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The main objective of this work is to present a novel methodology to assess the environmental, ecological, and conservation status of mid-latitude estuaries by means of an index-based method, EstuarIndex. The EstuarIndex is an integration of four sub-indexes, assessing the status of the main subsystems present on estuaries: sandy environments, dunes, tidal flats, and the drainage network. Each sub-index includes variables combining three types of factors: morphosedimentary and oceanographic factors, ecological factors, and management and protection factors. The environmental status is finally evaluated in five possible classes: (1) Very low, (2) Low, (3) Medium, (4) High, and (5) Very High, according to EU requirements for classifying the conservation status of habitats. Three pilot zones along the Spanish coast have been chosen for testing the method: San Vicente de la Barquera estuary (N Spain), Guadiana estuary (SW Spain), and Ebro River delta mouth (E Spain). They present different oceanographic and geomorphological conditions. The results obtained have proven that EstuarIndex is a suitable methodology for the application to other estuaries. The systematic application of EstuarIndex on broad time scales would allow evaluating the system trends, what seems key for implementation of more realistic restoration strategies, and it has a great potential as a tool for environmental management in natural protected areas. Furthermore, it may help in the detection of the most relevant site-specific vulnerabilities for long-term sustainability in response to both natural and artificial drivers. [ABSTRACT FROM AUTHOR]

This work presents the results of a beach-monitoring program carried out in the Bay of Cadiz (SW Spain), which consists of urban, natural and nourished beaches. In the present study, 24 topographic profiles have been monthly monitored during the 1996–1998 period, in order to draw the morphodynamic behavior of this coast and the general characterization of short-term coastal trends. This way, total volumetric budgets have been calculated for each beach profile in order to group beaches in different erosive/accreting sectors. Studied beaches recorded both erosion and accretion: the greatest accretionary trends have been observed at Aguadulce, La Costilla and Rota beaches, with values ranging from 30 to 70 m3/m. The largest erosion episodes have been recorded in the southernmost end of Valdelagrana spit, with values over 50 m3/m, and in Rota and Vistahermosa, after nourishment works. Main erosion and accretion pathways have been related to the existence of natural and human structures, which blocked the longshore drift suggesting the existence of littoral cells. [ABSTRACT FROM AUTHOR]

The present study assesses coastal vulnerability to erosion processes along a 23-km-long coastal sector that presents different morphological features and grades of human occupation. Seven photogrammetric flights, at different scales, were used for reconstructing the coastal evolution from 1956 to 2001. Several sources were compiled to assess human activities and land uses in the coastal zones that were mapped and divided into four different types. As a further step, coastal vulnerability to erosion was assessed combining the potential coastal retreat with land-use type. More than one third of the studied coast presents a very high–medium risk level and many human structures and activities at Sanlúcar village and La Ballena beach will be threatened by erosional processes in the near future. [ABSTRACT FROM AUTHOR]

We present a morphodynamic study of an apparently homogeneous rectilinear coast in SW Spain. The study area covers 14 km of mesotidal sandy beaches, interrupted in some places by rocky-shore platforms. The method used consisted of a monthly monitoring of 12 beach profiles during two years. According to the results obtained from the study, which also include granulometric analyses and in situ determination of the beach disturbance depth, three main beach classes have been differentiated: low-reflective beaches, dissipative beaches and rocky-shore platform beaches. Their longitudinal distribution is not linked to their distance to the main source of sediments in the area (mouth of the river Guadalquivir). Instead, a very irregular long-shore variation of morphodynamic beach states appears. It is deduced that this long-shore variation is mainly linked to local contouring conditions (e.g. the presence of rocky shoals which affect wave-breaking processes), and not to the regional long-shore currents prevailing in the zone. [ABSTRACT FROM AUTHOR]

Abstract. Coastal erosion in SW Spain is affecting man-made structures and beaches that represent an important economic resource in the area. In the last decade the Spanish government carried out several nourishment works that have limited durability. Most of the artificial beach fills consist of a spill of natural dredged sand on the visible beach, leading to a flat, artificial berm with an important seaward slope and a narrow foreshore. As a result, the initial dissipative profile was transformed into a fully reflective one. A beach monitoring pro-gram was carried out to record morphological evolution after the nourishment works. Several field assessments of disturbance depth were also made to characterize beach morpho-dynamics of a nourished beach (Rota) and a natural dissipative one (Tres Piedras), whose slope was similar to the pre-nourishment gradient of Rota beach. Natural dissipative beaches were characterized by spilling breakers that did not significantly affect bottom sand. The severe erosion recorded in the nourished zones was related to the new morphodynamic regime acting on these beaches, which was controlled by high erosive plunging breakers associated with high foreshore slopes. In conclusion, other nourishment practices should be used, better adapted to the natural beach morphodynamics of the zone, taking also into account the original grain size and density of the beach sands, in order to obtain more durable artificial beaches. [ABSTRACT FROM AUTHOR]

During the last decades many salt marshes worldwide have suffered important losses in their extent and associated ecosystem services. The salt marshes of San Vicente de la Barquera estuary (N Spain) are a clear example of this, with a drastic reduction in vegetation surface over the last 60 years. This paper provides insights into the main factors controlling salt marsh functioning in sheltered estuarine areas. Regional and local factors have been disaggregated to identify the main drivers controlling the functioning of the salt marsh to develop appropriate management measures according to the evolution of the system. These factors have been studied in their spatial context through detailed maps of change in vegetation cover combined with topographic data obtained from UAV and RTK-DGPS surveys. The results demonstrate that in this estuary the salt marsh area is declining following a fragmentation process. No clear pattern of vegetation loss/gain with elevation has been identified. However, the results point to increased hydrodynamic stress in the area, with stronger currents inside the estuary. This is probably the major factor responsible for the decline of the salt marshes in the San Vicente de la Barquera estuary. Furthermore, several human interventions during the 20th century (local drivers) have also probably contributed to a lower resilience against SLR (regional driver). This work demonstrates that both natural and human drivers of change need to be considered when characterizing the evolution of salt marshes, wherever efficient management strategies need to be designed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)