• 제목/요약/키워드: sea-level changes

검색결과 380건 처리시간 0.024초

지리정보시스템과 시뮬레이션 모델을 이용한 해면상승의 예측과 해안지형에 미치는 영향 (Estimating theimpacts of sea level rise using geoprocessing and simulation modeling)

  • ;;이재극;권순식
    • 대한지리학회지
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    • 제28권4호
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    • pp.298-311
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    • 1993
  • 지 구 온난화 현상에 의한 해안지역에서의 가능한 미래의 해수면 상승의 영향을 예측하기 위한 연구가 미국 Florida주 북동 해안지역을 대상으로 행해졌다. 시뮬레이션 모델링을 위한 토지 이용도, 지표고도, 그리고 그외 지역의 자연적 특성에 관한 자료가 원격 탐사와 지리정보시 스템을 이용해서 준비, 분석, 합성이 되었다. 준비된 모든 자료는 개발된 모델 (SLAMM 3) 에 의해 분석되어 침수와 침식에 대한 결과로서 발생될 수 있는 해안지역에서의 현상이 예 측되었다. 해수면 상승에 관한 0.5m, 1m, 1.25m의 세가지 시나리오로서 진행된 연구결과, 유 용한 환경자원인 해안 저습지의 손실이 최고 40%까지 예측되었다.

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영산강 하구둑 및 영암-금호방조제의 방류에 의한 목포항 주변수역의 유동변화 및 선박운용에 미치는 영향에 관한 연구 (A Study on the Change of Current in the Vicinity of Mokpo Harbor and Its Impact on Ship Operation due to the Discharge through Yongsan River Estuary Weir and Yongam-Kumho Sea Dike)

  • 정대득;이중우;국승기
    • 한국항만학회지
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    • 제13권1호
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    • pp.133-146
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    • 1999
  • Mokpo coastal area is connected to the adjacent a long river and two large basins. It is essential for port planning coastal zone management and environmental impact study to analyze the data related to the ship operation and variation of current and water quality due to the development of water area including dredging reclamation and estuary barrage. The Yongsan river estuary weir and Yongam-Kumho basins discharge much of water through water gates for the purpose of flood control and prohibit salt intrusion at the inland fresh water area. To meet this purpose discharge through the gates have been done at the period of maximum water level difference between inner river and sea level. This discharged water may cause the changes of current pattern and other environmental influences in the vicinity and inner area of semi-closed Mokpo harbor. In this study ADI method is applied to the governing equation for the analysis of the changes on current pattern due to discharged water. As the results of this study it is known that the discharging operation causes many changes including the increase of current velocity at the front water area at piers approaching passage and anchorages. Discussion made on the point of problems such as restricted maneuverability and the safety of morred vessels at pier and anchorage. To minimize this influence the linked gate operation discharging warning system and laternative mooring system are recommended.

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해수면 상승에 따른 연안 지역 불규칙파의 변화 (Change of Nearshore Random Waves in Response to Sea-level Rise)

  • 천세현;서경덕
    • 한국해안·해양공학회논문집
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    • 제25권4호
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    • pp.244-254
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    • 2013
  • 1994년 Townend가 해수면 상승으로 인한 연안 지역의 파랑 특성 변화를 산정하는 방법을 규칙파에 대하여 제시한 바 있으며, 본 연구에서는 이를 불규칙파로 확장하였다. 수심변화율에 따른 불규칙파의 파장, 굴절계수, 천수계수, 그리고 파고 등의 변화율을 계산하였다. 파장 및 굴절계수의 변화율은 규칙파 공식에 유의파 주기와 주파향을 사용하여 계산하였다. 한편, 천수계수와 파고의 변화율 산정을 위해서는 쇄파대를 포함한 연안 지역에서의 불규칙파의 천수 및 파랑 변형 계산을 위해 제안된 공식을 사용하였다. 각 결과는 식과 그래프의 형태로 제안되었으며 파고의 경우 규칙파에 대한 결과와 비교하였다.

남서부 동해에서 1970년대의 기후체제전환이 생태계의 구조에 미친 영향 (Effects of Climatic Regime Shift on the Structure of Marine Ecosystem in the Southwestern East Sea during the 1970s)

  • 장창익;윤상철
    • 한국수산과학회지
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    • 제36권4호
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    • pp.389-401
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    • 2003
  • The changes in structure and abundance of taxon or species groups in the East Sea ecosystem were compared between pre- and post-Climatic Regime Shift (CRS) occurred in the mid 1970s using an ECOPATH model. Although the East Sea ecosystem consisted of primary producers, primary consumers, secondary consumers and terminal consumers most species groups were classified as secondary consumers. The mean trophic level between pre- and post-CRS increased from 3.09 during the pre-CRS period to 3.28 during the post-CRS period. Total biomass of the species groups in the East Sea ecosystem increased by $9\%$ due to the CRS, and total catch increased by $48\%.$ The most significant differences between pre- and post-CRS models occurred at the mid/high trophic levels occupied by fishes and cephalopods. Relative contribution of the different species groups to the total energy flow was calculated for the trophic level III. As a result, the status by the dominant species in the East Sea ecosystem shifted from cephalopods to walleye pollock due to the CRS. Relative contribution of 5 species, which were commercially important, such as Pacific saury, Pacific sardine, filefish, walleye pollock and sandfish in trophic level III, were also changed due to the CRS. Finally, the CRS turned out to cause large variations in biomass and catch of fisheries resources as well as the status and role of the major species.

Space-time-dissociated differential sedimentation and its relationship with the rate of relative sea-level change: the Lower Ordovician Mungok Formation, Korea

  • Choi Yong Seok;Lee Yong Il
    • 한국석유지질학회:학술대회논문집
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    • 한국석유지질학회 2000년도 제7차 학술발표회 발표논문집
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    • pp.14-30
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    • 2000
  • Hierarchically controlled sequence stratigraphic analysis shows that the Lower Ordovician mixed carbonate-siliciclastic Mungok Formation, Korea consists of three depositional sequences: T1, T2, and T3. Sequence boundaries are generally marked by abrupt transition from coarse-grained shallow-water carbonates to fine-grained deeper-water carbonates mixed with fine-grained siliciclastics, and show indication of subaerial exposure such as karstification. Within this sequence stratigraphic framework, facies characteristics indicate that the Mungok sequences were mostly deposited in subtidal ramp environments. High-frequency cycles consist of upward-shallowing facies successions. Cycles of shallow-water and basinal deposits are not represented well, probably due to cycle amalgamation. Cycle stacking patterns do not show a consistent thickness change that reflects a large-scale sea-level change due to unfilled accommodation space. The Mungok sequences show that many factors including relative sea-level change and topography are involved in controlling sequence development on carbonate ramps. The depositional setting evolved from the high-energy ramps in the sequences T1 and T2 into the low-energy ramp in the sequence T3. Topography is interpreted to have been responsible for the different energy regimes of the carbonate ramps in the Mungok sequences. The high ramp gradient in the sequences T1 and T2 seems to be caused by space-time-dissociated differential sedimentation resulting in spatially narrow distribution of sediment filling, which in turn may be related to high rate of relative sea-level change. In contrast, low ramp gradient was maintained in the sequence T3 during slow changes of relative sea level resulting in broad distribution of sediment filling.

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기후변화·해수면 상승에 따른 농업부문 통합평가 사례연구 비교분석 및 개선방안 (Reviewing of Integrated Assessment of the Impacts of Climate Change and Sea-Level Rise on Agricultural Sector)

  • 안소은;오서연
    • 한국기후변화학회지
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    • 제7권3호
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    • pp.299-314
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    • 2016
  • The aim of this paper is to review integrated assessment studies conducted to address the impacts of climate change sea-level rise on agricultural sector and to derive suggestions for improving the integrated assessment process to assist decision-makers in establishing climate change adaptation policy. We collect integrated assessment studies which are based on the impact-pathway analysis, compare their step-by-step procedures and identify main factors addressed in each step. The assessment process is typically carried out in the sequence of scenario development, determination of assessment scope, physical impact assessment, economic analysis and synthesis of the outcomes from each step. We identify two types of integrated assessment. The first one examines the impacts of changes in temperature and/or precipitation on the crop-cultivation patterns and/or agricultural productivity and resulting economic effects on agricultural sector. The other investigates the impacts of sea-level rise on land use/coverage and resulting economic damages in terms of land-value loss where the effects on agriculture is treated as one sector among others. To enhance integrated assessment, we suggest that 1) scenarios need to incorporate the effects of climate change and sea-level rise simultaneously, 2) scope of the assessment needs to be extended to include ecosystem services as well as crop production, 3) social and cultural aspects need to be considered in addition to economic analysis, and 4) synthesis of the outcomes from each step should be able to combine quantitative as well as qualitative information.

탄뎀가속기에 의한 방사성탄소 년대측정과 한국해에의 적용 (Radio-Carbon Age Determination by Tandem Accelerator Mass Spectrometry Technique and Its Application To The Korean Sea)

  • Suk, Bong-Chool;Toshio Nakamura;Nobuyuki Nakai;Asahiko Taira
    • 한국제4기학회지
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    • 제4권1호
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    • pp.27-40
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    • 1990
  • 탄뎀가속기에 의한 방사성탄소 연대측정은 한국남해 및 남동해의 해저로부터 25개의 화석종 조개와 1개의 피트를 대상으로 실시되었다. 특히 AMS기술은 종래의 C-14측정방법에 비해 양적으로 수밀리그램의 원소태탄소만으로써 충분히 측정가능하다. 본고는 자체 제작한 분석라인에 의한 전처리방법 및 분석과정을 기술하고, 한국남해 및 남동해에 대한 후기경신세의 해수면변동사에 대하여 고찰한다. 측정결과년대는 -530$\pm$100년에서 3,500년 이상의 범위로 본해역의 퇴적상은 후기경신세 이후의 해수준변동에 의한 복잡한 퇴적환경을 시사한다.

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한국 동해 생태계의 어획강도 변화에 따른 자원량 예측 연구 (A study on the forecasting biomass according to the changes in fishing intensity in the Korean waters of the East Sea)

  • 임정현;서영일;장창익
    • 수산해양기술연구
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    • 제54권3호
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    • pp.217-223
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    • 2018
  • Overfishing capacity has become a global issue due to over-exploitation of fisheries resources, which result from excessive fishing intensity since the 1980s. In the case of Korea, the fishing effort has been quantified and used as an quantified index of fishing intensity. Fisheries resources of coastal fisheries in the Korean waters of the East Sea tend to decrease productivity due to deterioration in the quality of ecosystem, which result from the excessive overfishing activities according to the development of fishing gear and engine performance of vessels. In order to manage sustainable and reasonable fisheries resources, it is important to understand the fluctuation of biomass and predict the future biomass. Therefore, in this study, we forecasted biomass in the Korean waters of the East Sea for the next two decades (2017~2036) according to the changes in fishing intensity using four fishing effort scenarios; $f_{current}$, $f_{PY}$, $0.5{\times}f_{current}$ and $1.5{\times}f_{current}$. For forecasting biomass in the Korean waters of the East Sea, parameters such as exploitable carrying capacity (ECC), intrinsic rate of natural increase (r) and catchability (q) estimated by maximum entropy (ME) model was utilized and logistic function was used. In addition, coefficient of variation (CV) by the Jackknife re-sampling method was used for estimation of coefficient of variation about exploitable carrying capacity ($CV_{ECC}$). As a result, future biomass can be fluctuated below the $B_{PY}$ level when the current level of fishing effort in 2016 maintains. The results of this study are expected to be utilized as useful data to suggest direction of establishment of fisheries resources management plan for sustainable use of fisheries resources in the future.