scholarly journals Study on Storm Surge Using Parametric Model with Geographical Characteristics

2020 ◽  
Author(s):  
Yeon-joong KIM ◽  
Tea-woo KIM ◽  
Jong-sung YOON
Keyword(s):  
Natural Disasters ◽  
Storm Surge ◽  
Large Scale ◽  
Grid Point ◽  
Storm Surges ◽  
Parametric Model ◽  
Hazard Map ◽  
Pressure Fields ◽  
Holland Model ◽  
Geographical Characteristics

Recently, the intensities of natural disasters have increased significantly owing to climate change and various other environmental factors, causing unprecedented damage. Measures must be established to reduce damage from large-scale natural disasters caused by the rapidly changing environment. The Japanese government published a hazard map manual in 2015 and obligates the creation of a hazard map as a measure to reduce high-scale storm surges. This manual presents a typhoon model based on a parametric model that is used to create a hazard map. The Myers model assuming concentric circles, which is primarily used in East Asia, is disadvantageous as it cannot consider geographic characteristics. Therefore, a new parametric model is necessary to calculate wind and pressure fields, which change according to geographic characteristics. To improve this limitation of the Myers model, we calculated the wind and pressure fields considering geographical effects by combining the Holland model, which can consider the size of a developing typhoon, and the Mascon model, which changes by geographic characteristics. To determine the gradient coefficient of the Holland model, the coefficient that changes every moment was calculated using grid point value data. The result indicated excellent reproducibility of storm surge height according to the geographic characteristics.

scholarly journals Study on Storm Surge Using Parametric Model with Geographical Characteristics

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2251
Author(s):  
Yeon-joong Kim ◽  
Tea-woo Kim ◽  
Jong-sung Yoon
Keyword(s):  
Storm Surge ◽  
Wind Field ◽  
Global Climate ◽  
Grid Point ◽  
Storm Surges ◽  
Parametric Model ◽  
Hazard Map ◽  
Proposed Model ◽  
Pass Through ◽  
Geographical Characteristics

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.

The Study of the Impact for Coastal Engineering on High Water Level Induced by Storm Surges in Bohai Bay

2011 ◽  
Vol 94-96 ◽  
pp. 810-814
Author(s):  
Jin Shan Zhang ◽  
Wei Sheng Zhang ◽  
Chen Cheng ◽  
Lin Yun Sun
Keyword(s):  
Water Level ◽  
Storm Surge ◽  
Large Scale ◽  
Storm Surges ◽  
High Water ◽  
Coastal Engineering ◽  
Cold Wave ◽  
Bohai Bay ◽  
Ocean Engineering ◽  
The Impact

Bohai Bay is an semi-closed bay, the storm surge disaster is very serious in past. Now more and more large ocean engineering are built here, To study changes of storm surge induced by the construction of large-scale coastal engineering in Bohai Bay in present, 2D numerical storm surge model is established with large - medium - small model nested approach. The three most typical storms surges: 9216, 9711 and by cold wave in October 2003 are simulated in the condition of before and after implementation of planning projects in Bohai Bay. Changes of storm surge water level due to implementation of artificial projects are analysis in this paper.

A Study of Storm Surge Risk Index System

2014 ◽  
Vol 580-583 ◽  
pp. 2622-2627
Author(s):  
Qiang Liu ◽  
Zhen Zhen Yuan
Keyword(s):  
Natural Disasters ◽  
Storm Surge ◽  
Index System ◽  
Urban Areas ◽  
Risk Index ◽  
Storm Surges ◽  
Disaster Mitigation ◽  
Risk Indicator ◽  
Vulnerability Indicator ◽  
Set Up

Natural disasters refer to casualties, property damage and social instability. Coastal urban areas with a high population density coupled with the construction of man-made structures are particularly subjected to storm surge hazards, which have become an increasingly urgent problem. In this paper, we try to set up a risk index system, including risk indicator, vulnerability indicator and prevention and mitigation capability index. Each of the risk components has large number of variables and quantities. Through displaying losses and characteristics of the four natural disasters, we put forward suggestions for better disaster mitigation. So that a better understanding of storm surges risk profile and early disaster warning measurement could be achieved.

IMPACT ASSESSMENT ON STORM SURGE RISKS TO CONTAINERS CONSIDERING GLOBAL WARMING

2017 ◽  
Author(s):  
Rikito Hisamatsu ◽  
Rikito Hisamatsu ◽  
Kei Horie ◽  
Kei Horie
Keyword(s):  
Risk Assessment ◽  
Global Warming ◽  
Storm Surge ◽  
Storm Surges ◽  
Assessment Tools ◽  
Inundation Depth ◽  
Risk Assessment Tools ◽  
Risk Maps ◽  
The Impact ◽  
Vulnerability Functions

Container yards tend to be located along waterfronts that are exposed to high risk of storm surges. However, risk assessment tools such as vulnerability functions and risk maps for containers have not been sufficiently developed. In addition, damage due to storm surges is expected to increase owing to global warming. This paper aims to assess storm surge impact due to global warming for containers located at three major bays in Japan. First, we developed vulnerability functions for containers against storm surges using an engineering approach. Second, we simulated storm surges at three major bays using the SuWAT model and taking global warming into account. Finally, we developed storm surge risk maps for containers based on current and future situations using the vulnerability function and simulated inundation depth. As a result, we revealed the impact of global warming on storm surge risks for containers quantitatively.

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.

scholarly journals Storm Surges in the Bohai Sea: The Role of Waves and Tides

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1509
Author(s):  
Yuanyi Li ◽  
Huan Feng ◽  
Guillaume Vigouroux ◽  
Dekui Yuan ◽  
Guangyu Zhang ◽  
...  
Keyword(s):  
Storm Surge ◽  
Bohai Sea ◽  
Storm Surges ◽  
Wave Force ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Coastal Regions ◽  
The Bohai Sea ◽  
Tidal Phase ◽  
Set Up

A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this study, we set up a storm surge model, considering coupled effects of tides and waves on the surges. Validation against measured data shows that the coupled model is capable of simulating storm surges in the Bohai Sea. The simulation results indicate that the longshore currents, which are induced by the large gradient of radiation stress due to wave deformation, are one of the main contributors to the higher surges occurring in some coastal regions. The gently varying bathymetry is another factor contributing to these surges. With such bathymetry, the wave force direction is nearly uniform, and pushes a large amount of water in that direction. Under these conditions, the water accumulates in some parts of the coast, leading to higher surges in nearby coastal regions such as the south coast of the Bohai Bay and the west and south coasts of the Laizhou Bay. Results analysis also shows that the tidal phase at which the surge occurs influences the wave–current interactions, and these interactions are more evident in shallow waters. Neglecting these interactions can lead to inaccurate predictions of the storm surges due to overestimation or underestimation of wave-induced set-up.

scholarly journals The information complexity of learning tasks, their structure and their distance

2021 ◽  
Author(s):  
Alessandro Achille ◽  
Giovanni Paolini ◽  
Glen Mbeng ◽  
Stefano Soatto
Keyword(s):  
Kolmogorov Complexity ◽  
Large Scale ◽  
Parametric Model ◽  
Training Dataset ◽  
Optimization Scheme ◽  
Learning Tasks ◽  
Asymmetric Distance ◽  
Special Cases ◽  
Scale Models ◽  
Real World Datasets

Abstract We introduce an asymmetric distance in the space of learning tasks and a framework to compute their complexity. These concepts are foundational for the practice of transfer learning, whereby a parametric model is pre-trained for a task, and then fine tuned for another. The framework we develop is non-asymptotic, captures the finite nature of the training dataset and allows distinguishing learning from memorization. It encompasses, as special cases, classical notions from Kolmogorov complexity and Shannon and Fisher information. However, unlike some of those frameworks, it can be applied to large-scale models and real-world datasets. Our framework is the first to measure complexity in a way that accounts for the effect of the optimization scheme, which is critical in deep learning.

scholarly journals Modeling Study on the Asymmetry of Positive and Negative Storm Surges along the Southeastern Coast of China

2021 ◽  
Vol 9 (5) ◽  
pp. 458
Author(s):  
Dongdong Chu ◽  
Haibo Niu ◽  
Wenli Qiao ◽  
Xiaohui Jiao ◽  
Xilin Zhang ◽  
...  
Keyword(s):  
Storm Surge ◽  
Pressure Field ◽  
Three Dimensional ◽  
Storm Surges ◽  
Ocean Model ◽  
Central Pressure ◽  
Linear Interaction ◽  
Southeastern Coast ◽  
Zhoushan Archipelago ◽  
Wind Intensity

In this paper, a three-dimensional storm surge model was developed based on the Finite Volume Community Ocean Model (FVCOM) by the hindcasts of four typhoon-induced storm surges (Chan-hom, Mireille, Herb, and Winnie). After model validation, a series of sensitivity experiments were conducted to explore the effects of key parameters in the wind and pressure field (forward speed, radius of maximum wind (RMW), inflow angle, and central pressure), typhoon path, wind intensity, and topography on the storm surge and surge asymmetry between sea level rise (positive surge) and fall (negative surge) along the southeastern coast of China (SCC). The model results show that lower central pressure and larger RMW could lead to stronger surge asymmetry. A larger inflow angle results in a stronger surge asymmetry. In addition, the path of Chan-hom is the most dangerous path type for the Zhoushan Archipelago area, and that of Winnie follows next. The model results also indicate that the non-linear interaction between wind field and pressure field tends to weaken the peak surge elevation. The effect of topography on storm surges indicates that the peak surge elevation and its occurrence time, as well as the surge asymmetry, increase with a decreasing slope along the SCC.

scholarly journals Relationship between Shortwave Cloud Radiative Forcing and Local Meteorological Variables Compared in Observations and Several Global Climate Models

2006 ◽  
Vol 19 (17) ◽  
pp. 4344-4359 ◽  
Author(s):  
Markus Stowasser ◽  
Kevin Hamilton
Keyword(s):  
Relative Humidity ◽  
Vertical Velocity ◽  
Radiative Forcing ◽  
Large Scale ◽  
Climate Models ◽  
Grid Point ◽  
Global Climate Models ◽  
Coupled Models ◽  
Cloud Radiative Forcing ◽  
Cloud Forcing

Abstract The relations between local monthly mean shortwave cloud radiative forcing and aspects of the resolved-scale meteorological fields are investigated in hindcast simulations performed with 12 of the global coupled models included in the model intercomparison conducted as part of the preparation for Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). In particular, the connection of the cloud forcing over tropical and subtropical ocean areas with resolved midtropospheric vertical velocity and with lower-level relative humidity are investigated and compared among the models. The model results are also compared with observational determinations of the same relationships using satellite data for the cloud forcing and global reanalysis products for the vertical velocity and humidity fields. In the analysis the geographical variability in the long-term mean among all grid points and the interannual variability of the monthly mean at each grid point are considered separately. The shortwave cloud radiative feedback (SWCRF) plays a crucial role in determining the predicted response to large-scale climate forcing (such as from increased greenhouse gas concentrations), and it is thus important to test how the cloud representations in current climate models respond to unforced variability. Overall there is considerable variation among the results for the various models, and all models show some substantial differences from the comparable observed results. The most notable deficiency is a weak representation of the cloud radiative response to variations in vertical velocity in cases of strong ascending or strong descending motions. While the models generally perform better in regimes with only modest upward or downward motions, even in these regimes there is considerable variation among the models in the dependence of SWCRF on vertical velocity. The largest differences between models and observations when SWCRF values are stratified by relative humidity are found in either very moist or very dry regimes. Thus, the largest errors in the model simulations of cloud forcing are prone to be in the western Pacific warm pool area, which is characterized by very moist strong upward currents, and in the rather dry regions where the flow is dominated by descending mean motions.

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