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The aim of this study is to assess the potential effectiveness of GMES Space Component Sentinel Missions for land-based environmental policy support in the Azores Autonomous Region (Portugal). Sixteen different types of legal and spatial instruments are currently being applied in this region. Most of them require detailed and accurate Land-use/Land-cover cartography in order to deliver reliable outputs at municipal, island and archipelagic scales. Sentinel-2 Mission products can fulfill these requirements in a cost-effective way. A Spatial Data Infrastructure-based Regional GMES framework is proposed in order to process, assess, validate and integrate this GMES data into the decision support system of Azorean regional land policies.
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... To our knowledge, there is no study on RS vegetation mapping in the Mediterranean insular territories. On the other hand, the vegetation of some oceanic island territories has been established from RS data (Gil & Abadi, 2015;Gil et al., 2011Gil et al., , 2012Gil et al., , 2013Gil et al., , 2014Massetti et al., 2016). Therefore, in addition to the development of vegetation maps of targeted islands, this research aims to assess the utility of using an RF algorithm with high-resolution satellite imagery to classify island plant communities and to determine the ability of high-resolution satellite imagery to accurately map low vegetation cover, which is highly heterogeneous in very small areas. ...
... Considering the large surface area of the Azores and Madeira islands, Gil et al. (2012Gil et al. ( , 2013Gil et al. ( , 2014Gil et al. ( , 2015 used images with different resolutions: Aster of medium resolution 15-90 m, RapidEye 6.5 m spatial resolution, and IKONOS 0.6 m resolution, as well as different satellite image classification techniques. ...
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Despite their proximity to the coast, few studies have focused on identifying and mapping the vegetation of Algerian islands and islets. To fill this lacuna, our work, using satellite images and machine learning methods, is mainly aimed at identifying and mapping the main vegetation groups on a few islands, while evaluating the effectiveness of the random forest classifier, which is effectively used in the study of the vegetation of large areas. However, despite the high heterogeneity of their vegetation cover, the use of very high-resolution images (Pléaides and SPOT 6/7), through the fusion bands and derived bands (NDVI), has allowed the elaboration of a fairly precise vegetation map that can be used for the preparation of management and protection plans for these habitats. Our methodological approach revealed very satisfactory results, having allowed the identification of the plant communities inventoried in the field, while showing high accuracy values, ranging from 0.642 for the halophilic group of Asteriscus to 1 for the endemic Chasmophyte group of the Habibas archipelago (Pléiades images). The groups identified from SPOT 6/7 images show accuracy values between 0.67 for the Mediterranean cliff formations on Garlic Islet and 1 for the two formations (shrubby and herbaceous) of the Skikda islands. Our methodological approach, and notwithstanding the great heterogeneity and the very small surface areas of our islands and islets, has led to very satisfactory results, reflected with good overall accuracy and kappa index values (for Pléiades: overall accuracy > 92% and kappa index > 0.90; for SPOT 6/7: overall accuracy > 83% and kappa index > 0.80).
... In this context, it is important to study the evolution of pasture and the related LULC changes (LULCC), trying to identify possible threats to the sustainability of these territories in order to plan and manage them properly. Although the agricultural census can provide important data, accurate LULC mapping and LULCC temporal analysis (change detection and assessment) are crucial for a more reliable and effective land planning and management (Gil et al., 2012). ...
... In order to achieve this goal, the core methodological approach proposed in this study based on remote sensing and GIS-based LULCC detection may be used as a conceptual basis. Furthermore, as proposed by Gil et al. (2012), this conceptual approach is able to be costeffectively improved and technologically automatized by integrating, processing and assessing cost-free high/medium spatial resolution satellite data provided by the Copernicus programme's Sentinel-2 (multispectral, in synergy with Landsat 8) and Sentinel-1 (radar) missions in a periodic basis. Finally, this monitoring framework should be fully open and accessible to the decision-makers, land owners/managers, further stakeholders and the general public through an easy-to-use and attractive web (for decisionsupport and public awareness) and mobile (for in loco law enforcement purposes) GIS-based platform, eventually as a specific extension of the 'Na Minha Ilha' ('In My Island', in English) web platform capacities (http://servicos-sraa. ...
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Livestock production has been highly relevant in the Azores, boosted by European agricultural policies, increasing the demand for pasture and competing for space with other land uses. Therefore, it is important to understand the spatial evolution of pasture and related LULC trade-offs. This study describes a GIS-based LULC change detection approach to identify, map and assess pasture-related land use changes and respective trade-offs in Pico Island in the period between 1998 and 2013 (15 years). Pasture in 1998 occupied a total area of 17131 ha (about 39% of Pico Island surface), while in 2013 this same area was of 17621 ha (about 40% of Pico Island surface). During this period, about 16316 ha of pasture remained unchanged, while 2110 ha (about 5% of Pico Island surface) of land use have changed from pasture to another land use (810 ha), or from a previous land use to pasture (1300 ha). The whole pasture spatial dynamics and its net increase of 3% from 1998 to 2013 (490 ha, about 1% of Pico Island surface) were analyzed through the identification, mapping and assessment of LULC trade-offs, and interpreted according to several physical (elevation) and socioeconomic/policy drivers. Pasture and livestock grazing activity with adequate management may not constitute per se threats to nature conservation and biodiversity protection in Pico Island, as the identified issues have been shown to be mostly related to the pasture dynamics (changes and respective trade-offs).
... Importa ainda salientar que as regiões ultraperiféricas apresentam características geográficas e geológicas que as tornam excelentes laboratórios de pesquisa em diversas áreas de estudo, incluindo a das mudanças climáticas. Acresce ainda que a sua biodiversidade e ecossistemas marinhos excecionais são muito promissores em áreas, tais como a inovação em produtos farmacêuticos e agronomia (Gil, Fonseca, Lobo, & Calado 2012). ...
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In the European Union (EU) there are nine outermost regions (ORs), among which are the Autonomous Regional of the Azores (ARA) and the Autonomous Region of Madeira (ARM). The ORs have several specificities that limit their economic and social development, but its strategic importance is significant compared to the Exclusive Economic Zone (EEZ), so it is important to know. The aim of this paper is to deepen the knowledge and describe the evolution of business sector in ARA and ARM. Through a descriptive study using secondary data published by the Serviço Regional de Estatística dos Açores, Direção Regional de Estatística da Madeira and Instituto Nacional de Estatística, it was possible to verify that in the ARA and ARM between 2008 and 2017 there was initially a regression in the number of companies and a later recovery until 2017. In the RAA the total number of companies in 2017 still doesn´t equal the number of 2008. In addition, in both regions, the total numbers of small, medium and large companies in 2017 still do not add up to the figures for 2008. As for the legal form, in the RAA individual companies show a decrease in their expression, while in RAM the trend is reversed. About economic sectors activity, there were some variations over this period namely, in both regions, the construction sector has been decreasing its expression and the accommodation, restaurant and similar sector has increased its expression in relation to the global of companies evidencing a paradigm shift.
... OERs share several geographic similarities and proximity to SIDS and benefit from a particular political status within the European Union (Gil et al., 2012). Due to the support of the States and the European institutions, OERs are privileged areas in which to undertake demonstration projects that can be of high relevance for other small islands. ...
Article
The effects of climate change are global, but small islands are among the most vulnerable places. Local populations on small islands might have a ground-based perspective of the impacts that threaten them. This study was undertaken on Corvo (Azores), where 34% of the residents of both genders and different education levels were surveyed. Here, their understanding of climate change and their perception of its local impacts, the sense of risk, the local areas at risk, the willingness to propose mitigation and adaptation strategies, and the knowledge of regional procedures was analysed. Education played a crucial role in local understanding. The general perception was that the regional policies were insufficient to address climate change issues at the local level. This fact points out that the efforts to mitigate climate change impacts, and the public participation procedures for supporting policy-making, must be significantly increased and improved, in order to reach a real impact on local island communities. Full citation: Benedicto Royuela, J., Hervías-Parejo, S., Ambros, B., de la Cruz, A. and Gil, A. (2020) ‘Assessing the local perception of climate change in a small island: a case study’, Int. J. Global Warming, Vol. 22, No. 1, pp.30–53. DOI: 10.1504/IJGW.2020.110211
... OERs share several geographic similarities and proximity to SIDS and benefit from a particular political status within the European Union (Gil et al., 2012). Due to the support of the States and the European institutions, OERs are privileged areas in which to undertake demonstration projects that can be of high relevance for other small islands. ...
Article
The effects of climate change are global, but small islands are among the most vulnerable places. Local populations on small islands might have a ground-based perspective of the impacts that threaten them. This study was undertaken on Corvo (Azores), where 34% of the residents of both genders and different education levels were surveyed. Here, their understanding of climate change and their perception of its local impacts, the sense of risk, the local areas at risk, the willingness to propose mitigation and adaptation strategies, and the knowledge of regional procedures was analysed. Education played a crucial role in local understanding. The general perception was that the regional policies were insufficient to address climate change issues at the local level. This fact points out that the efforts to mitigate climate change impacts, and the public participation procedures for supporting policy-making, must be significantly increased and improved, in order to reach a real impact on local island communities. Full citation: Benedicto Royuela, J., Hervías-Parejo, S., Ambros, B., de la Cruz, A. and Gil, A. (2020) ‘Assessing the local perception of climate change in a small island: a case study’, Int. J. Global Warming, Vol. 22, No. 1, pp.30–53. DOI: 10.1504/IJGW.2020.110211
... Nevertheless, due to climate constraints and the consequent general lack of free-of-charge satellite multispectral remote sensing data (e.g. Landsat) covering most oceanic islands (Gil et al., 2012), few successful examples of land-cover mapping and monitoring are still available for insular territories. In the specific case of the populated Portuguese archipelagos, namely Azores and Madeira, most successful cases were developed by using high/mediumspatial resolution multispectral data and have focused on standard land-cover/land-use and vegetation mapping/assessment (e.g. ...
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Full citation: Tassi, A. and Gil, A., 2020. A low-cost Sentinel-2 data and Rao's Q diversity index-based application for detecting, assessing and monitoring coastal land-cover/land-use changes at high spatial resolution. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1315-1319. Coconut Creek (Florida), ISSN 0749-0208. DOI:10.2112/SI95-253.1 Abstract: Coastal zones in small oceanic islands as the Archipelago of the Azores (Portugal) are very sensitive territories severely threatened by climate change, natural disasters, biological invasions, infrastructure and tourism development, and also agriculture intensification. Land-cover/land-use changes are one of the most relevant indicators for monitoring and assessing coastal spatial planning and management policies in insular territories. This paper describes the application of a low-cost Rao's Q diversity index-based remote sensing tool able to provide a systematic and accurate coastal land-cover/land-use monitoring system in small oceanic islands, using free and open access Sentinel-2 multispectral satellite data and Terceira island (Archipelago of the Azores, Portugal) as the case-study area. Results indicate that about 7% (∼300 hectares) of Terceira Island's coastal zone (∼4290 hectares) have changed their land-cover/ land-use between March 2017 and December 2018 (21 months). Agricultural areas (4.1%), urban areas (2.1%) and bare soil areas (0.6%) are the categories showing more relevant changes.
... The use of optical Earth Observing data may constitute a cost-effective source for estimating AGC stocks in islands' terrestrial carbon pools (Chen et al., 2018;Mutanga, 2015, 2016;Sibanda et al., 2015;Güneralp et al., 2014). The frequent high degree of cloudiness that characterizes many oceanic islands throughout most of the year (Borges et al., 2018;Gil et al., 2012) can be mitigated thanks to the high revisit time capacity of most available satellite-based multispectral sensors with high/very high spatial resolution (for example, RapidEye, Worldview, Planet) and, particularly, by fusing the data obtained from different sensors (Anurogo et al., 2018;Fassnacht et al., 2014;Latifi and Koch, 2012). Island forest assessments are needed on a repeat basis in response to the inherent vulnerability of many these landscapes to rapid changes driven by human land exploitation, natural disasters, biological invasions and sea level rise (Asner et al., 2016). ...
Article
Small islands face environmental issues directly or indirectly related to land cover/land use changes (LCLUC), such as natural hazards, climate change, loss of biodiversity and proliferation of invasive alien species, some of which are caused by direct human exploitation. A Land Cover/Land Use Change (LCLUC) detection approach based on PCA and vegetation indices derived from low cost high-resolution RapidEye multispectral satellite data and available vegetation maps was developed to assess vegetated/forested aboveground carbon stocks and their changes in Madeira Island, Portugal, for the period between December 2009 and August 2011 due to catastrophic events occurred in 2010. During this period, the identified LCLUC revealed a relevant decrease of vegetated areas (especially those dominated by native/endemic communities) substituted by increases of non-vegetated and human-managed vegetated/forested areas. In particular, there was a decrease of 2% of vegetated areas, 30% of which were represented by native/endemic vegetation. The largest and most accurate LCLUC detected were used to estimate changes in aboveground biomass carbon (AGC) stocks. In 2010 more than 25,000 Mg of AGC stocks may have been released. Both relevant LCLUC and AGC stocks depletion in such short period of time may have been strongly enhanced by two catastrophic events that affected Madeira in February (flashflood and landslides) and August 2010 (wildfires). This straightforward and cost-effective methodological approach may be successfully applied in remote territories such as islands or mountainous areas, where the logistic and economic costs associated to periodic and standard airborne remote sensing campaigns for mapping, assessing and monitoring aboveground biomass carbon stocks are generally unaffordable for most decision-makers and land managers in these territories.
... The insular condition of the majority of the OERs as well as demographic pressure and the steady growth of tourism have had a great impact on the natural environment and increase the complexity and cost of sustainable development in these regions (Calado et al. 2014;Gil et al. 2012). Furthermore, from a scientific and social science perspective, "islands present themselves as self-contained units to examine sustainability" (Baldacchino 2007: 14). ...
Article
This paper evaluates the environmental behavior of SMEs in the Canary Islands (Spain), one of the Outermost European Regions. The islands’ fragile socioeconomic systems and scarce resources noticeably condition the competitiveness of their firms. An empirical analysis ranks environmental protection practices in SMEs and identifies differences on the basis of size and business sector. In addition, groups of firms with different environmental behavior are identified to facilitate the design of environmental policies, improve effectiveness in decision making and the more efficient use of resources. From a theoretical perspective, this paper contributes to the gap identified by the precursors of the Natural Resource-Based View of the firm by analyzing specific resource combinations that each firm can use to improve its environmental performance and achieve competitive advantages. The firms best positioned to develop the dynamic capabilities needed are identified not only considering the physical environment, but also the socio-economic one and key intangible resources are measured that shape firms’ environmental strategy.
... Nevertheless, due to its innovative technical features, applying a multi-method processing approach to the new ESA Copernicus Sentinel-2 sensor data might be able to cost-effectively address this relevant information gap at regional level, by providing accurate, detailed and periodic thematic cartography and change detection assessment (e.g. Immitzer et al., 2016;Gil et al., 2012). Furthermore, observing alien plants as acacia requires data collected from sensors pushing the limits of at least one type of resolution (spatial, temporal or spectral resolution) since the profiles of these species may be quite similar to those of native plants, from a RS perspective (Asner, 2008). ...
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Aim of the study: Acacia dealbata is an alien invasive species that is widely spread in Portugal. The main goal of this study was to produce an accurate and detailed map for this invasive species using ASTER multispectral imagery. Area of study: The central-eastern zone of Portugal was used as study area. This whole area is represented in an ASTER scene covering about 321.1 x 103 ha. Material and methods: ASTER imagery of two dates (flowering season and dry season) were classified by applying three supervised classifiers (Maximum Likelihood, Support Vector Machine and Artificial Neural Networks) to five different land cover classifications (from most generic to most detailed land cover categories). The spectral separability of the land cover categories was analyzed and the accuracy of the 30 produced maps compared. Main results: The highest classification accuracy for acacia mapping was obtained using the flowering season imagery, the Maximum Likelihood classifier and the most detailed land cover classification (overall accuracy of 86%; Kappa statistics of 85%; acacia class Kappa statistics of 100%). As a result, the area occupied by acacia was estimated to be approximated 24,770 ha (i.e. 8% of the study area). Research highlights: The methodology explored proved to be a cost-effective solution for acacia mapping in central-eastern of Portugal. The obtained map enables a more accurate and detailed identification of this species’ invaded areas due to its spatial resolution (minimum mapping unit of 0.02 ha) providing a substantial improvement comparably to the existent national land cover maps to support monitoring and control activities. Keywords: remote sensing; invasive alien species; land cover mapping; vegetation mapping.
... Madeira Island (Archipelago of Madeira, Portugal) is the main island of the Autonomous Region of Madeira, which is one of the European Union Outermost Regions. The majority of European Outermost Regions -except the French Guiana -are small islands or archipelagos [Gil et al., 2012]. Madeira Island is located in the Macaronesia biogeographic region, which is constituted by five oceanic archipelagos located on the eastern part of the Atlantic Ocean, facing the coasts of the African continent and the Iberian Peninsula. ...
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Abstract: Madeira Island is a biodiversity hotspot due to its high number of endemic/native plant species. In this work we developed and assessed a methodological framework to produce a RapidEye-based vegetation map. Reasonable accuracies were achieved for a 26 categories classification scheme in two different seasons. We tested pixel and object based approaches and the inclusion of a vegetation index band on top of the pre-processed RapidEye bands stack. Object based generally showed to outperform pixel based classification approaches except for linear or highly scattered classes. The addition of a vegetation index to the workflow increased the separability of the Jeffrey-Matusita least separable class pairs, but not necessarily the overall accuracy. The Pontius accuracy assessment highlighted class specific accuracy tradeoffs related to different combinations of the inputs and methods. The approach to be used, in conclusion, should be carefully considered on the basis of the desired result. Full Citation: Massetti A., Sequeira M.M., Pupo A., Figueiredo A., Guiomar N., & Gil, A. (2016). Assessing the effectiveness of RapidEye multispectral imagery for vegetation mapping in Madeira Island (Portugal). European Journal of Remote Sensing, 49:643 - 672. doi: 10.5721/EuJRS20164934. Freely available online at http://www.aitjournal.com/articleView.aspx?ID=1008
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Resumo Neste artigo apresentam-se as iniciativas do Instituto Geográfico Português (IGP) relacionadas com produção de cartografia temática de ocupação/uso do solo. Assim, descreve-se a Carta de Ocupação do Solo de 1990 (COS90) e de 2005 (COS2005) e o programa CORINE Land Cover (CLC). Neste artigo apresenta-se também o projecto COSMIC que tem como objectivo o desenvolvimento de metodologias automáticas e expeditas para produção futura de cartografia temática de ocupação/uso do solo com base em imagens de satélite, para os anos entre as actualizações da COS e da carta CLC.
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The amount of scientific literature on (Geographic) Object-based Image Analysis - GEOBIA or OBIA in short - has been and still is sharply increasing. The term OBIA is herein used for generic image processing tasks. OBIA researchers with backgrounds in geology, geography or mineralogy are joining forces with colleagues from cell biology, molecular biology, medicine, pharmacy or nanotechnology. More narrowly, GEOBIA's objective is the generation of geographic information (in GIS-ready format), from which new spatial knowledge can be obtained. GEOBIA is a relatively new field of research based upon two major concepts: A) dissecting images or any (pseudo- )continuous multidimensional fields of data, and b) allowing for multiple scales when organizing and utilizing the resulting objects. Analyses of the amount of scientific literature reveal that not only the number of articles is increasing, but that the rate of growth is also noticeably accelerating. Finally, it is discussed whether or not GEOBIA can be considered as an important paradigm in remote sensing. Copyright © (2013) by the American Society for Photogrammetry & Remote Sensing.
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GMES (Global Monitoring for Environment and Security) which is the European initiative for setting up a wide capability for Earth observation, and is the most ambitious Earth observation program is discussed. GMES has the goal of delivering operational information services for environment and security in six areas: Land, Marine, Atmosphere, Emergency Response, Security and Climate Change. ESA Member States have invested significantly in the set up of GMES by creating and funding the ESA optional GMES Space Component (GSC) Program. The GMES Space Component program will fulfill space-based observation requirements responding to European policy priorities. ESA's function as GSC Coordinator has been described at a high level in several policy documents related to European Space Policy, including several Space Council Orientations, in EU and ESA policy documents and in EC Communications related to GMES.
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Studies are needed to evaluate the ability of present or future SAR data to extract forest attributes over various sites. This study focuses on large unmanaged pine plantations in a vast flat area of ca. 500,000 ha where the tree biomass ranges from 0 to 200 m3/ha corresponding to different forest canopy structures. Results show a good correlation between the backscattering coefficient σ0 (with a 6-dB dynamic range and R2≥.8), the stand timber volume and the stand density. The trend is mainly driven by stand density and different relationships are observed according to age class, which explicitly points out the effects of canopy structure on the backscattering level. Stem volume is derived from the inversion of statistical and semiempirical models, which take these effects into account. Inversion results show that forest biomass attributes can be estimated with relatively small errors commensurate with those achieved by field measurements. Best overall accuracy of ca. 21 m3/ha is reached with the semiempirical model. Error decomposition as a function of age classes shows that, for the same biomass range, errors are higher for old stands than for young stands. Finally, the results indicate that (1) JERS-1 data can be used in an operational way for estimating the biomass of such plantations and (2) it is necessary to take forest stand structure into account. In order to develop reliable biomass-retrieval schemes, future research should focus on examining in a more mechanistic way the relationship between canopy structure and radar signature.