• Title/Summary/Keyword: 延安

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Evaluation of inundation damages based on the fluctuation of inundation height due to climate change in Haeundae Area (해운대 지역의 기후변화에 의한 해일고 변동에 따른 침수피해 평가)

  • MAENG, Da-Hye;JANG, Dong-Ho
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.141-152
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    • 2011
  • The fluctuation of inundation height due to climate change and sea level rise is expected to cause the socio-economical damage in the coastal zone. To evaluate the inundation damage in Haeundae Beach Area, the inundation height was calculated using the observed data and the range of inundated area and buildings was estimated by applying to DEM data, which was constructed with airborne LiDAR data. The range of inundated area and buildings were estimated with 5 scenario of sea level rise in the condition of minimum and maximum inundation height. When the 181cm, the area of 7.19ha and 5 buildings were expected to be inundated. As 20cm in sea level rises at the minimum of the inundation height, the area of 8.90ha and 8buildings were expected to be inundated. As 30cm, 40cm, 50cm, 60cm in sea level rise, 9.98ha and 9 buildings, 11.11ha and 11buildings, 12.41ha and 11buildings, 14.18ha and 14buildings were expected to be inundated, respectively. When the 526 cm, the area of 32.35ha and 42buildings were expected to be inundated. As 20cm, 30cm, 40cm, 50cm, 60cm in sea level rise at the maximum of the inundation height, 38.94ha and 47buildings, 42.46ha and 52buildings, 45.76ha and 58buildings, 49.51ha and 66buildings, 52.53ha and 72buildings were expected to be inundated, respectively. The leisure and industry facilities, socio-economical installation, habitation are located near by the estimated inundation area, then the inundation damage is expected to be greater scale.

Study on Development of Digital Ocean Information Contents for Climate Change and Environmental Education : Focusing on the 3D Simulator Experiencing Sea Level Rise (기후변화 환경교육을 위한 디지털 해양정보 콘텐츠 개발 방안 연구 - 해수면 상승 체험 3D 시뮬레이터를 중심으로 -)

  • Jin-Hwa Doo;Hong-Joo Yoon;Cheol-Young Lee
    • The Journal of the Korea institute of electronic communication sciences
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    • v.18 no.5
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    • pp.953-964
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    • 2023
  • Climate change is undeniably the most urgent challenge that humanity faces today. Despite this, the level of public awareness and understanding of climate change remains insufficient, indicating a need for more proactive education and the development of supportive content. In particular, it is crucial to intensify climate change education during elementary and secondary schooling when values and ethical consciousness begin to form. However, there is a significant lack of age-appropriate, experiential educational content. To address this, our study has developed an innovative 3D simulator, enabling learners to indirectly experience the effects of climate change, specifically sea-level rise. This simulator considers not only sea-level rise caused by climate change but also storm surges, which is a design based on the analysis of long-term wave observation big data. To make the simulator accessible and engaging for students, we utilized the 'Unity' game engine. We further propose using this simulator as a part of a comprehensive educational program on climate change.

Optimal Design of Overtopping Wave Energy Converter Substructure based on Smoothed Particle Hydrodynamics and Structural Analysis (SPH 및 구조해석에 기반한 월파수류형 파력발전기 하부구조물 최적 설계)

  • Sung-Hwan An;Jong-Hyun Lee;Geun-Gon Kim;Dong-hoon Kang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.992-1001
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    • 2023
  • OWEC (Overtopping Wave Energy Converter) is a wave power generation system using the wave overtopping. The performance and safety of the OWEC are affected by wave characteristics, such as wave height, period. To mitigate this issue, optimal OWEC designs based on wave characteristics must be investigated. In this study, the environmental conditions along the Ulleungdo coast were used. The hydraulic efficiency of the OWEC was calculated using SPH (Smoothed Particle Hydrodynamics) by comparing 4 models that changed the substructure. As a result, it was possible to change the substructure. Through design optimization, a new truss-type structure, which is a substructure capable of carrying the design load, was proposed. Through a case study using member diameter and thickness as design variables, structural safety was secured under allowable stress conditions. Considering wave load, the natural frequency of the proposed structure was compared with the wave period of the relevant sea area. Harmonic response analysis was performed using wave with a 1-year return period as the load. The proposed substructure had a reduced response magnitude at the same exciting force, and achieved weight reduction of more than 32%.

Okadaic Acid Group Toxins: Toxicity, Exposure Routes, and Global Safety Management (오카다익산 군 독소: 독성, 분석법 및 관리 동향)

  • Kyoungah Lee;Namhyun Kim;Jang Kyun Kim;Youn-Jung Kim;Jung Suk Lee;Young-Seok Han
    • Journal of Food Hygiene and Safety
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    • v.38 no.6
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    • pp.409-419
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    • 2023
  • Okadaic acid (OA) group toxins, including OA and its analogs, such as dinophysis toxins (DTXs), have been reported to cause diarrheal shellfish poisoning (DSP). These toxins are primarily produced by dinoflagellates and are accumulated in bivalves. Recently, the presence of Dinophysis sp., a causative alga of DSP, has been reported along the coasts of Korea, posing a potential risk of contamination to domestic seafood and exerting an impact on both the production and consumption of marine products. Accordingly, the European Food Safety Authority (EFSA) and the World Health Organization (WHO) have established standards for the permissible levels of OA group toxins in marine products for safety management. Additionally, in line with international initiatives, the domestic inclusion and regulation of DTX2 among the substances falling under the purview of management outlined by the 2022 diarrheal shellfish toxin standard have been implemented. In this study, we reviewed the physicochemical properties of OA group toxins, their various exposure routes (such as acute toxicity, genotoxicity, reproductive and developmental toxicity), and the relative toxicity factors associated with these toxins. We also performed a comparative assessment of the methods employed for toxin analysis across different countries. Furthermore, we aimed to conduct a broad review of human exposure cases and assess the international guideline for risk management of OA group toxins.

Development of Cloud-based VTS Integration Platform for IVEF Service Implementation (IVEF 서비스 구현을 위한 클라우드 기반 VTS 통합 플랫폼 개발)

  • Yunja Yoo;Dae-Won Kim;Chae-Uk Song;Jung-Jin Lee;Sang-Gil Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.7
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    • pp.893-901
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    • 2023
  • The International Association Marine Aids to Navigation and Lighthouse Authorities (IALA) proposed guidelines for VTS manual operation in 2016 for safe and efficient operation of ship. The Korea Coast Guard (KCG) established and operated 19 VTS centers in ports and coastal waters across the country by 2022 based on the IALA VTS manual and VTS operator's education and training guidelines. In addition, IALA proposed the Inter-VTS Exchange Format (IVEF) Service recommendation (V-145), a standard for data exchange between VTS, in 2011 for efficient e-Navigation system services and safe and efficient VTS service support by VTS authorities. The IVEF service in a common framework for ship information exchange, and it presents seven basic IVEF service (BISs) models. VTS service providers can provide safer and more efficient VTS services by sharing VTS information on joint area using IVEF standards. Based on the BIS data, interaction, and interfacing models, this paper introduced the development of the cloud-based VTS integration services performed by the KCG and the results of the VTS integration platform test-bed for IVEF service implementation. In addition, the results of establishing a cloud VTS integrated platform test-bed for the implementation of IVEF service and implementing the main functions of IVEF service were presented.

Assessing the Climatic Suitability for the Drywood Termite, Cryptotermes domesticus Haviland (Blattodea: Kalotermitidae), in South Korea (마른나무흰개미(가칭)의 국내 기후적합성 평가)

  • Min-Jung Kim;Jun-Gi Lee;Youngwoo Nam ;Yonghwan Park
    • Korean journal of applied entomology
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    • v.62 no.3
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    • pp.215-220
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    • 2023
  • A recent discovery of drywood termites (Cryptotermes domesticus) in a residential facility in Seoul has raised significant concern. This exotic insect species, which can damage timber and wooden buildings, necessitates an immediate investigation of potential infestation. In this study, we assessed the climatic suitability for this termite species using a species distribution modeling approach. Global distribution data and bioclimatic variables were compiled from published sources, and predictive models for climatic suitability were developed using four modeling algorithms. An ensemble prediction was made based on the mean occurrence probability derived from the individual models. The final model suggested that this species could potentially establish itself in tropical coastal regions. While the climatic suitability in South Korea was generally found to be low, a careful investigation is still warranted due to the potential risk of colonization and establishment of this species.

Unmanned AerialVehicles Images Based Tidal Flat Surface Sedimentary Facies Mapping Using Regression Kriging (회귀 크리깅을 이용한 무인기 영상 기반의 갯벌 표층 퇴적상 분포도 작성)

  • Geun-Ho Kwak;Keunyong Kim;Jingyo Lee;Joo-Hyung Ryu
    • 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.

A Review of Deep Learning-based Trace Interpolation and Extrapolation Techniques for Reconstructing Missing Near Offset Data (가까운 벌림 빠짐 해결을 위한 딥러닝 기반의 트레이스 내삽 및 외삽 기술에 대한 고찰)

  • Jiho Park;Soon Jee Seol;Joongmoo Byun
    • Geophysics and Geophysical Exploration
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    • v.26 no.4
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    • pp.185-198
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    • 2023
  • In marine seismic surveys, the inevitable occurrence of trace gaps in the near offset resulting from geometrical differences between sources and receivers adversely affects subsequent seismic data processing and imaging. The absence of data in the near-offset region hinders accurate seismic imaging. Therefore, reconstructing the missing near-offset information is crucial for mitigating the influence of seismic multiples, particularly in the case of offshore surveys where the impact of multiple reflections is relatively more pronounced. Conventionally, various interpolation methods based on the Radon transform have been proposed to address the issue of the nearoffset data gap. However, these methods have several limitations, leading to the recent emergence of deep-learning (DL)-based approaches as alternatives. In this study, we conducted an in-depth analysis of two representative DL-based studies to scrutinize the challenges that future studies on near-offset interpolation must address. Furthermore, through field data experiments, we precisely analyze the limitations encountered when applying previous DL-based trace interpolation techniques to near-offset situations. Consequently, we suggest that near-offset data gaps must be approached by extrapolation rather than interpolation.

Detection of Cold Water Mass along the East Coast of Korea Using Satellite Sea Surface Temperature Products (인공위성 해수면온도 자료를 이용한 동해 연안 냉수대 탐지 알고리즘 개발)

  • Won-Jun Choi;Chan-Su Yang
    • Korean Journal of Remote Sensing
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    • v.39 no.6_1
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    • pp.1235-1243
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    • 2023
  • This study proposes the detection algorithm for the cold water mass (CWM) along the eastern coast of the Korean Peninsula using sea surface temperature (SST) data provided by the Korea Institute of Ocean Science and Technology (KIOST). Considering the occurrence and distribution of the CWM, the eastern coast of the Korean Peninsula is classified into 3 regions("Goseong-Uljin", "Samcheok-Guryongpo", "Pohang-Gijang"), and the K-means clustering is first applied to SST field of each region. Three groups, K-means clusters are used to determine CWM through applying a double threshold filter predetermined using the standard deviation and the difference of average SST for the 3 groups. The estimated sea area is judged by the CWM if the standard deviation in the sea area is 0.6℃ or higher and the average water temperature difference is 2℃ or higher. As a result of the CWM detection in 2022, the number of CWM occurrences in "Pohang-Gijang" was the most frequent on 77 days and performance indicators of the confusion matrix were calculated for quantitative evaluation. The accuracy of the three regions was 0.83 or higher, and the F1 score recorded a maximum of 0.95 in "Pohang-Gijang". The detection algorithm proposed in this study has been applied to the KIOST SST system providing a CWM map by email.

Mapping Topography Change via Multi-Temporal Sentinel-1 Pixel-Frequency Approach on Incheon River Estuary Wetland, Gochang, Korea (다중시기 Sentinel-1 픽셀-빈도 기법을 통한 고창 인천강 하구 습지의 지형 변화 매핑)

  • Won-Kyung Baek;Moung-Jin Lee;Ha-Eun Yu;Jeong-Cheol Kim;Joo-Hyung Ryu
    • Korean Journal of Remote Sensing
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    • v.39 no.6_3
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    • pp.1747-1761
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    • 2023
  • Wetlands, defined as lands periodically inundated or exposed during the year, are crucial for sustaining biodiversity and filtering environmental pollutants. The importance of mapping and monitoring their topographical changes is therefore paramount. This study focuses on the topographical variations at the Incheon River estuary wetland post-restoration, noting a lack of adequate prior measurements. Using a multi-temporal Sentinel-1 dataset from October 2014 to March 2023, we mapped long-term variations in water bodies and detected topographical change anomalies using a pixel-frequency approach. Our analysis, based on 196 Sentinel-1 acquisitions from an ascending orbit, revealed significant topography changes. Since 2020, employing the pixel-frequency technique, we observed area increases of +0.0195, 0.0016, 0.0075, and 0.0163 km2 in water level sections at depths of 2-3 m, 1-2 m, 0-1 m, and less than 0 m, respectively. These findings underscore the effectiveness of the wetland restoration efforts in the area.