University of the Algarve

About: University of the Algarve is a education organization based out in Faro, Portugal. It is known for research contribution in the topics: Population & Tourism. The organization has 3649 authors who have published 10303 publications receiving 233536 citations.

Spring–summer climatological circulation in the upper layer in the region of Cape St. Vincent, Southwest Portugal

Abstract: Geostrophic transport and hydrographic measurements derived from a historical database (1900–1998) were used to study the spring–summer mean circulation in the upper layer south and west of Cape St. Vincent, Southwest (SW) Portugal. The larger-scale circulation scheme is forced by equatorward winds from May to September, when the Iberian coastal transition zone (CTZ) is dominated by a generalized upwelling of cold, low-salinity water. A partially separated surface jet intensified at the shelf break conveys � 1 Sv of upwelled water equatorward parallel to the bathymetry, while offshore a poleward flow transports � 0.4–0.6 Sv of upwelled water. Although alongshore transports dominate the circulation pattern of the upper layers, cross-shore transports are significant at the climatological scale. Anticyclonic circulation with an exchange of � 0.5 Sv from the equatorward jet to the offshore poleward flow and the partial re-circulation further north, back into the equatorward flow are discussed. A coherent, cyclonic re-circulation pattern inshore of the upwelling jet is also speculated. From these results the shelf break is considered a climatological border at both sides of which two major re-circulation cells occur. The climatological equatorward flow has offshore protrusions, interpreted as recurrent episodes of major contortions of the upwelling flow. These features bring about considerable ‘‘crossshelf flow’’ re-circulation reaching up to 50% of the main flow. The most significant exchanges are found to be associated with major changes of orientation of the coastline. Off Cape St. Vincent the upwelling front stretches to both west and south and contributes to the cross-shelf re-circulations. Additionally, convergence of the upwelling flow and a branch of the Azores current, with associated re-circulation is found diagonally from the cape. On the southern coast the upwelling jet is seen to meander offshore in the vicinity of Cape St. Maria. Individual synoptic cruise data showed agreement with the climatological circulation features. We conclude that these oceanographic features leave an imprint on the climatic circulation in spite of the ‘‘smoothing out’’ of recurrent events over the spring– summer period of the years of 1900–1998.

Tidal and river discharge forcing upon water and sediment circulation at a rock-bound estuary (Guadiana estuary, Portugal)

Abstract: The relative impacts of tidal (neap, spring) and river discharge (including a flood event) forcing upon water and sediment circulation have been examined at the rock-bound Guadiana estuary. Near-bed and vertical profiles of current, salinity, turbidity, plus surface suspended sediment concentrations (SSC, at some stations only), were collected at the lower and central/upper estuary during tidal and fortnightly cycles. In addition, vertical salinity and turbidity profiles were collected around high and low water along the estuary. Tidal asymmetry produced faster currents on the ebb than on the flood, especially at the mouth. This pattern of seaward current dominance was enhanced with increasing river flow, due to horizontal advection that was confined within the narrow estuarine channel. The freshwater inputs and, at a degree less, the tidal range controlled the vertical mixing and stratification importance. Well-mixed (spring) and partially stratified (neap) conditions alternated during periods of low river flows, with significant intratidal variations induced by tidal straining (especially at the partially stratified estuary). Highly stratified conditions developed with increasing river discharge. Intratidal variability in the pycnocline depth and thickness resulted from current shear during the ebb. A salt wedge with tidal motion was observed at the lower estuary during the flood event. Depending on the intensity of turbulent mixing, the residual water circulation was dominantly controlled either by tidal asymmetry or gravitational circulation. The SSC was governed by cyclical local processes (resuspension, deposition, mixing, advection) driven by the neap-spring fluctuations in tidal current velocities. More, intratidal variability in stratification indicated the significance of tidal pumping at the partially and highly stratified estuary. The estuary turbidity maximum (ETM) was enhanced with increasing current velocities, and displaced downstream during periods of high river discharge. During the flood event, the ETM was expelled out of the estuary, and the SSC along the estuary was controlled by the sediment load from the drainage basin. Under these highly variable river flow conditions, our observations suggest that sand is exported to the nearshore over the long-term (>years).

Residents’ attitudes towards tourism development in Cape Verde Islands

Abstract: The purpose of this study is to examine residents’ attitudes and perceptions towards tourism development in the Cape Verde islands, a little-explored issue in the context of small islands’ developing states, especially in Africa. Since the country is in the initial stage of tourism development, it is intended to show that residents predominantly share a positive attitude, which supports previous research. It is also intended to understand whether attitudes are homogeneously shared or instead tourism is differently perceived by residents. To address these objectives, a survey based on 492 questionnaires was applied to national residents in five countries that represent the major tourist areas of Cape Verde. The findings reveal that, in general, residents are optimistic about tourism. Yet, despite the overall positive attitude towards tourism, different segments of residents according to the way the tourism impacts are perceived could be identified. These segments report significant differences concerning socio-demographic characteristics and the degree of involvement in the tourism sector. This analysis provides important inputs for the planning process and sustainable development of tourism in the archipelago.