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Short- and long-term impacts of Acacia longifolia invasion on the belowground processes of a Mediterranean coastal dune ecosystem

Marchante, Elizabete; Kjøller, Annelise; Struwe, Sten; Freitas, Helena
Fonte: Universidade de Coimbra Publicador: Universidade de Coimbra
Tipo: Artigo de Revista Científica Formato: aplication/PDF
ENG
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36.21%
Many coastal dune ecosystems in Portugal are invaded by the leguminous tree Acacia longifolia (Andrews) Willd. This exotic species was first introduced over one hundred years ago in an effort to mitigate dune erosion and loss of coastal landscapes. However, since then A. longifolia has spread to new areas, displacing the native vegetation. These invaded ecosystems contrast with the native dune ecosystems that are typically dominated by herb and shrub communities. This study characterizes belowground changes to the native environment as a result of recent (<10 y) and long-term invasion (>20 y) by A. longifolia by analyzing a range of chemical and microbial parameters. Both invaded areas accumulated higher litter densities with greater N contents and lower C/N ratios than the native areas, which corresponded to lower C/N ratio and to higher potential rates of nitrification in the invaded soils. Long-term occupation by A. longifolia has significantly altered the soil properties with increased levels of organic C, total N and exchangeable cations resulting in higher microbial biomass, basal respiration, and [beta]-glucosaminidase activity. However, basal respiration and microbial biomass were significantly higher within recent invasion sites when calculated relative to soil organic C. The results from this study show that invasions by A. longifolia have altered the original native ecosystem processes and that the impacts are more pronounced within long-term invaded sites. A positive feedback mechanism is apparent for A. longifolia invading these Mediterranean dunes...

Dispersal Patterns of Coastal Fish: Implications for Designing Networks of Marine Protected Areas

Di Franco, Antonio; Gillanders, Bronwyn M.; De Benedetto, Giuseppe; Pennetta, Antonio; De Leo, Giulio A.; Guidetti, Paolo
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 15/02/2012 EN
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36.2%
Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (∼200 km) we investigated natal origin of fish and at a smaller scale (∼30 km) we assessed “site fidelity” (i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ∼30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.

Development of an Indicator to Monitor Mediterranean Wetlands

Sanchez, Antonio; Abdul Malak, Dania; Guelmami, Anis; Perennou, Christian
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 31/03/2015 EN
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Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered.

Dispersal patterns of coastal fish: implications for designing networks of marine protected areas

Di Franco, A.; Gillanders, B.; De Benedetto, G.; Pennetta, A.; De Leo, G.; Guidetti, P.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
36.2%
Information about dispersal scales of fish at various life history stages is critical for successful design of networks of marine protected areas, but is lacking for most species and regions. Otolith chemistry provides an opportunity to investigate dispersal patterns at a number of life history stages. Our aim was to assess patterns of larval and post-settlement (i.e. between settlement and recruitment) dispersal at two different spatial scales in a Mediterranean coastal fish (i.e. white sea bream, Diplodus sargus sargus) using otolith chemistry. At a large spatial scale (~200 km) we investigated natal origin of fish and at a smaller scale (~30 km) we assessed "site fidelity"(i.e. post-settlement dispersal until recruitment). Larvae dispersed from three spawning areas, and a single spawning area supplied post-settlers (proxy of larval supply) to sites spread from 100 to 200 km of coastline. Post-settlement dispersal occurred within the scale examined of ~30 km, although about a third of post-settlers were recruits in the same sites where they settled. Connectivity was recorded both from a MPA to unprotected areas and vice versa. The approach adopted in the present study provides some of the first quantitative evidence of dispersal at both larval and post-settlement stages of a key species in Mediterranean rocky reefs. Similar data taken from a number of species are needed to effectively design both single marine protected areas and networks of marine protected areas.; Antonio Di Franco...

Large Scale Screening of Seawater Intrusion Risk in Europe - Methodological Development and Pilot Application Along the Spanish Mediterranean Coast

WRIEDT Gunter; BOURAOUI Faycal
Fonte: OP Publicador: OP
Tipo: EUR - Scientific and Technical Research Reports Formato: Printed
ENG
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36.3%
Seawater intrusion caused by overabstraction has become an important problem in coastal areas of the Mediterranean. Intrusion processes highly depend on complex local conditions and studies generally focus on specific problems of individual aquifers. Seawater intrusion problems have hardly been addressed at large scale due to the strong impact of local conditions and the problems related to data collection for large geographical areas. To fill this gap and to explore the potential use of readily available data sources, we developed a simple screening methodology for large scale assessment of seawater intrusion risk along the Mediterranean coast of the EU based on a two tiered assessment procedure. Tier 1 is a simple risk assessment based on the balance of groundwater recharge and water abstractions for coastal areas. A positive net groundwater recharge results in transition of the saltwater-freshwater interface to a new equilibrium state. No equilibrium exists with negative net recharge (over-abstraction) and seawater is drawn into the aquifer compensating freshwater losses. Tier 2 provides a quantitative characterization of seawater intrusion for standardized aquifers considering generalized local geological conditions: A simple analytical intrusion model calculates freshwater loss and seawater progression for specified combinations of aquifer properties...

Polychlorinated Dibenzo-p-Dioxins and Dibenzofurans (PCDD/Fs) over the Mediterranean Sea

GHIANI MICHELA; MARIANI GIULIO; SKEJO HELLE; UMLAUF GUNTHER; WOLLGAST JAN
Fonte: Mediterranean Scientific Association of Environmental Protection - MESAEP Publicador: Mediterranean Scientific Association of Environmental Protection - MESAEP
Tipo: Contributions to Conferences Formato: Printed
ENG
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The marine environment is subjected to contamination by a wide spectrum of chemicals mainly due to anthropogenic activities. Among these chemicals, persistent organic pollutants (POPs) have gained a lot of attention in the last decades due to their ubiquity in many environmental compartments, and their adverse health effects in biota and humans. Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a family of POPs formed by 209 congeners. Seventeen of these congener have been described as the most toxic ones (2,3,7,8-substituted congeners) being able to bioaccumulate and enter the foowebs. Although certain amount of information on environmental levels and processes of PCDD/Fs is available for coastal areas, very little is known about their levels and behaviour far from the shore line (open seas). In this work environmental air concentrations and spatial distribution on PCDD/Fs across the Mediterranean Sea are presented. Data were collected during a sampling cruise (from Barcelona to Istanbul on board of the B/O Garcia del Cid, CSIC) performed within the framework of the IP THRESHOLDS of Environmental Sustainability. A distance of 3850 nautical miles (~ 7100km) was covered and a total of 5 transects were sampled along the Mediterranean and Marmara and Black seas. Air samples (particulate + gas phase) were collected by using two high volume samplers installed on the upper deck of the boat (around 6-7 m above the sea level) close to the bow. The samplers...

Remote Sensing of Marine Water Quality as a Component of ICZM: Case Studies in the Mediterranean Sea

BARALE VITTORIO
Fonte: RESEARCH PUBLISHING Publicador: RESEARCH PUBLISHING
Tipo: Articles in books Formato: Printed
ENG
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36.29%
Remote sensing of coastal zones has become increasingly common in both scientific research and environmental management applications. In particular, "ocean colour" techniques promise to develop into a major tool for the assessment of water quality. Surface optical properties can be used to study presence, nature and concentration of water constituents, runoff patterns and sediment dynamics, coastal plumes, filaments and eddies. Examples of the near-coastal features that can be surveyed are provided by imagery of the Mediterranean Sea, collected by the Seaviewing Wide Field-of-View Sensor (SeaWiFS). This basin has limited geographical size, but displays a variety of environmental and climatic conditions, and constitutes a unique scale model of the larger oceans. Its coastal areas, impacted by continental drainage or by exchanges with other water bodies, present special water quality problems, due to the inflow of dissolved and suspended materials. Where major rivers are present, the coastal zone appears to be permanently under the direct influence of their plumes, as in the case of the Po river outflow in the northern Adriatic Sea. The impact of river runoff can be enhanced by current patterns, as in the Strait of Otranto, in the southern Adriatic Sea. The Alboran Sea presents more examples of permanent features related to surface currents...

The Coastal Dimension of Maritime Spatial Planning

BARALE Vittorio
Fonte: MEDCOAST, Mediterranean Coastal Foundation Publicador: MEDCOAST, Mediterranean Coastal Foundation
Tipo: Contributions to Conferences Formato: Printed
ENG
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46.17%
Maritime Spatial Planning (MSP) is considered a key instrument for the implementation of the EU Integrated Maritime Policy (IMP), which aims to ensure the economic development of coastal and marine areas in a sustainable manner. Coastal zones constitute the “hinge” between land and sea developments, so that MSP must coordinate, and overlap where required, with Integrated Coastal Management (ICM), using a common ecosystem approach. The selection of suitable geographical units, where this approach can be taken, and MSP/ICM applied, requires the assessment of ecological provinces, characterized by a coherent set of environmental traits. Ideally this can be done on the basis of synoptic Remote Sensing (RS) data, to cover space/time scales not accessible by other means. Sample data for the Mediterranean Sea provide examples of the coverage obtainable for a set of complementary ecosystem indicators.; JRC.H.5-Land Resources Management

Mapping and quantifying habitat fragmentation in small coastal areas: a case study of three protected wetlands in Apulia (Italy)

TOMASELLI Valeria; TENERELLI PATRIZIA; SCIANDRELLO Saverio
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Articles in Journals Formato: Printed
ENG
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In the Mediterranean Region, habitat loss and fragmentation severely affect coastal wetlands, due to the rapid expansion of anthropogenic activities that has occurred in the last decades. Landscape metrics are commonly used to define landscape patterns and to evaluate fragmentation processes. This investigation focuses on the performance of a set of landscape pattern indices within landscapes characterized by coastal environments and extent below 1,000 ha. The aim is to assess the degree of habitat fragmentation for the monitoring of protected areas and to learn whether values of landscape metrics can characterize fine-resolution landscape patterns. The study areas are three coastal wetlands belonging to the Natura 2000 network and sited on the Adriatic side of Apulia (Southern Italy). The Habitat Maps were derived from the Vegetation Maps generated integrating phytosociological relevés and Earth Observation data. In the three sites, a total of 16 habitat types were detected. A selected set of landscape metrics was applied in order to investigate their performance in assessing fragmentation and spatial patterns of habitats. The final results showed that the most significant landscape patterns are related to highly specialized habitat types closely linked to coastal environments. In interpreting the landscape patterns of these highly specialized habitats...

Crecimiento urbano (1965-2005) y sellado antropogénico del suelo en el municipio de Alacant

Valera Lozano, Antonio; Añó Vidal, Carlos; Sánchez Díaz, Juan
Fonte: Universidad de Alcalá. Servicio de Publicaciones Publicador: Universidad de Alcalá. Servicio de Publicaciones
Tipo: Artigo de Revista Científica Formato: application/pdf
SPA
Relevância na Pesquisa
46.17%
En la Comunitat Valenciana el cambio en los usos del suelo provocado por la urbanización acelerada ha sido especialmente intenso en los centros metropolitanos costeros; llanos litorales que acogen los suelos con mayor capacidad de uso agrícola y que concentran la mayor parte de la población y las actividades económicas. En este trabajo se analiza la dinámica espacio-temporal de los usos urbanos durante la segunda mitad del siglo XX en el municipio de Alacant, perteneciente al entorno metropolitano de Alacant-Elx. El estudio, metodológicamente, se ha desarrollado en un entorno SIG. A partir de fotogramas aéreos correspondientes a las fechas de 1956, 1985, 1998 y 2005 y mediante métodos de análisis cartográficos con Sistemas de Información Geográfica, se han establecido los cambios acumulativos de los usos urbanos del suelo a escala detallada (1:10.000). Las tipologías de usos seleccionadas han sido tres, dos de ellas urbanas y una tercera no urbana. Las áreas urbanas en las que la superficie construida es superior al 80% se han considerado de Alta Densidad (UAD), clasificándose como Urbanas de Baja Densidad (UBD) las inferiores al 80%. La diferencia entre las dos clases urbanas responde al mayor o menor porcentaje de vegetación o suelo desnudo en la matriz construida. Los resultados muestran la gran expansión de los usos urbanos y el consecuente retroceso de los agrícolas y forestales. El ritmo de crecimiento fue especialmente rápido durante el periodo 1998-2005. Estos cambios se relacionan con las dinámicas económicas y demográficas regionales. La población se ha multiplicado por 3 en los últimos 50 años...

Towards a LOICZ Biogeochemical Budget for the Mediterranean Sea - Initial Steps

STROBL Robert; EVANS B.; SOMMA Francesca; GARCIA GORRIZ Elisa; STIPS Adolf; ZALDIVAR COMENGES Jose'
Fonte: The Land-Ocean Interactions in the Coastal Zone International Project Office Publicador: The Land-Ocean Interactions in the Coastal Zone International Project Office
Tipo: Articles in Journals Formato: Printed
ENG
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46.18%
Although making up about 1% of the total world ocean surface, the Mediterranean Sea is often used as a representative model of the world's oceans. Due to its practically enclosed character, it is also often used to assess the global change of the environment. Anthropogenic activities have contributed significantly to the existing nutrient enrichment and consequent eutrophication problems in the Mediterranean Sea. At the present, however, mainly due to the favourable circumstances regarding the hydrology, morphology as well as absence of significant upwelling of the Mediterranean basin as a whole, severe eutrophication cases are limited to specific coastal areas (UNEP 2003). To obtain a detailed knowledge of biogeochemical processes taking place in the Mediterranean Sea, a budget approach was adopted, as proposed by LOICZ. As part of the input to the LOICZ budget, the nutrient loads from contouring land need to be estimated. In fact, an evaluation of the nutrient loads from the adjacent land surfaces lends itself to be used to interpret past, existing and future legislation using scenario analyses, reflecting different expected or known events. The sequence of budgets follows four steps: water budget, salt budgets, nonconservative materials and stoichiometric linkages among non-conservative budgets.; JRC.H.3-Global environement monitoring

Long chain alkenones in hypersaline and marine coastal microbial mats

López Fernández, Jordi F.; García de Oteyza, Tirso; Teixidor, Pilar; Grimalt, Joan O.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
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12 pages, 8 figures, 1 table.-- Printed version published Jun 2005.; Long-chain alkenones in microbial mats from Mediterranean solar salterns and coastal areas from the Mediterranean Sea and North Sea have been studied. These ecosystems exhibit a distinct C37–C40 alkenone composition characterized by a predominance of triunsaturated compounds in all C37–C40 homologues and by a specific correspondence between carbonyl position and chain length. Thus, C37 and C39 homologues are methyl ketones and C38 and C40 homologues are ethyl ketones. The distribution also contains tetraunsaturated alkenones in significant proportion, particularly among the C37 homologues. The double bonds are located at Δ8,15,22,29 and Δ9,16,23,30 in the methyl and ethyl ketones, respectively, indicating that the number of carbon atoms between the carbonyl group and the first double bond remains constant.; This distribution is different from C37–C40 alkenone mixtures previously found in open sea waters or freshwater environments. It suggests a biological origin distinct from that previously described for marine algal cultures or recent or ancient open sea sediments. The uniformity of the distributions, despite the strong salinity differences considered in the present study (salinity of 35–200) is remarkable. Depth analysis of the microbial mats from hypersaline environments shows fluctuations in total alkenone concentration...

Spatio-temporal patterns in the north-western Mediterranean from MERIS derived chlorophyll a concentration; Patrones espacio-temporales de clorofila en el Mediterráneo Noroccidental derivados del sensor MERIS

Gordoa, Ana; Illas, Xenia; Cruzado, Antonio; Velásquez, Zoila
Fonte: Consejo Superior de Investigaciones Científicas (España) Publicador: Consejo Superior de Investigaciones Científicas (España)
Tipo: Artículo Formato: 2578976 bytes; application/pdf
ENG
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36.22%
[EN] We address the major surface signatures of chlorophyll a in the Catalan Sea within the context of the dynamics of the north-western Mediterranean basin. Monthly composites from MERIS measurements and CHL products for Case 1 waters were analysed from June 2002 to June 2005. Composite images of variability were used to identify surface dynamics. The results showed that coastal and open sea waters were separated by a belt of low variability, a permanent oligotrophic belt that is noticeable with respect to the bloom conditions of the surrounding areas. The width of this Catalan Oligotrophic Belt (COB) located along the continental slope, varied between 17 and 30 km and became blurred in the southernmost area. The chlorophyll a temporal pattern over the shelf showed an almost steady increase from September to March. A similar behaviour but with lower concentrations was observed in oceanic waters. Both temporal patterns showed a disruption during January and/or February that coincided with the well known deep water formation event in the Gulf of Lions. In 2004, the convection was weaker and the offshore temporal trend was not disrupted; however, the opposite was observed in 2005. The spatial chlorophyll a distribution of oceanic waters presented a clear north-south decreasing trend...

Trophic relationships in demersal communities of Western Mediterraneo occidentale: case studies from coastal and deep-sea ecosystems

Fanelli, Emanuela
Fonte: Università degli studi della Tuscia di Viterbo Publicador: Università degli studi della Tuscia di Viterbo
Tipo: Tesis Formato: 6987465 bytes; application/pdf
ENG
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36.23%
327 pages.-- PhD Tesis carried out at the Universitá degli Studi di Viterbo "La Tuscia", Dipartimento di Ecologia e Sviluppo Sostenibile, at the Institut de Ciències del Mar (ICM-CSIC) and at the Laboratorio di Ecologia Marina, IAMC-CNR.; The present thesis deals with the analysis of the trophic web structure and spatio-temporal variation in trophic levels of prey and predator in two different ecosystems: a coastal environment up to 80 m in the Northern Sicily (Italy) and a deep-sea ecosystem, the middle slope (450-750 m deep) of the Balearic basin (Cabrera Archipelago-Spain). As trophic relationships are fundamental to understand biological interaction, a detailed study of the food and feeding ecology of demersal fish species, in the coast and deep-sea, is attempted. Three fish species from costal ecosystems and three from deep-sea were selected as representative of different trophic guilds (benthophagous, suprabenthic feeder and planktophagous). Moreover to define the trophic structure of coastal and deep-sea communities a complete examination of prey (i.e. zooplankton, suprabenthos and benthos, where possible) and predator based on stable isotope analysis was carried out. Particularly suprabenthic resources were generally ignored or scarcely considered in trophic web studies...

Spawning environmental conditions of Sardinella aurita at the northern limit of its distribution range, the western Mediterranean

Sabatés, Ana; Salat, Jordi; Raya, Vanesa; Emelianov, Mikhail; Segura i Noguera, María del Mar
Fonte: Inter Research Publicador: Inter Research
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
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46.21%
10 pages, 4 figures, 1 table.-- Full-text version available Open Access at: http://www.icm.csic.es/files/oce/almacen/papers/doc_671.pdf; In the last 20 yr, an increasing abundance and northward expansion of Sardinella aurita has been reported in the western Mediterranean. The present study characterizes the spawning habitat of S. aurita at the northern limit of their geographic distribution and determines the hydrodynamic conditions that could control their northward expansion in the western Mediterranean. Data along the Catalan shelf and slope were obtained in 4 oceanographic cruises conducted in the summers of 2003 and 2004. A clear preference for spawning in coastal areas shallower than 100 m was determined, with larvae showing a wider distribution extending offshore up to the position of the 150 m isobath. The greatest abundance of eggs and larvae was found in the southern half of the area on the wide shelf near the mouth of the Ebro River. This zone was characterized by high values of surface chlorophyll a in association with relatively low salinity waters from the Ebro River. In the northern part of the area, a thermal front across the shelf, with higher sea surface temperatures on its southern side, marked the northern limit of egg and larvae distribution. The northern side of this front was under the direct influence of the shelf–slope current...

A comparative study on recurrent blooms of Alexandrium minutum in two Mediterranean coastal areas

Vila, Magda; Giacobbe, Maria Grazia; Masó, Mercedes; Gangemi, Ester; Penna, Antonella; Sampedro, Nagore; Azzaro, Filippo; Camp, Jordi; Galluzzi, Luca
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 8554193 bytes; application/pdf
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23 pages, 8 figures, 3 tables.-- Available online Dec 21, 2004.; Alexandrium minutum is a toxic dinoflagellate widespread along the Mediterranean coasts. This species is frequently detected year-round at low concentrations within the Mediterranean basin. However, it only proliferates recurrently in some localities. Two affected areas are the Catalan and Sicilian coasts. In order to identify the factors determining the A. minutum blooms in the Mediterranean Sea, we compare the bloom conditions in two harbours: Arenys de Mar (Catalan coast, Spain) and Syracuse (Sicily, Italy), during 2002–2003. Arenys de Mar harbour is a fishing and leisure harbour and receives an input of freshwater rich in nutrients. Likewise, the Syracuse harbour – located on the Ionian coast of Sicily – is subject to freshwater inputs. Some points of this site are used for productive activities such as shellfish farming. A. minutum from the two areas studied were morphologically and genetically identical. In both sites, recurrent blooms take place from winter to spring. Surface water temperatures and salinities during A. minutum bloom events were 12–14.5 °C and 32–38, and 16–24 °C and 32–37.7 for Arenys and Syracuse, respectively. During the blooms...

Exploring new approaches in urban water governance: case studies in mediterranean areas

Ridolfi, Elena
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2014 ENG
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46.32%
Muchas de las ciudades costeras del mundo se están volviendo cada vez más urbana y muchas de ellas están cambiando hacia el turismo, uno de los sectores de mayor crecimiento de la economía mundial. El agua es un elemento clave para el desarrollo y las funciones urbanas y de sostenimiento para las nuevas instalaciones turísticas. Sin embargo, los cambios y las rápidas transformaciones urbanas están estimulando una creciente preocupación con respecto a los recursos hídricos. En particular, los nuevos desarrollos urbanos crecen en complejidad, mientras que las densas redes de flujos de agua se intensifican dentro del tejido urbano y plantea un gran desafío para la gobernabilidad de este recurso. Considerando que el siglo pasado ha definido y representado el fenómeno del agua como una sustancia material (H2O), la investigación del siglo 21 ha puesto en duda esa perspectiva. De hecho, estudiosos sociales han demostrado recientemente que el enfoque físico ya no es suficiente para hacer frente a los desafíos presentes y futuros del agua urbana, la incertidumbre y la gobernabilidad. Por lo tanto, los geógrafos y ecologistas políticos, en particular, han desarrollado el concepto de "ciclo hidro-social" que integra tanto la natura física como sociopolítica del agua. Mediante el empleo de este concepto...

Medio siglo (1956-2005) de crecimiento urbano y pérdida de suelo en el litoral mediterráneo español : el entorno metropolitano de Alacant-Elx

Valera Lozano, Antonio; Añó Vidal, Carlos; Sánchez Díaz, Juan
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2013 SPA
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45.92%
En este trabajo, se analiza la dinámica espacio-temporal de los usos urbanos durante la segunda mitad del siglo xx en el entorno metropolitano de Alacant-Elx. A partir de fotogramas aéreos correspondientes a las fechas de 1956, 1985, 1998 y 2005, y mediante métodos de análisis cartográfico con sistemas de información geográfica, se han establecido los cambios a escala detallada (1:10.000). También se han aplicado diez indicadores para evaluar el nivel de sostenibilidad ambiental. Los resultados muestran la gran expansión de los usos urbanos y el consecuente retroceso de los agrícolas y forestales durante todo el periodo analizado. La superficie construida, que representaba 2.226 ha (un 2% del total) en 1956, alcanza 16.804 ha (un 15%) en 2005. Además, el crecimiento se ha intensificado sustancialmente en el periodo 1998-2005.; En aquest treball, s’hi analitza la dinàmica espacial i temporal dels usos urbans durant la segona meitat del segle xx a l’entorn metropolità d’Alacant-Elx. Partint de fotografies aèries corresponents a 1956, 1985, 1998 i 2005, i mitjançant mètodes d’anàlisi cartogràfica amb sistemes d’informació geogràfica, han estat establerts els canvis a escala de detall (1:10.000). També s’han aplicat deu indicadors per avaluar el nivell de sostenibilitat ambiental. Els resultats mostren la gran expansió dels usos urbans i el retrocés consegüent dels agrícoles i forestals al llarg del període analitzat. La superfície construïda...

Historical land-use legacy and Cortaderia selloana invasion in the Mediterranean region

Domènech i Masons, Roser; Pino i Vilalta, Joan
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2005 ENG
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56.06%
Two major components of global change: land-use changes and intentional or accidental species introduction are threatening the conservation of native species worldwide. In particular, Mediterranean coastal areas are highly susceptible to the invasion of alien species and they also have experienced major changes in land use such as agricultural abandonment and urbanization. However, there has been little research done which quantitatively links biological invasions and the components of land-use changes (i.e. number, trajectory and direction of the changes). We analysed the current distribution and abundance of Cortaderia selloana (Schultes et Schultes fil.) Asch. et Graebner, an alien ornamental species, in 332 fields in Aiguamolls de l'Empordà (Catalonia, NE Spain) and related the patterns of invasion to spatiotemporal data on land-use changes from 1956 to 2003. Our aim was to determine which land uses had been more susceptible to C. selloana invasion during the last 5 years and to find out which components of land-use changes triggered invasion. We found that 22.30% of the fields are currently invaded. In the last 5 years, fields have triplicated the total density of C. selloana. The presence of C. selloana decreases with the distance from urban areas. Invasion is over-represented in pastures and old-fields...

Recent warming in the Balearic Sea and Spanish Mediterranean coast. Towards an earlier and longer summer

López García,María José
Fonte: Centro de Ciencias de la Atmósfera, UNAM Publicador: Centro de Ciencias de la Atmósfera, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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This paper analyses recent changes in the temperature of the Balearic Sea and surrounding coastal areas. Monthly temperature data from several weather stations located around the Balearic basin have been used to obtain land temperatures during the period 1960-2010, and monthly thermal satellite images from the Physical Oceanography Distributed Active Archive Center (PO.DAAC) covering the period 1985-2009 have been processed to obtain sea surface temperatures (SSTs) in the Balearic Sea. A rise in temperature has been observed since 1980 and increasingly in the last 25 years, with an average warming trend of 0.039 °C/year on land for the period 1960-2010 and 0.026 °C/year in SSTs for 1985-2009. The seasonal analysis showed that, in the last 25 years, higher trends were registered during the transition from spring to summer, with the highest warming rates in June (0.12 °C/year on land and 0.08 °C/year in SSTs). Results show a recent tendency towards earlier and longer summers both on land and sea.