scholarly journals TOWARDS A PROBABILISTIC FLOOD BASE MODEL FOR CARIBBEAN COASTS

2012 ◽  
Vol 1 (32) ◽  
pp. 54
Author(s):  
Carol Subrath-Ali ◽  
Deborah Villarroel-Lamb ◽  
Ilan Kelman
Keyword(s):  
Water Level ◽  
Wind Wave ◽  
Driving Forces ◽  
Stochastic Approach ◽  
Cyclonic Activity ◽  
Total Water ◽  
Order Of Magnitude ◽  
Coastal Water Level ◽  
Two Parameters ◽  
Total Water Level

An estimate of the total water level setup at the coast is examined at a monthly resolution to assess the base combined contribution from wind, wave and pressure setup in the absence of cyclonic activity. A stochastic approach is used to estimate the total values of water level setup from the three parameters and the results indicate that while the total coastal water level setup closely follows the wave setup due to a difference of an order of magnitude of two with the wind and pressure setup from the inverse barometer effect, the latter two parameters have a greater impact during the first seven months of the year – the dry season with an approximate two month overlap into the rainy season. Using the generated moments from monthly combined probability density functions, we show that the average coastal setup from the three driving forces show a general decreasing trend from the highest coastal setup months of December, January and February.

Ensemble Water Level Prediction System: Improving the Representation of Model Uncertainty

2020 ◽  
Author(s):  
Natacha Bernier ◽  
Oleksandr Huziy ◽  
Keith Thompson ◽  
Pengcheng Wang ◽  
Benoit Pouliot ◽  
...  
Keyword(s):  
Water Level ◽  
Gulf Of Maine ◽  
Ocean Model ◽  
Total Water ◽  
Atmospheric Forcing ◽  
Operational Forecasts ◽  
Recent Case Study ◽  
Coastal Water Level ◽  
Total Water Level

<p>Concern over increased flooding and the need for earlier and more reliable risk forecasts motivate the continued development of operational forecasts of coastal water level. We report here on results from a year long ensemble of total water level forecasts calculated using a dynamical ocean model forced with ensemble atmospheric forcing and tidal boundary conditions. We focus on the east coast of Canada. The domain includes the Gulf of St. Lawrence, the Labrador Shelf, the Scotian Shelf, and the Gulf of Maine. The water level ensemble is made of a control and 20 perturbed members. Individual forecasts are produced twice daily for 16 days.</p><p> </p><p>The novelty of the present study is in the exploration of perturbations of the ocean contributions. In addition to examining how uncertainty in atmospheric forcing maps into flood risk, we also explore the feasibility, and impact, of perturbing the ocean tides. We use a recent case study to demonstrate our findings.</p><p> </p>

scholarly journals Deriving the 100-Year Total Water Level around the Coast of Corsica by Combining Trivariate Extreme Value Analysis and Coastal Hydrodynamic Models

2021 ◽  
Vol 9 (12) ◽  
pp. 1347
Author(s):  
Jessie Louisor ◽  
Jérémy Rohmer ◽  
Thomas Bulteau ◽  
Faïza Boulahya ◽  
Rodrigo Pedreros ◽  
...  
Keyword(s):  
Water Level ◽  
Return Period ◽  
Extreme Value ◽  
Coastal Areas ◽  
Extreme Value Analysis ◽  
Total Water ◽  
Hydrodynamic Models ◽  
Value Analysis ◽  
Multivariate Extreme Value ◽  
Total Water Level

As low-lying coastal areas can be impacted by flooding caused by dynamic components that are dependent on each other (wind, waves, water levels—tide, atmospheric surge, currents), the analysis of the return period of a single component is not representative of the return period of the total water level at the coast. It is important to assess a joint return period of all the components. Based on a semiparametric multivariate extreme value analysis, we determined the joint probabilities that significant wave heights (Hs), wind intensity at 10 m above the ground (U), and still water level (SWL) exceeded jointly imposed thresholds all along the Corsica Island coasts (Mediterranean Sea). We also considered the covariate peak direction (Dp), the peak period (Tp), and the wind direction (Du). Here, we focus on providing extreme scenarios to populate coastal hydrodynamic models, SWAN and SWASH-2DH, in order to compute the 100-year total water level (100y-TWL) all along the coasts. We show how the proposed multivariate extreme value analysis can help to more accurately define low-lying zones potentially exposed to coastal flooding, especially in Corsica where a unique value of 2 m was taken into account in previous studies. The computed 100y-TWL values are between 1 m along the eastern coasts and a maximum of 1.8 m on the western coast. The calculated values are also below the 2.4 m threshold recommended when considering the sea level rise (SLR). This highlights the added value of performing a full integration of extreme offshore conditions, together with their dependence on hydrodynamic simulations for screening out the coastal areas potentially exposed to flooding.

A Meta-Modelling Approach for Estimating Long-Term Wave Run-Up and Total Water Level on Beaches

2018 ◽  
Vol 342 ◽  
pp. 475-489 ◽  
Author(s):  
June Gainza ◽  
Ana Rueda ◽  
Paula Camus ◽  
Antonio Tomás ◽  
Fernando J. Méndez ◽  
...  
Keyword(s):  
Water Level ◽  
Total Water ◽  
Run Up ◽  
Total Water Level ◽  
Modelling Approach

scholarly journals SYNTHESIS OP HURRICANE RESPONSE HYDROGRAPHS

1982 ◽  
Vol 1 (18) ◽  
pp. 7
Author(s):  
Rodney J. Sobey
Keyword(s):  
Water Level ◽  
Historical Data ◽  
Breaking Wave ◽  
Total Water ◽  
Coastal Site ◽  
Data Set ◽  
Storm Tide ◽  
Synthesis Technique ◽  
Astronomical Tide ◽  
Total Water Level

A hindcasting methodology is described for the total water level and wave hydrographs at a coastal site during a hurricane. It accommodates phasing of the separate components of the sustained water level (astronomical tide, storm tide, breaking wave setup) , as well as storm variability and coastal bathymetry. Complete hindcast models are utilised, but an intermediate cost and precision is achieved by compromising the number of complete hindcast storms, rather than the precision of the hindcast model. A synthesis technique is developed to predict the response hydrographs of the remaining storms in the historical data set.

scholarly journals HURRICANE WATER LEVEL PREDICTION USING SURROGATE MODELING

2018 ◽  
pp. 57
Author(s):  
Jeffrey A. Melby ◽  
Fatima Diop ◽  
Norberto Nadal-Caraballo ◽  
Alex Taflanidis ◽  
Victor Gonzalez
Keyword(s):  
Water Level ◽  
Water Levels ◽  
High Fidelity ◽  
Forward Speed ◽  
Efficient Design ◽  
Total Water ◽  
Training Set ◽  
Kriging Approach ◽  
Total Water Level ◽  
Water Level Prediction

For this study, the surrogate was constructed using kriging (Jia et al. 2015). The high fidelity coupled surge and wave numerical modelling for the Gulf of Mexico was used as the training set. The numerical model was either ADCIRC and STWAVE or ADCIRC and SWAN in the nearshore. The surrogate models were trained using tropical storm parameters (latitude, longitude, central pressure, radius to maximum wind speed, storm heading, and forward speed) at a specific location as inputs and individual responses (e.g. surge) as outputs. Tide was computed separately using ADCIRC and linearly superimposed with surge to get total water level. The regional surrogates accurately reproduced both peaks and time series of water levels for historical storms. An extensive validation was conducted to determine the optimal application of the kriging approach. In this paper we will report the efficient design-of-experiments approach, surrogate training and validation.

Application of the Spectral Nudging on Global Tides Towards a Global Total Water Level Prediction System

2019 ◽  
Author(s):  
Tsubasa Kodaira ◽  
Natacha Bernier ◽  
Keith R. Thompson
Keyword(s):  
Water Level ◽  
Coastal Flooding ◽  
Ocean Model ◽  
Global Ocean ◽  
Total Water ◽  
Spectral Leakage ◽  
Spectral Nudging ◽  
Vector Difference ◽  
Tidal Constituents ◽  
Total Water Level

Abstract With the long-term goal of developing an ensemble forecast system for coastal flooding, we are developing a dynamically-based, numerical model of the global ocean. The model is based on the NEMO framework and has been used to predict global tides and surges in previous studies. This study focuses on the optimization of the joint prediction of both tides and surges, the two main components of total water level that cause coastal flooding. To improve the predictions of the tide we use a modified form of “spectral nudging”. We show this leads to significant improvements in the prediction of the M2 tide in the open ocean, and also in the shallow regions closer to shore where the model is not nudged. The median value of the vector difference of the tidal amplitude based on sea level observations and a data-assimilative model, and the predictions of our ocean model, is reduced from 11.2 cm to 2.66 cm by the nudging. The improvement deteriorates significantly however if additional tidal constituents are included in the model (most notably S2). This is explained in terms of spectral leakage between tidal bands associated with the nudging methodology and a straightforward solution is proposed.

Hydrodynamic Study of the Impact of Extreme Flooding Events on Wastewater Treatment Plants Considering Total Water Level

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Rouzbeh Nazari ◽  
Haralambos Vasiliadis ◽  
Maryam Karimi ◽  
Md Golam Rabbani Fahad ◽  
Stanley Simon ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Water Level ◽  
Wastewater Treatment Plants ◽  
Total Water ◽  
Hydrodynamic Study ◽  
Extreme Flooding ◽  
Flooding Events ◽  
The Impact ◽  
Total Water Level

Extreme Values of Total Water Level and Total Water Velocity in the Arabian Gulf

2008 ◽  
Author(s):  
Richard A. Sproson
Keyword(s):  
Water Level ◽  
Extreme Values ◽  
Water Velocity ◽  
Total Water ◽  
Structure Variable ◽  
Wave Orbital Velocity ◽  
Mean Current ◽  
Total Water Level ◽  
Surge Height ◽  
Crest Height

PERGOS hindcast model data from the north-east coast of Qatar has been analysed in order to estimate extreme values of total water level (crest height + surge height) and total water velocity (wave orbital velocity + in-line current velocity) based on analysis of 103 storms that occurred between 1961 and 2002. The PERGOS hindcast includes significant wave height, peak period, mean wave direction, surge height, depth-mean current speed and depth-mean current direction. Crest height has been derived from the source parameters using Fugro GEOS’ proprietary EXWAN program. Wave orbital velocity has been derived using stream function theory. Extreme values of total water level and total water velocity were estimated by: (i) univariate extremal analysis of the structure variable components, (ii) univariate extremal analysis of the structure variable, and (iii) bivariate extremal analysis of the structure variable components using Fugro GEOS’ proprietary GTMFIT program. The effect of the lag between the peak wave, current and surge events on extreme values of total water level and total water velocity has also been assessed. A reduction in the 10,000-year extreme water velocity of 14–21% and a reduction in the 10,000-year extreme water level of 3–14% have been achieved using the structure variable methods.

scholarly journals The CI-FLOW Project: A System for Total Water Level Prediction from the Summit to the Sea

2011 ◽  
Vol 92 (11) ◽  
pp. 1427-1442 ◽  
Author(s):  
Suzanne Van Cooten ◽  
Kevin E. Kelleher ◽  
Kenneth Howard ◽  
Jian Zhang ◽  
Jonathan J. Gourley ◽  
...  
Keyword(s):  
Water Level ◽  
Total Water ◽  
Total Water Level ◽  
Water Level Prediction

scholarly journals Evolution of extreme Total Water Levels along the northern coast of the Iberian Peninsula

2011 ◽  
Vol 11 (2) ◽  
pp. 613-625 ◽  
Author(s):  
D. F. Rasilla Álvarez ◽  
J. C. García Codron
Keyword(s):  
Iberian Peninsula ◽  
Water Level ◽  
Sea Level ◽  
Tide Gauge ◽  
Water Levels ◽  
Northern Coast ◽  
Atmospheric Conditions ◽  
Total Water ◽  
Total Water Level

Abstract. This paper assesses the evolution of storminess along the northern coast of the Iberian Peninsula through the calculation of extreme (1%) Total Water Levels (eTWL) on both observed (tide gauge and buoy data) and hindcasted (SIMAR-44) data. Those events were first identified and then characterized in terms of oceanographic parameters and atmospheric circulation features. Additionally, an analysis of the long-term trends in both types of data was performed. Most of the events correspond to a rough wave climate and moderate storm surges, linked to extratropical disturbances following a northern track. While local atmospheric conditions seem to be evolving towards lesser storminess, their impact has been balanced by the favorable exposure of the northern coast of the Iberian Peninsula to the increasing frequency and strength of distant disturbances crossing the North Atlantic. This evolution is also correctly reproduced by the simulated long-term evolution of the forcing component (meteorological sea level residuals and wave run up) of the Total Water Level values calculated from the SIMAR 44 database, since sea level residuals have been experiencing a reduction while waves are arriving with longer periods. Finally, the addition of the rate of relative sea level trend to the temporal evolution of the atmospheric forcing component of the Total Water Level values is enough to simulate more frequent and persistent eTWL.

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