scholarly journals A Conterminous USA-Scale Map of Relative Tidal Marsh Elevation

2022 ◽  
Author(s):  
James R. Holmquist ◽  
Lisamarie Windham-Myers
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Physical Map ◽  
High Tide ◽  
Tidal Wetlands ◽  
Tidal Amplitude ◽  
National Scale ◽  
Tidal Elevation ◽  
Elevation Gradients ◽  
Future Studies

AbstractTidal wetlands provide myriad ecosystem services across local to global scales. With their uncertain vulnerability or resilience to rising sea levels, there is a need for mapping flooding drivers and vulnerability proxies for these ecosystems at a national scale. However, tidal wetlands in the conterminous USA are diverse with differing elevation gradients, and tidal amplitudes, making broad geographic comparisons difficult. To address this, a national-scale map of relative tidal elevation (Z*MHW), a physical metric that normalizes elevation to tidal amplitude at mean high water (MHW), was constructed for the first time at 30 × 30-m resolution spanning the conterminous USA. Contrary to two study hypotheses, watershed-level median Z*MHW and its variability generally increased from north to south as a function of tidal amplitude and relative sea-level rise. These trends were also observed in a reanalysis of ground elevation data from the Pacific Coast by Janousek et al. (Estuaries and Coasts 42 (1): 85–98, 2019). Supporting a third hypothesis, propagated uncertainty in Z*MHW increased from north to south as light detection and ranging (LiDAR) errors had an outsized effect under narrowing tidal amplitudes. The drivers of Z*MHW and its variability are difficult to determine because several potential causal variables are correlated with latitude, but future studies could investigate highest astronomical tide and diurnal high tide inequality as drivers of median Z*MHW and Z*MHW variability, respectively. Watersheds of the Gulf Coast often had propagated Z*MHW uncertainty greater than the tidal amplitude itself emphasizing the diminished practicality of applying Z*MHW as a flooding proxy to microtidal wetlands. Future studies could focus on validating and improving these physical map products and using them for synoptic modeling of tidal wetland carbon dynamics and sea-level rise vulnerability analyses.

scholarly journals Contributions of Organic and Mineral Matter to Vertical Accretion in Tidal Wetlands across a Chesapeake Bay Subestuary

2021 ◽  
Vol 9 (7) ◽  
pp. 751
Author(s):  
Jenny R. Allen ◽  
Jeffrey C. Cornwell ◽  
Andrew H. Baldwin
Keyword(s):  
Organic Matter ◽  
Sea Level Rise ◽  
Chesapeake Bay ◽  
Sea Level ◽  
210Pb Dating ◽  
Sediment Supply ◽  
Mineral Matter ◽  
Tidal Wetlands ◽  
Vertical Accretion ◽  
Inorganic Matter

Persistence of tidal wetlands under conditions of sea level rise depends on vertical accretion of organic and inorganic matter, which vary in their relative abundance across estuarine gradients. We examined the relative contribution of organic and inorganic matter to vertical soil accretion using lead-210 (210Pb) dating of soil cores collected in tidal wetlands spanning a tidal freshwater to brackish gradient across a Chesapeake Bay subestuary. Only 8 out of the 15 subsites had accretion rates higher than relative sea level rise for the area, with the lowest rates of accretion found in oligohaline marshes in the middle of the subestuary. The mass accumulation of organic and inorganic matter was similar and related (R2 = 0.37). However, owing to its lower density, organic matter contributed 1.5–3 times more toward vertical accretion than inorganic matter. Furthermore, water/porespace associated with organic matter accounted for 82%–94% of the total vertical accretion. These findings demonstrate the key role of organic matter in the persistence of coastal wetlands with low mineral sediment supply, particularly mid-estuary oligohaline marshes.

Sea-level rise enhances carbon accumulation in United States tidal wetlands

One Earth ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 425-433
Author(s):  
Ellen R. Herbert ◽  
Lisamarie Windham-Myers ◽  
Matthew L. Kirwan
Keyword(s):  
United States ◽  
Sea Level Rise ◽  
Sea Level ◽  
Carbon Accumulation ◽  
Tidal Wetlands

scholarly journals Compounding effects of sea level rise and fluvial flooding

2017 ◽  
Vol 114 (37) ◽  
pp. 9785-9790 ◽  
Author(s):  
Hamed R. Moftakhari ◽  
Gianfausto Salvadori ◽  
Amir AghaKouchak ◽  
Brett F. Sanders ◽  
Richard A. Matthew
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Hazard Assessment ◽  
Failure Probability ◽  
River Flow ◽  
Flood Hazard ◽  
High Tide ◽  
Probability Method ◽  
Flood Hazards ◽  
Flood Hazard Assessment

Sea level rise (SLR), a well-documented and urgent aspect of anthropogenic global warming, threatens population and assets located in low-lying coastal regions all around the world. Common flood hazard assessment practices typically account for one driver at a time (e.g., either fluvial flooding only or ocean flooding only), whereas coastal cities vulnerable to SLR are at risk for flooding from multiple drivers (e.g., extreme coastal high tide, storm surge, and river flow). Here, we propose a bivariate flood hazard assessment approach that accounts for compound flooding from river flow and coastal water level, and we show that a univariate approach may not appropriately characterize the flood hazard if there are compounding effects. Using copulas and bivariate dependence analysis, we also quantify the increases in failure probabilities for 2030 and 2050 caused by SLR under representative concentration pathways 4.5 and 8.5. Additionally, the increase in failure probability is shown to be strongly affected by compounding effects. The proposed failure probability method offers an innovative tool for assessing compounding flood hazards in a warming climate.

scholarly journals Tidal wetland resilience to sea level rise increases their carbon sequestration capacity in United States

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Faming Wang ◽  
Xiaoliang Lu ◽  
Christian J. Sanders ◽  
Jianwu Tang
Keyword(s):  
Climate Change ◽  
United States ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Accumulation Rate ◽  
C Sequestration ◽  
Tidal Wetlands ◽  
Tidal Wetland ◽  
Climate Change Scenarios

AbstractCoastal wetlands are large reservoirs of soil carbon (C). However, the annual C accumulation rates contributing to the C storage in these systems have yet to be spatially estimated on a large scale. We synthesized C accumulation rate (CAR) in tidal wetlands of the conterminous United States (US), upscaled the CAR to national scale, and predicted trends based on climate change scenarios. Here, we show that the mean CAR is 161.8 ± 6 g Cm−2 yr−1, and the conterminous US tidal wetlands sequestrate 4.2–5.0 Tg C yr−1. Relative sea level rise (RSLR) largely regulates the CAR. The tidal wetland CAR is projected to increase in this century and continue their C sequestration capacity in all climate change scenarios, suggesting a strong resilience to sea level rise. These results serve as a baseline assessment of C accumulation in tidal wetlands of US, and indicate a significant C sink throughout this century.

scholarly journals New elevation data triple estimates of global vulnerability to sea-level rise and coastal flooding

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Scott A. Kulp ◽  
Benjamin H. Strauss
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
High Tide ◽  
Water Levels ◽  
Low Carbon ◽  
Digital Elevation ◽  
Elevation Data ◽  
Global Mean Sea Level ◽  
Elevation Model ◽  
Global Mean

Abstract Most estimates of global mean sea-level rise this century fall below 2 m. This quantity is comparable to the positive vertical bias of the principle digital elevation model (DEM) used to assess global and national population exposures to extreme coastal water levels, NASA’s SRTM. CoastalDEM is a new DEM utilizing neural networks to reduce SRTM error. Here we show – employing CoastalDEM—that 190 M people (150–250 M, 90% CI) currently occupy global land below projected high tide lines for 2100 under low carbon emissions, up from 110 M today, for a median increase of 80 M. These figures triple SRTM-based values. Under high emissions, CoastalDEM indicates up to 630 M people live on land below projected annual flood levels for 2100, and up to 340 M for mid-century, versus roughly 250 M at present. We estimate one billion people now occupy land less than 10 m above current high tide lines, including 230 M below 1 m.

scholarly journals Simulating the Effects of Sea Level Rise on the Resilience and Migration of Tidal Wetlands along the Hudson River

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0152437 ◽  
Author(s):  
Nava M. Tabak ◽  
Magdeline Laba ◽  
Sacha Spector
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Hudson River ◽  
Tidal Wetlands ◽  
And Migration

The effects of tidal changes on the frequency of nuisance flooding events in the United States

2020 ◽  
Author(s):  
Sida Li ◽  
Thomas Wahl ◽  
David Jay ◽  
Stefan Talke ◽  
Lintao Liu
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
High Tide ◽  
The United States ◽  
Tide Gauges ◽  
Relative Sea Level ◽  
Relative Sea Level Rise ◽  
Tidal Changes ◽  
Cape Fear ◽  
The U.S

<p>Nuisance flooding (NF) or high tide flooding describes minor nondestructive flooding which can nonetheless cause substantial negative socio-economic impacts to coastal communities. The frequency of NF events has increased and accelerated over the past decades along the U.S. coast, leading to changes ranging from 300% to 900%. This is mainly a result of sea level rise reducing the gap between high tidal datum and flood thresholds. While long-term relative sea level rise is the main driver for the increased number of NF events, other factors such as variability in the Gulf stream, the storm climate, and infragravity waves can also contribute. Another important driver that is often overlooked is related to changes in coastal and estuary tides, through secular trends in the amplitudes of major tidal constituents. In this presentation we assess the role of tidal changes in modulating the frequency of NF events along the U.S. coastline. We analyze hourly records from 49 U.S. tide gauges for which the National Weather Service has defined NF thresholds. We find that (1) overall across all tide gauges the number of NF days has increased since 1950 due to changes in coastal tides, adding up to 100 NF days in recent years (on top of the increase due to relative sea level rise), (2) more tide gauges experience an increase in NF events than a decrease due to changes in tides, (3) tide gauges in major estuaries which have undergone major anthropogenic alterations experience the strongest changes; in Wilmington (Cape Fear estuary), for example, 10-40% of NF events in recent years can be attributed to tidal changes. </p>

scholarly journals Local Sea-Level Rise Caused by Climate Change in the Northwest Pacific Marginal Seas Using Dynamical Downscaling

2021 ◽  
Vol 8 ◽  
Author(s):  
Yong-Yub Kim ◽  
Bong-Gwan Kim ◽  
Kwang Young Jeong ◽  
Eunil Lee ◽  
Do-Seong Byun ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Dynamical Downscaling ◽  
The Yellow Sea ◽  
Northwest Pacific ◽  
Tidal Amplitude ◽  
Marginal Seas ◽  
Rcp 8.5

Global climate models (GCMs) have limited capacity in simulating spatially non-uniform sea-level rise owing to their coarse resolutions and absence of tides in the marginal seas. Here, regional ocean climate models (RCMs) that consider tides were used to address these limitations in the Northwest Pacific marginal seas through dynamical downscaling. Four GCMs that drive the RCMs were selected based on a performance evaluation along the RCM boundaries, and the latter were validated by comparing historical results with observations. High-resolution (1/20°) RCMs were used to project non-uniform changes in the sea-level under intermediate (RCP 4.5) and high-end emissions (RCP 8.5) scenarios from 2006 to 2100. The predicted local sea-level rise was higher in the East/Japan Sea (EJS), where the currents and eddy motions were active. The tidal amplitude changes in response to sea-level rise were significant in the shallow areas of the Yellow Sea (YS). Dynamically downscaled simulations enabled the determination of practical sea-level rise (PSLR), including changes in tidal amplitude and natural variability. Under RCP 8.5 scenario, the maximum PSLR was ∼85 cm in the YS and East China Sea (ECS), and ∼78 cm in the EJS. The contribution of natural sea-level variability changes in the EJS was greater than that in the YS and ECS, whereas changes in the tidal contribution were higher in the YS and ECS. Accordingly, high-resolution RCMs provided spatially different PSLR estimates, indicating the importance of improving model resolution for local sea-level projections in marginal seas.

scholarly journals An Estimate of Increases in Storm Surge Risk to Property from Sea Level Rise in the First Half of the Twenty-First Century

2010 ◽  
Vol 2 (4) ◽  
pp. 271-293 ◽  
Author(s):  
Ross N. Hoffman ◽  
Peter Dailey ◽  
Susanna Hopsch ◽  
Rui M. Ponte ◽  
Katherine Quinn ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Full Range ◽  
High Tide ◽  
World Ocean ◽  
Sea Level Changes ◽  
Global Signal ◽  
The Impact ◽  
Zip Code

Abstract Sea level is rising as the World Ocean warms and ice caps and glaciers melt. Published estimates based on data from satellite altimeters, beginning in late 1992, suggest that the global mean sea level has been rising on the order of 3 mm yr−1. Local processes, including ocean currents and land motions due to a variety of causes, modulate the global signal spatially and temporally. These local signals can be much larger than the global signal, and especially so on annual or shorter time scales. Even increases on the order of 10 cm in sea level can amplify the already devastating losses that occur when a hurricane-driven storm surge coincides with an astronomical high tide. To quantify the sensitivity of property risk to increasing sea level, changes in expected annual losses to property along the U.S. Gulf and East Coasts are calculated as follows. First, observed trends in sea level rise from tide gauges are extrapolated to the year 2030, and these changes are interpolated to all coastal locations. Then a 10 000-yr catalog of simulated hurricanes is used to define critical wind parameters for each event. These wind parameters then drive a parametric time-evolving storm surge model that accounts for bathymetry, coastal geometry, surface roughness, and the phase of the astronomical tide. The impact of the maximum storm surge height on a comprehensive inventory of commercial and residential property is then calculated, using engineering models that take into account the characteristics of the full range of construction types. Average annual losses projected to the year 2030 are presented for regions and key states and are normalized by aggregate property value on a zip code by zip code basis. Comparisons to the results of a control run reflecting the risk today quantify the change in risk per dollar of property on a percentage basis. Increases in expected losses due to the effect of sea level rise alone vary by region, with increases of 20% or more being common. Further sensitivity tests quantify the impact on the risk of sea level rise plus additional factors, such as changes in hurricane frequency and intensity as a result of rising sea surface temperatures.

scholarly journals Differential Effects of Increasing Salinity on Germination and Seedling Growth of Native and Exotic Invasive Cordgrasses

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 372 ◽  
Author(s):  
Infante-Izquierdo ◽  
Castillo ◽  
Grewell ◽  
Nieva ◽  
Muñoz-Rodríguez
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Fresh Water ◽  
Seedling Growth ◽  
Salt Marshes ◽  
Germination Percentage ◽  
Tidal Elevation ◽  
Exotic Invasive ◽  
Specialist Species ◽  
And Sea Level

Soil salinity is a key environmental factor influencing germination and seedling establishment in salt marshes. Global warming and sea level rise are changing estuarine salinity, and may modify the colonization ability of halophytes. We evaluated the effects of increasing salinity on germination and seedling growth of native Spartina maritima and invasive S. densiflora from wetlands of the Odiel-Tinto Estuary. Responses were assessed following salinity exposure from fresh water to hypersaline conditions and germination recovery of non-germinated seeds when transferred to fresh water. The germination of both species was inhibited and delayed at high salinities, while pre-exposure to salinity accelerated the speed of germination in recovery assays compared to non-pre-exposed seeds. S. densiflora was more tolerant of salinity at germination than S. maritima. S. densiflora was able to germinate at hypersalinity and its germination percentage decreased at higher salinities compared to S. maritima. In contrast, S. maritima showed higher salinity tolerance in relation to seedling growth. Contrasting results were observed with differences in the tidal elevation of populations. Our results suggest S. maritima is a specialist species with respect to salinity, while S. densiflora is a generalist capable of germination of growth under suboptimal conditions. Invasive S. densiflora has greater capacity than native S. maritima to establish from seed with continued climate change and sea level rise.

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