Impact of Flash Flood Events on the Coastal Waters Around Madeira Island: The “Land Mass Effect”

The Island Mass Effect has been primarily attributed to nutrient enhancement of waters surrounding oceanic islands due to physical processes, whereas the role of land runoff has seldom been considered. Land runoff can be particularly relevant in mountainous islands, highly susceptible to torrential rainfall that rapidly leads to flash floods. Madeira Island, located in the Northeast Atlantic Ocean, is historically known for its flash flood events, when steep streams transport high volumes of water and terrigenous material downstream. A 22-year analysis of satellite data revealed that a recent catastrophic flash flood (20 February 2010) was responsible for the most significant concentration of non-algal Suspended Particulate Matter (SPM) and Chlorophyll-a at the coast. In this context, our study aims to understand the impact of the February 2010 flash flood events on coastal waters, by assessing the impact of spatial and temporal variability of wind, precipitation, and river discharges. Two specific flash floods events are investigated in detail (2 and 20 February 2010), which coincided with northeasterly and southwesterly winds, respectively. Given the lack of in situ data documenting these events, a coupled air-sea-land numerical framework was used, including hydrological modeling. The dynamics of the modeled river plumes induced by flash floods were strongly influenced by the wind regimes subsequently affecting coastal circulation, which may help to explain the differences between observed SPM and Chlorophyll-a distributions. Model simulations showed that during northeasterly winds, coastal confinement of the buoyant river plume persisted on the island’s north coast, preventing offshore transport of SPM. This mechanism may have contributed to favorable conditions for phytoplankton growth, as captured by satellite-derived Chlorophyll-a in the northeastern coastal waters. On the island’s south coast, strong ocean currents generated in the eastern island flank promoted strong vertical shear, contributing to vertical mixing. During southwesterly winds, coastal confinement of the plume with strong vertical density gradient was observed on the south side. The switch to eastward winds spread the south river plume offshore, forming a filament of high Chlorophyll-a extending 70 km offshore. Our framework demonstrates a novel methodology to investigate ocean productivity around remote islands with sparse or absent field observations.

New taxa to the flora of Madeira archipelago islands (Portugal)

73 new references for 72 taxa of vascular plant are here reported for the Madeira archipelago. 55 not previously recorded for Desertas Islands, 12 to Porto Santo Island and 6 for Madeira Island. Of the 72 taxa, 28 are xenophytes, and 10 are new taxa to the flora of the archipelago (of these 9 are xenophytes). Their native status, taxonomy and distribution are briefly discussed.

Land Uses Allocation: The Execution of an Artificial Beach and Its Complementary Infrastructures – Madeira Island – Machico, Portugal

The present study aims to propose the creation of an artificial beach in the municipality of Machico and its complementary infrastructures, located on the south-eastern coast of the Madeira Island (Portugal). Machico’s beach sand consists of a mixture of black volcanic sand and round basalt stones. Usually, it has clear waters and a quiet sea. This beach also has a mooring infrastructure, thus allowing access to the sea. In order to achieve this study’s main goals, it was initially carried out an extensive review and bibliographic research. Subsequently, a sand beach and its shelter groins were simulated and designed to hypothetically promote the retention of the sand and mitigate the tidal effects. In addition to model the beach dynamics, an extensive characterization of the extreme maritime regime was performed. The model was developed based on topographic and hydrographic site surveys and the data using Wave Watch III model at 32.0°N, 17.0°W—obtained from SONEL web page, which gathers new data every 6 hours. Besides, the study also contemplated the analysis of the sea inundation quota for a return period of 100 and 500 years and its development along with the Master Plan of the City of Machico. Furthermore, some final remarks and conclusions will be shown; besides, some future projects should be developed to expand the knowledge of this thematic field.

Estudo prosódico comparativo de declarativas e interrogativas totais do português brasileiro e do português europeu / Prosodic Comparative Study of Declarative and Total Interrogative Sentences in Brazilian Portuguese and European Portuguese

Resumo: Este trabalho tem por objetivo comparar a prosódia utilizada em sentenças declarativas e interrogativas no português brasileiro (falado nas cidades de Belém, Belo Horizonte, Florianópolis e São Paulo) e no português europeu – falado nas cidades de Vinhais (continente), Fenais (ilhas Açores) e Calheta (ilha da Madeira). Foram explorados acusticamente os parâmetros de frequência fundamental, duração e intensidade em 252 enunciados que figuram no corpus AMPER-Por. Os movimentos melódicos pré-nuclear, nuclear e final foram observados e permitiram encontrar algumas diferenças entre o português brasileiro e o europeu, principalmente aquele falado nas ilhas. Em relação à duração, a principal diferença entre o português brasileiro e o europeu consiste na maior duração nos dados do Brasil. A intensidade não se mostrou um parâmetro relevante para diferenciar prosodicamente o português europeu do brasileiro.Palavras-chave: prosódia; AMPER-Por; português europeu; português brasileiro; dialetologia.Abstract: This work aims to compare the prosody used in declarative and interrogative sentences in Brazilian Portuguese (spoken in the cities of Belém, Belo Horizonte, Florianópolis and São Paulo) and in European Portuguese – spoken in the cities of Vinhais (mainland), Fenais (Azores) and Calheta (Madeira Island). The acoustic parameters of fundamental frequency, duration and intensity were analyzed in 252 sentences which are part of the AMPER-Por corpus. The pre-nuclear, nuclear and final pitch were observed and this allowed to find some differences between Brazilian and European Portuguese, mainly that spoken on the islands. Regarding the duration, the main difference between Brazilian and European Portuguese is the longer duration in the Brazilian data. Intensity is not a relevant parameter to differentiate European Portuguese from Brazilian Portuguese.Keywords: prosody; AMPER-Por; European Portuguese; Brazilian Portuguese; Dialectology.

GIS-based Assessment of Morphological and Hydrological Parameters of Ribeira dos Socorridos and Ribeira do Vigario Basins, Madeira Island, Portugal

The main objective is to identify hydraulic and hydrologic features of drainage basins of Ribeira dos Socorridos, and Ribeira do Vigário located in Madeira Island, (Câmara de Lobos).So, the research analyzed, theoretically, the sediment transport in the above-mentioned cases, and consequently, possible measures for torrential correction were studied. Thereby, hydrographic, geological, and hydrological features of this Archipelago were analyzed in the first phase. Thus, a geographic framing of drainage basins was made - using digital terrain models and deep characterization of the understudy drainage basins. In this regard, it was possible to obtain data regarding the geometric, relief, and drainage system components, using the Geographic Information Systems (GIS).In fact, the use of GIS makes it possible to characterize all descriptive indices/parameters of a hydrographic basin. These indices/parameters linked to the region's climate explain the need for human intervention to construct river hydraulic infrastructure and implement mitigation measures.Moreover, torrential correction techniques were presented to anticipate and mitigate this typology of events. Contextually, this study provides us several goals to consider in the future, including the most relevant actions and guidelines to enhance the characterization of drainage basins and clarify the characterization and accounting of sediment transport.

The collapse of marine forests: drastic reduction in populations of the family Sargassaceae in Madeira Island (NE Atlantic)

Species of the genera Cystoseira, Ericaria, Gongolaria, and Sargassum (family Sargassaceae) are key components of the Mediterranean-Atlantic marine forests, essential for biodiversity and ecosystem functioning. Populations of these foundational species are particularly vulnerable to anthropogenic impacts, likely to be intensified under future scenarios of climate change. The decline and even disappearance of these species have been reported in different areas of the world. At Madeira Island (NE Atlantic), populations of Gongolaria abies-marina, Ericaria selaginoides, Sargassum vulgare, and Sargassum filipendula, the most ecologically relevant species in Macaronesian marine forests, have been suffering a drastic decline during the last decades, especially on the southern coast of the island, where anthropogenic pressure is higher than on the north coast. The lack of sufficient temporal coverage on qualitative and quantitative studies of Sargassaceae communities in Madeira poses a challenge to establish a specific period for this decline. Consulting qualitative studies and historical records, we have set for the first time a timeline that shows an evident decrease in Sargassaceae populations in the last 20 years on Madeira Island. Following this timeline, we pinpoint the start of this decline in the first decade of the 2000s. This can be particularly confirmed for places like Funchal and Reis Magos, with significantly higher historical records. Currently, most benthic communities on shallow subtidal rocky reefs along the south coast are dominated by sea urchins and crustose coralline algae, the so-called sea urchin barrens. However, in some cases, they are entirely covered by a layer of sediment. We discuss the possible factors contributing to these drastic changes, bringing Madeira’s marine forests to a dramatic decline. As many animal species rely on marine forests, the decline of Sargassaceae populations represents an invaluable ecological loss for the coastal ecosystem of the island.

Forest Fires in Madeira Island and the Fire Weather Created by Orographic Effects

Understanding the effects of weather and topography on fire spread in specific contexts, such as oceanic islands, is critical for supporting fire prevention and suppression strategies. In this study, we analyse the atmospheric conditions associated with historical forest fires that have occurred over complex terrain in Madeira Island, Portugal. The atmospheric Meso-NH model was used to identify the mesoscale environment during three forest fires events. The model was configured into two nested horizontal domains, the outer domain at 2.5 km resolution and the inner domain at 500 m. The paper brings a comprehensive analysis on the factors favouring the evolution of significant large fires occurring in Madeira Island in August 2010, July 2012 and August 2016. These fire events were selected because they are characterized by their large size (between 324.99 ha and 7691.67 ha) that expanded in a short-time period, threatening people and property in the wildland-urban interfaces. The study highlights that local terrain produce orographic effects that enhance the fire danger over the southern slope during typical summer atmospheric conditions.