Mangroves play a pivotal role in tropical and subtropical coastal ecosystem,yet they are highly vulnerable to the effects of climate change,particularly the accelerated global sea level rise(SLR)and stronger tropical ...Mangroves play a pivotal role in tropical and subtropical coastal ecosystem,yet they are highly vulnerable to the effects of climate change,particularly the accelerated global sea level rise(SLR)and stronger tropical cyclones(TCs).However,there is a lack of research addressing future simultaneous combined impacts of the slow-onset of SLR and rapid-onset of TCs on China's mangroves.In order to develop a comprehensive risk assessment method considering the superimposed effects of these two factors and analyze risk for mangroves in Dongzhaigang,Hainan Island,China,we used observational and climate model data to assess the risks to mangroves under low,intermediate,and very high greenhouse gas(GHG)emission scenarios(such as SSP1-2.6,SSP2-4.5,and SSP5-8.5)in 2030,2050,and 2100,and compiled a risk assessment scheme for mangroves in Dongzhaigang,China.The results showed that the combined risks from SLR and TCs will continue to rise;however,SLRs will increase in intensity,and TCs will decrease.The comprehensive risk of the Dongzhaigang mangroves posed by climate change will remain low under SSP1-2.6 and SSP2-4.5 scenarios by 2030,but it will increase substantially by 2100.While under SSP5-8.5 scenario,the risks to mangroves in Dongzhaigang are projected to increase considerably by 2050,and approximately 68.8%of mangroves will be at very high risk by 2100.The risk to the Dongzhaigang mangroves is not only influenced by the hazards but also closely linked to their exposure and vulnerability.We therefore propose climate resilience developmental responses for mangroves to address the effects of climate change.This study for the combined impact of TCs and SLR on mangroves in Dongzhaigang,China can enrich the method system of mangrove risk assessment and provide references for scientific management.展开更多
As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the trans...As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the transportation infrastructure. Many people living in low elevation coastal areas can become trapped by flooding with no way in or out. With Delaware being a coastal state, this would affect a large portion of the population and will have detrimental effects over time if nothing is done to combat sea level rise. The issue with sea level rise in transportation is that once the roads become flooded, they become virtually unusable and detour routes would be needed. If all the roads in a coastal area were to be affected by sea level rise, the options for detours would become limited. This article looks at direct solutions to combat sea level rise and indirect solutions that would specifically help transportation infrastructure and evacuation routes in Delaware. There is not one solution that can fix every problem, so many solutions are laid out to see what is applicable to each affected area. Some solutions include defense structures that would be put close to the coast, raising the elevation of vulnerable roads throughout the state and including pumping stations to drain the water on the surface of the road. With an understanding of all these solutions around the world, the ultimate conclusion came in the form of a six-step plan that Delaware should take in order to best design against sea level rise in these coastal areas.展开更多
Mangrove distribution along shorelines shows distinct zonation patterns;thus,different communities may face various influences from sea level rise(SLR)and land use.However,long-term change predictions are usually base...Mangrove distribution along shorelines shows distinct zonation patterns;thus,different communities may face various influences from sea level rise(SLR)and land use.However,long-term change predictions are usually based only on the total extent of mangroves.Few studies have revealed how SLR and land development such as agriculture,aquaculture,and urbanization jointly affect different intertidal mangrove communities.This study proposed a novel framework combining SLAMM(Sea Level Affecting Marshes Model)and the CLUE-S(Conversion of Land Use and its Effect at Small regional extent)model to assess the potential impacts on upper and lower intertidal mangrove communities.Maoweihai in Guangxi,China,was selected as the study area and the potential impacts from the squeeze effect and mangrove expansion potential were evaluated.We established three scenarios combining SLR and land use patterns to predict mangrove coverage projections by 2070.The results showed that,under a single SLR driver,the upper intertidal mangroves would be more adaptive to rapid SLR than the lower intertidal mangroves.However,under the combined influence of the two drivers,the upper intertidal mangroves would experience larger squeeze effects than the lower intertidal mangroves,with up to 80.5%of suitable habitat lost.Moreover,the expansion potential of upper intertidal mangroves would be considerably more limited than that of lower intertidal mangroves.The length of the expandable habitat patch boundary of upper intertidal mangroves only reached 1.4–1.8 km,while that of the lower intertidal mangroves reached up to99.2–111.2 km.Further,we found that aquaculture ponds and cropland are the top two land development types that could occupy suitable habitat and restrict the mangrove expansion potential.Our results highlight that timely improvement of land use policies to create available landward accommodation space for mangrove migration is essential to maintain the coverage and diversity of mangrove communities under SLR.The proposed method can be a helpful tool for adaptive mangrove conservation and management under climate change.展开更多
Mangrove forests are under the stress of sea level rise(SLR)which would affect mangrove soil biogeochemistry.Mangrove soils are important sources of soil-atmosphere greenhouse gas(GHG)emissions,including carbon dioxid...Mangrove forests are under the stress of sea level rise(SLR)which would affect mangrove soil biogeochemistry.Mangrove soils are important sources of soil-atmosphere greenhouse gas(GHG)emissions,including carbon dioxide(CO_(2)),methane(CH_(4))and nitrous oxide(N_(2)O).Understanding how SLR influences GHG emissions is critical for evaluating mangrove blue carbon capability.In this study,potential effects of SLR on the GHG emissions were quantified through static closed chamber technique among three sites under different intertidal elevations,representing tidal flooding situation of SLR values of 0 cm,40 cm and 80 cm,respectively.Compared with Site SLR 0 cm,annual CO_(2) and N_(2)O fluxes decreased by approximately 75.0%and 27.3%due to higher soil water content,lower salinity and soil nutrient environments at Site SLR 80 cm.However,CH_(4) fluxes increased by approximately 13.7%at Site SLR 40 cm and 8.8%at Site SLR 80 cm because of lower salinity,higher soil water content and soil pH.CO_(2)-equivalent fluxes were 396.61 g/(m^(2)·a),1423.29 g/(m^(2)·a)and 1420.21 g/(m^(2)·a)at Sites SLR 80 cm,SLR 40 cm and SLR 0 cm,respectively.From Site SLR 0 cm to Site SLR 80 cm,contribution rate of N_(2)O and CH_(4) increased by approximately 7.42%and 3.02%,while contribution rate of CO_(2) decreased by approximately 10.44%.The results indicated that warming potential of trace CH_(4) and N_(2)O was non-negligible with SLR.Potential effects of SLR on the mangrove blue carbon capability should warrant attention due to changes of all three greenhouse gas fluxes with SLR.展开更多
Bangladesh is vulnerable to climate change-induced sea level rise due to its location and socioeconomic position. The study examines the Beel Kapalia region in polder no. 24 of the Monirampur upazila of Jessore distri...Bangladesh is vulnerable to climate change-induced sea level rise due to its location and socioeconomic position. The study examines the Beel Kapalia region in polder no. 24 of the Monirampur upazila of Jessore district, Khulna division. To assess local attitudes on sea level rise-related permanent flooding, Kapalia, Monoharpur, Nehalpur, Balidaha, and Panchakori were polled. This flooding has disrupted residents’ lifestyles, making them vulnerable to increasing sea levels. Viability and adaptability were assessed using livelihood capitals. Participants’ thoughts and knowledge about their resilience in several livelihood factors were gathered using participatory rural appraisal (PRA) instruments and a questionnaire survey in the area. Major discoveries include the impact of permanent floods on Beel Kapalia’s livelihoods, vulnerability and resilience assessments in numerous villages, and community viewpoints on regional adaptation methods to mitigate these consequences. The study found that a sustained 30.5 cm inundation would reduce local human, natural, physical, financial, and social capital resilience to 69.6%, 30.7%, 69.1%, 68.9%, and 69.1%. A constant 61 cm inundation would lower resistance to 40.9%, 8.7%, 42.4%, 45.6%, and 43.8%. Residents believe they can weather a 30.5 cm inundation with local adaptation measures, but if the water level rises to 61 cm, they may be displaced.展开更多
Future potential sea level change in the South China Sea (SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway (RCP) scenarios. By the end of the 21st century (2081–210...Future potential sea level change in the South China Sea (SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway (RCP) scenarios. By the end of the 21st century (2081–2100 relative to 1986–2005), the multimodel ensemble mean dynamic sea level (DSL) is projected to rise 0.9, 1.6, and 1.1 cm under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, resulting in a total sea level rise (SLR) of 40.9, 48.6, and 64.1 cm in the SCS. It indicates that the SCS will experience a substantial SLR over the 21st century, and the rise is only marginal larger than the global mean SLR. During the same period, the steric sea level (SSL) rise is estimated to be 6.7, 10.0, and 15.3 cm under the three scenarios, respectively, which accounts only for 16%, 21% and 24% of the total SLR in this region. The changes of the SSL in the SCS are almost out of phase with those of the DSL for the three scenarios. The central deep basin has a slightly weak DSL rise, but a strong SSL rise during the 21st century, compared with the north and southwest shelves.展开更多
Sea level rise (SLR) is one of the major socioeconomic risks associated with global warming. Mass losses from the Greenland ice sheet (GrIS) will be partially responsible for future SLR, although there are large u...Sea level rise (SLR) is one of the major socioeconomic risks associated with global warming. Mass losses from the Greenland ice sheet (GrIS) will be partially responsible for future SLR, although there are large uncertainties in modeled climate and ice sheet behavior. We used the ice sheet model SICOPOLIS (Simulation COde for POLythermal Ice Sheets) driven by climate projections from 20 models in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) to estimate the GrlS contribution to global SLR. Based on the outputs of the 20 models, it is estimated that the GrIS will contribute 0-16 (0-27) cm to global SLR by 2100 under the Representative Concentration Pathways (RCP) 4.5 (RCP 8.5) scenarios. The projected SLR increases further to 7-22 (7-33) cm with 2~basal sliding included. In response to the results of the multimodel ensemble mean, the ice sheet model projects a global SLR of 3 cm and 7 cm (10 cm and 13 cm with 2~basal sliding) under the RCP 4.5 and RCP 8.5 scenarios, respectively. In addition, our results suggest that the uncertainty in future sea level projection caused by the large spread in climate projections could be reduced with model-evaluation and the selective use of model outputs.展开更多
It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, ...It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4~16 cm by the year 2030 with the optimum estimated value of 6~14cm. It will be 9~26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47~65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ~24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%~2. 0% in the Huanghe River Delta.展开更多
Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st cent...Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st century, the Zhujiang(Pearl River) Estuary was chosen as a prototype to study the responses of the estuary to potential sea level rise. The numerical model results show that the average salt content, saltwater intrusion distance, and stratification will increase as the sea level rises. The changes of these parameters have obvious seasonal variations. The salt content in the Lingdingyang shows more increase in April and October(the transition periods). The saltwater intrusion distance has larger increase during the low-flow periods than during the highflow periods in the Lingdingyang. The result is just the opposite in Modaomen. The stratification and its increase are larger during the low-flow periods than during the high-flow periods in Lingdingyang. The response results of transport processes to sea level rise demonstrate that:(1) The time of vertical transport has pronounced increase.The increased tidal range and currents would reinforce the vertical mixing, but the increased stratification would weaken the vertical exchange. The impact of stratification changes overwhelms the impact of tidal changes. It would be more difficult for the surface water to reach the bottom.(2) The lengthways estuarine circulation would be strengthened. Both the offshore surface residual current and inshore bottom residual current will be enhanced.The whole meridional resident flow along the transect of the Lingdingyang would be weakened. These phenomena are caused by the decrease of water surface slope(WWS) and the change of static pressure with the increase of water depth under sea level rise.展开更多
Mean sea level rise and climatological wind speed changes occur as part of the ongoing climate change and future projections of both variables are still highly uncertain. Here the Baltic Sea’s response in extreme sea...Mean sea level rise and climatological wind speed changes occur as part of the ongoing climate change and future projections of both variables are still highly uncertain. Here the Baltic Sea’s response in extreme sea levels to perturbations in mean sea level and wind speeds is investigated in a series of simulations with a newly developed storm surge model based on the nucleus for European modeling of the ocean(NEMO)-Nordic. A simple linear model with only two tunable parameters is found to capture the changes in the return levels extremely well. The response to mean sea level rise is linear and nearly spatially uniform, meaning that a mean sea level rise of 1 m increases the return levels by a equal amount everywhere. The response to wind speed perturbations is more complicated and return levels are found to increase more where they are already high. This behaviour is alarming as it suggests that already flooding prone regions like the Gulf of Finland will be disproportionally adversely affected in a future windier climate.展开更多
According to the space-geodetic data recorded at globally distributed stations over solid land spanning a period of more than 20-years under the International Terrestrial Reference Frame 2008,our previous estimate of ...According to the space-geodetic data recorded at globally distributed stations over solid land spanning a period of more than 20-years under the International Terrestrial Reference Frame 2008,our previous estimate of the average-weighted vertical variation of the Earth's solid surface suggests that the Earth's solid part is expanding at a rate of 0.24 ± 0.05 mm/a in recent two decades.In another aspect,the satellite altimetry observations spanning recent two decades demonstrate the sea level rise(SLR) rate 3.2 ± 0.4 mm/a,of which1.8 ± 0.5 mm/a is contributed by the ice melting over land.This study shows that the oceanic thermal expansion is 1.0 ± 0.1 mm/a due to the temperature increase in recent half century,which coincides with the estimate provided by previous authors.The SLR observation by altimetry is not balanced by the ice melting and thermal expansion,which is an open problem before this study.However,in this study we infer that the oceanic part of the Earth is expanding at a rate about 0.4 mm/a.Combining the expansion rates of land part and oceanic part,we conclude that the Earth is expanding at a rate of 0.35 ± 0.47 mm/a in recent two decades.If the Earth expands at this rate,then the altimetry-observed SLR can be well explained.展开更多
Local communities want to know the cost of improvements needed to their drainage system based on projected sea level rise. Prior research demonstrates that in coastal areas, groundwater will rise with sea level. As a ...Local communities want to know the cost of improvements needed to their drainage system based on projected sea level rise. Prior research demonstrates that in coastal areas, groundwater will rise with sea level. As a result the combination of groundwater levels and tidal data must be used to predict local impacts of sea level rise on the drainage system. However, it would appear to complicate the situation if the amount of data available for making sea level rise projections with groundwater is limited. The objectives of this task were to identify available data in a data limited community, compare the available data, assess the impact of sea level rise on the community, and its impact on the stormwater system, identify vulnerable areas in the City, provide an estimate of long-term costs for improvements, and provide a toolbox of strategies to employ at the appropriate time. The project was conducted using ArcGIS tools to import tidal, groundwater, topographic LiDAR and infrastructure improvements into GIS software and performing analysis based on current data. The cost of improvements was based on applying actual 2015 construction costs in the subject comments across a larger vulnerable area. It was found that the data sources provided similar results, despite different timelines and dates so did not interfere with the subsequent analysis. The data revealed that over $400 million in current dollars might be needed to address stormwater issues arising from sea level rise before 2100.展开更多
The two main factors contributing to depletion of freshwater resources are climate change and anthropological variables. This study presents statistical analyses that are local in its specifics yet global in its relev...The two main factors contributing to depletion of freshwater resources are climate change and anthropological variables. This study presents statistical analyses that are local in its specifics yet global in its relevance. The decline in Gulf Coast aquifer water quality and quantity has been alarming especially with the increased demand on fresh water in neighboring non-coastal communities. This study used seawater levels, groundwater use, and well data to investigate the association of these factors on the salinity of water indicated by chloride levels. Statistical analyses were conducted pointing to the high significance of both sea water level and groundwater withdrawals to chloride concentrations. However, groundwater withdrawal had higher significance which points to the need of water management systems in order to limit groundwater use. The findings also point to the great impact of increased groundwater salinity in the Gulf Coast aquifer on agriculture and socioeconomic status of coastal communities. The high costs of desalinization point to the increased signification of water rerouting and groundwater management systems. Further investigation and actions are in dire need to manage these vulnerabilities of the coastal communities.展开更多
Against a background of climate change, Macao is very exposed to sea level rise (SLR) because of its low elevation, small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macao, both h...Against a background of climate change, Macao is very exposed to sea level rise (SLR) because of its low elevation, small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macao, both historical and, especially, possible future scenarios, aiming to provide knowledge and a framework to help accommodate and protect against future SLR. Sea level in Macao is now rising at an accelerated rate: 1.35 mm yr-1 over 1925-2010 and jumping to 4.2 mm yr I over 1970-2010, which outpaces the rise in global mean sea level. In addition, vertical land movement in Macao contributes little to local sea level change. In the future, the rate of SLR in Macao will be about 20% higher than the global average, as a consequence of a greater local warming tendency and strengthened northward winds. Specifically, the sea level is projected to rise 8-12, 22-51 and 35-118 cm by 2020, 2060 and 2100, respectively, depending on the emissions scenario and climate sensitivity. Under the --8.5 W m 2 Representative Concentration Pathway (RCP8.5) scenario the increase in sea level by 2100 will reach 65 118 cm--double that under RCP2.6. Moreover, the SLR will accelerate under RCP6.0 and RCP8.5, while remaining at a moderate and steady rate under RCP4.5 and RCP2.6. The key source of uncertainty stems from the emissions scenario and climate sensitivity, among which the discrepancies in SLR are small during the first half of the 21st century but begin to diverge thereafter.展开更多
A total of 103 surface sediment samples collected from the water depth range of 15-3300 m along Vijaydurg-Karwar stretch of central west coast of India were analyzed for foraminiferal content. Relict benthic foraminif...A total of 103 surface sediment samples collected from the water depth range of 15-3300 m along Vijaydurg-Karwar stretch of central west coast of India were analyzed for foraminiferal content. Relict benthic foraminiferal assemblage was noted within 50--135 m water depth. The relict benthic foraminiferal assemblage that includes Amphistegina, Operculina and Alveolinella in sediment samples within the water depth of 85-- 135 m indicates presence of coral reef at this depth during Early Holocene. The presence of barnacle fouling on Relict foraminifera at 60--90 m confirms the paleo-shoreline. The shallow depth zone is characterized by presence of agglutinated relict foraminifera. The agglutinated forms indicate freshwater influx, which eventually increased the sea level and subsequently deteriorated the paleo-coral reef.展开更多
Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other cli...Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other climate threat investigators revealed that atmosphere-ocean modeling is an imperfect representation, paleo-data consist of proxy climate information with ambiguities, and modern observations are limited in scope and accuracy. It is revealed that global warming and polar ice-melt although a reality would not contribute to any sea level rise. Floating-ice of the polar region on melting would reoccupy same displaced volume by floating ice-sheets. Land-ice cover in the polar region on melting can reduce load from the crust to activate elastic rebound that would raise land for its isostatic equilibrium.Such characteristics would not contribute to sea level rise. Equatorial bulge, polar flattening, elevation difference of the spheroidal surface between equator and pole with lower in the pole, strong gravity attraction of the polar region and week gravity attraction of the equatorial region, all these phenomena would play dominant role in preventing sea level rise. Palaeo-sea level rise and fall in macro-scale(10-100 m or so) were related to marine transgression and regression in addition to other geologic events like converging and diverging plate tectonics, orogenic uplift of the collision margin, basin subsidence of the extensional crust, volcanic activities in the oceanic region, prograding delta buildup, ocean floor height change and sub-marine mass avalanche. This study also reveals that geophysical shape, gravity attraction and the centrifugal force of spinning and rotation of the earth would continue acting against sea level rise.展开更多
The evolution of the natural and pristine Mediterranean coastline Port aux Princes-Sidi Daoued(Gulf of Tunis,NE-Tunisia) is studied during the period of 1887–2010 on the basis of an ancient minute of bathymetry(1887)...The evolution of the natural and pristine Mediterranean coastline Port aux Princes-Sidi Daoued(Gulf of Tunis,NE-Tunisia) is studied during the period of 1887–2010 on the basis of an ancient minute of bathymetry(1887) and aerial photographs treated by numerical photogrammetric methods. Morphological changes of the coastline shows a general retreat despite the absence of the various anthropogenic actions. Adding to the drift currents and the currents of high energy that are generated by the N-W dominant waves along steeply sub-marine funds, the erosion is mainly due to the sea level rise which increased since the beginning of the 2000 s. The Port aux PrincesSidi Daoued coastline works as a single littoral cell limited by Jbel Korbous to the SW and the fishing harbor of Sidi Daoued to the N-E.展开更多
Due to the dual dris oftural and man-made factors, relative sea leverise in China's coastal plains can be 2 to 3 times over the global mean dunng thefirst half of the 21st Century, it will strongly whuence the van...Due to the dual dris oftural and man-made factors, relative sea leverise in China's coastal plains can be 2 to 3 times over the global mean dunng thefirst half of the 21st Century, it will strongly whuence the vanous coastal projectsand installations and the development of coastal dhes and towns. Research resultsshow that a 50-cm-nse in relative sea leve will cause maed decline in the functionof coastal defense and drainage projects and seriously endangur the functionalworking of the vast majority of coastal harbors. Meanwhile, it will also whuence thedevelopment of coastal dhes and towns throwi deterioratin water quality of thesource of urban water supply, increasing urban fiood risk and damagin seasidetounst resources etc.. Tianin, Shanghai and Guangzhou, the three most importancoastal dhes of China, will be Strongly affeded.展开更多
[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station w...[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station were analyzed firstly on the basis of regression models, and then sea level rise in Pearl River Estuary in 2050 was predicted to estimate the 1-in-50-year peak water level in the same year. [Result] Regression analyses showed that the increasing rate of peak water level over past years was 6.3 mm/a at Denglongshan station and 5.8 mm/a at Hengmen station. In addition, if sea level will rise by 20, 30 and 60 cm respectively in 2050, it was predicted that the 1-in-50-year peak water level will reach 3.04, 3.14 and 3.44 m at Denglongshan station, and 3.19, 3.29 and 3.59 m at Hengmen station separately. [Conclusion] The estimation of peak water level in Pearl River Estuary could provide theoretical references for water resources planning.展开更多
基金Under the auspices of the National Key Research and Development Program of China (No.2017YFA0604902,2017YFA0604903,2017YFA0604901)。
文摘Mangroves play a pivotal role in tropical and subtropical coastal ecosystem,yet they are highly vulnerable to the effects of climate change,particularly the accelerated global sea level rise(SLR)and stronger tropical cyclones(TCs).However,there is a lack of research addressing future simultaneous combined impacts of the slow-onset of SLR and rapid-onset of TCs on China's mangroves.In order to develop a comprehensive risk assessment method considering the superimposed effects of these two factors and analyze risk for mangroves in Dongzhaigang,Hainan Island,China,we used observational and climate model data to assess the risks to mangroves under low,intermediate,and very high greenhouse gas(GHG)emission scenarios(such as SSP1-2.6,SSP2-4.5,and SSP5-8.5)in 2030,2050,and 2100,and compiled a risk assessment scheme for mangroves in Dongzhaigang,China.The results showed that the combined risks from SLR and TCs will continue to rise;however,SLRs will increase in intensity,and TCs will decrease.The comprehensive risk of the Dongzhaigang mangroves posed by climate change will remain low under SSP1-2.6 and SSP2-4.5 scenarios by 2030,but it will increase substantially by 2100.While under SSP5-8.5 scenario,the risks to mangroves in Dongzhaigang are projected to increase considerably by 2050,and approximately 68.8%of mangroves will be at very high risk by 2100.The risk to the Dongzhaigang mangroves is not only influenced by the hazards but also closely linked to their exposure and vulnerability.We therefore propose climate resilience developmental responses for mangroves to address the effects of climate change.This study for the combined impact of TCs and SLR on mangroves in Dongzhaigang,China can enrich the method system of mangrove risk assessment and provide references for scientific management.
文摘As the global temperature continues to increase, the sea level continues to rise at a rapid rate that has never been seen before. This becomes an issue for many facets of life but one of the most impacted is the transportation infrastructure. Many people living in low elevation coastal areas can become trapped by flooding with no way in or out. With Delaware being a coastal state, this would affect a large portion of the population and will have detrimental effects over time if nothing is done to combat sea level rise. The issue with sea level rise in transportation is that once the roads become flooded, they become virtually unusable and detour routes would be needed. If all the roads in a coastal area were to be affected by sea level rise, the options for detours would become limited. This article looks at direct solutions to combat sea level rise and indirect solutions that would specifically help transportation infrastructure and evacuation routes in Delaware. There is not one solution that can fix every problem, so many solutions are laid out to see what is applicable to each affected area. Some solutions include defense structures that would be put close to the coast, raising the elevation of vulnerable roads throughout the state and including pumping stations to drain the water on the surface of the road. With an understanding of all these solutions around the world, the ultimate conclusion came in the form of a six-step plan that Delaware should take in order to best design against sea level rise in these coastal areas.
基金financially supported by the National Key Research and Development Program of China(2022YFF0802204,2019YFE0124700)the Provincial Natural Science Foundation of Fujian(2020J05078)the National Natural Science Foundation of China(41906127 and 42076163)。
文摘Mangrove distribution along shorelines shows distinct zonation patterns;thus,different communities may face various influences from sea level rise(SLR)and land use.However,long-term change predictions are usually based only on the total extent of mangroves.Few studies have revealed how SLR and land development such as agriculture,aquaculture,and urbanization jointly affect different intertidal mangrove communities.This study proposed a novel framework combining SLAMM(Sea Level Affecting Marshes Model)and the CLUE-S(Conversion of Land Use and its Effect at Small regional extent)model to assess the potential impacts on upper and lower intertidal mangrove communities.Maoweihai in Guangxi,China,was selected as the study area and the potential impacts from the squeeze effect and mangrove expansion potential were evaluated.We established three scenarios combining SLR and land use patterns to predict mangrove coverage projections by 2070.The results showed that,under a single SLR driver,the upper intertidal mangroves would be more adaptive to rapid SLR than the lower intertidal mangroves.However,under the combined influence of the two drivers,the upper intertidal mangroves would experience larger squeeze effects than the lower intertidal mangroves,with up to 80.5%of suitable habitat lost.Moreover,the expansion potential of upper intertidal mangroves would be considerably more limited than that of lower intertidal mangroves.The length of the expandable habitat patch boundary of upper intertidal mangroves only reached 1.4–1.8 km,while that of the lower intertidal mangroves reached up to99.2–111.2 km.Further,we found that aquaculture ponds and cropland are the top two land development types that could occupy suitable habitat and restrict the mangrove expansion potential.Our results highlight that timely improvement of land use policies to create available landward accommodation space for mangrove migration is essential to maintain the coverage and diversity of mangrove communities under SLR.The proposed method can be a helpful tool for adaptive mangrove conservation and management under climate change.
基金The National Natural Science Foundation of China under contract Nos 42076142 and 41776097the Provincial Natural Science Foundation of Fujian under contract No.2020J06030the Fund of Fujian Provincial Key Laboratory of Marine Ecological Conservation and Restoration under contract No.EPR2020003.
文摘Mangrove forests are under the stress of sea level rise(SLR)which would affect mangrove soil biogeochemistry.Mangrove soils are important sources of soil-atmosphere greenhouse gas(GHG)emissions,including carbon dioxide(CO_(2)),methane(CH_(4))and nitrous oxide(N_(2)O).Understanding how SLR influences GHG emissions is critical for evaluating mangrove blue carbon capability.In this study,potential effects of SLR on the GHG emissions were quantified through static closed chamber technique among three sites under different intertidal elevations,representing tidal flooding situation of SLR values of 0 cm,40 cm and 80 cm,respectively.Compared with Site SLR 0 cm,annual CO_(2) and N_(2)O fluxes decreased by approximately 75.0%and 27.3%due to higher soil water content,lower salinity and soil nutrient environments at Site SLR 80 cm.However,CH_(4) fluxes increased by approximately 13.7%at Site SLR 40 cm and 8.8%at Site SLR 80 cm because of lower salinity,higher soil water content and soil pH.CO_(2)-equivalent fluxes were 396.61 g/(m^(2)·a),1423.29 g/(m^(2)·a)and 1420.21 g/(m^(2)·a)at Sites SLR 80 cm,SLR 40 cm and SLR 0 cm,respectively.From Site SLR 0 cm to Site SLR 80 cm,contribution rate of N_(2)O and CH_(4) increased by approximately 7.42%and 3.02%,while contribution rate of CO_(2) decreased by approximately 10.44%.The results indicated that warming potential of trace CH_(4) and N_(2)O was non-negligible with SLR.Potential effects of SLR on the mangrove blue carbon capability should warrant attention due to changes of all three greenhouse gas fluxes with SLR.
文摘Bangladesh is vulnerable to climate change-induced sea level rise due to its location and socioeconomic position. The study examines the Beel Kapalia region in polder no. 24 of the Monirampur upazila of Jessore district, Khulna division. To assess local attitudes on sea level rise-related permanent flooding, Kapalia, Monoharpur, Nehalpur, Balidaha, and Panchakori were polled. This flooding has disrupted residents’ lifestyles, making them vulnerable to increasing sea levels. Viability and adaptability were assessed using livelihood capitals. Participants’ thoughts and knowledge about their resilience in several livelihood factors were gathered using participatory rural appraisal (PRA) instruments and a questionnaire survey in the area. Major discoveries include the impact of permanent floods on Beel Kapalia’s livelihoods, vulnerability and resilience assessments in numerous villages, and community viewpoints on regional adaptation methods to mitigate these consequences. The study found that a sustained 30.5 cm inundation would reduce local human, natural, physical, financial, and social capital resilience to 69.6%, 30.7%, 69.1%, 68.9%, and 69.1%. A constant 61 cm inundation would lower resistance to 40.9%, 8.7%, 42.4%, 45.6%, and 43.8%. Residents believe they can weather a 30.5 cm inundation with local adaptation measures, but if the water level rises to 61 cm, they may be displaced.
基金The National Basic Research Program(973 Program)of China under contract No.2010CB950501the National Natural Science Foundation of China under contract No.41276035the National Natural Science Foundation of China–Shandong Province Joint Fund of Marine Science Research Centers under contract No.U1406404
文摘Future potential sea level change in the South China Sea (SCS) is estimated by using 24 CMIP5 models under different representative concentration pathway (RCP) scenarios. By the end of the 21st century (2081–2100 relative to 1986–2005), the multimodel ensemble mean dynamic sea level (DSL) is projected to rise 0.9, 1.6, and 1.1 cm under RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, resulting in a total sea level rise (SLR) of 40.9, 48.6, and 64.1 cm in the SCS. It indicates that the SCS will experience a substantial SLR over the 21st century, and the rise is only marginal larger than the global mean SLR. During the same period, the steric sea level (SSL) rise is estimated to be 6.7, 10.0, and 15.3 cm under the three scenarios, respectively, which accounts only for 16%, 21% and 24% of the total SLR in this region. The changes of the SSL in the SCS are almost out of phase with those of the DSL for the three scenarios. The central deep basin has a slightly weak DSL rise, but a strong SSL rise during the 21st century, compared with the north and southwest shelves.
基金funded by the National Basic Research Program of China(Grant Nos.2010CB950102 and 2009CB421406)the Nansen Scientific Society(Norway)part of the SeaLev projects at the Centre of Climate Dynamics/Bjerknes Center in Bergen
文摘Sea level rise (SLR) is one of the major socioeconomic risks associated with global warming. Mass losses from the Greenland ice sheet (GrIS) will be partially responsible for future SLR, although there are large uncertainties in modeled climate and ice sheet behavior. We used the ice sheet model SICOPOLIS (Simulation COde for POLythermal Ice Sheets) driven by climate projections from 20 models in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) to estimate the GrlS contribution to global SLR. Based on the outputs of the 20 models, it is estimated that the GrIS will contribute 0-16 (0-27) cm to global SLR by 2100 under the Representative Concentration Pathways (RCP) 4.5 (RCP 8.5) scenarios. The projected SLR increases further to 7-22 (7-33) cm with 2~basal sliding included. In response to the results of the multimodel ensemble mean, the ice sheet model projects a global SLR of 3 cm and 7 cm (10 cm and 13 cm with 2~basal sliding) under the RCP 4.5 and RCP 8.5 scenarios, respectively. In addition, our results suggest that the uncertainty in future sea level projection caused by the large spread in climate projections could be reduced with model-evaluation and the selective use of model outputs.
文摘It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4~16 cm by the year 2030 with the optimum estimated value of 6~14cm. It will be 9~26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47~65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ~24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%~2. 0% in the Huanghe River Delta.
基金The National Natural Science Foundation of China under contract No.51409286the Scientific Research Innovation Project of Jiangsu Province Ordinary University Graduate Student under contract No.CXZZ12_0223the Open Fund Project of Zhujiang River Water Resources Commission of the Zhujiang River Water Conservancy Science Research Institute under contract No.[2013]KJ02
文摘Understanding the changes of hydrodynamics in estuaries with respect to magnitude of sea level rise is important to understand the changes of transport process. Based on prediction of sea level rise over the 21st century, the Zhujiang(Pearl River) Estuary was chosen as a prototype to study the responses of the estuary to potential sea level rise. The numerical model results show that the average salt content, saltwater intrusion distance, and stratification will increase as the sea level rises. The changes of these parameters have obvious seasonal variations. The salt content in the Lingdingyang shows more increase in April and October(the transition periods). The saltwater intrusion distance has larger increase during the low-flow periods than during the highflow periods in the Lingdingyang. The result is just the opposite in Modaomen. The stratification and its increase are larger during the low-flow periods than during the high-flow periods in Lingdingyang. The response results of transport processes to sea level rise demonstrate that:(1) The time of vertical transport has pronounced increase.The increased tidal range and currents would reinforce the vertical mixing, but the increased stratification would weaken the vertical exchange. The impact of stratification changes overwhelms the impact of tidal changes. It would be more difficult for the surface water to reach the bottom.(2) The lengthways estuarine circulation would be strengthened. Both the offshore surface residual current and inshore bottom residual current will be enhanced.The whole meridional resident flow along the transect of the Lingdingyang would be weakened. These phenomena are caused by the decrease of water surface slope(WWS) and the change of static pressure with the increase of water depth under sea level rise.
基金funding from the project “Future flooding risks at the Swedish Coast: Extreme situations in present and future climat”, Ref. No. P02/12 by Lansforsakringsbolagens Forskningsfondthrough the Swedish Civil Contingencies Agency (MSB) through the project “Hazard Support: Risk-based decision support for adaptation to future natural hazards”
文摘Mean sea level rise and climatological wind speed changes occur as part of the ongoing climate change and future projections of both variables are still highly uncertain. Here the Baltic Sea’s response in extreme sea levels to perturbations in mean sea level and wind speeds is investigated in a series of simulations with a newly developed storm surge model based on the nucleus for European modeling of the ocean(NEMO)-Nordic. A simple linear model with only two tunable parameters is found to capture the changes in the return levels extremely well. The response to mean sea level rise is linear and nearly spatially uniform, meaning that a mean sea level rise of 1 m increases the return levels by a equal amount everywhere. The response to wind speed perturbations is more complicated and return levels are found to increase more where they are already high. This behaviour is alarming as it suggests that already flooding prone regions like the Gulf of Finland will be disproportionally adversely affected in a future windier climate.
基金supported by National 973 Project China(2013CB733305,2013CB733301)National Natural Science Foundation of China(41174011,41429401,41210006,41128003,41021061)
文摘According to the space-geodetic data recorded at globally distributed stations over solid land spanning a period of more than 20-years under the International Terrestrial Reference Frame 2008,our previous estimate of the average-weighted vertical variation of the Earth's solid surface suggests that the Earth's solid part is expanding at a rate of 0.24 ± 0.05 mm/a in recent two decades.In another aspect,the satellite altimetry observations spanning recent two decades demonstrate the sea level rise(SLR) rate 3.2 ± 0.4 mm/a,of which1.8 ± 0.5 mm/a is contributed by the ice melting over land.This study shows that the oceanic thermal expansion is 1.0 ± 0.1 mm/a due to the temperature increase in recent half century,which coincides with the estimate provided by previous authors.The SLR observation by altimetry is not balanced by the ice melting and thermal expansion,which is an open problem before this study.However,in this study we infer that the oceanic part of the Earth is expanding at a rate about 0.4 mm/a.Combining the expansion rates of land part and oceanic part,we conclude that the Earth is expanding at a rate of 0.35 ± 0.47 mm/a in recent two decades.If the Earth expands at this rate,then the altimetry-observed SLR can be well explained.
文摘Local communities want to know the cost of improvements needed to their drainage system based on projected sea level rise. Prior research demonstrates that in coastal areas, groundwater will rise with sea level. As a result the combination of groundwater levels and tidal data must be used to predict local impacts of sea level rise on the drainage system. However, it would appear to complicate the situation if the amount of data available for making sea level rise projections with groundwater is limited. The objectives of this task were to identify available data in a data limited community, compare the available data, assess the impact of sea level rise on the community, and its impact on the stormwater system, identify vulnerable areas in the City, provide an estimate of long-term costs for improvements, and provide a toolbox of strategies to employ at the appropriate time. The project was conducted using ArcGIS tools to import tidal, groundwater, topographic LiDAR and infrastructure improvements into GIS software and performing analysis based on current data. The cost of improvements was based on applying actual 2015 construction costs in the subject comments across a larger vulnerable area. It was found that the data sources provided similar results, despite different timelines and dates so did not interfere with the subsequent analysis. The data revealed that over $400 million in current dollars might be needed to address stormwater issues arising from sea level rise before 2100.
文摘The two main factors contributing to depletion of freshwater resources are climate change and anthropological variables. This study presents statistical analyses that are local in its specifics yet global in its relevance. The decline in Gulf Coast aquifer water quality and quantity has been alarming especially with the increased demand on fresh water in neighboring non-coastal communities. This study used seawater levels, groundwater use, and well data to investigate the association of these factors on the salinity of water indicated by chloride levels. Statistical analyses were conducted pointing to the high significance of both sea water level and groundwater withdrawals to chloride concentrations. However, groundwater withdrawal had higher significance which points to the need of water management systems in order to limit groundwater use. The findings also point to the great impact of increased groundwater salinity in the Gulf Coast aquifer on agriculture and socioeconomic status of coastal communities. The high costs of desalinization point to the increased signification of water rerouting and groundwater management systems. Further investigation and actions are in dire need to manage these vulnerabilities of the coastal communities.
基金supported by the National Basic Research Program of China (Grant No. 2012CB955604)the National Outstanding Youth Science Fund Project of China (Grant No. 41425019)+1 种基金the National Natural Science Foundation of China (Grant Nos. 91337105, 41461144001, 41230527, and 41275083)Public science and technology research funds projects of ocean (201505013)
文摘Against a background of climate change, Macao is very exposed to sea level rise (SLR) because of its low elevation, small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macao, both historical and, especially, possible future scenarios, aiming to provide knowledge and a framework to help accommodate and protect against future SLR. Sea level in Macao is now rising at an accelerated rate: 1.35 mm yr-1 over 1925-2010 and jumping to 4.2 mm yr I over 1970-2010, which outpaces the rise in global mean sea level. In addition, vertical land movement in Macao contributes little to local sea level change. In the future, the rate of SLR in Macao will be about 20% higher than the global average, as a consequence of a greater local warming tendency and strengthened northward winds. Specifically, the sea level is projected to rise 8-12, 22-51 and 35-118 cm by 2020, 2060 and 2100, respectively, depending on the emissions scenario and climate sensitivity. Under the --8.5 W m 2 Representative Concentration Pathway (RCP8.5) scenario the increase in sea level by 2100 will reach 65 118 cm--double that under RCP2.6. Moreover, the SLR will accelerate under RCP6.0 and RCP8.5, while remaining at a moderate and steady rate under RCP4.5 and RCP2.6. The key source of uncertainty stems from the emissions scenario and climate sensitivity, among which the discrepancies in SLR are small during the first half of the 21st century but begin to diverge thereafter.
文摘A total of 103 surface sediment samples collected from the water depth range of 15-3300 m along Vijaydurg-Karwar stretch of central west coast of India were analyzed for foraminiferal content. Relict benthic foraminiferal assemblage was noted within 50--135 m water depth. The relict benthic foraminiferal assemblage that includes Amphistegina, Operculina and Alveolinella in sediment samples within the water depth of 85-- 135 m indicates presence of coral reef at this depth during Early Holocene. The presence of barnacle fouling on Relict foraminifera at 60--90 m confirms the paleo-shoreline. The shallow depth zone is characterized by presence of agglutinated relict foraminifera. The agglutinated forms indicate freshwater influx, which eventually increased the sea level and subsequently deteriorated the paleo-coral reef.
文摘Two major causes of global sea level rise such as thermal expansion of the oceans and the loss of landbased ice for increased melting have been claimed by some researchers and recognized by the IPCC.However, other climate threat investigators revealed that atmosphere-ocean modeling is an imperfect representation, paleo-data consist of proxy climate information with ambiguities, and modern observations are limited in scope and accuracy. It is revealed that global warming and polar ice-melt although a reality would not contribute to any sea level rise. Floating-ice of the polar region on melting would reoccupy same displaced volume by floating ice-sheets. Land-ice cover in the polar region on melting can reduce load from the crust to activate elastic rebound that would raise land for its isostatic equilibrium.Such characteristics would not contribute to sea level rise. Equatorial bulge, polar flattening, elevation difference of the spheroidal surface between equator and pole with lower in the pole, strong gravity attraction of the polar region and week gravity attraction of the equatorial region, all these phenomena would play dominant role in preventing sea level rise. Palaeo-sea level rise and fall in macro-scale(10-100 m or so) were related to marine transgression and regression in addition to other geologic events like converging and diverging plate tectonics, orogenic uplift of the collision margin, basin subsidence of the extensional crust, volcanic activities in the oceanic region, prograding delta buildup, ocean floor height change and sub-marine mass avalanche. This study also reveals that geophysical shape, gravity attraction and the centrifugal force of spinning and rotation of the earth would continue acting against sea level rise.
文摘The evolution of the natural and pristine Mediterranean coastline Port aux Princes-Sidi Daoued(Gulf of Tunis,NE-Tunisia) is studied during the period of 1887–2010 on the basis of an ancient minute of bathymetry(1887) and aerial photographs treated by numerical photogrammetric methods. Morphological changes of the coastline shows a general retreat despite the absence of the various anthropogenic actions. Adding to the drift currents and the currents of high energy that are generated by the N-W dominant waves along steeply sub-marine funds, the erosion is mainly due to the sea level rise which increased since the beginning of the 2000 s. The Port aux PrincesSidi Daoued coastline works as a single littoral cell limited by Jbel Korbous to the SW and the fishing harbor of Sidi Daoued to the N-E.
文摘Due to the dual dris oftural and man-made factors, relative sea leverise in China's coastal plains can be 2 to 3 times over the global mean dunng thefirst half of the 21st Century, it will strongly whuence the vanous coastal projectsand installations and the development of coastal dhes and towns. Research resultsshow that a 50-cm-nse in relative sea leve will cause maed decline in the functionof coastal defense and drainage projects and seriously endangur the functionalworking of the vast majority of coastal harbors. Meanwhile, it will also whuence thedevelopment of coastal dhes and towns throwi deterioratin water quality of thesource of urban water supply, increasing urban fiood risk and damagin seasidetounst resources etc.. Tianin, Shanghai and Guangzhou, the three most importancoastal dhes of China, will be Strongly affeded.
基金Supported by National Natural Science Foundation of China (50839005)Major State Basic Research Development Program (973 Program)(2010CB428405)+1 种基金Scientific Research Project of Public Welfare Industry of the Ministry of Water Resources,China (201001022)Scientific Research Project of China Water Resources Pearl River Planning Surveying and Designing Co.Ltd.(2012)
文摘[Objective] The study aimed to predict the peak water level in Pearl River Estuary under the background of sea level rise. [Method] The changing trends of peak water level at Denglongshan station and Hengmen station were analyzed firstly on the basis of regression models, and then sea level rise in Pearl River Estuary in 2050 was predicted to estimate the 1-in-50-year peak water level in the same year. [Result] Regression analyses showed that the increasing rate of peak water level over past years was 6.3 mm/a at Denglongshan station and 5.8 mm/a at Hengmen station. In addition, if sea level will rise by 20, 30 and 60 cm respectively in 2050, it was predicted that the 1-in-50-year peak water level will reach 3.04, 3.14 and 3.44 m at Denglongshan station, and 3.19, 3.29 and 3.59 m at Hengmen station separately. [Conclusion] The estimation of peak water level in Pearl River Estuary could provide theoretical references for water resources planning.