scholarly journals NATIONAL SCALE MULTI-HAZARD MODEL PLATFORM FOR EXTREME CYCLONE IMPACTS ON COASTS AND INFRASTRUCTURE

2018 ◽  
pp. 105
Author(s):  
David Taylor ◽  
Joanna Aldridge ◽  
Jarrod Dent ◽  
Jim Churchill
Keyword(s):  
Storm Surge ◽  
Extreme Event ◽  
Hazard Model ◽  
Model System ◽  
Process Models ◽  
Long Duration ◽  
Hazard And Risk ◽  
Australian Coastline ◽  
Model Platform ◽  
Short Time

Extreme event impacts on coastlines and infrastructure is often driven by a combination of processes and factors. In cyclone (hurricane) prone coastlines, wind, rain, storm surge, tide and waves can all contribute to damage and loss of infrastructure. With increasing value of coastal assets, hazard and risk management is increasingly assessing multi-hazard impacts from extreme events, and cumulative damage from multiple events within short time frames. A novel multi-hazard model system has been developed to assess cyclone hazards on the Australian coastline from a combination of wind, rain, tide, storm surge and wave impacts. The model system is capable of deriving return period hazard levels for single and combined hazards, and also long-duration, for example 10,000 year duration, event sets to analyze cumulative impacts. The hazard model system is comprised of high-resolution, calibrated process models addressing the various physical processes that contribute to the overall hazard.

Towards Control of an Estuary

1987 ◽  
Vol 19 (9) ◽  
pp. 155-174
Author(s):  
Henk L. F. Saeijs
Keyword(s):  
Shallow Water ◽  
Storm Surge ◽  
Salt Marshes ◽  
Large Scale ◽  
Western Europe ◽  
Oxygen Depletion ◽  
Negative Effects ◽  
Intertidal Flats ◽  
Environmental Consequences ◽  
Short Time

The Delta Project is in its final stage. In 1974 it was subjected to political reconsideration, but it is scheduled now for completion in 1987. The final touches are being put to the storm-surge barrier and two compartment dams that divide the Oosterschelde into three areas: one tidal, one with reduced tide, and one a freshwater lake. Compartmentalization will result in 13% of channels, 45% of intertidal flats and 59% of salt marshes being lost. There is a net gain of 7% of shallow-water areas. Human interventions with large scale impacts are not new in the Oosterschelde but the large scale and short time in which these interventions are taking place are, as is the creation of a controlled tidal system. This article focusses on the area with reduced tide and compares resent day and expected characteristics. In this reduced tidal part salt marshes will extend by 30–70%; intertidal flats will erode to a lower level and at their edges, and the area of shallow water will increase by 47%. Biomass production on the intertidal flats will decrease, with consequences for crustaceans, fishes and birds. The maximum number of waders counted on one day and the number of ‘bird-days' will decrease drastically, with negative effects for the wader populations of western Europe. The net area with a hard substratum in the reduced tidal part has more than doubled. Channels will become shallower. Detritus import will not change significantly. Stratification and oxygen depletion will be rare and local. The operation of the storm-surge barrier and the closure strategy chosen are very important for the ecosystem. Two optional closure strategies can be followed without any additional environmental consequences. It was essential to determine a clearly defined plan of action for the whole area, and to make land-use choices from the outset. How this was done is briefly described.

Relocatable Tide Prediction and Storm Surge Forecasting

2018 ◽  
Author(s):  
Thomas Prime
Keyword(s):  
Sea Level ◽  
Storm Surge ◽  
Marine Environment ◽  
Agricultural Land ◽  
Extreme Event ◽  
Negative Impact ◽  
Early Warning Systems ◽  
Coastal Communities ◽  
Prevention Measures ◽  
Storm Surge Forecasting

The marine environment represents a large and important resource for communities around the world. However, the marine environment increasingly presents hazards that can have a large negative impact. One important marine hazard results from storms and their accompanying surges. This can lead to coastal flooding, particularly when surge and astronomical high tides align, with resultant impacts such as destruction of property, saline degradation of agricultural land and coastal erosion. Where tide and storm surge information are provided and accessed in a timely, accurate and understandable way, the data can provide: 1. Evidence for planning: Statistics of past conditions such as the probability of extreme event occurrence can be used to help plan improvements to coastal infrastructure that are able to withstand and mitigate the hazard from a given extreme event. 2. Early warning systems: Short term forecasts of storm surge allow provide early warnings to coastal communities enabling them to take actions to allow them to withstand extreme events, e.g. deploy flood prevention measures or mobilise emergency response measures. Data regarding sea level height can be provided from various in-situ observations such as tide gauges and remote observations such as satellite altimetry. However, to provide a forecast at high spatial and temporal resolution a dynamic ocean model is used. Over recent decades the National Oceanography Centre has been a world leading in developing coastal ocean models. This paper will present our progress on a current project to develop an information system for the Madagascan Met Office. The project, C-RISC, being executed in partnership with Sea Level Research Ltd, is translating the current modelling capability of NOC in storm surge forecasting and tidal prediction into a system that will provide information that can be easily transferred to other regions and is scalable to include other hazard types The outcome, an operational high-resolution storm surge warning system that is easy to relocate, will directly benefit coastal communities, giving them information they need to make effective decisions before and during extreme storm surge events.

scholarly journals Observations of High-Frequency Activity of EV Lacertae

1995 ◽  
Vol 151 ◽  
pp. 82-84
Author(s):  
B.E. Zhilyaev ◽  
I.A. Verlyuk
Keyword(s):  
High Frequency ◽  
Sudden Onset ◽  
X Rays ◽  
Long Duration ◽  
Cataclysmic Binaries ◽  
Wide Range ◽  
Classical Models ◽  
Low Mass ◽  
Ev Lac ◽  
Short Time

The flare star EV Lac shows a wide variety of activity phenomena on a wide range of time scales. These are the well-known “classical” solar-like flares, the short-time flare events (Gershberg & Petrov 1986, Karapetian & Zalinian 1991, Tovmassian & Zalinian 1988, Tsvetkov et al. 1986, Zhilyaev 1994), and the long-duration variations caused by starspots and rotation (Petterson 1980). However, the “classical” flares are not such a frequent phenomenon as one gets used to think. As noted by Roizman & Kabitchev (1985), a considerable fraction of flares shows a complicated multipeak structure with sudden onset and decay. Their interpretation along the lines of classical models favored for solar-like flares is very problematic.Here, we report the detection of high-frequency chaotic variability (flickering) in EV Lac. Optical flickering is observed in cataclysmic binaries, and in X-rays it is observed in low-mass X-ray binaries. As a rule, flickering is an accretion phenomenon. Strange as it may seem, EV Lac as a visual binary has the analogous property.

scholarly journals Storm Surge, Blocking, and Cyclones: A Compound Hazards Analysis for the Northeast United States

2021 ◽  
Author(s):  
James F. Booth ◽  
Veeshan Narinesingh ◽  
Katherine L. Towey ◽  
Jeyavinoth Jeyaratnam
Keyword(s):  
United States ◽  
Tropical Cyclones ◽  
Storm Surge ◽  
Short Duration ◽  
Extratropical Cyclones ◽  
Northeast United States ◽  
Long Duration ◽  
Medium Range ◽  
Slow Moving ◽  
The Relationship

AbstractStorm surge is a weather hazard that can generate dangerous flooding and is not fully understood in terms of timing and atmospheric forcing. Using observations along the Northeast United States, surge is sorted based on duration and intensity to reveal distinct time-evolving behavior. Long-duration surge events slowly recede, while strong, short-duration events often involve negative surge in quick succession after the maximum. Using Lagrangian track information, the tropical and extratropical cyclones and atmospheric blocks that generate the surge events are identified. There is a linear correlation between surge duration and surge maximum, and the relationship is stronger for surge caused by extratropical cyclones as compared to those events caused by tropical cyclones. For the extremes based on duration, the shortest-duration strong surge events are caused by tropical cyclones, while the longest-duration events are most often caused by extratropical cyclones. At least half of long-duration surge events involve anomalously strong atmospheric blocking poleward of the cyclone, while strong, short-duration events are most often caused by cyclones in the absence of blocking. The dynamical influence of the blocks leads to slow-moving cyclones that take meandering paths. In contrast, for strong, short-duration events, cyclones travel faster and take a more meridional path. These unique dynamical scenarios provide better insight for interpreting the threat of surge in medium-range forecasts.

The Early Effects of Prefrontal Leucotomy on Disturbed Patients with Mental Illness of Long Duration

1943 ◽  
Vol 89 (375) ◽  
pp. 182-188 ◽  
Author(s):  
E. Cunningham Dax ◽  
E. J. Radley Smith
Keyword(s):  
Mental Illness ◽  
Progress Report ◽  
Long Duration ◽  
Early Effects ◽  
Short Time

The following findings apply to 50 cases who were operated upon in the last six months of 1942. The very short time which has elapsed since the operations were performed makes it necessary to treat the results with the greatest reserve. It is therefore hoped that this account will be regarded as a progress report.

scholarly journals Using automated sanding to homogeneously break seed dormancy in black locust (Robinia pseudoacacia L., Fabaceae)

2017 ◽  
Vol 27 (3) ◽  
pp. 243-250 ◽  
Author(s):  
Xavier P. Bouteiller ◽  
Annabel J. Porté ◽  
Stéphanie Mariette ◽  
Arnaud Monty
Keyword(s):  
Seed Dormancy ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Dormancy Breaking ◽  
Physical Dormancy ◽  
Long Duration ◽  
Dry Heating ◽  
Two Temperatures ◽  
Robinia Pseudoacacia L ◽  
Short Time

AbstractPhysical dormancy of Robinia pseudoacacia seeds makes it a challenge for scientists and forest managers to obtain a homogeneous germination for larger seed samples. Water imbibition of the seeds can be achieved through manual piercing of the seed coat, but this method remains time consuming and heterogeneous. We tested several ecologically friendly methods to break seed dormancy, including manual pin puncture, water soaking, oven dry-heating (two temperatures) and sanding. Sanding was performed using an automatic grinder to control shaking duration (three durations) and get a homogeneous scraping of the coat. All methods, except dry-heating, resulted in successful dormancy breaking; water soaking was the least efficient method, attaining 57% germination. Sanding proved to be as efficient as puncturing (97%) but long duration sanding (10 or 15 min) could damage cotyledons, which would impede further development of the plant. Short-time sanding (5 min) proved to be the best method to reach high total germination and healthy (undamaged cotyledon) seedlings, and was successfully applied to 500 seeds. The reference puncture method and the automatic sanding were also tested on seeds of nine Fabaceae species and proved to be efficient for some species. Automated sanding can thus be used as a standard to break physical dormancy of black locust or other Fabaceae seeds to allow further comparative studies of plant populations or genotypes.

Research on Two-Dimensional Landslide Model Control System Based on Support Vector Machine Modeling

2014 ◽  
Vol 580-583 ◽  
pp. 947-953
Author(s):  
Zhong Tao Liu ◽  
Zheng Hua Feng
Keyword(s):  
Support Vector Machine ◽  
Control System ◽  
Hydraulic Cylinder ◽  
Model System ◽  
Support Vector ◽  
System Control ◽  
Two Dimensional ◽  
Model Control ◽  
Model Platform ◽  
Landslide Model

Two-dimensional landslide model system is an important experimental platform for studying geological disaster, landslide behavior in different conditions are achieved by controlling the hydraulic pump drive model platform uplifting cabinet inclination. During the process of automation transformation of the two-dimensional landslide model system, control system based on computer is used to achieve a smooth lifting and precise angle of landslide model platform. Thanks to predictive control algorithm of least squares support vector machine (LS-SVM) model used in this paper, random real-time change of equivalent load applied on the hydraulic cylinder system effectively solved. The control system of the two-dimensional landslide model effectively eliminated crawling effect and pulse lifting in the condition of low speed and high load conditions of hydraulic system.

scholarly journals Classification of Coronavirus Images using Shrunken Features

2020 ◽  
Author(s):  
Saban Ozturk ◽  
Umut Ozkaya ◽  
Mucahid Barstugan
Keyword(s):  
Feature Extraction ◽  
Feature Vector ◽  
Principal Component ◽  
Extraction Methods ◽  
X Ray ◽  
Effective Interventions ◽  
Long Duration ◽  
Clinical Diagnoses ◽  
Short Time

AbstractNecessary screenings must be performed to control the spread of the Corona Virus (COVID-19) in daily life and to make a preliminary diagnosis of suspicious cases. The long duration of pathological laboratory tests and the wrong test results led the researchers to focus on different fields. Fast and accurate diagnoses are essential for effective interventions with COVID-19. The information obtained by using X-ray and Computed Tomography (CT) images is vital in making clinical diagnoses. Therefore it was aimed to develop a machine learning method for the detection of viral epidemics by analyzing X-ray images. In this study, images belonging to 6 situations, including coronavirus images, are classified. Since the number of images in the dataset is deficient and unbalanced, it is more convenient to analyze these images with hand-crafted feature extraction methods. For this purpose, firstly, all the images in the dataset are extracted with the help of four feature extraction algorithms. These extracted features are combined in raw form. The unbalanced data problem is eliminated by producing feature vectors with the SMOTE algorithm. Finally, the feature vector is reduced in size by using a stacked auto-encoder and principal component analysis to remove interconnected features in the feature vector. According to the obtained results, it is seen that the proposed method has leveraging performance, especially in order to make the diagnosis of COVID-19 in a short time and effectively.

Extreme Responses of Bilinear Stiff Systems

2007 ◽  
Author(s):  
Laura K. Alford ◽  
Chris Wozniak ◽  
Armin W. Troesch
Keyword(s):  
Monte Carlo ◽  
Extreme Event ◽  
Single Point ◽  
Mooring System ◽  
Stiff Systems ◽  
Stiff System ◽  
Equivalent Linear ◽  
Time Period ◽  
Short Time ◽  
Extreme Responses

A single-point mooring system is modeled as a bilinear-stiff system. Long-term statistics of the nonlinear mooring system are estimated by Monte Carlo computer simulation. In an effort to generate an extreme event in a short time period (as opposed to lengthy Monte Carlo simulations), an equivalent linear system is devised along with an excitation designed to elicit a large, linear response. This design wave and the resulting system excitation are used in simulations to generate both the design nonlinear and equivalent linear responses.

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