Storm Surges and River Flooding Bangladesh: A Rising Challenge in a Changing Global Climate

1996 ◽  
pp. 113-138 ◽  
Author(s):  
Selina Begum
Author(s):  
Yasser Hamdi ◽  
Emmanuel Garnier ◽  
Nathalie Giloy ◽  
Claire-Marie Duluc ◽  
Vincent Rebour

Abstract. This paper aims to demonstrate the technical feasibility of a historical study devoted to French Nuclear Power Plants (NPPs) which can be prone to the extreme marine flooding events. It has been shown in the literature that the use of HI can significantly improve the probabilistic and statistical modeling of extreme events. There is a significant lack of historical data about marine flooding (storms and storm surges) compared to river flooding events. To address this data scarcity and to improve the estimation of the risk associated to the marine flooding hazards, a dataset of historical storms and storm surges that hit the Nord-Pas-de-Calais region during the five past centuries were recovered from archival sources, examined and used in a frequency analysis (FA) in order to assess its impact on the frequency estimations. This work on the Dunkirk site (representative of the Gravelines NPP) is a continuation of previous work performed on the La Rochelle site in France. Indeed, the frequency model (FM) used in the present paper had some success in the field of coastal hazards and it has been applied in previous studies to surge datasets to prevent marine flooding in the La Rochelle region in France. In a first step, only information collected from the literature (published reports, journal papers and PhD theses) is considered. A 1954 Coastal Engineering journal issue (Le Gorgeu and Guitonneau, 1954) on the reconstruction of the eastern dyke in Dunkirk has been more than a reference for this paper. It has indeed served as a main source of historical information (HI) in this study. Although this first historical dataset has extended the gauged record back in time to 1897, serious questions related to the exhaustiveness of the information and about the validity of the developed FM have remained unanswered. Additional qualitative and quantitative HI were extracted in a second step from many older archival sources. This work has led to the construction of storms and marine flooding sheets summarizing key data on each identified event. The quality control and the cross-validation of the collected information, which have been carried out systematically, indicate that it is valid and complete as regards extreme storms and storm surges. Most of the HI gathered displays a good agreement with other archival sources and documentary climate reconstructions. The probabilistic and statistical analysis of a dataset containing an exceptional observation considered as an outlier (i.e. the 1953 storm surge) has been significantly improved when the additional HI gathered in both literature and archives are used. As the historical data tend to be extreme, the right tail of the distribution has been reinforced and the 1953 exceptional event don't appear as an outlier any more. This new dataset provides a valuable source of information on storm surges for future characterization of coastal hazards.


Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 369-378 ◽  
Author(s):  
A. Sterl ◽  
H. van den Brink ◽  
H. de Vries ◽  
R. Haarsma ◽  
E. van Meijgaard

Abstract. The height of storm surges is extremely important for a low-lying country like The Netherlands. By law, part of the coastal defence system has to withstand a water level that on average occurs only once every 10 000 years. The question then arises whether and how climate change affects the heights of extreme storm surges. Published research points to only small changes. However, due to the limited amount of data available results are usually limited to relatively frequent extremes like the annual 99%-ile. We here report on results from a 17-member ensemble of North Sea water levels spaning the period 1950–2100. It was created by forcing a surge model of the North Sea with meteorological output from a state-of-the-art global climate model which has been driven by greenhouse gas emissions following the SRES A1b scenario. The large ensemble size enables us to calculate 10 000 year return water levels with a low statistical uncertainty. In the one model used in this study, we find no statistically significant change in the 10 000 year return values of surge heights along the Dutch during the 21st century. Also a higher sea level resulting from global warming does not impact the height of the storm surges. As a side effect of our simulations we also obtain results on the interplay between surge and tide.


2019 ◽  
Vol 54 (1-2) ◽  
pp. 1007-1021 ◽  
Author(s):  
Job C. M. Dullaart ◽  
Sanne Muis ◽  
Nadia Bloemendaal ◽  
Jeroen C. J. H. Aerts

Abstract This study examines the implications of recent advances in global climate modelling for simulating storm surges. Following the ERA-Interim (0.75° × 0.75°) global climate reanalysis, in 2018 the European Centre for Medium-range Weather Forecasts released its successor, the ERA5 (0.25° × 0.25°) reanalysis. Using the Global Tide and Surge Model, we analyse eight historical storm surge events driven by tropical—and extra-tropical cyclones. For these events we extract wind fields from the two reanalysis datasets and compare these against satellite-based wind field observations from the Advanced SCATterometer. The root mean squared errors in tropical cyclone wind speed reduce by 58% in ERA5, compared to ERA-Interim, indicating that the mean sea-level pressure and corresponding strong 10-m winds in tropical cyclones greatly improved from ERA-Interim to ERA5. For four of the eight historical events we validate the modelled storm surge heights with tide gauge observations. For Hurricane Irma, the modelled surge height increases from 0.88 m with ERA-Interim to 2.68 m with ERA5, compared to an observed surge height of 2.64 m. We also examine how future advances in climate modelling can potentially further improve global storm surge modelling by comparing the results for ERA-Interim and ERA5 against the operational Integrated Forecasting System (0.125° × 0.125°). We find that a further increase in model resolution results in a better representation of the wind fields and associated storm surges, especially for small size tropical cyclones. Overall, our results show that recent advances in global climate modelling have the potential to increase the accuracy of early-warning systems and coastal flood hazard assessments at the global scale.


2015 ◽  
Vol 18 (3) ◽  
pp. 288-307 ◽  
Author(s):  
Tracey Skillington

Storm surges, flooding, heatwaves, and prolonged drought, as ever more regular features of life under deteriorating climate conditions, are unmistakably violent. Their effects on the lives of vulnerable human populations and ecosystems across the world are widely known to be devastating. Yet a legal order that denies the victims of such ecological persecution safe haven, no matter how great its use of force (e.g., detention, arrest, forced return) cannot, by definition, be violent. The power of law, used to protect states’ rights to exclude from their jurisdictions growing numbers displaced involuntarily by global climate harms, in being a source of ‘legitimate right’, is never the same as violence. This article challenges the ongoing validity of this assumption. It points to some of the ways in which legal instruments are used today to deny those displaced by climatic conditions sufficient normative status to guarantee their safety. What is needed instead is a new critical normative understanding of the evolving relationship between climate change, violence, justice, and law, one that re-assesses the democratic justificatory grounds for the current positions of non-responsibility for the climate displaced whilst re-affirming such people’s legal and political status as equal co-members of the politically constituted international community of humanity.


2014 ◽  
Vol 11 (7) ◽  
pp. 8537-8569 ◽  
Author(s):  
P. A. Dirmeyer ◽  
G. Fang ◽  
Z. Wang ◽  
P. Yadav ◽  
A. D. Milton

Abstract. Results from ten global climate change models are synthesized to investigate changes in extremes, defined as wettest and driest deciles in precipitation, soil moisture and runoff based on each model's historical twentieth century simulated climatology. Under a moderate warming scenario, regional increases in drought frequency are found with little increase in floods. For more severe warming, both drought and flood become much more prevalent, with nearly the entire globe significantly affected. Soil moisture changes tend toward drying while runoff trends toward flood. To determine how different sectors of society dependent the on various components of the surface water cycle may be affected, changes in monthly means and interannual variability are compared to data sets of crop distribution and river basin boundaries. For precipitation, changes in interannual variability can be important even when there is little change in the long-term mean. Over 20% of the globe is projected to experience a combination of reduced precipitation and increased variability under severe warming. There are large differences in the vulnerability of different types of crops, depending on their spatial distributions. Increases in soil moisture variability are again found to be a threat even where soil moisture is not projected to decrease. The combination of increased variability and greater annual discharge over many basins portends increased risk of river flooding, although a number of basins are projected to suffer surface water shortages.


2021 ◽  
Author(s):  
◽  
Shivani Patel

<p><b>Science tells us that we are close to the irreversible tipping point into an unknown climate of the Anthropocene in which humanity has no option but to adapt or to be destroyed. Human influence is changing the earth and a major factor is urbanisation. Cities are one of the largest contributors to global climate change.</b></p> <p>This thesis develops a design-led research methodology and approach that develops alternative, speculative landscape intervention strategies to bridge the gap between climate change science and the landscape and the residents of Island Bay, in the city of Wellington, New Zealand. This research aims to take full advantage of new technologies and systems to provide resilient social, ecological and physical solutions for the coastal neighbourhood in the face of climate-related change. These solutions form a comprehensive framework and tools that anticipate a foreseeable future of saturated landscapes. It is a strategy that builds the adaptive capacity of the coastal zone, enhances existing natural systems, accommodates a variety of best coastal management practices and integrates alternative concepts in the coastal neighbourhood adaptation management plan.</p> <p>These solutions address the unpredictable issue of rising sea levels, storm surges and coastal inundation. In addition, the approach fosters urban environment solutions at various scales, such what a property owner can do and what public/private cooperation can do. Overall, this new integrated system approach has the potential to recalibrate urban coastal environments, catalyse resiliency and provide a robust model for designing mitigative, adaptative coastal communities in response to rising sea-levels and to support a new set of relationships between nature and urbanity.</p>


Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2251
Author(s):  
Yeon-joong Kim ◽  
Tea-woo Kim ◽  
Jong-sung Yoon

The coastal area of Japan has been damaged yearly by storm surges and flooding disasters in the past, including those associated with typhoons. In addition, the scale of damage is increasing rapidly due to the changing global climate and environment. As disasters due to storm surges become increasingly unpredictable, more measures should be taken to prevent serious damage and casualties. The Japanese government published a hazard map manual in 2015 and obligates the creation of a hazard map based on a parametric model as a measure to reduce high-scale storm surges. Parametric model (typhoon model) accounting for the topographical influences of the surroundings is essential for calculating the wind field of a typhoon. In particular, it is necessary to calculate the wind field using a parametric model in order to simulate a virtual typhoon (the largest typhoon) and to improve the reproducibility. Therefore, in this study, the aim was to establish a hazard map by assuming storm surges of the largest scale and to propose a parametric model that considers the changing shape of typhoons due to topography. The main objectives of this study were to analyze the characteristics of typhoons due to pass through Japan, to develop a parametric model using a combination of Holland’s and Myers’s models that is appropriate for the largest scale of typhoon, and to analyze the parameters of Holland’s model using grid point values (GPVs). Finally, we aimed to propose a method that considers the changing shape of typhoons due to topography. The modeling outcomes of tide levels and storm surge heights show that the reproduced results obtained by the analysis method proposed in this study are more accurate than those obtained using GPVs. In addition, the reproducibility of the proposed model was evaluated showing the high and excellent reproducibility of storm surge height according to the geographic characteristics.


2008 ◽  
Vol 113 (D11) ◽  
Author(s):  
B. Decharme ◽  
H. Douville ◽  
C. Prigent ◽  
F. Papa ◽  
F. Aires

2013 ◽  
Vol 13 (8) ◽  
pp. 2017-2029 ◽  
Author(s):  
S. F. Kew ◽  
F. M. Selten ◽  
G. Lenderink ◽  
W. Hazeleger

Abstract. The low-lying Netherlands is at risk from multiple threats of sea level rise, storm surges and extreme river discharges. Should these occur simultaneously, a catastrophe will be at hand. Knowledge about the likelihood of simultaneous occurrence or the so-called "compound effect" of such threats is essential to provide guidance on legislation for dike heights, flood barrier design and water management in general. In this study, we explore the simultaneous threats of North Sea storm surges and extreme Rhine river discharge for the current and future climate in a large 17-member global climate model ensemble. We use a simple approach, taking proxies of north-northwesterly winds over the North Sea and multiple~day precipitation averaged over the Rhine basin for storm surge and discharge respectively, so that a sensitivity analysis is straightforward to apply. By investigating soft extremes, we circumvent the need to extrapolate the data and thereby permit the model's synoptic development of the extreme events to be inspected. Our principle finding based on the climate model data is that, for the current climate, the probability of extreme surge conditions following extreme 20-day precipitation sums is around 3 times higher than that estimated from treating extreme surge and discharge probabilities as independent, as previously assumed. For the future climate (2070–2100), the assumption of independence cannot be rejected, at least not for precipitation sums exceeding 7 days.


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