Beach Nourishment: A 21st Century Review

Long-term erosion is experienced by most of the coastlines worldwide, and it is usually attributed not only to sea level rise but also to the retention of sand in dams, the occupation of dry beaches by urbanized areas, the disturbance of the natural patterns of longshore drift, the mining of sand as building material for construction, and so on. Beach nourishment has evolved as the favored erosion-mitigation strategy in many areas of the world. The increasing number of people living on the coast, the safety of those people, and the high values of coastal property are all factors that have made beach nourishment a cost-effective strategy for managing erosion in many locations. However, a new scenario of sand scarcity and environmental care has arisen in recent decades. There have been a number of different and interesting cases of various aspects of beach nourishment in the last years. The purpose of this Special Issue has been to publish the different experiences and research related to this topic. After a careful review process, nine papers were included. Their thematic contributions include the use of field methods such as the use of remotely piloted aircraft systems (RPAS) or un-manned aerial vehicles (UAV) for faster and automated mapping of the coastal area or the acquisition of geomagnetic data in marine environments; the use of multi-approach methodologies to assess the interaction between coastal structures and beaches and in particular of submerged pipelines; the need to adopt a plan for the optimal use of limited resources of available sediment from a regional perspective and the assessment of the effectiveness of beach nourishments; the understanding of the role of submerged geological control of beach profiles together with the implementation of innovative beach nourishment strategies while facing the non-trivial challenge of visualizing and communicating mesoscale modeling assumptions, uncertainties and outcomes to both coastal specialists and decision makers; and the influence of sea-level rise and erosion on diminution of beach habitats

Lupinus mariae-josephii (Leguminosae) en la comarca de Camp de Turia (Valencia)

Se aporta para la comarca valenciana de Camp de Túria una nueva población de Lupinus mariae-josephae (Leguminosae), especie endémica de la Comunidad Valenciana (España), catalogada como Vulnerable en el Catálogo Valenciano de Especies de Flora Amenazadas. La población se localiza en el término municipal de Riba-roja de Túria y representa hasta el momento la más septentrional de su área de distribución.A new population of Lupinus mariae-josephae (Leguminosae) from Camp de Túria region is provided. This species is an endemic plant of Valencian Community (Spain) and it is listed as Vulnerable in the Valencian Catalog of Threatened Plant Species. This population is located in Riba-roja de Túria and constitutes the most northern of this species

A Comparison of Beach Nourishment Methodology and Performance at Two Fringing Reef Beaches in Waikiki (Hawaii, USA) and Cadiz (SW Spain)

Fringing reefs have significant impacts on beach dynamics, yet there is little research on how they should be considered in beach nourishment design, monitoring, and conservation works. Thus, the behavior and characteristics of nourishment projects at two reef protected beaches, Royal Hawaiian Beach (RHB) in Hawaii, USA, and Victoria Beach (VB) in Cadiz, Spain, are compared to provide transferable information for future nourishment projects and monitoring in fringing reef environments. The nourishment cost at RHB was nine times higher than VB. This is partly due to lower total volume and a more complex placement and spreading method at RHB, despite the much closer borrow site at RHB. There was a significant difference in post-nourishment monitoring frequency and assessment of accuracy. RHB elevation was monitored quarterly for 2.7 years at 30 m-spaced profiles, compared to 5 years of biannual surveys of 50 m-spacing at VB. An additional problem related to the presence of reefs at both RHB and VB was estimating the beach volume increase after nourishment, due to variable definitions of the 'beach' area and high alongshore variability in reef topography. At sites where non-native sediment is used, it is imperative to understand how wave and current energy changes due to reefs will influence nourishment longevity. Thus, differences in erosion and accretion mechanisms at both beaches have been detected, though are still little understood. Moreover, discrepancies in sediment porosity between the two sites (which should be surveyed in future nourishments) have been found, probably due to differences in the nourishment sand transportation and distribution methods. In summary, more dialogue is needed to explicitly consider the influence of fringing reefs on coastal processes and beach nourishment projects

Scissor-Hinged Deployable Structures Supported Perimetrally on Rectangular Bases

[Abstract] Deployable bar structures on a rectangular base present the problems of closing the ends and longitudinal stabilization. Some proposals have been made to resolve them, mainly by creating mouths, but their application to composite geometries is problematic. On-the-bias deployable structures adequately solve both problems as they are supported around their entire perimeter, have a strong three-dimensional operation and only use load-bearing bars. The text analyses this type of deployable structures, their requirements and possibilities. A study on the combination of polar and translational units in a single deployable structure is then carried out, focusing on the study of on-the-bias deployable structures with perimeter polar modules that allow the effective height of the designs to be increased. Finally, the architectural possibilities of the system are studied, which make it possible to resolve overhangs, vertical openings in the roof, and T- or L-shaped ground plans, guaranteeing the modularity of the system.This research was carried out as a part of the Spanish Research Project on Deployable and Modular Constructions for Situations of Humanitarian Catastrophe, CODEMOSCH (Reference BIA2016-79459-R), funded by the Spanish Ministry of Industry, Energy, and Competitiveness (MINECO)

Modified Bistable Modules for Bias Deployable Structures

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Bias deployable grids are meshes with two directions of rotation on the ground plan with respect to the edges. They offer benefits such as three-dimensional resistance with supports around the entire perimeter of a rectangular layout, and consist exclusively of load-bearing scissors as opposed to the usual combinations of load-bearing scissors and bracing scissors. However, their resistance to angular distortion is limited, and they require auxiliary elements to maintain the fully deployed position. Nevertheless, they are very promising solutions for medium-span emergency buildings. This paper proposes a bistable module adapted to bias deployable structures. The geometrical incompatibilities of several modules are analysed together with their behaviour based on the kinematic models that were built, which alternate different types of nodes and different geometries of the perimeter scissors, making it possible to calibrate the level of incompatibility introduced. The dimensions of the nodes are also taken into account. The tests are checked against the results of several series of dynamic calculations.This research was carried out as a part of the Spanish Research Project on Deployable and Modular Constructions for Situations of Humanitarian Catastrophe, CODEMOSCH (Reference BIA2016-79459-R), funded by the Spanish Ministry of Industry, Energy, and Competitiveness (MINECO). Financing of the open access fee: Universidade da Coruña / CISU

Evidencias del incremento en la movilidad de dunas costeras en el último medio siglo como respuesta a la intervención humana

Given the risk of two roads being buried by the sand of two highly mobile coastal dunes (Valdevaqueros and Bolonia, SW Spain), several measures have been taken over the last half century in order to stabilize them or at least slow their progress: installation of several rows of 1-m-high concrete structures, planting of species such as Pinus pinea, Retama monosperma and Ammophila arenaria, wicker and wooden fencing, and sand mining (only performed on the Valdevaqueros dunefield). The evolution of the two dunes was investigated through the interpretation of intensive topographical monitoring and aerial photography. Average migration rates of approximately 10 m yr–1 were detected and the burial of anthropic structures has eventually occurred. This process has caused a serious regional problem, making dune management of these areas a difficult challenge. The comparison of the evolution of these two dunes has been of great importance in assessing the effect of historical human intervention and has provided a new perspective for future dune management strategies. The results obtained show that management measures based on sand removal have been proven to be unsustainable. Moreover, the monitoring methodology presented herein has proven very useful in predicting dune advance rates. For instance, the Bolonia dune could reach the nearest road in approximately 12 years.Se han tomado diferentes medidas a lo largo del último medio siglo tratando de estabilizar o al menos ralentizar el progreso de dos dunas costeras de alta movilidad (Valdevaqueros y Bolonia, SW España) dado el riesgo de enterramiento de sendas carreteras: Entre las medidas tomadas cabe destacar la instalación de filas de estructuras de hormigón de 1 m de altura, la plantación de diferentes especies (como el Pinus pinea, la Retama monosperma o la Ammophila arenaria), vallas de madera y brezo, y la extracción de arena (sólo en la duna de Valdevaqueros). La evolución de ambas dunas se ha investigado a través de la comparación de levantamientos topográficos y fotografías aéreas. Se han detectado tasas medias de avance de aproximadamente 10 m/año hasta que, finalmente, se han enterrado estructuras antrópicas. Este proceso ha causado graves problemas convirtiendo en un difícil reto la gestión de dunas de estas áreas. La comparación de la evolución de estas dos dunas ha resultado de gran importancia a la hora de evaluar el efecto de la intervención humana, y ha proporcionado una nueva perspectiva para las futuras estrategias de gestión. Entre los resultados obtenidos, debería destacarse el que la gestión basada en la retirada de arena ha resultado insostenible. Además, la metodología de seguimiento aquí presentada ha probado ser de gran utilidad al predecir las tasas de avance de las dunas. Por ejemplo, la duna de Bolonia podría alcanzar la carretera próxima en unos 12 años

Evidence of coastal dune mobility increases over the last half century in response to historical human intervention

Given the risk of two roads being buried by the sand of two highly mobile coastal dunes (Valdevaqueros and Bolonia, SW Spain), several measures have been taken over the last half century in order to stabilize them or at least slow their progress: installation of several rows of 1-m-high concrete structures, planting of species such as Pinus pinea, Retama monosperma and Ammophila arenaria, wicker and wooden fencing, and sand mining (only performed on the Valdevaqueros dunefield). The evolution of the two dunes was investigated through the interpretation of intensive topographical monitoring and aerial photography. Average migration rates of approximately 10 m yr–1 were detected and the burial of anthropic structures has eventually occurred. This process has caused a serious regional problem, making dune management of these areas a difficult challenge. The comparison of the evolution of these two dunes has been of great importance in assessing the effect of historical human intervention and has provided a new perspective for future dune management strategies. The results obtained show that management measures based on sand removal have been proven to be unsustainable. Moreover, the monitoring methodology presented herein has proven very useful in predicting dune advance rates. For instance, the Bolonia dune could reach the nearest road in approximately 12 years

Naturalization: a New Concept Developed and Carried Out in the Subject " Environmental Technology " of Degree in Industrial Engineering

Environmental Technology is a 6 credits transversal subject included in the curriculum of all the degrees in Industrial Engineering at the Higher Polytechnic School of the University of Seville. In the last 5 academic courses, the students of this matter have been working with the concept of “Naturalization”. In the different topics which are studied in this subject, they have to apply the naturalization of the systems in order to use natural resources for improving processes. The Naturalization implies improvements in energetic efficiency, development of green spaces and CO2 capture and can be applied the majority of the industrial and urban activities. Some of the most meaningful results that our students have researched are: i) Naturalization of a large pond in a business park in Jaen (Spain) performing its layout and eventually implementing it, using plants to improve water quality and stones for fix them and to give support for bacterial biofilms. The students have improved their skills not only in the increase of new knowledge but in the ability of work in groups and carry out a real project under different points of view. ii) Project of naturalization of a neighbourhood in Seville, based on the increase of green spaces, with vegetal species which are able to capture electromagnetic radiations and CO2 emissions as well. iii) Naturalization of the margins of one lagoon in a park in Seville, transforming the precast panelled walls in breakwater bed of stones planted with bank river plants in order to improve the water quality and the landscape

Master in water engineering a “semi-attendance” university-specific degree with international participation

The Water Engineering Master Course is a university-specific degree at the University of Seville which nowadays can be coursed in two different modalities: “on line” and “semi-attendance”. Its first edition took place at 2000 and since then, the average of graduated students has been of 40 students per course. The semi-attendance mode offers the possibility of being followed in an on-line way from November to June. A Moodle platform provides all the documentation that is required to attend every module, at the end of each one some online questionnaires are also uploaded in order to evaluate the students. Only one of the 10 mandatory modules which make up the course have to be attended in a classroom mode. It takes place during 15 days in July and allows the students to come into contact with the lecturers, professionals of the sector and their own mates as well. During this period both, teachers and students, are lodged in the same residence and all of them have the chance of interchanging experiences in a full teaching-learning process, solving doubts and improving their skills thanks to specific courses, specially designed in function of the lack of knowledge which has been detected during de previous modules, o even, the suggestions received directly from students. Most of the students come from Hispanic countries and in less amount from African and European countries. Actually every July about 80 students and teachers from 25 different countries around the world, meet in Seville to attend this Master. The classes are given in Spanish with translator support if it’s necessary. Different environments, problematic and conditioning factors are studied and a large kind of solutions in water cycle are designed during these days. The requirements to elaborate the final master project are mainly that this one can be used to resolve a real local problem in the student’s origin place and moreover the student can obtain better marks if he/she finds financing to carry it out. In the last 8 years a useful module named “Tools for design” has been included in the program of the Master in order to enable the student in IT, specifically spreadsheets, cad, software for budgeting and measurement, topography and decision support systems. Students who graduate are able to evaluate the most proper technology from a social, technic and economic point of view, as well as, select the most efficient alternatives in order to achieve a sustainable development

Multiplexed vortex beam-based optical tweezers

The design and implementation of a multiplexed spiral phase mask in an experimental optical tweezer setup are presented. This diffractive optical element allows the generation of multiple concentric vortex beams with independent topological charges. The generalization of the phase mask for multiple concentric vortices is also shown. The design for a phase mask of two multiplexed vortices with different topological charges is developed. We experimentally show the transfer of angular momentum to the optically trapped microparticles by enabling orbiting dynamics around the optical axis independently within each vortex. The angular velocity of the confined particles versus the optical power in the focal region is also discussed for different combinations of topological charges