scholarly journals FRICTION IN HURRICANE-INDUCED SURGES

1986 ◽  
Vol 1 (20) ◽  
pp. 62
Author(s):  
Shang-Yih Wang ◽  
B.A. Christensen
Keyword(s):  
Friction Factor ◽  
Land Use Planning ◽  
Numerical Models ◽  
Storm Surges ◽  
Coastal Areas ◽  
Ocean Bottom ◽  
Friction Factors ◽  
Forested Areas ◽  
Insurance Rate ◽  
Saltwater Marshes

With the increasing development of coastal areas, it is necessary to have a sound method for predicting hurricane-induced flooding in these areas, especially for studies such as the coastal construction set-back line, flood insurance rate-making and county land use planning. The objective of this study is to develop the capability of describing the friction factor in coastal areas for improved representation in numerical models of storm surges. Five types of areas are considered: A, ocean bottom with bed forms and some vegetation; B, mangrove fringes and areas; C, forested areas and cypress swamps; D, grassy areas and saltwater marshes; and E, developed residential and commercial areas. The friction factors, which incorporate both the bottom friction coefficient and drag coefficient due to the submerged parts of obstructions were verified by conducting laboratory experiments for mangrove and developed areas, using the typical distribution found in each of these coastal areas. The formulas of the friction factor for the ocean bottom, forested areas and grassy areas are determined by adopting results from previous investigations and discussed with the results of the current study.

scholarly journals ADVANCES IN COASTAL DISASTERS RISK MANAGEMENT – LESSONS FROM THE 2011 TOHOKU TSUNAMI

2012 ◽  
Vol 1 (33) ◽  
pp. 13 ◽  
Author(s):  
Sebastiaan Jonkman ◽  
Tomohiro Yasuda ◽  
V. Tsimopoulou ◽  
H. Kawai ◽  
F. Kato
Keyword(s):  
Emergency Management ◽  
Land Use Planning ◽  
Storm Surges ◽  
Coastal Areas ◽  
Coastal Protection ◽  
2011 Tohoku Tsunami ◽  
Effective Combination ◽  
Protection Systems ◽  
Tohoku Tsunami ◽  
Theoretical Issues

The earthquake and tsunami of March 2011 led to death and destruction in coastal areas in Japan. A seminar was held in June 2012 for Japanese and Dutch coastal researchers to discuss lessons for the management of the risks in coastal areas associated with tsunamis, typhoons and storm surges. The seminar has highlighted important practical and theoretical issues in coastal protection, risk and emergency management, and climate change and sea level rise research that are of importance for the Netherlands and Japan and other coastal regions. The performance of the system during historical events gives important lessons for the (re)design of resilient coastal protection systems in the future. It has also been discussed how risk assessments can be utilized to determine how an effective combination of prevention, land use planning and emergency management can be implemented to minimize future risks in the coastal zone.

scholarly journals Integrated Inundation Modeling of Flooded Water in Coastal Cities

2019 ◽  
Vol 9 (7) ◽  
pp. 1313 ◽  
Author(s):  
Eun Shin ◽  
Jaehyun Shin ◽  
Dong Rhee ◽  
Hyung-Jun Kim ◽  
Chang Song
Keyword(s):  
Numerical Models ◽  
Storm Surges ◽  
Coastal Flooding ◽  
Coastal Areas ◽  
Simultaneous Occurrence ◽  
River Flooding ◽  
Coastal Cities ◽  
Flood Simulations ◽  
River Inundation ◽  
Inundation Modeling

Climate change has increased the damage caused by subtropical rainfall and typhoons in coastal areas. Major flooding factors in coastal areas can be classified as storm surges, river inundation, and inland submergence. Because previous studies usually applied a linear sum of individual inundation components to predict comprehensive flood phenomena, this approach does not consider weighted effects associated with the simultaneous occurrence of complex flooding. In this study, a series of comprehensive flood simulations were performed using two numerical models: HDM-2D and FLUval Modeling ENgine (FLUMEN). The results revealed that an integrated flood analysis considering the effects of inundation flooding, river flooding, and coastal flooding required evaluation of the risk of flooding in coastal cities.

scholarly journals On the improvement of waves and storm surge hindcasts by downscaled atmospheric forcing: Application to historical storms

2017 ◽  
Author(s):  
Émilie Bresson ◽  
Philippe Arbogast ◽  
Lotfi Aouf ◽  
Denis Paradis ◽  
Anna Kortcheva ◽  
...  
Keyword(s):  
Storm Surge ◽  
Initial Conditions ◽  
Numerical Models ◽  
Storm Surges ◽  
Atmospheric Model ◽  
Coastal Areas ◽  
Wind Forcing ◽  
Small Scale ◽  
Whole Process ◽  
The Impact

Abstract. Winds, waves and storm surges can induce severe damages in coastal areas. The FP7 IncREO project aims to understand the impact of climate change on coastal areas and also to assess the predictability of such extreme events. Reproduce efficiently past events is the fisrt step to reach this purpose. This paper shows the use of atmospheric downscaling techniques in order to improve waves and storm surge hindcasts. Past storms which caused damages on European coastal areas are investigated using atmosphere, wave and storm surge numerical models and downscaling techniques are based on existing ECMWF reanalyses. The results show clearly that the 10 km resolution wind forcing provided by the downscaled atmospheric model gives better waves and surges hindcast against using wind from the reanalysis. Furthermore, the analysis of the most extreme mid-latitude cyclones indicates that a 4D blending approach improves the whole process as it includes small scale processes in the initial conditions.

scholarly journals Numerical Models in Coastal Hazards and Coastal Environment

2021 ◽  
Vol 9 (5) ◽  
pp. 494
Author(s):  
Han Soo Lee ◽  
Young-Jin Choi ◽  
Seung-Buhm Woo
Keyword(s):  
United Nations ◽  
Numerical Models ◽  
Coastal Environment ◽  
Coastal Areas ◽  
Coastal Hazards ◽  
The United Nations

According to the United Nations (UN) Atlas of the Oceans, about 44% of the world’s population lives in coastal areas within 150 km of the sea [...]

scholarly journals Effects of climate change on spatiotemporal patterns of tropical cyclone tracks and their implications for coastal agriculture in Myanmar

2021 ◽  
Author(s):  
Akira Hirano
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Considerable Increase ◽  
Hot Spot ◽  
Coastal Region ◽  
Storm Surges ◽  
Coastal Areas ◽  
Spatiotemporal Patterns ◽  
Sea Levels ◽  
Rising Sea Levels

AbstractImportant aspects for understanding the effects of climate change on tropical cyclones (TCs) are the frequency of TCs and their tracking patterns. Coastal areas are increasingly threatened by rising sea levels and associated storm surges brought on by TCs. Rice production in Myanmar relies strongly on low-lying coastal areas. This study aims to provide insights into the effects of global warming on TCs and the implications for sustainable development in vulnerable coastal areas in Myanmar. Using TC records from the International Best Track Archive for Climate Stewardship dataset during the 30-year period from 1983 to 2012, a hot spot analysis based on Getis-Ord (Gi*) statistics was conducted to identify the spatiotemporal patterns of TC tracks along the coast of Myanmar. The results revealed notable changes in some areas along the central to southern coasts during the study period. These included a considerable increase in TC tracks (p value < 0.01) near the Ayeyarwady Delta coast, otherwise known as “the rice bowl” of the nation. This finding aligns with trends in published studies and reinforced the observed trends with spatial statistics. With the intensification of TCs due to global warming, such a significant increase in TC experiences near the major rice-producing coastal region raises concerns about future agricultural sustainability.

Numerical and Experimental Analysis of Turbulent Flow in Corrugated Pipes

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Henrique Stel ◽  
Rigoberto E. M. Morales ◽  
Admilson T. Franco ◽  
Silvio L. M. Junqueira ◽  
Raul H. Erthal ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Magnitude ◽  
Geometric Configurations ◽  
Corrugated Surfaces ◽  
Friction Factors

This article describes a numerical and experimental investigation of turbulent flow in pipes with periodic “d-type” corrugations. Four geometric configurations of d-type corrugated surfaces with different groove heights and lengths are evaluated, and calculations for Reynolds numbers ranging from 5000 to 100,000 are performed. The numerical analysis is carried out using computational fluid dynamics, and two turbulence models are considered: the two-equation, low-Reynolds-number Chen–Kim k-ε turbulence model, for which several flow properties such as friction factor, Reynolds stress, and turbulence kinetic energy are computed, and the algebraic LVEL model, used only to compute the friction factors and a velocity magnitude profile for comparison. An experimental loop is designed to perform pressure-drop measurements of turbulent water flow in corrugated pipes for the different geometric configurations. Pressure-drop values are correlated with the friction factor to validate the numerical results. These show that, in general, the magnitudes of all the flow quantities analyzed increase near the corrugated wall and that this increase tends to be more significant for higher Reynolds numbers as well as for larger grooves. According to previous studies, these results may be related to enhanced momentum transfer between the groove and core flow as the Reynolds number and groove length increase. Numerical friction factors for both the Chen–Kim k-ε and LVEL turbulence models show good agreement with the experimental measurements.

Delineating soil landscape facets from digital elevation models using compound topographic index in a geographic information system

Soil Research ◽  
2007 ◽  
Vol 45 (8) ◽  
pp. 569 ◽  
Author(s):  
X. Yang ◽  
G. A. Chapman ◽  
J. M. Gray ◽  
M. A. Young
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
Land Use Planning ◽  
Digital Elevation Models ◽  
Geographic Information ◽  
Coastal Areas ◽  
Topographic Index ◽  
Digital Elevation ◽  
Soil Landscape ◽  
Compound Topographic Index

Soil landscapes and their component facets (or sub-units) are fundamental information for land capability assessment and land use planning. The aim of the study was to delineate soil landscape facets from readily available digital elevation models (DEM) to assist soil constraint assessment for urban and regional planning in the coastal areas of New South Wales (NSW), Australia. The Compound Topographic Index (CTI) surfaces were computed from 25 m DEM using a D-infinity algorithm. The cumulative frequency distribution of CTI values within each soil landscape was examined to identify the values corresponding to the area specified for each unmapped facet within the soil landscape map unit. Then these threshold values and CTI surfaces were used to generate soil landscape facet maps for the entire coastal areas of NSW. Specific programs were developed for the above processes in a geographic information system so that they are automated, fast, and repeatable. The modelled facets were assessed by field validation and the overall accuracy reached 93%. The methodology developed in this study has been proven to be efficient in delineating soil landscape facets, and allowing for the identification of land constraints at levels of unprecedented detail for the coast of NSW.

A Review of Explicit Friction Factor Equations

1985 ◽  
Vol 107 (2) ◽  
pp. 280-283 ◽  
Author(s):  
D. J. Zigrang ◽  
N. D. Sylvester
Keyword(s):  
Friction Factor ◽  
Pipe Flow ◽  
Turbulent Pipe Flow ◽  
Explicit Equation ◽  
Flow Friction ◽  
Friction Factors ◽  
High Degree ◽  
Very High

A review of the explicit friction factor equations developed to replace the Colebrook equation is presented. Explicit friction factor equations are developed which yield a very high degree of precision compared to the Colebrook equation. A new explicit equation, which offers a reasonable compromise between complexity and accuracy, is presented and recommended for the calculation of all turbulent pipe flow friction factors for all roughness ratios and Reynold’s numbers.

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