Dynamics and morpho-sedimentary interactions in the lower mesotidal estuary of Villaviciosa (NW Spain) : A management proposal

The accumulation of sediment in the mouth of Villaviciosa estuary (NW Spain) is becoming an obstaclefor the safe navigation in this estuary. One sector of its outer inlet is characterised by a broad shoal linkedwith a longshore bar of a beach, whose erosion is causing the silting of this area. On this basis, this paperaims to describe the processes that occurred in the lower part of the estuary due to the anthropogenicactivities in the channel and inlet. For this purpose, several measurements were made in the watercolumn and in the sedimentary bottoms to characterise the processes that occur in this area. Based onthese results, a dynamic and morpho-sedimentary model was developed to examine the interactionsbetween the lower estuary and the exposed part of the confining barrier beach, which allows to establishthe evolutionary trends of sedimentary bottoms linked to the marina of El Puntal. Different managementmeasures are carried out to reduce the impact of the sediment accumulation on the navigability, such asperiodically dredging in the inlet of the estuary, and the subsequent dumping of the sediments in areasnear to the closure depth. Consequently, future retreat of narrow inlet and sandy shoal can be avoided,maintaining the sedimentary volume in the system

Estuarios de arroyos costeros del occidente de Asturias

Los estuarios menores de Viavélez y Ortiguera con rellenos deficitarios se estudian geomorfológicamente. Las zonaciones longitudinales revelan que las bahías son las mejor desarrolladas, con un segmento externo sumergido permanentemente de tipo arenoso y otro emergido en bajamares sobre el que se construye una gran barra horquillada de reflujo de gravas y arenas. Las colas estuarinas difieren entre sí. dominando las fracciones más groseras. Hay ausencias importantes, como las barreras y las llanuras fangosas y marismas

Morphodynamics, sedimentary and anthropogenic influences in the San Vicente de la Barquera estuary (North coast of Spain)

The estuary of San Vicente de la Barquera occupies two valleys that have incised into soft sedimentary rocks (Lower Mesozoic) and are controlled by inactive faults. These two estuary subsystems, the Escudo (main valley) and Gandarilla, share outer estuarine zones, i.e., a sandy bay and mouth complex. There is a confining barrier consisting of an aeolian dune/beach system that is currently fixed by a NE-trending jetty that has allowed system progradation over the past 50 years. Connected to the inner inlet in the sand bay is a flood-tidal delta, the most important dynamic and sedimentary unit, which exhibits a heart shape caused by the large amplitude of flows in this estuarine zone and channelizes the flows and sediments into the estuary, primarily during rising and high tides. In particular, a counterclockwise rotation due to the Coriolis effect is essential to the development of this sand structure, including the ebb and flood tide structures, primarily spill-over lobes, sand waves and megaripples.The presence of estuarine beaches into the bay is common in many Cantabrian estuaries, even culminating in small dune fields, in this case with anthropic origin.This paper explains the human occupation and port management, besides the dynamic and sedimentary distribution of a bar-barrier estuary and the changes produced in its distal part by construction of two jetties in the mouth

Características morfológicas y sedimentarias de la playa artificial de Poniente (Gijón. Asturias). Evolución 1995-2004

La playa arenosa de Poniente, construida como una playa confinada entre diques artificiales, ha evolucionado como una playa reflejante, caracterizada por el desarrollo de una barra supramareal en los 2/3 centrales de la playa y un frente inter-supraniareal de cierta pendiente, suavizado hacia los extremos laterales, el occidental más protegido. Asimismo, los vientos del NE y NO han generado campos de dunas en ambos extremos de la playa, disminuyendo el espacio original a medida que el oleaje ha removilizado las áreas más interna

Analyzing coastal environments by means of functional data analysis

Here we used Functional Data Analysis (FDA) to examine particle-size distributions (PSDs) in a beach/shallow marine sedimentary environment in Gijón Bay (NW Spain). The work involved both Functional Principal Components Analysis (FPCA) and Functional Cluster Analysis (FCA). The grainsize of the sand samples was characterized by means of laser dispersion spectroscopy. Within this framework, FPCA was used as a dimension reduction technique to explore and uncover patterns in grain-size frequency curves. This procedure proved useful to describe variability in the structure of the data set. Moreover, an alternative approach, FCA, was applied to identify clusters and to interpret their spatial distribution. Results obtained with this latter technique were compared with those obtained by means of two vector approaches that combine PCA with CA (Cluster Analysis). The first method, the point density function (PDF), was employed after adapting a log-normal distribution to each PSD and resuming each of the density functions by its mean, sorting, skewness and kurtosis. The second applied a centered-log-ratio (clr) to the original data. PCA was then applied to the transformed data, and finally CA to the retained principal component scores. The study revealed functional data analysis, specifically FPCA and FCA, as a suitable alternative with considerable advantages over traditional vector analysis techniques in sedimentary geology studies

Textural and mineralogical relations of beach/dune systems in a rocky coast: case study of Cantabria (NW Spain)

Se estudian los parámetros texturales y los contenidos sílice/carbonato de playas arenosas emergidas y campos eólicos dunares asociados a lo largo de la costa acantilada de Cantabria. Muchos sistemas fluviales drenan en esta costa, suministrando volúmenes significativos de arenas siliciclásticas, y la expulsión de nutrientes desde los estuarios controla la formación de carbonatos biogénicos en la franja costera estrecha, resultando un sedimento arenoso mixto, que forma parte de playas y dunas costeras. La distribución mineralógica de las arenas en esta costa muestra una cierta complejidad, pero de manera generalizada son más siliciclásticas en las desembocaduras de estuarios de grandes cuencas hidrográficas, aumentando los contenidos bioclásticos hacia el E. Se pueden deducir tendencias del transporte arenoso en sentido transversal y longitudinal, fundamentándose principalmente en una disminución generalizada de los tamaños y del contenido carbonatado en la dirección de la corriente. A partir de gráficos binarios, se determina el contraste entre el tamaño medio de grano y los restantes parámetros granulométricos, incluyendo el porcentaje carbonatado biogénico, que permite establecer las modalidades del trasporte por tracción: arrastre sobre el fondo y rodamiento y por suspensión: suspensión uniforme y saltación o suspensión gradada con la velocidad límite entre ambos asignada al tamaño medio de 2,05 φ (0,24 mm).Textural parameters and silica/carbonate contents of sand intertidal beaches and associated aeolian dune fields along this cliff coast are studied. Many fluvial systems draining in this coast supply large volumes of siliciclastic sands, and the output of nutrients from estuaries controls the biogenic carbonate formation in the narrow coastal belt, resulting mixed sand sediment that is part of beaches and coastal dunes. The mineralogical distribution of sands in this coast has a certain complexity but they are more siliciclastic in the estuary mouths linked to great fluvial basins, increasing the carbonate bioclasts to the eastern side. Transverse and longitudinal transitions of sand transport tendencies, mainly based on a general decrease in particle size and carbonate percentage in the direction of downflow can be deduced. From bivariate plots, the contrasting between main size and other granulometric parameters, including the biogenic carbonate percent, allows to establish the tractive (rolling and bottom drag) and suspension (uniform suspension and saltation or graded suspension) transport modalities for a limit speed assigned among them to an average size of 2,05 φ (0,24 mm)

Analysis of storms (1985-2016) and coastline changes (1875-2016) in “El Puntal-Somo-Las Quebrantas-Loredo” beach (Cantabria)

Producción CientíficaLa barra de arena de El Puntal-Somo-Las Quebrantas-Loredo es el rompeolas “natural” de la Bahía de Santander. Para analizar la dinámica histórica de toda la playa se ha utilizado cartografía de los años 1875, 1908, 1920 y 1950 y vuelos fotogramétricos (no se dispone de datos de las cámaras) de los años 1985, 1988 y 2001. De cada cartografía y vuelo se han escaneado, y posteriormente digitalizado las curvas de nivel de 0 m y 5 m. Para continuar con el estudio dinámico de la playa, se han restituido las curvas de nivel de 0 m y 5 m, la cabeza y pie del talud arenoso, de los vuelos fotogramétricos de los años 2005, 2007, 2010 y 2014. En toda la playa, entre los años 1988-1993, se hicieron campañas topo-batimétricas, mediante la ejecución de perfiles. En la zona de Las Quebrantas, se ha seleccionado una zona donde se están haciendo dos mediciones anuales (2011-2016) con escáner láser terrestre (TLS). Los retrocesos significativos de la línea de costa se producen con los temporales donde existe la coincidencia horaria de oleajes mayores a 5 metros, y coeficientes de pleamar superiores a 80. Así, desde 1875 hasta la actualidad, la playa de El Puntal-Somo-Las Quebrantas-Loredo ha tenido un retroceso superior a los 450 m.The sand bank El Puntal-Somo-Las Quebrantas-Loredo is the 'natural' breakwater of the Bay of Santander. In order to analyze the historical dynamic of the whole beach, maps were used from the years 1875, 1908, 1920 and 1950, as well as photogrammetric flights (camera data are not available) from 1985, 1988 and 2001. The 0 m and 5 m contours from each map and flight were scanned and digitized. To continue the dynamic study of the beach, the 0 m and 5 m contours, the head and the foot of the sand slope were restituted from the photogrammetric flights of the years 2005, 2007, 2010 and 2014. Topo-bathymetric surveys were conducted by profiles throughout the beach between 1988 and 1993. In Las Quebrantas, an area was selected for which measurements by Terrestrial Laser Scanner (TLS) are available from 2011 to 2016. The regression coastline occurs when storms coincide with tides of over 5 meters and high-tide coefficients greater than 80. From 1875 to the present time, the beach of El Puntal-Somo-Las Quebrantas-Loredo has had a regression higher than 450 m.Junta de Extremadura - Fondo Europeo de Desarrollo Regional (project GR15069

Dynamics and morpho-sedimentary interactions in the lower mesotidal estuary of Villaviciosa (NW Spain) : A management proposal

The accumulation of sediment in the mouth of Villaviciosa estuary (NW Spain) is becoming an obstaclefor the safe navigation in this estuary. One sector of its outer inlet is characterised by a broad shoal linkedwith a longshore bar of a beach, whose erosion is causing the silting of this area. On this basis, this paperaims to describe the processes that occurred in the lower part of the estuary due to the anthropogenicactivities in the channel and inlet. For this purpose, several measurements were made in the watercolumn and in the sedimentary bottoms to characterise the processes that occur in this area. Based onthese results, a dynamic and morpho-sedimentary model was developed to examine the interactionsbetween the lower estuary and the exposed part of the confining barrier beach, which allows to establishthe evolutionary trends of sedimentary bottoms linked to the marina of El Puntal. Different managementmeasures are carried out to reduce the impact of the sediment accumulation on the navigability, such asperiodically dredging in the inlet of the estuary, and the subsequent dumping of the sediments in areasnear to the closure depth. Consequently, future retreat of narrow inlet and sandy shoal can be avoided,maintaining the sedimentary volume in the system