scholarly journals The Increased Risk of Flooding in Hampton Roads: On the Roles of Sea Level Rise, Storm Surges, Hurricanes, and the Gulf Stream

2018 ◽  
Vol 52 (2) ◽  
pp. 34-44 ◽  
Author(s):  
Tal Ezer
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Gulf Stream ◽  
Storm Surges ◽  
Water Levels ◽  
Tropical Storms ◽  
Tidal Flooding ◽  
Hampton Roads ◽  
Elevated Water ◽  
The Impact

AbstractThe impact of sea level rise on increased tidal flooding and storm surges in the Hampton Roads region is demonstrated, using ~90 years of water level measurements in Norfolk, Virginia. Impacts from offshore storms and variations in the Gulf Stream (GS) are discussed as well, in view of recent studies that show that weakening in the flow of the GS (daily, interannually, or decadal) is often related to elevated water levels along the U.S. East Coast. Two types of impacts from hurricanes on flooding in Hampton Roads are demonstrated here. One type is when a hurricane like Isabel (2003) makes a landfall and passes near the Chesapeake Bay, causing a large but short-term (hours to a day) storm surge. The second type is when Atlantic hurricanes like Joaquin (2015) or Matthew (2016) stay offshore for a relatively long time, disrupting the flow of the GS and leading to a longer period (several days or more) of higher water levels and tidal flooding. Analysis of the statistics of tropical storms and hurricanes since the 1970s shows that, since the 1990s, there is an increase in the number of days when intense hurricanes (Categories 3‐5) are found in the subtropical western North Atlantic. The observed Florida Current transport since the 1980s often shows less transport and elevated water levels when tropical storms and hurricanes pass near the GS. Better understanding of the remote influence of the GS and offshore storms will improve future prediction of flooding and help mitigation and adaptation efforts.

Geospatial Risk Assessment of Marine Terminal Infrastructure to Storm Surge Inundation and Sea Level Rise

2018 ◽  
Vol 2672 (11) ◽  
pp. 19-29 ◽  
Author(s):  
George M. McLeod ◽  
Thomas R. Allen ◽  
Joshua G. Behr
Keyword(s):  
Risk Assessment ◽  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Storm Surges ◽  
Risk Tolerance ◽  
Water Levels ◽  
Rapid Screening ◽  
Tidal Flooding ◽  
The Future

Planning resiliency and sustainability of port operations and critical infrastructure requires risk assessment of storm surge exposure and potential sea level rise. An approach for rapid, screening-level assessment is developed to estimate the current and future risk of exposure to severe storm surges posed to marine terminal facilities in Norfolk, Virginia. The approach estimates the vertical elevation of local mean sea level fifty years into the future and attendant increases in potential storm surge heights. Inundation models are designed for baseline water levels and storm surges for category 1–3 hurricanes across five precautionary future sea level rise scenarios. In addition, tidal flooding poses an emerging threat because sea level rise will also force tides to higher elevations, suggesting that today’s extreme high tides may be the future mean high tide and today’s “nuisance” tidal flooding may in the future recur with chronic regularity. Potential tidal flooding levels are also modeled for each sea level scenario. This approach allows a port to assess relative risk tolerance across the range from lesser to more severe flooding events. Maps and tabular information in linked scenarios are used to summarize the extent, pattern, and depth of potential flooding. The methodology and data developed in this study may be applied to inform the timing and placement of planned assets and can be leveraged in the broader pursuit of optimization in support of long-term master planning at marine terminals.

scholarly journals Determining Extreme Still Water Levels for Design and Planning Purposes Incorporating Sea Level Rise: Sydney, Australia

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 95
Author(s):  
Phil J. Watson
Keyword(s):  
Sea Level Rise ◽  
Water Level ◽  
Sea Level ◽  
Tide Gauge ◽  
Water Levels ◽  
Extreme Value Analysis ◽  
Tide Gauge Record ◽  
Value Analysis ◽  
Mean Sea Level ◽  
The Impact

This paper provides an Extreme Value Analysis (EVA) of the hourly water level record at Fort Denison dating back to 1915 to understand the statistical likelihood of the combination of high predicted tides and the more dynamic influences that can drive ocean water levels higher at the coast. The analysis is based on the Peaks-Over-Threshold (POT) method using a fitted Generalised Pareto Distribution (GPD) function to estimate extreme hourly heights above mean sea level. The analysis highlights the impact of the 1974 East Coast Low event and rarity of the associated measured water level above mean sea level at Sydney, with an estimated return period exceeding 1000 years. Extreme hourly predictions are integrated with future projections of sea level rise to provide estimates of relevant still water levels at 2050, 2070 and 2100 for a range of return periods (1 to 1000 years) for use in coastal zone management, design, and sea level rise adaptation planning along the NSW coastline. The analytical procedures described provide a step-by-step guide for practitioners on how to develop similar baseline information from any long tide gauge record and the associated limitations and key sensitivities that must be understood and appreciated in applying EVA.

scholarly journals Impact of Human Intervention and Sea Level Rise on Water-Logging Scenarios inside Polders-24 And 25 of Bangladesh

2022 ◽  
Vol 12 (3) ◽  
pp. 73-83
Author(s):  
Jamal M Haider ◽  
Haque M Aminul ◽  
Hossain Md Jahid ◽  
Haque Anisul
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Region ◽  
Storm Surges ◽  
Climate Change Scenarios ◽  
South Central ◽  
Water Logging ◽  
Natural Man ◽  
The Impact

Coastal region of Bangladesh possesses a fragile ecosystem and is exposed to hazards like cyclones, floods, storm surges, and water-logging. A detail understanding on the impact of water-logging due to various natural, man-made and climate change scenarios is still lacking. Considering this research gap, the present research is aimed to study impacts of these scenarios inside polders-24 and 25 which are situated on the western part of the coastal region. In this Study as natural scenario, sedimentation in the Hari River; as man-made scenario, new polders in the south-central region and as SLR scenario, an extreme sea level rise of 1.48m are considered. Long-term satellite images are analyzed, and numerical model is applied in the study area. The result shows that water-logging is more acute inside polder-25 compared to polder-24. Sedimentation in Hari River aggravates the water-logging condition. Dredging in Hari River does improve the situation. Journal of Engineering Science 12(3), 2021, 73-83

scholarly journals Modelling Coastal Flood Propagation under Sea Level Rise: A Case Study in Maria, Eastern Canada

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 76 ◽  
Author(s):  
David Didier ◽  
Marion Bandet ◽  
Pascal Bernatchez ◽  
Dany Dumont
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Overland Flow ◽  
Water Levels ◽  
Model Complexity ◽  
Flood Mapping ◽  
Eastern Canada ◽  
Coastal Flood ◽  
The Impact ◽  
Flow Velocities

Coastal management often relies on large-scale flood mapping to produce sea level rise assessments where the storm-related surge is considered as the most important hazard. Nearshore dynamics and overland flow are also key parameters in coastal flood mapping, but increase the model complexity. Avoiding flood propagation processes using a static flood mapping is less computer-intensive, but generally leads to overestimation of the flood zone, especially in defended urban backshore. For low-lying communities, sea level rise poses a certain threat, but its consequences are not only due to a static water level. In this paper, the numerical process-based model XBeach is used in 2D hydrodynamic mode (surfbeat) to reproduce an observed historical flood in Maria (eastern Canada). The main goal is to assess the impacts of a future storm of the same magnitude in the horizon 2100 according to an increase in sea level rise. The model is first validated from in situ observations of waves and water levels observed on the lower foreshore. Based on field observations of a flood extent in 2010, the simulated flooded area was also validated given a good fit (59%) with the actual observed flood. Results indicate that the 2010 storm-induced surge generated overwash processes on multiple areas and net landward sediment transport and accumulation (washover lobes). The flood was caused by relatively small nearshore waves (Hs < 1 m), but despite small water depth (>1.2 m), high flow velocities occurred in the main street (U > 2 m/s) prior to draining in the salt marsh. The impact of sea level rise on the low-lying coastal community of Maria could induce a larger flood area in 2100, deeper floodwater, and higher flow velocities, resulting in higher hazard for the population.

scholarly journals The large-scale impact of climate change to Mississippi flood hazard in New Orleans

2013 ◽  
Vol 6 (2) ◽  
pp. 81-87 ◽  
Author(s):  
T. L. A. Driessen ◽  
M. van Ledden
Keyword(s):  
Climate Change ◽  
Sea Level Rise ◽  
New Orleans ◽  
Sea Level ◽  
Mississippi River ◽  
Flood Hazard ◽  
Water Levels ◽  
Impact Of Climate Change ◽  
High Flows ◽  
The Impact

Abstract. The objective of this paper was to describe the impact of climate change on the Mississippi River flood hazard in the New Orleans area. This city has a unique flood risk management challenge, heavily influenced by climate change, since it faces flood hazards from multiple geographical locations (e.g. Lake Pontchartrain and Mississippi River) and multiple sources (hurricane, river, rainfall). Also the low elevation and significant subsidence rate of the Greater New Orleans area poses a high risk and challenges the water management of this urban area. Its vulnerability to flooding became dramatically apparent during Hurricane Katrina in 2005 with huge economic losses and a large number of casualties. A SOBEK Rural 1DFLOW model was set up to simulate the general hydrodynamics. This model included the two important spillways that are operated during high flow conditions. A weighted multi-criteria calibration procedure was performed to calibrate the model for high flows. Validation for floods in 2011 indicated a reasonable performance for high flows and clearly demonstrated the influence of the spillways. 32 different scenarios were defined which included the relatively large sea level rise and the changing discharge regime that is expected due to climate change. The impact of these scenarios on the water levels near New Orleans were analysed by the hydrodynamic model. Results showed that during high flows New Orleans will not be affected by varying discharge regimes, since the presence of the spillways ensures a constant discharge through the city. In contrary, sea level rise is expected to push water levels upwards. The effect of sea level rise will be noticeable even more than 470 km upstream. Climate change impacts necessitate a more frequent use of the spillways and opening strategies that are based on stages.

scholarly journals Long-Term Regional Environmental Risk Assessment and Future Scenario Projection at Ningbo, China Coupling the Impact of Sea Level Rise

2019 ◽  
Vol 11 (6) ◽  
pp. 1560
Author(s):  
Yongjiu Feng ◽  
Qianqian Yang ◽  
Xiaohua Tong ◽  
Jiafeng Wang ◽  
Shurui Chen ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Environmental Risk ◽  
Socioeconomic Development ◽  
Principal Component ◽  
Storm Surges ◽  
Disaster Mitigation ◽  
Northern Coast ◽  
The Impact

Regional environmental risk (RER) denotes potential threats to the natural environment, human health and socioeconomic development caused by specific risks. It is valuable to assess long-term RER in coastal areas with the increasing effects of global change. We proposed a new approach to assess coastal RER considering spatial factors using principal component analysis (PCA) and used a future land use simulation (FLUS) model to project future RER scenarios considering the impact of sea level rise (SLR). In our study, the RER status was classified in five levels as highest, high, medium, low and lowest. We evaluated the 30 m × 30 m gridded spatial pattern of the long-term RER at Ningbo of China by assessing its 1975–2015 history and projecting this to 2020–2050. Our results show that RER at Ningbo has increased substantially over the past 40 years and will slowly increase over the next 35 years. Ningbo’s city center and district centers are exposed to medium-to-highest RER, while the suburban areas are exposed to lowest-to-medium lower RER. Storm surges will lead to strong RER increases along the Ningbo coast, with the low-lying northern coast being more affected than the mountainous southern coast. RER at Ningbo is affected principally by the combined effects of increased human activity, rapid population growth, rapid industrialization, and unprecedented urbanization. This study provides early warnings to support practical regulation for disaster mitigation and environmental protection.

Coastal flooding protection will change salt-marsh sedimentation dynamics

2021 ◽  
Author(s):  
Davide Tognin ◽  
Andrea D'Alpaos ◽  
Marco Marani ◽  
Luca Carniello
Keyword(s):  
Salt Marsh ◽  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Sedimentation Rate ◽  
Urban Areas ◽  
Storm Surges ◽  
Venice Lagoon ◽  
Water Levels ◽  
Sedimentation Dynamics

&lt;p&gt;Coastal wetlands lie at the interface between submerged and emerged environments and therefore represent unique yet delicate ecosystems. Their existence, resulting from complex interactions between hydrodynamics and sediment dynamics, is challenged by increasing rates of sea-level rise, lowered fluvial sediment input as well as an increasing anthropogenic pressure. The future survival of these peculiar morphologies is becoming even more complicated, because of the construction and planning of coastal defence structures designed to protect urban areas from flooding. Important examples are the flood protection systems built to protect New Orleans (USA), the river Scheldt Estuary (The Netherlands) and Venice (Italy). In this context, understanding the physical processes on which coastal marshes are grounded and how engineering measures can alter them is of extreme importance in order to plan conservation interventions.&lt;/p&gt;&lt;p&gt;To understand marsh sedimentation dynamics in flood-regulated environments, we investigated through field observations and modelling the effect of the storm-surge barrier designed to protect the city of Venice, the so-called Mo.S.E. system, which has in fact become operational since October 2020.&lt;/p&gt;&lt;p&gt;Sedimentation measurements in different salt marshes of the Venice lagoon carried out in the period October 2018-October 2020 show that more than 70% of yearly sedimentation accumulates during storm-surge conditions, despite their short duration. Moreover, the sedimentation rate displays a highly non-linear increase with marsh inundation intensity, due to the interplay between higher water levels and greater suspended sediment concentration. Barrier operations during storm surges to avoid flooding of urban areas will reduce water levels and marsh inundation. Therefore, we computed sedimentation in a flood-regulated scenario for the same observation period, using the relation we obtained between tidal forcing and sedimentation rate. Our results show that some occasional closures during intense storm surges (70 hours/year on average) suffice to reduce the yearly sedimentation of the same order of magnitude of the relative sea-level rise rate experienced by the Venice lagoon during the last century (2.5 mm/y).&lt;/p&gt;&lt;p&gt;We conclude that storm-surge barrier operations can dangerously reduce salt-marsh vertical accretion rate, thus challenging wetland survival in face of increasing sea-level rise.&lt;/p&gt;

The impact of sea level rise on storm surge water levels in the northern part of the German Bight

2015 ◽  
Vol 96 ◽  
pp. 118-131 ◽  
Author(s):  
A. Arns ◽  
T. Wahl ◽  
S. Dangendorf ◽  
J. Jensen
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
German Bight ◽  
Water Levels ◽  
The Impact

scholarly journals Hydrodynamic and Waves Response during Storm Surges on the Southern Brazilian Coast: A Hindcast Study

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3538
Author(s):  
Andre de Souza de Lima ◽  
Arslaan Khalid ◽  
Tyler Will Miesse ◽  
Felicio Cassalho ◽  
Celso Ferreira ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Storm Surge ◽  
Storm Surges ◽  
Coastal Communities ◽  
Brazilian Coast ◽  
Forecast System ◽  
Modeling Framework ◽  
Meteorological Forcing ◽  
The Impact

The Southern Brazilian Coast is highly susceptible to storm surges that often lead to coastal flooding and erosive processes, significantly impacting coastal communities. In addition, climate change is expected to result in expressive increases in wave heights due to more intense and frequent storms, which, in conjunction with sea-level rise (SLR), has the potential to exacerbate the impact of storm surges on coastal communities. The ability to predict and simulate such events provides a powerful tool for coastal risk reduction and adaptation. In this context, this study aims to investigate how accurately storm surge events can be simulated in the Southwest Atlantic Ocean employing the coupled ADCIRC+SWAN hydrodynamic and phase-averaged wave numerical modeling framework given the significant data scarcity constraints of the region. The model’s total water level (TWL) and significant wave height (Hs) outputs, driven by different sources of meteorological forcing, i.e., the Fifth Generation of ECMWF Atmospheric Reanalysis (ERA 5), the Climate Forecast System Version 2 (CFSv2), and the Global Forecast System (GFS), were validated for three recent storm events that affected the coast (2016, 2017, and 2019). In order to assess the potentially increasing storm surge impacts due to sea-level rise, a case study was implemented to locally evaluate the modeling approach using the most accurate model setup for two 2100 SLR projections (RCP 4.5 and 8.5). Despite a TWL underestimation in all sets of simulations, the CFSv2 model stood out as the most consistent meteorological forcing for the hindcasting of the storm surge and waves in the numerical model, with an RMSE range varying from 0.19 m to 0.37 m, and an RMSE of 0.56 m for Hs during the most significant event. ERA5 was highlighted as the second most accurate meteorological forcing, while adequately simulating the peak timings. The SLR study case demonstrated a possible increase of up to 82% in the TWL during the same event. Despite the limitations imposed by the lack of continuous and densely distributed observational data, as well as up to date topobathymetric datasets, the proposed framework was capable of expanding TWL and Hs information, previously available for a handful of gauge stations, to a spatially distributed and temporally unlimited scale. This more comprehensive understanding of such extreme events represents valuable knowledge for the potential implementation of more adequate coastal management and engineering practices for the Brazilian coastal zone, especially under changing climate conditions.

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