scholarly journals ARTIFICIAL ROUGHNESS IN PHYSICAL MODELS OF ESTUARIES FOR STORM SURGE INVESTIGATIONS

1980 ◽  
Vol 1 (17) ◽  
pp. 147
Author(s):  
D. Berndt ◽  
E. Giese ◽  
H. Schwarze ◽  
H.J. Vollmers
Keyword(s):  
Storm Surge ◽  
Storm Surges ◽  
Physical Models ◽  
Tidal Range ◽  
The North ◽  
Physical Model Tests ◽  
German Coast ◽  
The North Sea ◽  
Surge Protection ◽  
Autumn And Winter

One of the characteristics of the North Sea between the British Isles, the Netherlands, Germany and Denmark is the occurrence of heave storm surges especially in autumn and winter with heights of about 4 m above spring highwater. Coastal areas and especially the estuaries of the tidal rivers are hit by these storm surge events. The mean tidal range at the German coast comes to about 3 m with relatively low daily and semimonthly inequalities of less than 0.5m. Within the framework of long-term developments of the navigation channels of the estuaries as well as of the storm surge protection works, physical model tests had to be carried out in order to predict the influences of such measures on the storm surge heights to be expected.

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 Nonlinear chaotic model for predicting storm surges

2010 ◽  
Vol 17 (5) ◽  
pp. 405-420 ◽  
Author(s):  
M. Siek ◽  
D. P. Solomatine
Keyword(s):  
Storm Surge ◽  
Network Models ◽  
Storm Surges ◽  
Neural Network Models ◽  
The North ◽  
Chaotic Model ◽  
Model Predictions ◽  
The North Sea ◽  
Reconstructed Phase Space ◽  
Prediction Techniques

Abstract. This paper addresses the use of the methods of nonlinear dynamics and chaos theory for building a predictive chaotic model from time series. The chaotic model predictions are made by the adaptive local models based on the dynamical neighbors found in the reconstructed phase space of the observables. We implemented the univariate and multivariate chaotic models with direct and multi-steps prediction techniques and optimized these models using an exhaustive search method. The built models were tested for predicting storm surge dynamics for different stormy conditions in the North Sea, and are compared to neural network models. The results show that the chaotic models can generally provide reliable and accurate short-term storm surge predictions.

scholarly journals North Sea Storminess from a Novel Storm Surge Record since AD 1843*

2014 ◽  
Vol 27 (10) ◽  
pp. 3582-3595 ◽  
Author(s):  
Sönke Dangendorf ◽  
Sylvin Müller-Navarra ◽  
Jürgen Jensen ◽  
Frederik Schenk ◽  
Thomas Wahl ◽  
...  
Keyword(s):  
Storm Surge ◽  
North Sea ◽  
Decadal Variability ◽  
Storm Surges ◽  
Late Nineteenth Century ◽  
Circulation Index ◽  
The North ◽  
The North Sea ◽  
Late Nineteenth

Abstract The detection of potential long-term changes in historical storm statistics and storm surges plays a vitally important role for protecting coastal communities. In the absence of long homogeneous wind records, the authors present a novel, independent, and homogeneous storm surge record based on water level observations in the North Sea since 1843. Storm surges are characterized by considerable interannual-to-decadal variability linked to large-scale atmospheric circulation patterns. Time periods of increased storm surge levels prevailed in the late nineteenth and twentieth centuries without any evidence for significant long-term trends. This contradicts with recent findings based on reanalysis data, which suggest increasing storminess in the region since the late nineteenth century. The authors compare the wind and pressure fields from the Twentieth-Century Reanalysis (20CRv2) with the storm surge record by applying state-of-the-art empirical wind surge formulas. The comparison reveals that the reanalysis is a valuable tool that leads to good results over the past 100 yr; previously the statistical relationship fails, leaving significantly lower values in the upper percentiles of the predicted surge time series. These low values lead to significant upward trends over the entire investigation period, which are in turn supported by neither the storm surge record nor an independent circulation index based on homogeneous pressure readings. The authors therefore suggest that these differences are related to higher uncertainties in the earlier years of the 20CRv2 over the North Sea region.

scholarly journals The North Sea surge of 31 October–1 November 2006 during Storm Britta

2018 ◽  
Vol 45 ◽  
pp. 273-279 ◽  
Author(s):  
Anthony James Kettle
Keyword(s):  
The Netherlands ◽  
Storm Surge ◽  
North Sea ◽  
Tide Gauge ◽  
Storm Surges ◽  
Tide Gauge Records ◽  
The North ◽  
Short Period ◽  
The North Sea ◽  
Sea Storm

Abstract. Offshore energy infrastructure, including the petroleum and wind energy sectors, are susceptible to damage and interruption by extreme meteorological events. In northwest Europe and especially the North Sea, these extreme meteorological events are mostly associated with severe storms in the autumn and winter seasons. In the North Sea, storm surges have an impact on the offshore energy sector mainly from the flooding of port facilities and from strong ocean currents causing extra structural loading and bottom scouring. Storm Britta on 31 October–1 November 2006 was an important North Sea storm with a high surge along the coast of the Netherlands and Germany and a significant number of high wave reports. The paper presents an analysis of the national tide gauge records of the United Kingdom, the Netherlands, Germany, and Denmark to spectrally isolate and reconstruct time series components corresponding to the storm surge, semi-diurnal tide, and short period contribution. The semi-diurnal tides and storm surge during Storm Britta are tracked counter-clockwise around the North Sea from Scotland to northern Denmark. The storm surge was remarkable for its pronounced peak in the coastal area between the Netherlands and Germany with no precedent in the ∼100 year measurement record. The short period component of the tide gauge records show large oscillations during the height of the storm that may correspond with reports of unusually high waves at nearby coastal locations.

scholarly journals STORM SURGE PREDICTION IN TIDAL RIVERS: A NEW CONCEPTION

1978 ◽  
Vol 1 (16) ◽  
pp. 57
Author(s):  
Winfried Siefert
Keyword(s):  
Storm Surge ◽  
North Sea ◽  
High Tide ◽  
Storm Surges ◽  
Tidal Dynamics ◽  
The North ◽  
Highly Sensitive ◽  
Tidal Rivers ◽  
The North Sea ◽  
Warning Services

The heights of extreme storm surges in the North Sea rise up to U or 5 m above mean high tide. Warning services are established along the coast, mainly based on empirical connections between weather and tide data. A lot of wrong announcements are given especially for places up the tidal rivers. This can become disasterous for a lot of modern, highly sensitive harbour facilities. Thus storm surges are the famous plagues of the southern North Sea coast. Moreover, the "ten plagues of Germany" occurred during the last 16 years. So recently a new conception for storm surge prediction in tidal rivers was developed - with the result of a lot of new understandings of tidal dynamics in rivers (SIEFERT, 1968). We investigated about 130 storm surges, hindcasting all of them and forecasting about 20 of them, and analysed their behaviour in tidal rivers. Now we are able to forecast the upstream heights and even the shape of the surge curve in the Elbe with an accuracy of ± 2 dm, ' 6 hours in advance.

scholarly journals A NOVEL HIGH-RESOLUTION STORM SURGE FORECAST FOR THE GERMAN BIGHT

2018 ◽  
pp. 80
Author(s):  
Sebastian Niehüser ◽  
Sönke Dangendorf ◽  
Arne Arns ◽  
Jürgen Jensen
Keyword(s):  
Storm Surge ◽  
High Frequency ◽  
State Of The Art ◽  
Tide Gauge ◽  
Storm Surges ◽  
Weather Forecast ◽  
The North ◽  
The North Sea ◽  
Numerical Weather Forecast ◽  
Model Output Statistics

Storm surges are one of the most dangerous natural hazards in coastal areas and have the ability to cause great damages including fatalities. To be prepared when another storm surge hits the coast, reliable storm surge forecasts are indispensable. Storm surge warnings are routinely provided for selected tide gauge locations along a coastline through state-of-the-art forecast systems. In Germany, the Federal Maritime and Hydrographic Agency (BSH) (in cooperation with the German Weather Service (DWD)) have the responsibility for storm surge forecasts and warnings along the German North and Baltic Sea coastlines. The operational system in place for the North Sea consists of numerical weather forecast systems, a surge model and model output statistics. It provides accurate high frequency water level forecasts up to six days ahead at selected tide gauge sites (Müller-Navarra and Knüpfer, 2010), but not for the coastline in between. Spatial forecasts are, however, currently not available for two reasons: first, the shallow coast with complex morphological structures leads to strong non-linearities between individual sites hampering simple interpolation schemes (Arns et al. 2015). Second, tidal predictions are limited to tide gauge locations, which do not fall dry during low tide, since the traditional estimation of tidal coefficients requires complete time series covering both low and high waters.

The Environmental Effects of Flood Control in the Yare Basin

1984 ◽  
Vol 16 (3-4) ◽  
pp. 477-484
Author(s):  
H L Wakeling
Keyword(s):  
Flood Control ◽  
Storm Surges ◽  
Poor Quality ◽  
Grazing Land ◽  
Flood Prevention ◽  
Scenic Beauty ◽  
The North ◽  
Economic Justification ◽  
The North Sea ◽  
Improved Pasture

The paper reviews various methods of flood control in the lower Yare Basin which has been subject to serious flooding caused by storm surges in the North Sea and by fluvial floods. This area is known as the Broads and is an area of scenic beauty, includes many sites of scientific interest and is a popular tourist area. The effects of the different flood control options on the environment are discussed. The primary economic justification for flood prevention was found to arise from the conversion of poor quality marsh grazing land to arable or improved pasture once the risk of saline flooding was removed. The consequences of this change in land use on the flora and fauna have aroused much concern among environmentalists.

Storm surges in the North Sea during the winter 1953-4

1956 ◽  
Vol 235 (1201) ◽  
pp. 260-274 ◽  
Keyword(s):  
Sea Level ◽  
North Sea ◽  
Storm Surges ◽  
Rate Of Change ◽  
The North ◽  
Order Of Magnitude ◽  
The North Sea ◽  
Sea Ports ◽  
Phase Angles

Records of sea level for several North Sea ports for the winter of 1953-4 have been in vestigated. They were split into 14-day intervals, and each 14-day record was Fourieranalyzed to determine if any non-astronomical periods were present. There was evidence of some activity between 40 and 50 h period, and a determination of the phase angles at different ports showed that the activity could be due to a disturbance travelling southwards from the north of the North Sea. The disturbance was partly reflected somewhere near the line from Lowestoft to Flushing, so that one part returned past Flushing and Esbjerg towards Bergen while the other part travelled towards Dover, and there was evidence of its existence on the sea-current records taken near St Margaret's Bay. These results were confirmed by subtracting the predicted astronomical tidal levels from the observed values of sea level and cross-correlating the residuals so obtained for each port with those found at Lowestoft. The residuals at Lowestoft and Aberdeen were compared with the meteorological conditions, and it was found that, although they could be attributed to a large extent to conditions within the North Sea, there was an additional effect due to a travelling surge which was of the same order of magnitude at both Lowestoft and Aberdeen and which was closely related to the rate of change with time of the atmospheric pressure difference between Wick and Bergen.

Sign in / Sign up

Export Citation Format

Share Document