimentation, especially from Gahwacheon river, for the role of artificial draining flooding waters from Jinyang Reservoir, almost in the summer season. In the coastal area with less tidal current, more fine materials are deposited. The influence of currental deposition are higher on small pockets with west coast of well developed terraces. The lower skirt of alluvial fans developed into the tidal zone of shallow sea. Small pocket type bays are closed by coastal current, and less influenced from tidal deposition. The bank of Jinju Bay are developed originally from submerging of remnant erosional mountain ranges, and play on the role of trapping fine materials.

• 한국해양학회지
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• v.25 no.2
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• pp.106-116
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• 1990

The dynamics and seasonal succession of dinoflagellate community, and their correlations with environmental parameters were investigated during the period from April, 1986 to March, 1987 at 6 selected stations in Masan Bay, Korea. The dinoflagellate standing crops varied extensively with months and stations: ranging from 44 to 2,789,900 cella/ l at surface layer and from 52 to 165,714 cells/ l at bottom layer, respectively. The distribution of standing crops by size class of dinoflagellate species showed that a group of 20-um size class was predominant throughout the present survey, since the most of dominant species have belonged to the size category. Among dominant species, Gyrodinium fissum was most dominant throughout the year in all sampling stations, particulary in June. Scripsiella trochoidea was predominant in May, Protoperidinium bipes and Prorocentrum minimum from June to September, Prorocentrum triestinum, P micans and Ceratium fusus from September to December, and Heterocapsa triquetra from December to April. The stepwise multiple regression analysis between dinoflagellate and environmental parameters revealed that salinity, nitrate-N, pH, and transparency were correlated with the variations of standing crops of dinoflagellate.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.17-22
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• 2011

The distributional pattern of benthic diatoms in tidal flats of Hampyeong Bay, Korea, was studied from January to October in 2009. As benthic diatoms of Hampyeong Bay tidal flats, 45 species were identified, and the most dominant species was Paralia sulcata. The most diverse flora was observed at Gaip and Songseok sites in April with 22 species, and the least at Hyeonhwa site in January. The ranges of chlorophyll-a concentration in tidal flats were 21.2~31.8 mg$m^{-2}$ at Hyeonhwa site, 23.6~35.4 mg $m^{-2}$ at Gaip site, and 24.2~34.3 mg $m^{-2}$ at Songseok site. The concentrations of pheopigment ranged between 25.3 and 45.2 mg$m^{-2}$. The standing crops of benthic diatoms showed highest density in April and lowest in January, February, and October. The cell volumes of benthic diatoms were highest in April. The taxa and biomass of benthic diatoms showed correlations with temperature. On temperature variables, the benthic diatoms showed optimal occurrences at the range of $14{\sim}17^{\circ}C$.

• Journal of Environmental Impact Assessment
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• v.33 no.2
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• pp.64-73
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• 2024

As the seriousness of habitat destruction caused by development projects emerges, the importance of environmental impact assessment (EIA) is increasing to preserve biodiversity. In previous studies, research is being conducted to quantitatively evaluate the biodiversity impact of development factors and surrounding environmental factors on the landscape scale, but research on the factors affecting the reduction of biodiversity based on development projects is insufficient. This study examined whether independent variables (size of development project, type of the development, DEM, ecosystem and nature map, distance from the green land, distance from the protected area), which have been proven to effect biodiversity through the previous researches, have a significant effect on the change of richness index (RI) through multi-class logistic regression analysis, T-test, and analysis of the development type. As a result, only the size of development project and the first richness index in EIA showed p-value less than 0.05. And it was confirmed that the reduction in biodiversity was significantly changed in the following construction types: installation of sports facilities, energy development, and development of industrial location and industrial complex. Since the results of this study confirmed that the impact of the variables may be inconsistent depending on the analysis scale, additional study of necessary indicators at the development project is needed to analyze biodiversity changes in EIA accurately.

• Journal of Life Science
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• v.30 no.1
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• pp.26-31
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• 2020

Heterosigma akashiwo is a globally distributed raphidophyte that forms blooms and causes significant losses to the aquaculture industry in many coastal countries. The development of a fast and sensitive detection method is therefore required to facilitate the appropriate warning of harmful algal blooms. In this study, a nuclease protection integrated with sandwich hybridization (NPA-SH) assay was developed to both qualitatively and quantitatively detect H. akashiwo. The NPA, capture and signal probes were designed by nucleotide sequencing of H. akashiwo. The applicability of NPA-SH was evaluated using cultured H. akashiwo cells and field samples collected at Goseong Bay, Korea. The results show that this method has good applicability and effectiveness in analyzing cultured cells and field samples. A linear regression equation for the quantitative analysis of H. akashiwo was obtained, and the lower detection limit of the assay was 1×10⁴ cells/ml. There was no statistically significant difference in the results of H. akashiwo quantitation using NPA-SH compared to those obtained using a microscope. These results indicate that NPA-SH can be a good alternative to the traditional microscopic method used to monitor H. akashiwo.

• ALGAE
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• v.23 no.4
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• pp.289-294
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• 2008

To estimate seaweed biomass or standing crop, a nondestructive sampling can be beneficial because of not much destroying living plants and saving time in field works. We suggest a methodological procedure to estimate seaweed biomass per unit area in marine benthic habitats by using species-specific regression equations. Percent cover data are required from the field samplings for most species to convert them to weight data. However, for tall macroalgae such as kelps we need density data and their size (e.g., size class for subtidal kelps) of individuals. We propose that the field sampling should be done with 5 replicates of 50 cm x 50 cm quadrat at three zones of intertidals (upper, middle, lower) and three depth points (1, 5, 10 m) in subtidals. To obtain a reliable regression equation for a species, a substantial number of replicate is necessary from destructive samplings. The regression equation of a species can be further specified by different locality and different season, especially for the species with variable morphology temporally and spatially. Example estimation carried out in Onpyung, Jeju Island, Korea is provided to compare estimated values with real weight data.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.224-224
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• 2022

물부족, 수질오염, 조류발생 등 효율적 물관리를 위해서는 물정보 통합이 필요하지만 부처별/목적별로 개별 생산·관리되어 물관리 현안에 효과적으로 대응하기 어려운 실정이다. 물관리 현안 대응 의사결정을 위해서는 현재 상황에 대한 정확한 인식과 장래(1,3개월) 수자원 상황을 고려한 예측·분석체계 구축 필요하며, 이를 위해서는 수원별 가용수량, 지역별 물사용량 및 회귀수량 등 지자체, 유역, 하천을 연계한 실제 물이용 정보 기반의 물배분 현황 분석체계 구축이 필요하다. 본 연구에서는 물수급 관련 수요·공급 시설의 위치를 연결하는 물수급 분석 알고리즘 개발을 통해 지형공간정보의 위상(topology) 관계를 설정하여 물수급 분석의 계산순서를 선정하고, 시계열 DB를 입력하여 전국 약 40만개 이상의 일단위 물수급 분석 정보생산체계를 구축하였다. 본 연구에서 개발된 물수급 분석 모형은 향후 물관련 이슈 지역의 용수공급능력 평가 및 디지털트윈 등 다양한 수자원 정책평가에 활용될 것으로 기대된다.