• Title, Summary, Keyword: sea level change

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The Holocene Depositonal Environment and Sea-Level Change at Ilsan Area (일산충적평야의 홀로세 퇴적환경변화와 해면변동)

  • 황상일
    • Journal of the Korean Geographical Society
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    • v.33 no.2
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    • pp.143-163
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    • 1998
  • In order to clarify the depositional environment and sea-level change at Ilsan area including Gawaji and Saemal valley plains, which is located at the right side in downstream of the Han River, boring data, radiocabon dating and diatom analysis were comprehensively investigated. As a result, the palaeogeographies fo this area altered by the transgressions and regressions after 7,000 y. BP could be restored. The high tide sea-level(mean high water level of spring tide) was arrived ca. 7,000y. BP at the valley plain and risen to ca. 5.5m at ca. 5000y. BP. Since then, the sea-level was kept up the same level to ca. 3,200 BP. The descended sea-level to ca. 2,300 BP was risen up to ca. 5.8m in ca. 1,800 y. BP. It is presumed that such a sea-level change as well as the different sediments in quantity supplied from the river basin of the valley plain could be effected to change diversely the depositional environment of the study area and eventually to the prehistoric human life.

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Long-term Change in Sea Level along the Eastern Coastal Waters of Korea using Tide Gauge, Water Temperature and Salinity (조위 및 수온, 염분 데이터를 이용한 동해 연안의 해수면 변화)

  • Park, Se-Young;Lee, Chung-Il
    • Journal of Environmental Science International
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    • v.23 no.5
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    • pp.801-806
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    • 2014
  • Long-term change in sea level along the eastern coast of Korea was illustrated using four tide-gauge station (Pohang, Mukho, Sokcho, Ulleung) data, water temperature and salinity. Seasonal variation in the sea level change was dominant. The sea level change by steric height derived from water temperature and salinity was relatively lower than that measured from the tide-gauge stations. Sea level rising rate per year by steric height increased with latitude. The effect of salinity(water temperature) on the sea level change is greater in winter(in summer).

Projection of Future Sea Level Change Based on HadGEM2-AO Due to Ice-sheet and Glaciers (HadGEM2-AO 기반의 빙상과 빙하에 의한 미래 해수면 변화 전망)

  • Kim, Youngmi;Goo, Tae-Young;Moon, Hyejin;Choi, Juntae;Byun, Young-Hwa
    • Atmosphere
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    • v.29 no.4
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    • pp.367-380
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    • 2019
  • Global warming causes various problems such as the increase of the sea surface temperature, the change of coastlines, ocean acidification and sea level rise. Sea level rise is an especially critical threat to coastal regions where massive population and infrastructure reside. Sea level change is affected by thermal expansion and mass increase. This study projected future sea level changes in the 21st century using the HadGEM2-AO with RCP8.5 scenario. In particular, sea level change due to water mass input from ice-sheets and glaciers melting is studied. Sea level based on surface mass balance of Greenland ice-sheet and Antarctica ice-sheet rose 0.045 m and -0.053 m over the period 1986~2005 to 2081~2100. During the same period, sea level owing to dynamical change on Greenland ice-sheet and Antarctica ice-sheet rose 0.055 m and 0.03 m, respectively. Additionally, glaciers melting results in 0.145 m sea level rise. Although most of the projected sea level changes from HadGEM2-AO are slightly smaller than those from 21 ensemble data of CMIP5, both results are significantly consistent each other within 90% uncertainty range of CMIP5.

Trend of Sea Level Change Along the Coast of Korean Peninsula

  • An Byoung Woong;Kang Hyo Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.6
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    • pp.803-808
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    • 1999
  • Trend of sea level change has been analysed by using the tidal data gathered at the 12 tide stations along the coast of Korean peninsula. Analysis and prediction of the sea level change were performed by Principal Component Analysis (PCA). For the period of 20 years from 1976 to 1995, the trend generally shows a rising pattern such as 0.22 cm/yr, 0.29 cm/yr, and 0.59 cm/yr along the eastern, southern, and western coast of Korea, respectively. On the average the sea level around the Korean peninsula seems to be rising at a rate of 0.37 cm/yr. Adopting the average rate to the sea level prediction model proposed by EPA (Titus and Narrayanan, 1995), the sea level may be approximately 50$\~$60 cm higher than the present sea level by the end of the next century.

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Effect of climate change and sea level rise on taking water of South Thai Binhirrigation system in Vietnam

  • Nguyen, Thu Hien;Nguyen, Canh Thai
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.222-222
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    • 2015
  • Vietnam is one of the most vulnarable countries affected by climate change and sea level rise. One of the consequences of climate change and sea level rise is the increase of salinity intrusion into the rivers which is challenging to irrigation systems in coastal areas. This indicates the necessary to study the ability of taking water through sluice gates of irrigation systems in coastal zones, especially in the dry season with the effects of climate change and sea level rise in the future. In this paper, Nam Thai Binh irrigation system is selected as a case study. The irrigation system is one of 22 biggest irrigation systems of the Red River delta in Vietnam located in coastal region. The computed duration is selected in dry season to irrigate for Winter-Spring crops. The irrigation water for the study area is taken from different sluice gates along the Red River and the Tra Ly River. In this paper, MIKE-11 model was applied to assess the ability of taking water for irrigation of the study area in current situation and in the context of climate change and sea level rise senario in 2050 (under the medium emissions scenario (B2) published by the Ministry of Natural Resources and Environment of Vietnam published in 2012) with different condition of water availability. The operation of the gates depends on the water levels and sanility conditions. The sanility and water level at different water intake gates of Nam Thai Binh irrigation system were simulated with different senarios with and without climate change and sea level rise. The result shows that, under climate change and sea water level rise, some gates can take more water but some can not take water because of salinity excess and the total water taking from the different gates along the rivers decrease while the water demand is increase. The study indicates the necessary to study quantitatively some recommended solutions in the study area particularly and in coastal region generally in Vietnam to ensure water demand for irrigation and other purposes in the context of climate change and sea level rise in the future.

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A Prediction on the Wetlands Change of Suncheon Bay by the Sea Level Rise (해수면 상승에 따른 순천만 습지 변화 예측)

  • MOON, Bora;KIM, Dong-Myung;LEE, Suk-Mo
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.3
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    • pp.627-635
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    • 2017
  • Sea level rise caused by climate change has become a global issue. Sea level rise seems to be an important factor of the research for coastal areas as it affects topography and vegetation of coasts and especially for the plan of coastal wetlands restoration which needs to be carried out for a long term, it has to be considered sufficiently. The coastal wetlands in Korea was damaged by the land reclamation project but recent concerns on the restoration have increased as its value is evaluated highly. Suncheon Bay had also reclaimed from wetlands to rice field once however this site is very active for restoration nowadays. This study estimated an effect according to sea level rise by 2100, reappearing the none dike condition of Suncheon Bay so that it can be taken account of a future plan of wetland restoration. The Sea Level Affecting Marshes Model(SLAMM) was selected as predicting model. The input data such as DEM(Digital Elevation Model), slope, wetlands category, sea level rise senario, tidal range and accretion rate was applied for the simulation. The results showed a decrease in tidal flat, an increase in sea area and a change of the rice field to transitional salt marsh consistently by 2100. These results of this study could be used as baseline data in the future plan of ecological restoration in Suncheon Bay.

Potential of regression models in projecting sea level variability due to climate change at Haldia Port, India

  • Roshni, Thendiyath;K., Md. Sajid;Samui, Pijush
    • Ocean Systems Engineering
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    • v.7 no.4
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    • pp.319-328
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    • 2017
  • Higher prediction efficacy is a very challenging task in any field of engineering. Due to global warming, there is a considerable increase in the global sea level. Through this work, an attempt has been made to find the sea level variability due to climate change impact at Haldia Port, India. Different statistical downscaling techniques are available and through this paper authors are intending to compare and illustrate the performances of three regression models. The models: Wavelet Neural Network (WNN), Minimax Probability Machine Regression (MPMR), Feed-Forward Neural Network (FFNN) are used for projecting the sea level variability due to climate change at Haldia Port, India. Model performance indices like PI, RMSE, NSE, MAPE, RSR etc were evaluated to get a clear picture on the model accuracy. All the indices are pointing towards the outperformance of WNN in projecting the sea level variability. The findings suggest a strong recommendation for ensembled models especially wavelet decomposed neural network to improve projecting efficiency in any time series modeling.

The Sea Level Change and Human Activities at Sejuk-Ri, Ulsan City, Southeastern Coast of Korea during the Early Neolitic Period

  • Hwang, Sang-Ill;Yoon, Soon-Ock
    • The Korean Journal of Quaternary Research
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    • v.18 no.2
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    • pp.75-86
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    • 2004
  • The sea level curve and environmental change were reconstructed at Sejuk-ri during the early Neolitic Age, based on the sedimentary facies, the distribution of remains and carbon datings. Before 6,500 years BP, the sea-level experienced one oscillation. The Neolitic men utilized geomorphic environment which formed according to the sea-level change. They might be occupied in gathering, fishing and hunting including whales hunting. The Neolitic men made acom hollows in order to remove tannin. Besides, they remained shell mounds which were formed from 6,500 years BP to around 6,000 years BP. They left the living place about 6,000 years BP because of transgression.

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Interpolation and Reconstruction of the Holocene Sea-levels Using Inverse Fractal Interpolation functions (프랙탈 내삽함수 역산법을 이용한 홀로세 해수면의 내삽 및 재구성)

  • CHUNG, SANG YONG;KIM, DAE CHOUL;YI, HI-IL
    • 한국해양학회지
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    • v.29 no.3
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    • pp.228-238
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    • 1994
  • The change of sea-level is a good indicator of the change of climate during the Quaternary period. The sea-levels in the world have been changing very irregularly during that time. The pattern of the Quaternary sea-level change was assumed to be a stochastic fractal in this study. We measured fractal dimensions of the Holocene sea-levels of the Hudson river estuary and the Delaware coast. A box counting method gave almost the same values. i.e., D=1.358 for the Hudson sea-level changes and D+1.346 for the Delaware sea-level changes. the ability of the inverse method of fractal interposea-levels. IFIF reproduction the realistic sea-levels for the both of them. The delaware sea-level data made less statistical errors for the interpolation of IFIF than the Hudson and the Delaware sea-levels. IFIF reproduction the realistic sea-levels for the both of them. The Delaware sea-level data made less statistical errors for the interpolation of IFIF than the Hudson sea-level data. This suggests that the Delaware sea-level data are more reliable than the Hudson sea-level data was calculated from the fractal dimension of the Delaware sea-level data. Fractal interpolation functions (FIF) was used to reconstruct the peleosea-levels of the Korean coasts and the Atlantic Ocean coasts of the United States. The Korean Peleosea-level change generacted by FIF is different from the peleosea-level change of the eastern U.S.. The Korean peleosea-levels are much higher than the eastern U.S. Paleosea-levels, comparing to each other from the present to 8,000 BP.

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ESTIMATION OF SEAWATER LEVEL ON SEA FARMS USING L-BAND RADAR INTERFEROMETRY

  • Kim, Sang-Wan;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • pp.312-316
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    • 2002
  • Satellite radar interferometry data shows a strong coherent signal on oyster sea farms where artificial structures installed on the bottom. We obtained 21 highly coherent interferograms from eleven JERS-1 SAR data sets despite of large orbital baseline (~2 km) or large temporal baseline (~l year). The phases observed in sea farms are probably induced by double bouncing on sea surface, and consequently reveal a tide height variation. To restore the absolute sea level changes we counted the number of wrapping by exploiting the intensity of backscattering. Backscattering intensity is closely correlated with the change in water surface height, while interferometry gives the detailed variation within the limit of 2$\pi$ (or 15.3 cm). Comparing the radar measurements with the tide gauge records yielded a correlation coefficient of 0.96 and an ms error of 6.0 cm. The results demostrate that radar interferometry is promising to measure sea level.

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