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Marina Navarro

Universidad de Cadiz, Applied Physics, Post-Doc

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Address: Puerto Real, Andalucia, Spain

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Gregorio Gomez Pina

F. Javier Gracia

Isabel Caballero

Luis Abraham Domínguez González

Luis Hernández-Calvento

Patricia Ciccioli

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Papers by Marina Navarro

Actual aeolian sand drift power in the Valdevaqueros dune system (Tarifa)

La duna de Valdevaqueros está situada en uno de los puntos más ventosos de Europa. Su elevada mov... more La duna de Valdevaqueros está situada en uno de los puntos más ventosos de Europa. Su elevada movilidad y la frecuente aparición de vientos de levante de gran intensidad han provocado un serio problema de invasión masiva y continua de arena sobre la carretera autonómica, que lleva a la población de Punta Paloma (Tarifa). En el cálculo de transporte eólico de sedimentos, se suelen utilizar varias formulaciones, pero que parecen no ajustarse a la situación real de Valdevaqueros. Por ello, se han colocado una torre de anemómetros y una trampa de arena de fabricación propia, capaz de recoger arena a distintas alturas o niveles. La tasa media de transporte in situ para un viento de intensidad moderada ha sido de hasta 3 veces superior a la obtenida teóricamente. Los resultados granulométricos obtenidos han sido de gran ayuda para la comprensión de la distribución de los granos de arena a diferentes alturas.Valdevaqueros dune is located in one of the windiest points of Europe. The high du...

Study of sand density variation to achieve beach nourishment optimization

Para reducir la erosión costera, las regeneraciones de playas han desempeñado un papel fundamenta... more Para reducir la erosión costera, las regeneraciones de playas han desempeñado un papel fundamental en la protección de la costa a nivel mundial. Muchos países invierten grandes cantidades de dinero en este tipo de actuaciones pese a las consecuencias económicas, sociales y ambientales. A pesar de las numerosas investigaciones realizadas respecto a la eficiencia de las regeneraciones de playa, existen aspectos técnicos que aún no han sido investigados. Con el fin de estudiar la variación de volumen de arena tras una regeneración de playa, en este estudio, se describe una técnica rápida y novedosa para medir in situ la densidad de la arena mediante un densímetro nuclear. Junto a estas medidas, se han desarrollado análisis granulométricos y levantamientos topográficos en diferentes playas de la provincia de Cádiz. Tras las regeneraciones, se han apreciado importantes diferencias de nivel del terreno debidas, en parte, a la variación de la densidad y porosidad de la arena. Desde un punt...

Audiovisual Resources as a Useful Tool to Improve the Teaching of Coastal Engineering (Marine Science BSC Degree)

Lessons for a technical subject were explained in videos which were later uploaded to YouTube and... more Lessons for a technical subject were explained in videos which were later uploaded to YouTube and to a virtual classroom within the Marine Science BSc degree. In this way, these files, complemented with ppt slide presentations, were also useful for the Erasmus students with a low level of Spanish. Finally, some online questionnaires were also uploaded in order to allow the users check by themselves their knowledge. The different steps of the followed methodology are explained and screenshots of the virtual are also displayed. The use of Moodle was therefore highly encouraged and the results of a survey conducted by the teachers of the course showed the utility of the technique proposed herein.

Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)

Geologica Acta, 2015

The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occ... more The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence ofstrong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array anda self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in orderto determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results showthat 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoreticaltransport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected,which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis ofdifferent statistical grain-size parameters helped to understand sand transport distribution at different heights.

Different behaviour and management of two littoral dunes in southern Spain

The northwestern coast of Cadiz (Spain) presents a variety of coastal engineering and coastal man... more The northwestern coast of Cadiz (Spain) presents a variety of coastal engineering and coastal management problems whose solution is not an easy task due to the complexity of the parameters involved. Two cases of dune zone management in this a rea are described in this paper. Punta Candor beach, a very popular recreational area in Rota municipality, experiences one of the highest dune erosion rates in Spain of more than 1 m/yr. In order to address this coastal degradation, the Atlantic Andalusian Coastal District has performed beach and dune restoration planning, described in this paper as an example of sustainable coastal management. The Valdevaqueros dune area also represents an

Success on Increasing Number of Students That Pass the Coastal Engineering Subject

Spanish universities are currently undergoing an educational transition that implies significant ... more Spanish universities are currently undergoing an educational transition that implies significant changes in learning and teaching methodologies, in compliance with the European Higher Education Area (EHEA). Within this phase, the use of information and communication technologies (ICT) provides the opportunity to enhance student performance and improve academic assessment. An experimental procedure has been implemented within the Coastal Engineering course (Sea Sciences Faculty) to decrease academic failure (to date, 25% of no-show and 35% of fails), and to allow students to achieve better grades. During the last academic year, students were encouraged to follow a new learning plan based on coursework performance, the duration of which was similar to the theoretical lessons, i.e., two hours a week. Assignments were not mandatory, and they only represented 10% of the final mark. Weekly homework was directly related to the main aspects of the theoretical lessons, and included practical...

Comparación entre el transporte eólico teórico y real en la duna de Valdevaqueros (Cádiz)

Resumen La duna de Valdevaqueros se caracteriza por su elevada movilidad y capacidad de transport... more Resumen La duna de Valdevaqueros se caracteriza por su elevada movilidad y capacidad de transporte sedimentario, cuyos efectos suponen un reto constante para el conocimiento de su dinámica eólica y el control de su avance. A pesar de que existen varias formulaciones clásicas para el cálculo del transporte potencial de sedimentos, se desconoce en qué grado éstas se ajustan a la realidad. Para ello, se hace necesario el estudio de la tasa real de transporte eólico de la duna de Valdevaqueros, mediante la colocación de trampas de arena y anemómetros. Planteando la calibración de la ecuación de Bagnold, nos permitirá obtener una relación más precisa entre la capacidad de transporte téorica y la real hallada para dicha duna.

Mobility evolution of a highly active coastal dune (SW Spain) in several terms

Diapositiva 1 MNP66 Con la venia del tribunal, procedo a defender mi tesis doctoral titulada:

Optimization of beach profile spacing: an applicable tool for coastal monitoring

Scientia Marina, 2011

This paper presents a simplified and straightforward method for determining optimal beach profile... more This paper presents a simplified and straightforward method for determining optimal beach profile spacing from an economic point of view with an admissible error. This error can be computed theoretically by comparing different profile spacings from two consecutive bathymetries. When a beach sediment budget (from previous monitoring surveys) or the volume density of a beach nourishment project is known, a virtual bathymetry can be designed; therefore, a unique real bathymetry would be needed. The method is applied and analysed for beaches with different characteristics regarding tide, energy, morphology and natural features. The results indicate that the estimated errors are proportional to a beach heterogeneity factor, depending on each particular beach case, such that large spacings do not necessarily induce large errors. In our case, profile spacings of 100 m induce average errors of less than 5%. Moreover, differences in tidal range and the existence of rocky reefs do not seem to affect the results.

Turbidity and Other Effects Resulting from Trafalgar Sandbank Dredging and Palmar Beach Nourishment

Journal of Waterway, Port, Coastal, and Ocean Engineering, 2011

Beach-nourishment requirements on the southwestern Spanish coast have led to a significant increa... more Beach-nourishment requirements on the southwestern Spanish coast have led to a significant increase in offshore dredging. Following a new research line, assessment of changes recorded in physicochemical and biological parameters due to dredging and dumping operations was performed at the Cape of Trafalgar and Palmar Beach during June and July 2008. Turbidity, salinity, pH, dissolved oxygen, temperature, and suspended-sediment data were collected at 10 stations. At the end of the study, a three-campaign monitoring program was implemented for 1 year to assess the possible effects on biological communities and sediment properties. The relevant results, such as the average extent of the sediment plume (< 400 m) and its persistence in the environment (< 10 min), are discussed in this paper. A precise correlation between turbidity and suspended sediments and the recovery time of ecological balance were also established. Furthermore, minimal and reversible effects caused by dredging and dumping operations in this type of marine environment were identified.

Beach nourishment effects on sand porosity variability

Coastal Engineering, 2014

A standard assumption in coastal engineering is that the porosity of natural beach sand (non-cohe... more A standard assumption in coastal engineering is that the porosity of natural beach sand (non-cohesive) is 40%. However, is this assumption correct for all beach sand? This paper proposes an accurate and simplified method to assess changes in sand porosity after beach nourishment by means of in-situ density surveys through a nuclear densimeter. This novel application has been applied to different beaches in the southwest of Spain according to the tidal range, grain size and beach morphology in several terms. General results show that sand porosities range from 25.6% to 43.4% after beach nourishment works. This research can be considered a support tool in coastal engineering to find shifting sand volumes as a result of sand porosity variability after beach nourishment and later marine influence.

Actuaciones de realimentación, conservación y obras de emergencia en el litoral gaditano: aspectos técnicos, medioambientales y sociales

Comparación De La Turbidez Natural Del Placer De Meca Frente a La Generada Por Un Dragado

La erosión de las playas y el retroceso de la línea de costa se presenta como un hándicap a resol... more La erosión de las playas y el retroceso de la línea de costa se presenta como un hándicap a resolver para las administraciones con competencia. La actual problemática que presenta la escasez de fuentes de arena apta para regeneraciones de playa a lo largo del litoral español, conlleva a la búsqueda de yacimientos de arena marítimos mediante obras de

Evolución de las tasas de avance de dos sistemas dunares costeros: Bolonia y Valdevaqueros (TM TARIFA)

Assessment high dune activity Navarro et al 2011

by Haim Tsoar, Marina Navarro, and Juan J Munoz-perez

Dune activity or stability has usually been studied over long time periods; however, this may not... more Dune activity or stability has usually been studied over long time periods; however, this may not reflect changes that occur in the short term, especially for highly active dunefields. Extreme wind conditions that are generated near the Strait of Gibraltar (SW Spain) have given rise to the transgressive Valdevaqueros dunefield. The current work focuses on analyzing the sand drift potential and the evolution of the dune profile in the medium term (months), the short term (days) and the very short term (hours). Topographic data, which were collected with a differential GPS, were interpreted from reconstructed empirical orthogonal functions (EOF). The results showed that generally the dune profile presented shifting morphologies, especially around the crest and brink, and a trend towards migration to a gentler steady state. As a result, the leeward side adopted continuous slope variations during the different survey periods, whereas the windward slope did not undergo any significant change. Lateral and vertical displacements were analyzed during a severe easterly sandstorm, when the dune brink experienced an advance migration rate of 1.75 m in 24 h. Sand transport rates of 25.5-36.5 m 3 m − 1 month − 1 , 22.52 m 3 m − 1 day − 1 and 0.93 m 3 m − 1 h − 1 were measured for the medium term, short term and very short term, respectively. These values were compared to the theoretical sand transport rate for Valdevaqueros dune, based on the classic Bagnold equation as well other more recent formulae, to obtain a ratio between the real and the theoretical rates for each study period. These results together with the sand drift potential (up to 10,000 vector units) demonstrate that Valdevaqueros (Tarifa) is a dunefield with one of the highest sand transport capacities in Europe.

Actual aeolian sand drift power in the Valdevaqueros dune system (Tarifa)

La duna de Valdevaqueros está situada en uno de los puntos más ventosos de Europa. Su elevada mov... more La duna de Valdevaqueros está situada en uno de los puntos más ventosos de Europa. Su elevada movilidad y la frecuente aparición de vientos de levante de gran intensidad han provocado un serio problema de invasión masiva y continua de arena sobre la carretera autonómica, que lleva a la población de Punta Paloma (Tarifa). En el cálculo de transporte eólico de sedimentos, se suelen utilizar varias formulaciones, pero que parecen no ajustarse a la situación real de Valdevaqueros. Por ello, se han colocado una torre de anemómetros y una trampa de arena de fabricación propia, capaz de recoger arena a distintas alturas o niveles. La tasa media de transporte in situ para un viento de intensidad moderada ha sido de hasta 3 veces superior a la obtenida teóricamente. Los resultados granulométricos obtenidos han sido de gran ayuda para la comprensión de la distribución de los granos de arena a diferentes alturas.Valdevaqueros dune is located in one of the windiest points of Europe. The high du...

Study of sand density variation to achieve beach nourishment optimization

Para reducir la erosión costera, las regeneraciones de playas han desempeñado un papel fundamenta... more Para reducir la erosión costera, las regeneraciones de playas han desempeñado un papel fundamental en la protección de la costa a nivel mundial. Muchos países invierten grandes cantidades de dinero en este tipo de actuaciones pese a las consecuencias económicas, sociales y ambientales. A pesar de las numerosas investigaciones realizadas respecto a la eficiencia de las regeneraciones de playa, existen aspectos técnicos que aún no han sido investigados. Con el fin de estudiar la variación de volumen de arena tras una regeneración de playa, en este estudio, se describe una técnica rápida y novedosa para medir in situ la densidad de la arena mediante un densímetro nuclear. Junto a estas medidas, se han desarrollado análisis granulométricos y levantamientos topográficos en diferentes playas de la provincia de Cádiz. Tras las regeneraciones, se han apreciado importantes diferencias de nivel del terreno debidas, en parte, a la variación de la densidad y porosidad de la arena. Desde un punt...

Audiovisual Resources as a Useful Tool to Improve the Teaching of Coastal Engineering (Marine Science BSC Degree)

Lessons for a technical subject were explained in videos which were later uploaded to YouTube and... more Lessons for a technical subject were explained in videos which were later uploaded to YouTube and to a virtual classroom within the Marine Science BSc degree. In this way, these files, complemented with ppt slide presentations, were also useful for the Erasmus students with a low level of Spanish. Finally, some online questionnaires were also uploaded in order to allow the users check by themselves their knowledge. The different steps of the followed methodology are explained and screenshots of the virtual are also displayed. The use of Moodle was therefore highly encouraged and the results of a survey conducted by the teachers of the course showed the utility of the technique proposed herein.

Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)

Geologica Acta, 2015

The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occ... more The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence ofstrong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array anda self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in orderto determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results showthat 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoreticaltransport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected,which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis ofdifferent statistical grain-size parameters helped to understand sand transport distribution at different heights.

Different behaviour and management of two littoral dunes in southern Spain

The northwestern coast of Cadiz (Spain) presents a variety of coastal engineering and coastal man... more The northwestern coast of Cadiz (Spain) presents a variety of coastal engineering and coastal management problems whose solution is not an easy task due to the complexity of the parameters involved. Two cases of dune zone management in this a rea are described in this paper. Punta Candor beach, a very popular recreational area in Rota municipality, experiences one of the highest dune erosion rates in Spain of more than 1 m/yr. In order to address this coastal degradation, the Atlantic Andalusian Coastal District has performed beach and dune restoration planning, described in this paper as an example of sustainable coastal management. The Valdevaqueros dune area also represents an

Success on Increasing Number of Students That Pass the Coastal Engineering Subject

Spanish universities are currently undergoing an educational transition that implies significant ... more Spanish universities are currently undergoing an educational transition that implies significant changes in learning and teaching methodologies, in compliance with the European Higher Education Area (EHEA). Within this phase, the use of information and communication technologies (ICT) provides the opportunity to enhance student performance and improve academic assessment. An experimental procedure has been implemented within the Coastal Engineering course (Sea Sciences Faculty) to decrease academic failure (to date, 25% of no-show and 35% of fails), and to allow students to achieve better grades. During the last academic year, students were encouraged to follow a new learning plan based on coursework performance, the duration of which was similar to the theoretical lessons, i.e., two hours a week. Assignments were not mandatory, and they only represented 10% of the final mark. Weekly homework was directly related to the main aspects of the theoretical lessons, and included practical...

Comparación entre el transporte eólico teórico y real en la duna de Valdevaqueros (Cádiz)

Resumen La duna de Valdevaqueros se caracteriza por su elevada movilidad y capacidad de transport... more Resumen La duna de Valdevaqueros se caracteriza por su elevada movilidad y capacidad de transporte sedimentario, cuyos efectos suponen un reto constante para el conocimiento de su dinámica eólica y el control de su avance. A pesar de que existen varias formulaciones clásicas para el cálculo del transporte potencial de sedimentos, se desconoce en qué grado éstas se ajustan a la realidad. Para ello, se hace necesario el estudio de la tasa real de transporte eólico de la duna de Valdevaqueros, mediante la colocación de trampas de arena y anemómetros. Planteando la calibración de la ecuación de Bagnold, nos permitirá obtener una relación más precisa entre la capacidad de transporte téorica y la real hallada para dicha duna.

Mobility evolution of a highly active coastal dune (SW Spain) in several terms

Diapositiva 1 MNP66 Con la venia del tribunal, procedo a defender mi tesis doctoral titulada:

Optimization of beach profile spacing: an applicable tool for coastal monitoring

Scientia Marina, 2011

This paper presents a simplified and straightforward method for determining optimal beach profile... more This paper presents a simplified and straightforward method for determining optimal beach profile spacing from an economic point of view with an admissible error. This error can be computed theoretically by comparing different profile spacings from two consecutive bathymetries. When a beach sediment budget (from previous monitoring surveys) or the volume density of a beach nourishment project is known, a virtual bathymetry can be designed; therefore, a unique real bathymetry would be needed. The method is applied and analysed for beaches with different characteristics regarding tide, energy, morphology and natural features. The results indicate that the estimated errors are proportional to a beach heterogeneity factor, depending on each particular beach case, such that large spacings do not necessarily induce large errors. In our case, profile spacings of 100 m induce average errors of less than 5%. Moreover, differences in tidal range and the existence of rocky reefs do not seem to affect the results.

Turbidity and Other Effects Resulting from Trafalgar Sandbank Dredging and Palmar Beach Nourishment

Journal of Waterway, Port, Coastal, and Ocean Engineering, 2011

Beach-nourishment requirements on the southwestern Spanish coast have led to a significant increa... more Beach-nourishment requirements on the southwestern Spanish coast have led to a significant increase in offshore dredging. Following a new research line, assessment of changes recorded in physicochemical and biological parameters due to dredging and dumping operations was performed at the Cape of Trafalgar and Palmar Beach during June and July 2008. Turbidity, salinity, pH, dissolved oxygen, temperature, and suspended-sediment data were collected at 10 stations. At the end of the study, a three-campaign monitoring program was implemented for 1 year to assess the possible effects on biological communities and sediment properties. The relevant results, such as the average extent of the sediment plume (< 400 m) and its persistence in the environment (< 10 min), are discussed in this paper. A precise correlation between turbidity and suspended sediments and the recovery time of ecological balance were also established. Furthermore, minimal and reversible effects caused by dredging and dumping operations in this type of marine environment were identified.

Beach nourishment effects on sand porosity variability

Coastal Engineering, 2014

A standard assumption in coastal engineering is that the porosity of natural beach sand (non-cohe... more A standard assumption in coastal engineering is that the porosity of natural beach sand (non-cohesive) is 40%. However, is this assumption correct for all beach sand? This paper proposes an accurate and simplified method to assess changes in sand porosity after beach nourishment by means of in-situ density surveys through a nuclear densimeter. This novel application has been applied to different beaches in the southwest of Spain according to the tidal range, grain size and beach morphology in several terms. General results show that sand porosities range from 25.6% to 43.4% after beach nourishment works. This research can be considered a support tool in coastal engineering to find shifting sand volumes as a result of sand porosity variability after beach nourishment and later marine influence.

Actuaciones de realimentación, conservación y obras de emergencia en el litoral gaditano: aspectos técnicos, medioambientales y sociales

Comparación De La Turbidez Natural Del Placer De Meca Frente a La Generada Por Un Dragado

La erosión de las playas y el retroceso de la línea de costa se presenta como un hándicap a resol... more La erosión de las playas y el retroceso de la línea de costa se presenta como un hándicap a resolver para las administraciones con competencia. La actual problemática que presenta la escasez de fuentes de arena apta para regeneraciones de playa a lo largo del litoral español, conlleva a la búsqueda de yacimientos de arena marítimos mediante obras de

Evolución de las tasas de avance de dos sistemas dunares costeros: Bolonia y Valdevaqueros (TM TARIFA)

Assessment high dune activity Navarro et al 2011

by Haim Tsoar, Marina Navarro, and Juan J Munoz-perez

Dune activity or stability has usually been studied over long time periods; however, this may not... more Dune activity or stability has usually been studied over long time periods; however, this may not reflect changes that occur in the short term, especially for highly active dunefields. Extreme wind conditions that are generated near the Strait of Gibraltar (SW Spain) have given rise to the transgressive Valdevaqueros dunefield. The current work focuses on analyzing the sand drift potential and the evolution of the dune profile in the medium term (months), the short term (days) and the very short term (hours). Topographic data, which were collected with a differential GPS, were interpreted from reconstructed empirical orthogonal functions (EOF). The results showed that generally the dune profile presented shifting morphologies, especially around the crest and brink, and a trend towards migration to a gentler steady state. As a result, the leeward side adopted continuous slope variations during the different survey periods, whereas the windward slope did not undergo any significant change. Lateral and vertical displacements were analyzed during a severe easterly sandstorm, when the dune brink experienced an advance migration rate of 1.75 m in 24 h. Sand transport rates of 25.5-36.5 m 3 m − 1 month − 1 , 22.52 m 3 m − 1 day − 1 and 0.93 m 3 m − 1 h − 1 were measured for the medium term, short term and very short term, respectively. These values were compared to the theoretical sand transport rate for Valdevaqueros dune, based on the classic Bagnold equation as well other more recent formulae, to obtain a ratio between the real and the theoretical rates for each study period. These results together with the sand drift potential (up to 10,000 vector units) demonstrate that Valdevaqueros (Tarifa) is a dunefield with one of the highest sand transport capacities in Europe.