• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.352-359
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• 2018

Purpose: This study aims to suggest new strategy of planning water management and land use in response to abnormal weather which allow waterfront to be the cities through the experience of Netherlands resilient project. Method: A planning direction is developed based on Dutch national resilient policy and strategy as well as resilient theory of technical and social aspects, focusing on a new waterfront development that responds to abnormal weather. Results: The water control strategy, for flexibly responding to the sea level rise and flooding caused by the climate change through the experience of Dutch resilience, is as follows: 1)Customized prevention plan according to the local property 2)Creating spatial planning by considering disaster risk level and fragility 3)Establishing urban planning by considering the flood risk level. Conclusion: A new urban development method, particularly a resilience strategy based on the waterfront space where is most vulnerable to climate change, is required to cope with the abnormal climate beyond the conventional planning.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.9-20
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• 1991

The characteristics of the unconsolidated sediment in Gwangyang bay was analyzed from the core samples. The porosity of the sediment showed irregular variation with respect to the sedimentation depth, which indicated that sediment weight-induced consolidation was not significant. Numerical analysis for the mechanical and hydraulic behavior of the unconsolidated sediment due to the tidal sea level change was processed. Because of the delayed excessive pore pressure change in the very low permeable mud medium, the magnitude of the excessive pore pressure for the duration of the minimum sea level exceeded the total stress from the sea water weight, which resulted in the negative (tensional) effective stress below the top surface. The in-situ effective stress, obtained by superposing the tensional effective stress on the solid weight-induced compressive stress, was remained to be tensile (quick-sand condition) near the top surface of the mud deposit. The occurrence of the quirk-sand condition provided a theoretical evidence for the insignificant consolidation and the irregular porosity variation of the sediment. When the sand is distributed on the top surface of the mud layer, the quick-sand condition occurred below the sandy mud layer and the downward movement of sand particles was facilitated.

• Journal of Korea Water Resources Association
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• v.47 no.9
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• pp.753-766
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• 2014

The future mean sea level rise (MSLR) due to climate change in major harbors of Korean Peninsula has been estimated by some statistical methods in this article. Firstly, Mann-Kendall non-parametric trend test to find some trend in the observed long-term tidal data has been performed and also Bayesian change point analysis has been used also to detect the location of change points and their magnitude quantitatively. Especially, in this study, the results from Bayesian change point analysis have been applied to combine 4 future MSLR scenario projections with local MSLR data at 5 tidal gauges. This proposed procedure including Bayesian change point analysis results can improve the step for the determination of starting years of future MLSR scenario projections with 18.6-year lunar node tidal cycle and effectively consider local characteristics at each gauge. The final results by the proposed procedure in this study have shown that the future MSLR in Jeju region (Jeju tidal gauge) is in the largest increment and also the future MSLRs in Western region (Boryeong tidal gauge) and Southern region (Busan tidal gauge) are in the second largest one. Finally, it has been shown that the future MSLRs in Southern region (Yeosu tidal gauge) and Eastern region (Sokcho tidal gauge) seem to be in the relatively smallest growth among 5 gauges.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.5
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• pp.505-513
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• 2010

This study investigate the characteristics of tidal constituents, and long-term mean sea level oscillations at Incheon bay. For this, the conditions of three tide stations around Incheon bay have examined, and carried out harmonic analysis on water level data for periods of about 40 years(1960~2007). Four major tidal constituents($M_2$, $S_2$, $K_1$, $O_1$) of each tide station showed tendency that change over the 18.61year lunar node cycle, and the type of tide at three stations is mainly semi-diurnal tides. And also, the past monthly tidal modulations are especially sensitive to the cumulative year of water level data in accuracy of tidal prediction. In case that regard the detached data at three tide stations as a single time series data of 40 years, the results of analysis on a single time series, long-term mean sea level oscillations and modulations of tidal datum at tide stations appears with a range of about 10cm, respectively. In addition, the predicted tides at the Inchcon harbor by global and regional tide models of OSU(Oregon State University) based on various satellite altimetric(Topex Poseidon, Topex Tandem, ERS, GFO) data are compared with the observed tides by KHOA(the Korea Hydrographic and Oceanographic Administration). The results show that the high resolution regional model is a quite good agreement at coastal shallow water region.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.145-145
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• 2018

Small islands rely heavily on groundwater resources in addition to rainwater as the source of freshwater since surface water bodies are often absent. The groundwater resources are vulnerable to sea level rise, coastal flooding, saltwater intrusion, irregular pattern of precipitation resulting in long droughts and flash floods. Increase in population increases the demand for the limited groundwater resources, thus aggravating the problem. In this study, the effects of climate change on Tongatapu Island, Kingdom of Tonga, a small island in Pacific Ocean, are investigated using a sharp interface transient groundwater flow model. Twenty nine downscaled General Circulation Model(GCM) predictions are input to a water balance model to estimate the groundwater recharge. The temporal variation in recharge is predicted over the period of 2010 to 2099. A set of GCM models are selected to represent the ensemble of 29 models based on cumulative recharge at the end of the century. This set of GCM model predictions are then used to simulate a total of six climate scenarios, three each (2010-2039, 2040-2069, and 2070-2099) under RCP 4.5 and RCP 8.5. The impacts of predicted climate change on groundwater resources is evaluated in terms of freshwater volume changes and saltwater ratios in pumping wells compared to present conditions. Though the cumulative recharge at the end of the century indicates a wetter climate compared to the present conditions the large variability in rainfall pattern results in frequent periods of groundwater drought leading to saltwater intrusion in pumping wells. Thus for sustaining the limited groundwater resources in small islands, implementation of timely assessment and management practices are of utmost importance.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.64-70
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• 2015

We investigated the branchial osmoregulatory response of black sea bream Acanthopagrus schlegelii to short-term (3-48 h) exposure to a hyposaline environment (5 psu). Gill $Na^+/K^+$-ATPase (NKA) activity was decreased after 3 h in fish transferred to 5 psu compared to salt water-acclimated (control) fish, but the level of activity returned to that observed in the control fish at 6 h after transfer. NKA activity increased significantly at 24 h after transfer, but it returned to the level observed in the control fish at 48 h after transfer. Immunohistochemical staining revealed that gill NKA was localized to chloride cells. The number of chloride cells tended to change in parallel with NKA activity. Substantial decreases in plasma $Na^+$, $Cl^-$, and osmolality were observed after 12 h of exposure to 5 psu; however, these parameters began to recover to the values detected in the controls at 24 h after transfer. In conclusion, our results suggest that black sea bream are able to adjust their osmoregulatory mechanisms to shift from hypo- to hyperosmoregulation within 6 h of exposure to a hypoosmotic environment.

• Ocean and Polar Research
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• v.45 no.2
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• pp.71-87
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• 2023

Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.746-752
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• 2022

Kiribati, a South Pacific island, and its surrounding countries are gradually submerging to rising sea levels. The sea level continues to change according to the degree of thermal expansion of glaciers and seawater that decreases with increase in temperature. Global warming affects both the amount and volume of seawater, thus increasing sea level. Tidal phenomena occur twice a day to the attraction of celestial bodies such as the moon and the sun. The moon changes the angle of orbiting surface with the Earth equator every 18.6 years, and the magnitude of the tidal force changes depending on the distance between the Earth equator and the moon orbital surface. The University of Hawaii Sea Level Center selected Tarawa, Christmas, Kanton of Kiribati,, Lautoka, Suva of Fiji,Funafuti of Tuvalu, Nuk1u'alofa of Tonga, and Port Vila of Vanuatu. When comparing tide levels for each year for 19 years, the focus was on checking the change in sleep to Tide levels, and rising sea levels was the effect of Tide levels. The highest astronomical tides (HAT) and lowest astronomical tides (LAT) were identified as Tarawa 297.0, 50.8 cm, Christmas 123.8, 19.9 cm, Kanton 173.7, 39.9 cm, Lautoka 240.7, 11.3 cm, Funafuti 328.6, 98.4 cm, Nuk1u'alofa 188.8, 15.5 cm, Port Vila 161.5, -0.5cm, respectively. The Sea level rising speed was Tarawa 3.1 mm/year, Christmas -1.0 mm/year, Kanton 1.6 mm/year, Lautoka 3.1 mm/year, Suva 7.4 mm/year, Funafuti 1.4 mm/year, Nuk1u'alofa 4.2 mm/year, and Port Vila -1.2 mm/year, respectively

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.3
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• pp.375-384
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• 2009

The GRACE satellite, Launched in March 2002, is applied to research on glacial melt of polar regions, glacial isostatic adjustment(GIA), sea level change, terrestrial water storage(TWS) variation of river basin and large-scale earthquake etc. In this research, the TWS variation of Yangtze river basin from August, 2002 to January, 2009 is analyzed using Level-2 GRACE monthly gravity field model. Particularly, gravity changes of the Three Gorges Dam during the impoundment process in 2003, 2006 and 2008 is observed by estimating equivalent water thickness(EWT). The research results show the distinct annual and seasonal changes of Yangtze river basin, and its amplitude of annual variation is 2.3cm. In addition, we compare the results with water resource statistics and hydrologic observation data to confirm the possibility of research of TWS variation of river basin using GRACE observation data, and also the satellite gravity data is of great help for the research on the movement and periodic changes of river basin.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.4
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• pp.259-264
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• 2001

Typhoon and neap tide on Cochlodinium polykrikoides bloom and water temperature on disappearance of C. polykrikoides bloom were investigated to elucidate the outbreak mechanism of C. polykrikoides blooms at Naro and Namhae coastal area in South Sea of Korea. The first observation of C. polykrikoides blooms were observed when thermocline was disappeared by typhoon, tide, etc. The first blooms of C. polykrikoides were observed on neap tide or before one day from neap tide in 1996-1998 and 2000. However, thermocline was disappeared by typhoon in 1994 and 1999, the first blooms were observed early 12-30 day than 1996-1998 and 2000. The main reason of disappearance of C. polykrikoides blooms after typhoon on 1997-2000 seems to be other environmental change by typhoon rather than low water temperature. In the future, the first C. polykrikoides bloom will be appear around the first neap tide of latter part of August with breaking down of thermocline, but if the thermocline be collapsed by typhoon in July, the C. polykrikoides bloom will be appear at beginning of August. The outbreak of C. polykrikoides blooms will be explain as follows: The vegetative cells, which was germinated by environmental change or already exist in surface water at low level, input to the surface water, and then nutrients and trace metals which were suppled from out side of C. polykrikoides bloom area inflow to surface. The vegetative cells are growth by the nutrients and trace metals at suitable environmental conditions e.g. water temperature, salinity, and sufficient light.