scholarly journals Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)

2019 ◽  
Vol 19 (1) ◽  
pp. 287-298 ◽  
Author(s):  
Francesco De Leo ◽  
Giovanni Besio ◽  
Guido Zolezzi ◽  
Marco Bezzi
Keyword(s):  
Field Measurements ◽  
Computational Procedure ◽  
Wave Climate ◽  
Data Availability ◽  
Limited Data ◽  
Coastal Vulnerability ◽  
Wave Characteristics ◽  
Local Wave ◽  
Run Up ◽  
Offshore Wave

Abstract. Coastal vulnerability is evaluated against inundation risk triggered by wave run-up through the evaluation of vulnerability levels (referred to as VLs) introduced by Bosom and Jiménez (2011). VLs are assessed through different wave climate characterizations, referring to regional (offshore wave climate) or local (nearshore wave climate) scales. The study is set along the Bay of Lalzit, a coastal area near Durrës (Albania). The analysis reveals that the results vary due to uncertainties inherent in the run-up estimation, showing that the computational procedure should be developed by taking into account detailed information about the local wave climate. Different approaches in choosing wave characteristics for run-up estimation significantly affect the estimate of shoreline vulnerability. The analysis also shows the feasibility and challenges of applying VL estimates in contexts characterized by limited data availability through targeted field measurements of the coast geomorphology and an overall understanding of the recent coastal dynamics and related controlling factors.

scholarly journals Coastal vulnerability assessment: through regional to local downscaling of wave characteristics along the Bay of Lalzit (Albania)

2018 ◽  
Author(s):  
Francesco De Leo ◽  
Giovanni Besio ◽  
Guido Zolezzi ◽  
Marco Bezzi
Keyword(s):  
Field Measurements ◽  
Computational Procedure ◽  
Wave Climate ◽  
Data Availability ◽  
Coastal Vulnerability ◽  
Wave Characteristics ◽  
Local Wave ◽  
Climate Scale ◽  
Run Up ◽  
Offshore Wave

Abstract. Coastal vulnerability is evaluated against inundation risk triggered by waves run-up, through the employment of coastal vulnerability indexes (referred to as “CVI”) introduced by Bosom García and Jiménez Quintana (2011). CVI are assessed through different wave climate characterizations, referring to regional (offshore wave climate) or local (near-shore wave climate) scale. The study is set along the Lalzit bay, a coastal area nearby Durres (Albania). The analysis reveals that the results vary due to uncertainties inherent in the run-up estimation, showing that the computational procedure should be developed by taking into account detailed information about local wave climate, especially concerning seasonal behaviour and fluctuations. Different approaches in choosing wave characteristics for run-up estimation affect significantly the estimate of shoreline vulnerability. The analysis also shows the feasibility and challenges of applying CVI estimates in contexts characterized by limited data availability, through targeted field measurements of the coast geomorphology and an overall understanding of the recent coastal dynamics and related controlling factors.

scholarly journals Probabilistic coastal vulnerability assessment to storms at regional scale – application to Catalan beaches (NW Mediterranean)

2011 ◽  
Vol 11 (2) ◽  
pp. 475-484 ◽  
Author(s):  
E. Bosom ◽  
J. A. Jiménez
Keyword(s):  
Probability Distributions ◽  
Regional Scale ◽  
Probabilistic Approach ◽  
Wave Climate ◽  
Coastal Vulnerability ◽  
Large Variability ◽  
Probability Of Occurrence ◽  
Nw Mediterranean ◽  
Offshore Wave ◽  
Extreme Probability

Abstract. A methodology to assess storm-induced coastal vulnerability taking into account the different induced processes separately (inundation and erosion) is presented. It is based on a probabilistic approach where hazards time series are built from existing storm data and later used to fit an extreme probability function. This is done for different sectors along the coast defined in terms of the wave climate and for representative beach types of the area to be analyzed. Once probability distributions are available, coastal managers must decide the probability of occurrence to be accepted as well as the period of concern of the analysis in function of the importance of the hinterland. These two variables will determine the return period to be considered in the assessment. The comparison of hazards and vulnerabilities associated with the selected probability of occurrence permit to identify the most hazardous areas along the coast in a robust manner by including the spatial variability in forcing (storm climate) and receptor (beaches). The methodology has been applied to a 50 km long coastal stretch of the Catalonia (NW Mediterranean) where offshore wave conditions can be assumed to be homogeneous. In spite of this spatially constant wave field, obtained results indicate a large variability in hazards intensity and vulnerability along the coast.

scholarly journals WAVE RUN-UP CAUSED BY NATURAL STORM SURGE WAVES

1982 ◽  
Vol 1 (18) ◽  
pp. 49
Author(s):  
Joachim Grune
Keyword(s):  
Storm Surge ◽  
German Bight ◽  
Field Measurements ◽  
Wave Climate ◽  
Wave Runup ◽  
Sea State ◽  
Run Up

This paper describes results of field measurements on wave run-up caused by storm surge waves. The measurements have been done with newly developed run-up probes at two locations at the German Bight with different dyke profiles. It was found from the results that the wave runup, measured under real sea state conditions, have greater values than predicted by commonly used formulae. Furthermore the wave climate and the breaker type seem to have an influence on the magnitudes of wave run-up.

scholarly journals Multimodel Ensemble Projections of Wave Climate in the Western North Pacific Using CMIP6 Marine Surface Winds

2021 ◽  
Vol 9 (8) ◽  
pp. 835
Author(s):  
Mochamad Riam Badriana ◽  
Han Soo Lee
Keyword(s):  
North Pacific ◽  
General Circulation ◽  
Western North Pacific ◽  
Wave Climate ◽  
Coastal Development ◽  
Climate Projections ◽  
Surface Winds ◽  
Time Step ◽  
Wave Characteristics ◽  
Marine Surface

For decades, the western North Pacific (WNP) has been commonly indicated as a region with high vulnerability to oceanic and atmospheric hazards. This phenomenon can be observed through general circulation model (GCM) output from the Coupled Model Intercomparison Project (CMIP). The CMIP consists of a collection of ensemble data as well as marine surface winds for the projection of the wave climate. Wave climate projections based on the CMIP dataset are necessary for ocean studies, marine forecasts, and coastal development over the WNP region. Numerous studies with earlier phases of CMIP are abundant, but studies using CMIP6 as the recent dataset for wave projection is still limited. Thus, in this study, wave climate projections with WAVEWATCH III are conducted to investigate how wave characteristics in the WNP will have changed in 2050 and 2100 compared to those in 2000 with atmospheric forcings from CMIP6 marine surface winds. The wave model runs with a 0.5° × 0.5° spatial resolution in spherical coordinates and a 10-min time step. A total of eight GCMs from the CMIP6 dataset are used for the marine surface winds modelled over 3 hours for 2050 and 2100. The simulated average wave characteristics for 2000 are validated with the ERA5 Reanalysis wave data showing good consistency. The wave characteristics in 2050 and 2100 show that significant decreases in wave height, a clockwise shift in wave direction, and the mean wave period becomes shorter relative to those in 2000.

Regional Bicycle Network Evaluation and Strategic Planning: A Quantitative Methodological Approach Despite Limited Data Sources for Cycling

2021 ◽  
pp. 036119812110288
Author(s):  
Alex van Dulmen ◽  
Martin Fellendorf
Keyword(s):  
Travel Demand ◽  
Choice Model ◽  
Methodological Approach ◽  
Data Availability ◽  
Data Sources ◽  
Test Case ◽  
Demand Model ◽  
Limited Data ◽  
Demand Models ◽  
Bicycle Infrastructure

In cases where budgets and space are limited, the realization of new bicycle infrastructure is often hard, as an evaluation of the existing network or the benefits of new investments is rarely possible. Travel demand models can offer a tool to support decision makers, but because of limited data availability for cycling, the validity of the demand estimation and trip assignment are often questionable. This paper presents a quantitative method to evaluate a bicycle network and plan strategic improvements, despite limited data sources for cycling. The proposed method is based on a multimodal aggregate travel demand model. Instead of evaluating the effects of network improvements on the modal split as well as link and flow volumes, this method works the other way around. A desired modal share for cycling is set, and the resulting link and flow volumes are the basis for a hypothetical bicycle network that is able to satisfy this demand. The current bicycle network is compared with the hypothetical network, resulting in preferable actions and a ranking based on the importance and potentials to improve the modal share for cycling. Necessary accompanying measures for other transport modes can also be derived using this method. For example, our test case, a city in Austria with 300,000 inhabitants, showed that a shift of short trips in the inner city toward cycling would, without countermeasures, provide capacity for new longer car trips. The proposed method can be applied to existing travel models that already contain a mode choice model.

scholarly journals Automated classification of the atmospheric circulation patterns that drive regional wave climates

2014 ◽  
Vol 14 (8) ◽  
pp. 2145-2155 ◽  
Author(s):  
J. Pringle ◽  
D. D. Stretch ◽  
A. Bárdossy
Keyword(s):  
Atmospheric Circulation ◽  
Low Pressure ◽  
Wave Climate ◽  
Automated Classification ◽  
Coastal Vulnerability ◽  
Extreme Wave ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
Spatially Distributed ◽  
Wave Heights

Abstract. Wave climates are fundamental drivers of coastal vulnerability; changing trends in wave heights, periods and directions can severely impact a coastline. In a diverse storm environment, the changes in these parameters are difficult to detect and quantify. Since wave climates are linked to atmospheric circulation patterns, an automated and objective classification scheme was developed to explore links between synoptic-scale circulation patterns and wave climate variables, specifically wave heights. The algorithm uses a set of objective functions based on wave heights to guide the classification and find atmospheric classes with strong links to wave behaviour. Spatially distributed fuzzy numbers define the classes and are used to detect locally high- and low-pressure anomalies. Classes are derived through a process of simulated annealing. The optimized classification focuses on extreme wave events. The east coast of South Africa was used as a case study. The results show that three dominant patterns drive extreme wave events. The circulation patterns exhibit some seasonality with one pattern present throughout the year. Some 50–80% of the extreme wave events are explained by these three patterns. It is evident that strong low-pressure anomalies east of the country drive a wind towards the KwaZulu-Natal coastline which results in extreme wave conditions. We conclude that the methodology can be used to link circulation patterns to wave heights within a diverse storm environment. The circulation patterns agree with qualitative observations of wave climate drivers. There are applications to the assessment of coastal vulnerability and the management of coastlines worldwide.

scholarly journals Combining probability distributions of sea level variations and wave run-up to evaluate coastal flooding risks

2018 ◽  
Author(s):  
Ulpu Leijala ◽  
Jan-Victor Björkqvist ◽  
Milla M. Johansson ◽  
Havu Pellikka ◽  
Lauri Laakso ◽  
...  
Keyword(s):  
Sea Level ◽  
Probability Distributions ◽  
Field Measurements ◽  
Joint Effect ◽  
Mean Sea Level ◽  
Safety Margins ◽  
Acceptable Risks ◽  
Flooding Hazards ◽  
Sea Level Variations ◽  
Run Up

Abstract. Tools for estimating probabilities of flooding hazards caused by the simultaneous effect of sea level and waves are needed for the secure planning of densely populated coastal areas that are strongly vulnerable to climate change. In this paper we present a method for combining location-specific probability distributions of three different components: (1) long-term mean sea level change, (2) short-term sea level variations, and (3) wind-generated waves. We apply the method in two locations in the Helsinki Archipelago to obtain run-up level estimates representing the joint effect of the still water level and the wave run-up. These estimates for the present, 2050 and 2100 are based on field measurements and mean sea level scenarios. In the case of our study locations, the significant locational variability of the wave conditions leads to a difference in the safe building levels of up to one meter. The rising mean sea level in the Gulf of Finland and the uncertainty related to the associated scenarios contribute significantly to the run-up levels for the year 2100. We also present a sensitivity test of the method and discuss its applicability to other coastal regions. Our approach allows for the determining of different building levels based on the acceptable risks for various infrastructure, thus reducing building costs while maintaining necessary safety margins.

scholarly journals ASSESSMENT OF COASTAL VULNERABILITY BASED ON THE USE OF INTEGRATED LOW-COST MONITORING APPROACH AND BEACH MODELLING: TWO ITALIAN STUDY

2020 ◽  
pp. 13
Author(s):  
Renata Archetti ◽  
Maria Gabriella Gaeta ◽  
Fabio Addona ◽  
Leonardo Damiani ◽  
Alessandra Saponieri ◽  
...  
Keyword(s):  
Low Cost ◽  
Integrated Approach ◽  
Video Monitoring ◽  
Monitoring Systems ◽  
Swash Zone ◽  
Coastal Vulnerability ◽  
Italian Study ◽  
Shoreline Evolution ◽  
Low Costs ◽  
Run Up

The use of video-monitoring techniques is significantly increased due to the diffusion of high-resolution cameras at relatively low-costs and they are largely used to estimate the shoreline evolution and wave run-up, as important coastal state indicators to be monitored and predicted for the assessment of flooding and erosion risks. In this work, we present an integrated approach based on the results from the low-cost video monitoring systems and the numerical modeling chain by means of SWAN and XBeach to accurately simulate and predict the swash zone processes.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/nLGNneJzmIU

scholarly journals Complex coastlines responding to climate change: do shoreline shapes reflect present forcing or "remember" the distant past?

2016 ◽  
Author(s):  
Christopher W. Thomas ◽  
A. Brad Murray ◽  
Andrew D. Ashton ◽  
Martin D. Hurst ◽  
Andrew K. A. P. Barkwith ◽  
...  
Keyword(s):  
Climate Change ◽  
Wave Climate ◽  
Quasi Equilibrium ◽  
Morphological Response ◽  
Antecedent Conditions ◽  
Coastline Evolution ◽  
Aspect Ratios ◽  
Order Of Magnitude ◽  
Offshore Wave ◽  
Hysteresis Behaviour

Abstract. A range of planform morphologies emerge along sandy coastlines as a function of offshore wave climate. It has been implicitly assumed that the morphological response time is rapid compared to the time scales of wave-climate change, meaning that coastal morphologies simply reflect the extant wave climate. This assumption has been explored by focussing on the response of two distinctive morphological coastlines – flying spits and cuspate cusps – to changing wave climates, using a coastline evolution model. Results indicate that antecedent conditions are important in determining the evolution of morphologies, and that sandy coastlines can demonstrate hysteresis behaviour. In particular, antecedent morphology is particularly important in the evolution of flying spits, with characteristic timescales of morphological adjustment on the order of centuries for large spits. Characteristic timescales vary with the square of aspect ratios of capes and spits; for spits, these timescales are an order of magnitude longer than for capes (centuries vs. decades). When wave climates change more slowly than the relevant characteristic timescales, coastlines are able to adjust in a quasi-equilibrium manner. Our results have important implications for the management of sandy coastlines where decisions may be implicitly and incorrectly based on the assumption that present-day coastlines are in equilibrium with current conditions.

scholarly journals STUDY OF AN ARTIFICIAL ISLAND

1976 ◽  
Vol 1 (15) ◽  
pp. 202
Author(s):  
J.P. Lepetit ◽  
S. Moreau
Keyword(s):  
Mathematical Models ◽  
Industrial Effluents ◽  
Pollutant Dispersion ◽  
Wave Climate ◽  
Tidal Currents ◽  
Sea Bed ◽  
Local Wave ◽  
Industrial Zones ◽  
Near Future ◽  
Reduced Scale

The location of large surface industrial zones along sea shores often competes with other coastal activities, such as recreational pursuits, fishing, nature reserves, etc. The construction of an artificial island in the sea, near the shore, is a solution to which it will perhaps be necessary to have recourse in the fairly near future. The design of such a project poses many problems particularly in respect of its impact on the environment. We present here the results of a study which examines this aspect. The problems are as follows : - influence of the island on the local wave climate, or swell, and consequent shoreline changes, - influence of the island on tidal currents and resulting evolution of the sandy sea bed, - dispersion of industrial effluents. The effect of the island on swell and on shore stability and the calculation of pollutant dispersion are approached by the use of mathematical models ; the effect of the island on tidal currents is analysed on a reduced scale physical model.

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