307 research outputs found
Morphological response of the saltmarsh habitats of the Guadiana estuary due to flow regulation and sea-level rise
In the context of rapid sea-level rise in the 21st century, the reduction of fluvial sediment supply due to the regulation of river discharge represents a major challenge for the management of estuarine ecosystems. Therefore, the present study aims to assess the cumulative impacts of the reduction of river discharge and projected sea-level rise on the morphological evolution of the Guadiana estuary during the 21st century. The assessment was based on a set of analytical solutions to simplified equations of tidal wave propagation in shallow waters and empirical knowledge of the system. As methods applied to estimate environmental flows do not take into consideration the fluvial discharge required to maintain saltmarsh habitats and the impact of sea-level rise, simulations were carried out for ten cases in terms of base river flow and sea-level rise so as to understand their sensitivity on the deepening of saltmarsh platforms.Results suggest saltmarsh habitats may not be affected severely in response to lower limit scenarios of sea-level rise and sedimentation. A similar behaviour can be expected even due to the upper limit scenarios until 2050, but with a significant submergence afterwards. In the case of the upper limit scenarios under scrutiny, there was a net erosion of sediment from the estuary. Multiplications of amplitudes of the base flow function by factors 1.5, 2, and 5 result in reduction of the estimated net eroded sediment volume by 25, 40, and 80%, respectively, with respect to the net eroded volume for observed river discharge. The results also indicate that defining the minimum environmental flow as a percentage of dry season flow (as done presently) should be updated to include the full spectrum of natural flows, incorporating temporal variability to better anticipate scenarios of sea-level rise during this century. As permanent submergence of intertidal habitats can be significant after 2050, due to the projected 79 cm rise of sea-level by the year 2100, a multi-dimensional approach should be adopted to mitigate the consequences of sea-level rise and strong flow regulations on the ecosystem of the Guadiana Estuary. (C) 2016 Elsevier Ltd. All rights reserved
Guadiana estuary: present state, past evolution and prospects for the future
The Guadiana catchment extends over an area of 66 889 km2, between the catchments of the Tagus and Guadalquivir rivers, of which 11 525 km2 are in Portugal. Its upper part in Spain corresponds to what is called the Western La Mancha province. To the North the watershed is limited by alignments, of the Sierra de Altomira http://www.castillalamancha.es/sites/default/files/documentos/paginas/archivos/altomira_liczepa_fich.pdf ) with heights between 700 and 1,000 meters and the Mancha de Toledo, with profusion of endorheic lagoons between 600 and 800 meters above sea level. The origin of the Guadiana was historically placed in the area of Campo de Montiel under the name Rio Pinilla.info:eu-repo/semantics/publishedVersio
Love in Novels: Preferences for Authentic and Fake Gender Characters Among Poles and Americans (At Home and in the Other Country)
Salt harvesting
Saltworks (other terms: salterns, saltponds, solar ponds) are man-made hypersaline systems where table salt or halite (NaCl, sodium chloride) is harvested. Salt production in the Guadiana River estuary is based on solar evaporation of sea water. In other areas, salt is obtained from solid state or brine mining.
Saltworks using sea water are usually located in low coastal areas, allowing gravitational filling of ponds during the high tides. Evaporative salt production is restricted to geographical areas where this process is favoured by combined action of wind, solar radiation, low rain rates, and high temperatures. Hence, the Mediterranean and part of the European Atlantic coastal areas fulfil these conditions, particularly during
the summer months where the evaporation greatly exceeds precipitation.info:eu-repo/semantics/publishedVersio
Cultural Conception of Friendship: What do Ecuadorians and Poles Expect from a Friend?
The present study investigates similarities and differences in perception of emotional support and conversational intimacy between friends. Burleson’s (1994) typology of emotional support and analysis of Polish vs. Latin American cultures served as the theoretical framework for this study. Participants (Ecuadorians=87, Poles=60) completed a questionnaire consisting of five episodes-dialogues between two women whose behaviors reflected two variables: (i) Type of emotional support: Low versus High person-centered; and (ii) Success versus Failure story. Both partners, in dyads, where emotional support was high person-centered, enjoyed more positive evaluation than friends in low person-centered support dyads. Poles were more sensitive to how the needs of the self-disclosing partner were served by her friend, while Ecuadorians paid more attention to the quality of interaction. Also, personal matters attracted more interest of Poles, unlike Ecuadorians, for whom a casual small talk was more enjoyable
Sediment Imbalance Between Portuguese And Spanish Sectors Of Guadiana River Estuary
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
The evolution of the European framework for coastal management, linked to the new environmental challenges. The Portuguese case
The sharing of space by various human activities leading to social conflicts and threats to ecosystems,
alongside increased awareness of the threats to coastal zones has created the need to legislate on coastal planning and integrated management by developing international guidelines. A new management challenge has emerged due to climate change that had not previously been considered in legislation or policies. Therefore, the European tools and frameworks applied in Portugal, their implementation and effectiveness will be analysed. Extensive bibliographic data was analysed including EU directives and policies, and Portuguese governmental documents from national to a municipal level. We found that all the European Union guidelines and frameworks are being implemented in the Portuguese Governmental planning and are very well substantiated, whereas the base of all land management instruments (IGT), have a questionable implementation, mainly due to the number of entities involved and the long implementation process.MACOMA SGA ERASMUS MUNDUS 2015-1626/001-001-EMJDinfo:eu-repo/semantics/publishedVersio
Organic carbon accumulation in coastal zones since the last glacial maximum? A clue for varying atmospheric CO2 levels?
It is a generally accepted concept that the carbon storage within the principal earth surface reservoirs varies in a multitude
of time scales. The shallow water continental margins belong to the most fertile areas in terms of organic carbon (OC)
production and are also very effective carbon traps
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