scholarly journals INVESTIGATIONS OF THE TIDES AND STORM SURGES FOR THE DELTAWORKS IN THE SOUTHWESTERN PART OF THE NETHERLANDS

2011 ◽  
Vol 1 (7) ◽  
pp. 32
Author(s):  
J.J. Dronkers
Keyword(s):  
The Netherlands ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Southwestern Part ◽  
Delta Area ◽  
Free Discharge ◽  
Tidal Movement ◽  
Very High ◽  
Fresh Water Lake

In order to protect the southwestern part of the Netherlands against inundation by storm surges, the "Delta project" has been undertaken. This entails the closure of three large sea arms situated between Western Scheldt and Rotterdam Waterway and will bring about radical changes in the tidal movement and stormflood levels of the estuaries and tidal rivers. The contours of the project are shown in fig. 1. It includes three big dams to be built in the mouths of Eastern Scheldt, Brouwershavense Gat and Haringvliet, as well as two smaller ones to be constructed further inland. An idea of the extent of these works may be gained by knowing the tidal volumes of the estuaries: Veerse Gat 2.5.109 cu. ft; Grevelingen 4.109 cu. ft? Haringvliet 9.109 cu. ft; Brouwershavense Gat 12,5.109 cu. ft and Eastern Scheldt 39>.109 ou.ft. The waters of the Delta area will then be divided into two separate basins by means of a dam in the Volkerak. The southern basin will be entirely cut off from the sea, becoming a fresh water lake. The northern, comprising the mouths of the Rhine and the Meuse will remain in communication with the sea, because the Rotterdam Waterway must stay open to shipping. Consequently, the tides and storm surges will still be able to penetrate inland via this mouth, but they can cause high water levels in the Waterway only; in the rest of the basin their effect will be considerably weakened. In the situation at present, however, the upland flow of the rivers Rhine and Meuse is mainly into the Haringvliet estuary and not the Rotterdam Waterway. As the Haringvliet estuary will be closed, large sluices are to be built in the enclosure dam as a substitute for the existing free discharge of the river water. Until this project is completed the inhabitants of the area which it will affect are insufficiently safe against storm surges. It is, of course, always possible that floods too high for existing dike systems will occur, but in the present situation the risk is too great. This was demonstrated in February 1953 when the southwestern part of the Netherlands was suddenly hit by an exceptionally high storm surge which caused many dike breaches and vast inundation. The occurrence of a similar surge or a higher one may be estimated as once in two hundred and fifty years, as an average, which is much too high. After the realization of the Deltaplan and the heightening of the dikes of Western Scheldt, Rotterdam Waterway and the northern parts of the country, the dikes are safe tip to very high storm surges of which the occurrence is smaller than once in ten thousand years, or in other words there is only one procent chance in hundred years that a major inundation will occur.

scholarly journals PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 261-266
Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  
Keyword(s):  
Management Practices ◽  
Morphological Changes ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Airborne Lidar ◽  
Coastline Change ◽  
The Mean ◽  
The Impact

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>

scholarly journals Role of intertidal wetlands for tidal and storm tide attenuation along a confined estuary: a model study

2015 ◽  
Vol 3 (5) ◽  
pp. 3181-3224 ◽  
Author(s):  
S. Smolders ◽  
Y. Plancke ◽  
S. Ides ◽  
P. Meire ◽  
S. Temmerman
Keyword(s):  
Surface Area ◽  
Wave Attenuation ◽  
Spring Tide ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Storm Tide ◽  
Flood Risks ◽  
Model Study

Abstract. Coastal lowlands and estuaries are subjected to increasing flood risks during storm surges due to global and regional changes. Tidal wetlands are increasingly valued as effective natural buffers for storm surges by dissipating wave energy and providing flood water storage. While previous studies focused on flood wave attenuation within and behind wetlands, this study focuses on the effects of estuarine wetland properties on the attenuation of a storm tide that propagates along the length of an estuary. Wetland properties including elevation, surface area, and location within the estuary were investigated using a numerical model of the Scheldt estuary (Belgium, SW Netherlands). For a spring tide lower wetland elevations result in more attenuation of high water levels along the estuary, while for a higher storm tide higher elevations provide more attenuation compared to lower wetland elevations. For spring and storm tide a arger wetland surface area results in a better attenuation along the estuary up to a threshold wetland size for which larger wetlands do not further contribute to more attenuation. Finally a wetland of the same size and elevation, but located more upstream in the estuary, can store a larger proportion of the local flood volume and therefore has a larger attenuating effect on upstream high water levels. With this paper we aim to contribute towards a better understanding and wider implementation of ecosystem-based adaptation to increasing estuarine flood risks associated with storms.

scholarly journals THE DUTCH PROGRAM OF INVESTIGATIONS ON STORM SURGES IN THE NORTH SEA

2011 ◽  
Vol 1 (5) ◽  
pp. 34
Author(s):  
J. B. Schijf
Keyword(s):  
The Netherlands ◽  
North Sea ◽  
Storm Surges ◽  
Water Levels ◽  
Wind Effects ◽  
Shallow Sea ◽  
The North ◽  
The North Sea ◽  
Western Germany ◽  
North Western

The North Sea is a shallow sea and therefore it is very sensitive to wind effects. As a result the water levels along the coasts are, in addition to the tidal oscillations subject to a considerable wind setup and exceptionally severe gales throughout history have been accompanied by inundations of the low-lying regions bordering the North Sea, in particular its southern part. No stretch of coast has suffered more than that belonging to the Netherlands and the adjacent parts of Belgium and North Western Germany. Several factors combine to bestow on us this doubtful privilege.

scholarly journals ADJUSTMENT AND VERIFICATION OF THE RANDDELTA II MODEL

1978 ◽  
Vol 1 (16) ◽  
pp. 61
Author(s):  
A. Langerak ◽  
M.A.M. De Ras ◽  
J.J. Leendertse
Keyword(s):  
The Netherlands ◽  
North Sea ◽  
Sand Dunes ◽  
Storm Surges ◽  
Water Levels ◽  
Tidal Marshes ◽  
Tidal Range ◽  
Offshore Area ◽  
The North ◽  
The North Sea

In the mid-1950s the Netherlands government embarked on a massive construction program, called the Delta Plan. Its purpose was to enhance protection from floods caused by the North Sea in the estuaries of the Rhine, Meuse and Scheldt. According to the plan, all connections to the sea were to be closed by dams, except the New Waterway to Rotterdam and the Western Scheldt. In 1974 all dams and dikes were complete except the dam closing off the Eastern Scheldt from the sea. In view of growing opposition to a complete closure, plans were revised in 1976, and instead of the dam, a storm surge barrier will be constructed. This barrier will reduce the tidal range in the Eastern Scheldt and will be closed during storm surges. In support of engineering and environmental studies related to the construction and operation of this barrier, a large numerical model has been developed, which covers the Eastern and Western Scheldt and the adjacent offshore area. The section of the North Sea which is included in the model is about 120 km long and 30 km wide, running from Blankenberghe in Belgium to Scheveningen in the Netherlands (Fig. 1). The bathymetry of the model area varies widely. In general it slopes from the shore to about 25 m at 30 km from the coast. In certain sections of the offshore area, the bottom is relatively flat; in other areas it has offshore bars and the bottom contains underwater sand dunes with a height of several meters. In the estuaries the tidal flow has scoured deep channels. The tidal flats near the North Sea are generally sandy, but the ecologically important tidal marshes located more inland contain much finer material. The flow and the water levels in the region which is modeled are generally tide-induced. However, the influence of meteorological effects is always present and sometimes dominates water movements and water levels (storm surges). The influence of the fresh water discharges is of much less importance; generally their effects can only be noticed in the immediate vicinity of the discharge. The tides in the offshore area of the model are part of the complicated tide system in the North Sea. The semidiurnal tidal wave propagates along the coast in a northeasterly direction. During this propagation the amplitude reduces from about 1.90 m near Blankenberghe to about .85 m near Scheveningen.

scholarly journals STORM SURGE FORECASTING METHODS IN ENCLOSED SEAS

1978 ◽  
Vol 1 (16) ◽  
pp. 58
Author(s):  
P.F. Hamblin
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Storm Surges ◽  
High Water ◽  
Computational Effort ◽  
Water Levels ◽  
Large Lakes ◽  
Forecasting Methods ◽  
The Stability ◽  
Storm Surge Forecasting

Storm surges in enclosed seas although generally not as large in amplitude as their oceanic counterparts are nonetheless of considerable importance when low lying shoreline profiles, shallow water depth, and favourable geographical orientation to storm winds occur together. High water may result in shoreline innundation and in enhanced shoreline erosion. Conversely low water levels are hazardous to navigation. The purpose of this paper is to discuss the problem of storm surge forecasting in enclosed basins with emphasis on automated operational procedures. In general, operational forecasting methods must be based on standard forecast parameters, require a minimum of computational effort in the preparation of the forecast, must be applicable to lakes of different geometry and to any point on the shore, and to be able to resolve water level changes on an hourly basis to 10 cm in the case of high water level excursions associated with large lakes and less than that for smaller lakes. Particular physical effects arising in lakes which make these constraints difficult to fulfill are the reflections of resurgences of water levels arising from lateral boundaries, the stability of the atmospheric boundary layer and the presence of such subsynoptic disturbances as squall lines and travelling pressure jumps.

scholarly journals Flood and drought risk assessment for agricultural areas (Tagus Estuary, Portugal)

2021 ◽  
Author(s):  
Paula Freire ◽  
Marta Rodrigues ◽  
André B. Fortunato ◽  
Alberto Freitas
Keyword(s):  
Risk Assessment ◽  
Local Level ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Tagus Estuary ◽  
Risk Level ◽  
Drought Risk ◽  
Local Conditions ◽  
Agricultural Areas

Abstract. Estuaries are coastal systems particularly vulnerable to climate change effects and within these systems, agriculture is one of the most potentially affected sectors. This paper proposes a risk assessment approach for helping the decision-making process at a local level, addressing two risks that affect agricultural areas located in estuarine margins: the unavailability of fresh water for irrigation resulting from the upstream propagation of estuarine brackish water during droughts, and land inundation by high water levels associated with high tides and storm surges. For each risk, quantitative consequence descriptors are presented to support risk level determination and evaluation through a continuous consequence/probability diagram. The approach applicability is discussed through its application to the Lezíria Grande de Vila Franca de Xira, located in the Tagus Estuary (Portugal). Results indicate that the approach is appropriate to support risk owners in taking actions to mitigate the risk. The flexibility of the approach to be adapted to local conditions and updated through time, and the ease of its application by the risk owner can be pointed out as the main strengths.

scholarly journals Storm Surge Assessment Methodology Based on Numerical Modelling

10.29007/hrlw ◽  
2018 ◽  
Author(s):  
Lara Santos ◽  
Mariana Gomes ◽  
Luis Vieira ◽  
José Pinho ◽  
José Antunes Do Carmo
Keyword(s):  
Numerical Modelling ◽  
Storm Surge ◽  
Storm Surges ◽  
High Water ◽  
Automatic Generation ◽  
Water Levels ◽  
Tropical Storms ◽  
Assessment Methodology ◽  
Coastal Zones ◽  
Generation Procedure

Coastal zones face severe weaknesses and high-risk situations due to coastal threats like erosion and storms and due to an increasing intensive occupation. Tropical storms events can contribute to the occurrence of these situations, by causing storm surges with high water levels and, consequently, episodes of waves overtopping and coastal flooding. This work aims to describe a methodology to estimate the storm surge occurrences in the Portuguese coastal zone, recurring to historical tropical storms data that occurred in the vicinity of Portugal and to numerical modeling of its characteristics. Delft3D software together with DelfDashboard tools were applied for the numerical modelling. An automatic generation procedure of storms was implemented based on the few available historical storms data characteristics. Obtained results allows to characterize storm surges along the Portuguese coast, identifying the most vulnerable areas and, consequently contributing for its proper planning and management.

scholarly journals Upriver sightings of beluga whales (Delphinapterus leucas) follow storm surges and high water in the Mackenzie Delta, Northwest Territories, Canada

2020 ◽  
pp. 1-11
Author(s):  
Kevin C. Scharffenberg ◽  
Shannon A. MacPhee ◽  
Lisa L. Loseto
Keyword(s):  
Monitoring Program ◽  
River Estuary ◽  
Storm Surges ◽  
High Water ◽  
Small Sample ◽  
Water Levels ◽  
River Delta ◽  
Delphinapterus Leucas ◽  
Beluga Whales ◽  
Mackenzie River

Each summer, Eastern Beaufort Sea beluga whales (Delphinapterus leucas (Pallas, 1776)) form a large congregation in the Tarium Niryutait Marine Protected Area (TNMPA) in the Mackenzie River estuary, a behaviour thought to be linked to warm, freshwater conditions. In 2018, >50 belugas were observed upriver near Aklavik in the Mackenzie River Delta. Community members noted that this upriver occurrence of belugas was unusual and suggested that wind-driven high water levels in the Mackenzie River were a primary driver. We investigated this explanation by searching past communications and reports for documentation of beluga sightings upriver and identifying storm surges and water-level changes at six hydrometric stations in the Mackenzie River Delta. We found three previous occurrences of belugas upriver dating back to 2000, all of which followed prominent surges in river level attributable to coastal storms. Although acknowledging a small sample size, we suggest that upriver occurrences of beluga whales warrant further investigation through extension of the TNMPA beluga monitoring program. As climate-driven changes cause more frequent and intense Arctic storm surges, we expect storm events to increasingly overlap with the annual summer beluga congregation. This may cause upriver movements to become more common, and population-level implications are not known.

scholarly journals 300 years of coastal salinization research in Germany – the Homann (1718) map of the Christmas Flood of 1717

2018 ◽  
Vol 54 ◽  
pp. 00011
Author(s):  
Georg J. Houben
Keyword(s):  
The Netherlands ◽  
Agricultural Land ◽  
High Tide ◽  
High Water ◽  
Water Levels ◽  
The North ◽  
The North Sea ◽  
The Mean ◽  
The Village ◽  
Two Sides

The Christmas Flood of 1717 was one of the most destructive storm floods in the North Sea region and affected large parts of the shores of Germany, the Netherlands and Germany (e.g. Jakubowski-Tiessen 1992). It occurred in the night from the 24th to the 25th of December 1717, when a strong northwesterly storm front pushed massive volumes of water into the funnel-shaped German Bight. Adding to the astronomical high tide occurring this night, water levels rose up to 4 m higher than the mean tidal high water mark. This lead to widespread overtopping and breaching of the dikes, which had been neglected in the preceding years due to extended periods of war and unrest. Since the event happened at night, the population was unable to react. About 9,000 people in Germany lost their lives and around 2,500 in the Netherlands. The small German town of Jever alone lost 1,700 people. In the village of Stollhamm, located on the peninsula of Butjadingen, which was exposed to the flood from two sides, 582 out of a population of 1,200 perished and only a third of the houses were not destroyed. In Eastern Frisia, 922 houses were completely destroyed and 1,672 damaged. In all of the affected regions in Germany, at least 3,000 houses were completely destroyed. Agriculture was severely affected by the salinization of large tracts of agricultural land and the loss of 2,300 horses, 9,500 cows, 2,800 sheep and 1,800 pigs was recorded in Eastern Frisia. In the following years, famines and epidemic plagues took a further toll on the population. Many people emigrated. It took several decades to reconstruct the dikes and to restore the livelihoods of the population.

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