Preparing the books to read every day is enjoyable for many people. However, there are still many people who also don't like reading. This is a problem. But, when you can support others to start reading, it will be better. One of the books that can be recommended for new readers is dynamics and modelling of ocean waves. This book is not kind of difficult book to read. It can be read and understand by the new readers.

Dynamics and Modelling of Ocean Waves

Beach–dune system morphodynamics is probably one of the most classical coastal engineering problems. While the topic has been studied extensively and literature is plentiful of considerable research contributions, from the authors’ knowledge the subject is still challenging for coastal and environmental sciences. As a part of the Special Issue entitled “Beach–dune system morphodynamics” of this Journal, the present paper reviews traditional issues and design advances building bridges between potential risks and adaptation measures. The benefits of nature-based and hybrid solutions and the need for multidisciplinary studies and approaches to promote sustainable and resilient conservation of the coastal environment are emphasized. Considering the importance and complexity of the subject, this work cannot be fully complete. It is limited to providing a general overview and outlining some important directions intending to serve as a springboard for further research in the field of beach–dune system morphodynamics.

https://www.mdpi.com/2077-1312/10/5/627/pdf?version=1651746846

Beach–Dune System Morphodynamics

Numerous questions and problems on Earth and questions with respect to other planets arise from morphodynamic processes caused by sediment movements driven by flows of fluids, such as water, air and other gases. A sediment surface opposes the current with a resistance that is determined by its skin or grain roughness. As soon as sand waves, such as ripples and/or dunes, are formed, these bedforms cause a further resistance to the flow, the so-called form roughness. Dependent on the dimensions of the ripples and dunes, the form roughness can be much more pronounced than the skin roughness. The relevant literature provides a large number of solution approaches based on different basic ideas and different result quality. The aim of this paper is a comparative analysis of solution approaches from the literature. For this purpose, 14 approaches to bedform-related friction in the subaqueous case are evaluated using 637 measurements from laboratory and natural settings. We found that all approaches were significantly more accurate for ripples than for dunes. Since this was equally the case for all approaches tested, it is reasonable to assume that this is caused by measurement inaccuracies for dunes in the natural case rather than due to the approaches themselves. The approach of Engelund 1977 proved to be most accurate among all approaches investigated here. It is based on the Borda–Carnot formulation and an additional empirical term. An analytical derivation and justification is provided for this additional term.

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Roughness Effects of Subaquaeous Ripples and Dunes

This study explores the spatiotemporal variability of extreme wave storms around the Canary archipelago, with special focus on the southern coastal flank of Tenerife island, a strategic beach tourism destination of large socioeconomic importance. To this end, experimental and simulated data of winds and waves are used to study the severity, seasonality, and directionality of wave storms with considerable potential to cause significant impact on beaches. Furthermore, tidal experimental records are employed to test the joint occurrence of wave storms and significantly high sea levels. Long-term statistical analysis of extreme wave storms at different locations reveals a complex spatial pattern of wave storminess around the islands and in the southern flank of Tenerife, due to the intricacy of the coastline geometry, the presence of deep channels between islands, the high altitude and complex topography of the islands, and the sheltering effects exerted by each island over the others, depending on the directionality of the incident wave fields. In particular, south of Tenerife, the energy content and directionality of wave storms show substantial spatial variability, while the timing of extreme wave storms throughout the year exhibits a marked seasonal character. A specific extreme storm is examined in detail, as an illustrative case study of severe beach erosion and infrastructure damage.

https://www.mdpi.com/2076-3263/11/6/237/pdf

Spatiotemporal variability of extreme wave storms in a beach tourism destination area

After the construction of desert highway, the physiognomy changes caused by surface wind erosion and accumulation not only seriously threaten the stability of road structure, but also have a tremendous impact on the safety of the highway operation and the maintenance work on the highway. The purpose of this paper is to explore the change of sand sedimentation and the law of sand transport along the highway in the moving dune areas, and to clarify the change of sand flow and the formation mechanism of sand damage in the moving dune areas. Taking the test section of Wuhai-Maqin Expressway in the hinterland of Tengger Desert as the research object, the on-site observation of sand accumulation and the recording of wind information by small weather stations were adopted, supplemented by CFD numerical simulation method, in order to provide reference for the construction of sand control system in moving dune areas. The study results show that: (1) Dunes not only obstruct wind-drift sand but are also the sediment source condition for forming road sand. The windward dunes near the road are affected by wind and the deposition of sand will quickly bury the road in the strong wind season. (2) Compared with highways with flat terrain, the existence of dunes affects the flow field structure and the distribution of sand sedimentation on the highway, in which, under the influence of the gathering effect, the flow velocity reaches the maximum at the top of the dune and a large low-speed recirculation zone is formed on the lee side of the dune, easily causing sand accumulation. (3) Sediment accumulates at the windward side of the embankment or dune where sandy air current is easy to saturate. However, with the increase of wind speed, in addition to the grit carried by the sandy air current itself, new sand rolled up on the windward side of the dunes also form deposits on the road surface and the amount of sand-accumulation on highway surface and leeward side tends to increase. As a result, for the highway in drifting sand dunes areas, sediment prevention and control measures should be taken actively. It is necessary to remove sediment from the road in time and reduce the moving speed of sand dunes and the deposition range of wind-sand flow, ultimately for the purpose of reducing the damage wind-sand activity causes to the highway in desert.

/pdf/study-on-sand-accumulation-changes-of-highway-and-formation-2j06swbj.pdf

Study on Sand-Accumulation Changes of Highway and Formation Mechanism of Sand Damage in Drifting Dunes Areas

Dune recovery interventions that integrate natural, sustainable, and soft solutions have become increasingly popular in coastal communities. In the present study, the reliability of an innovative non-toxic colloidal silica-based solution for coastal sand dunes has been verified for the first time by means of laboratory experiments. An extensive experimental campaign aimed at studying the effectiveness of the use of nanosilica has been conducted in the 2D wave flume of the EUMER laboratory at the University of Salento (Italy). The study was first based on a horizontal seabed and then a cross-shore beach-dune profile was drawn similar to those generally observed in nature. Detailed measurements of wave characteristics and observed bed and cross-shore beach-dune profiles were analyzed for a wide range of wave conditions. In both cases, two sets of experiments were carried out. After the first set of experiments performed resembling the native conditions of the models composed with natural sand, the effects of the injection of the mineral colloidal silica-based grout were investigated. The observations show that mineral colloidal silica increases the mechanical strength of non-cohesive sediments reducing the volume of dune erosion, thus improving the resistance and longevity of the beach-dune system.

Use of Nanosilica for Increasing Dune Erosion Resistance during a Sea Storm

Between the evening of October 23rd and the evening of October 24th 2017, a sea storm hit the city of Bari, along the Adriatic coast, in the south of Italy, causing widespread damages. Due to the a...

Davide Strafella

Papers

Use of Nanosilica for Increasing Dune Erosion Resistance during a Sea Storm

Analysis of the sea storm of 23rd-24th October 2017 offshore Bari (Italy)