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- Projections of maximum tidal inundation limits of estuaries and lagoons of the south Algarve, forced by mean sea level rise: RCP8.5 scenarioPublication . Sampath, Dissanayake; Boski, Tomasz; Moura, Delminda; Veiga-Pires, C.In the present study, we adopted the Hybrid Estuarine Sedimentation Model to simulate the estuarine and lagoon evolution in the South Algarve region due to projected mean sea level rise (MSLR) and sediment deficit scenarios during the 21st century. Thus, we forecasted morphological evolution of six large and medium size estuaries (Guadiana Alcantarilha, Arade, Gilão, Quarteira River, Alvor and a coastal lagoon system (Ria Formosa lagoon) due to the imposed scenarios of MSLR. The projected digital elevation models were used to identify the maximum tidal limits of each system by the year 2100. According to the results, in all cases, saltmarsh habitats and sand flats will be affected severely in response to upper-limit of RCP8.5 scenario of MSLR by 2100. The conjugation of the increase of the mud-flat area and the decrease of saltmarshes will result in the reduction of habitats and then of biodiversity. Habitats associated with the Ria Formosa coastal lagoon and the Guadiana estuary are highly vulnerable to the worst case scenario of MSLR (90 cm higher relative to the year 2011). Agricultural and aquaculture areas in all study areas will be affected due to the landward translation limits of the intertidal areas. Accordingly, it would be advisable to adopt measures to minimize the socioeconomic impacts and loss of ecosystem services in the South Algarve due to climate change driven MSLR during the 21st century and beyond while taking adaptation actions to prevent the loss of environmentally sensitive habitats like salt marshes and sand dunes.
- Characterization of the sedimentary environment of the Gilão River Mouth, based on sedimentological and mineralogical analysisPublication . Rocha, F.; Boski, T.; Gomes, Celso; Moura, Delminda; Veiga-Pires, C.The main objective of this paper is to use the mineralogical composition of the fine and clay fractions of the sediments from the studied borehole to a better characterization of the Gilão Estuary sedimentary environment.
- Guadiana estuary: present state, past evolution and prospects for the futurePublication . Boski, T.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.
- Fleur de sel composition and production: analysis and numerical simulation in an artisanal salternPublication . Sainz, Noa; Boski, T.; DMR, SampathThis study is a first approach to modelling of fleur de sel production, aimed at increasing its efficiency and contributing to the scarce literature on the topic. Quantitative forecasting of daily production of fleur de sel was applied to an artisanal solar pond unit in the environmentally protected area of Castro Marim, SE Portugal. The numerical model was based on simulations of the evaporation process, taking into account the effect of reduced vapour pressure of the brine solution. The controlling variables chosen as input parameters to the forecast model were brine temperature, brine concentration, harvesting efficiency, albedo, incoming solar radiation, precipitation, air relative humidity, air temperature, atmospheric pressure, day of the year, wind direction, and wind speed. Production predicted by the model was tested against actual production in two crystallisers in the years 2015 and 2017. The statistically evaluated match between the estimated and actual production was highly significant with a mean R-2 of 0.8 and overall error of estimation was 14.5%. The chemical composition of nine samples of fleur de sel was analysed, showing the temporal evolution of several components during the harvesting period. A decrease of NaCl content from 96% to 87% and an increase by one order of magnitude of Mg, S, K, Br, and As were observed. The range of Ca, Si, Al, and Sr contents was 0.12-0.65%, 0.1-0.85%, 0.08- 0.3%, and 0.009-0.013%, respectively. Ba, Fe, Mn, Mo, Pb, and Sn contents had the following ranges: 0.051-0.145, 1.2-5.5, 0.44-1.66, 0.03-0.05, <0.05-0.55, and <0.05-0.1 mg/kg, respectively. The following elements were below the detection limit and below the limits of the Codex Alimentarius: Cd, Th, U, Cu, Cr, Co, Ni, V, Bi, Zn, Rb, and Hg.
- Chronology of the sedimentary processes during the postglacial sea level rise in two estuaries of the Algarve coast, Southern PortugalPublication . Boski, T.; Camacho, Sarita; Moura, Delminda; Fletcher, William; Wilamowski, A.; Veiga-Pires, C.; Correia, Victor; Loureiro, C.; Santana, PauloFour profiles of estuarine sediments obtained from boreholes drilled in the Algarve, Southern Portugal were studied in order to reconstruct the process of sediment accumulation driven by the postglacial sea level rise. In addition to the sedimentological analysis, the Foraminifera Index of Marine Influence (FIMI) permitted assessment of the nature and organization of sedimentary facies in the BelicheeGuadiana and Gilão-Almargem estuaries. The Beliche- Guadiana CM5 and Almargem G2 profiles accumulated in a sheltered environment, with the former presenting an almost continuous record of the sea level rise since ca 13 000 cal yr BP. The G1 and G3 profiles from the Gilão-Almargem area represent a more discontinuous record of the last 8000 years, which accumulated in the more dynamic environment of an outer estuary. The integration of all radiocarbon ages of dated levels, led to an estimate of sediment accumulation rates. Assuming a constant position of the sediment surface with respect to the tidal range and a negligible compaction of sediment, the sea level rose at the rate of 7 mm yr ^-1 in the period from 13 000 to 7500 cal yr BP. This process slowed down to ca 0.9 mm yr 1 from 7500 cal yr BP until the present. The marked historical change in the rate of sediment accumulation in these estuaries also occurred with the accumulation of organic matter and is, therefore, important data for global biogeochemical models of carbon. The main obstacle to obtain higher temporal resolution of the sedimentary processes was the intense anaerobic respiration of organic matter via sulphate reduction, which did not allow any accumulation of peat and, furthermore, led to erasure of the palaeontological record by acid formed from the subsequent oxidation of sulphides.
- Variação do nível do mar na costa algarvia durante o PlistocénicoPublication . Albardeiro, L.; Moura, Delminda; Veiga-Pires, C.; Boski, T.São objectivos do presente trabalho, o estudo da evolução da morfologia costeira durante o Plistocénico Superior, a correlação de plataformas de abrasão marinha com a estratigrafia isotópica marinha e a utilização da informação recolhida como uma ferramenta de gestão costeira.
- Salt harvestingPublication . Sainz, Noa; Boski, T.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.
- Aplicação multimédia sobre a Ria Formosa e seus fins educacionais (ForDid)Publication . Oliveira, Sónia; Boski, T.; Moura, Delminda; Mendes da Silva de Sousa, Carlos A; Gomes, Ana; Pereira, LauraNa atualidade torna-se inquestionável a necessidade de integrar a aprendizagem com as novas tecnologias de modo a cativar e facilitar a compreensão dos temas abordados através de aplicações didáticas. Durante a última década o Centro de Investigação Marinha e Ambiental (CIMA) assumiu a responsabilidade de criar meios eficazes de comunicação entre o público em geral e a comunidade científica, através de plataformas multimédia interativas. Foram objecto destas aplicações didáticas as várias vertentes do património natural do Algarve. Após o sucesso das primeiras aplicações GuaDid e MonDid visando o Estuário do Rio Guadiana e a Serra de Monchique respectivamente, o desafio de criar e inovar foi acrescido, resultando numa nova aplicação – ForDid, visando a divulgação do importante sistema lagunar Ria Formosa.
- Ensaio de caracterização do meio sedimentar do estuário do Rio Gilão, com base em análises de parâmetros mineralógicos e sedimentológicosPublication . Rocha, F.; Boski, T.; Gomes, Celso; Moura, Delminda; Veiga-Pires, C.Foram realizadas análises sedimentológicas e mineralógicas ao sedimento recolhido numa sondagem realizada no estuário do Rio Gilão próximo do Arraial Ferreira Neto. A sondagem atingiu o substrato rochoso pré-holocénico aos 18 m de profundidade.
- Biomarker patterns in a time-resolved holocene/terminal Pleistocene sedimentary sequente from the Guadiana river estuarine area (SW Portugal/Spain border)Publication . González-Vila, Francisco; Polvillo, Olivia; Boski, T.; Moura, Delminda; Andrés, JoséThe vertical distribution of terrestrial and phytoplankton biomarker compounds in a sediment core from the coastal estuarine zone of the Guadiana river (southwest border between Portugal and Spain) was determined by gas chromatography–mass spectrometry. Significant downcore fluctuations were observed in the patterns of the most abundant alkyl series (n-alkanes and n-fatty acids), as well as in several biomarker ratios. In addition, a specific contribution from conifers is reflected in the presence of a resin acid series that first appears 6500 years BP. The observed changes in the lipid assemblage within the Holocene suggest recent variations in the planktonic and terrigenous supply, which are attributed mainly to the evolution of the circulation pattern in the estuary and to the alteration of vegetation cover within the Guadiana drainage basin. Our data suggest that on a 103–104 year time-scale, little or no diagenetic change occurred with respect to the compounds in question.