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García-Álvarez, D., Viana, C. M., Gomes, E., Marcelino, F., Caetano, M., & Rocha, J. (2023). Dealing with the uncertainty of technical changes in the CORINE Land Cover dataset: The Portuguese approach. International Journal of Applied Earth Observation and Geoinformation, 122, 1-11. [103389]. https://doi.org/10.1016/j.jag.2023.103389 --- This work was supported by the Spanish Ministry of Science and Innovation [Ayudas para contratos Juan de la Cierva-formación 2019 - FJC2019-040043]. The first author is also grateful to the University of Alcalá for funding his research visit at the Instituto de Geografia e Ordenamento do Território (IGOT) of the University of Lisbon, where this research was carried out. The authors are also grateful to the IGOT for funding the Open Access fee of this paper. Land Use and Land Cover (LULC) datasets are widely used across disciplines, with many users demanding more and better information. Understanding the uncertainties and errors associated to the main LULC datasets is a required step to facilitate their correct use, as well as to identify what could be improved in the future production of these products. CORINE Land Cover is probably the most well-known and used LULC dataset in Europe, especially valuable for the rich time-series that it provides. Despite being produced through a change mapping first approach, which tries to avoid technical errors and uncertainties in the temporal analysis of LULC changes, the Copernicus Land Monitoring Service distributes status layers of CORINE (CSL), which are not valid for change analysis because of their associated errors and uncertainties. The CORINE layers of changes (CHA) remove a lot of these issues, but do not meet the needs of many users. In Portugal, the national authority in charge of producing CORINE, the DGT, has implemented a backdating approach to produce consistent CSL layers that allow change analysis with low levels of uncertainty. Throughout this paper, we evaluate the changes that can be analyzed through all available CORINE layers in Portugal: Copernicus CSL layers; the national DGT CSL layers; and CHA layers. To this end, we aim to assess what type of changes can be studied through each type of layer, their associated sources of uncertainty and the relevance and utility of the Portuguese backdating approach to produce a consistent time-series of LULC maps. The results prove how the Portuguese CORINE layers distributed by the Copernicus Land Monitoring Service contain important sources of uncertainty, which however have been removed through the national backdating methodology. This methodology can be therefore exported for the production of CORINE in other European countries. publishersversion published

Alves, A.; Moraes, D.; Barbosa, B.; Costa, H.; Moreira, F.; Benevides, P.; Caetano, M. and Campagnolo, M. (2023). Exploring Spectral Data, Change Detection Information and Trajectories for Land Cover Monitoring over a Fire-Prone Area of Portugal. In Proceedings of the 9th International Conference on Geographical Information Systems Theory, Applications and Management - GISTAM; ISBN 978-989-758-649-1; ISSN 2184-500X, SciTePress, pages 87-97. DOI: 10.5220/0011993100003473---This research was conducted under the collaboration contract DGT-ISA 261/2021 with funding from Compete2020 (POCI-05-5762-FSE-000368), supported by the European Social Fund, and Centro Exploring Spectral Data, Change Detection Information and Trajectories for Land Cover Monitoring over a Fire-Prone Area of Portugal 95 de Investigação em Gestão de Informação (MagIC), Project UIDB/00239/2020 (Forest Research Centre), both supported by the Portuguese Foundation for Science and Technology (FCT) Land use/land cover (LULC) change detection and classification in maps based on automated data processing are becoming increasingly sophisticated in Earth Observation (EO). There is a growing number of annual maps available, with diverse but related production structures consisting primarily of classification and post-classification phases, the latter of which deals with inaccuracies of the first. The methodology production of the “Carta de Ocupação do Solo conjuntural” (COSc), a thematic land cover map of continental Portugal produced by the Directorate-General for Territory (DGT) mostly based on Sentinel-2 images classification, includes a semi-automatic phase of correction that combines expert knowledge and ancillary data in if-then-else rules validated by photointerpretation. Although this approach reduces misclassifications from an initial Random Forest (RF) prediction map, improving consistency between years and compliance with ecological succession, requires a lot of time-consuming semi-automatic procedures. This work evaluates the relevance of exploring an additional set of variables for automatic classification over disturbance-prone areas. A multitemporal dataset with 124 variables was analysed using data dimensionality reduction techniques, resulting in the identification of 35 major explanatory indicators, which were then used as inputs for RF classification with cross-validation. The estimated importance of the explanatory variables shows that composites of spectral bands, which are already included in the current COSc workflow, in conjunction with the inclusion of additional data namely, historical land cover information and change detection coefficients, from the Continuous Change Detection and Classification (CCDC) algorithm, are relevant for predicting land cover classes after disturbance. Since map updating is a more challenging task for disturbed pixels, we focused our analysis on locations where COSc indicated potential land cover change. Nonetheless, the overall classification accuracy for our experiments was 72.34 % which is similar to the accuracy of COSc for this region of Portugal. The findings suggest new variables that could improve future COSc maps. publishersversion published

Costa, H., Benevides, P., Moreira, F. D., & Caetano, M. (2022). Detection and classification of changes in agriculture, forest, and shrublands for land cover map updating in Portugal. In C. M. U. Neale, & A. Maltese (Eds.), Proceedings of SPIE.Remote Sensing for Agriculture, Ecosystems, and Hydrology XXIV (Vol. 12262, pp. 19). SPIE. Society of Photo-Optical Instrumentation Engineers. https://doi.org/10.1117/12.2636127 - ----Funding Information: The work has been supported by projects foRESTER (PCIF/SSI/0102/2017), and SCAPE FIRE (PCIF/MOS/0046/2017), and by Centro de Investigação em Gestão de Informação (MagIC), all funded by the Portuguese Foundation for Science and Technology (FCT). Value-added data processed by CNES for the Theia data centre www.theia-land.fr using Copernicus products. The processing uses algorithms developed by Theia's Scientific Expertise Centres. Portugal produced a land cover map for 2018 based on Sentinel-2 data and represents 13 classes, including agriculture, six tree forest species, and shrubland. The map was updated for 2020. The strategy focused on three strata where annual changes occur: S1 (agriculture) due to crop rotation, S2 (forest and shrubland) due to wildfires and clear-cuts, and S3 (fire scars and clear-cuts of previous years) where vegetation regeneration occurs. The methodology included i) change detection, ii) classification, and iii) knowledge-based rules. Stratum S1 was classified with images of the entire 2020 crop year and a training dataset extracted from the national Land Parcel Identification Systems (LPIS) of 2020. The land cover nomenclature was expanded and class agriculture was split in three distinct classes, hence resulting a map with 15 classes in total. Change detection, implemented in stratum S2, analyzed the profile of NDVI since 2018 to find potential loss of vegetation. S2 and S3 were classified through two stages. First, images of the entire 2020 crop year were used and then data of October 2020 (end of crop year) to capture late changes. The training points of the 2018 land cover map were used, but only if not associated with NDVI change. For all the three strata, knowledge-based rules corrected misclassifications and ensured consistency between the maps. A comparison between 2018 and 2020 reveal important land cover dynamics related to vegetation loss and regeneration on ~5% of the country. authorsversion published

Duarte, A., Borralho, N., Cabral, P., & Caetano, M. (2022). Recent Advances in Forest Insect Pests and Diseases Monitoring Using UAV-Based Data: A Systematic Review. Forests, 13(6), 1-31. [911]. https://doi.org/10.3390/f13060911 ------------- Funding Information: This study was supported by national funds through Fundação para a Ciência e a Tecnologia (FCT) under the project UIDB/04152/2020—Centro de Investigação em Gestão de Informação (MagIC). Unmanned aerial vehicles (UAVs) are platforms that have been increasingly used over the last decade to collect data for forest insect pest and disease (FIPD) monitoring. These machines provide flexibility, cost efficiency, and a high temporal and spatial resolution of remotely sensed data. The purpose of this review is to summarize recent contributions and to identify knowledge gaps in UAV remote sensing for FIPD monitoring. A systematic review was performed using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) protocol. We reviewed the full text of 49 studies published between 2015 and 2021. The parameters examined were the taxonomic characteristics, the type of UAV and sensor, data collection and pre-processing, processing and analytical methods, and software used. We found that the number of papers on this topic has increased in recent years, with most being studies located in China and Europe. The main FIPDs studied were pine wilt disease (PWD) and bark beetles (BB) using UAV multirotor architectures. Among the sensor types, multispectral and red–green–blue (RGB) bands were preferred for the monitoring tasks. Regarding the analytical methods, random forest (RF) and deep learning (DL) classifiers were the most frequently applied in UAV imagery processing. This paper discusses the advantages and limitations associated with the use of UAVs and the processing methods for FIPDs, and research gaps and challenges are presented. publishersversion published

Nicolau, R., David, J., & Caetano, M. (2018). Proposta metodológica para a determinação do indicador 11.3.1: Rácio entre a taxa de consumo do solo e a taxa de crescimento da população. Paper presented at Encontro Ciência' 2018, Lisbon, Portugal. publishersversion published

Mestrado em Materiais e Dispositivos Biomédicos O óxido de zinco, sob a forma de nanopartículas (npZnO), é um tema de elevado interesse na actualidade. É no entanto sabido que as suas propriedades e efeitos biológicos são muito dependentes do método de síntese. Nesse contexto, características como o comportamento antibacteriano e a citotoxicidade encontram-se ainda pouco estudadas. Tal como outros materiais nanoestruturados, o óxido de zinco, quando na forma de nanopartículas, pode ser potencialmente perigoso para o organismo humano caso as suas propriedades não sejam bem controladas. A fixação destas nanopartículas numa matriz de poliuretano, formando compósitos de PU/npZnO, é uma possível via de controlar essas propriedades. Trabalhos preliminares anteriormente realizados no Departamento de Engenharia de Materiais e Cerâmica da Universidade de Aveiro estabeleceram as condições necessárias para a síntese de npZnO, e para a preparação de compósitos de PU/npZnO, com características promissoras para utilização como agentes antibacterianos. O presente estudo teve como objectivo avaliar as propriedades antibacterianas de partículas de óxido de zinco nanoestruturadas, e de compósitos de PU/npZnO. Mais concretamente, pretende-se compreender qual o impacto das nanopartículas de óxido de zinco, sintetizadas com diferentes características físicas e químicas, bem como os compósitos, nos organismos vivos, designadamente bactérias. Foram sintetizadas nanopartículas de óxido de zinco, por precipitação química à temperatura ambiente, em condições de sobressaturação diferentes. Obtiveram-se nanoestruturas porosas e de elevada área superficial, mas com características fortemente condicionadas pelas condições de síntese. Além disso, as npZnO sintetizadas evidenciaram também características de superficie diferentes, refletidas pelas suas curvas de potencial zeta, que são distintas. Efectuaram-se estudos antibacterianos, com a estirpe de bactérias E.Coli ATCC 25922. Observou-se que, embora tendam a favorecer a proliferação bacteriana, se usadas em baixa concentração, as npZnO apresentam comportamento antibacteriano que se acentua quando se aumenta a concentração das npZnO. Deve referir-se que as npZnO, com menor valor de área superficial específica e potencial zeta mais acentuado foram as que apresentaram uma redução quase total da viabilidade bacteriana para a máxima concentração testada. Os compósitos PU/npZnO, preparados com as mesmas npZnO acima referidas, evidenciaram o mesmo comportamento. Estes resultados indiciam que o estado de superfície das npZnO tem um contributo efetivo para o comportamento antibacterianos das mesmas. Em conclusão, as npZnO sintetizadas no presente trabalho possuem propriedades antibacterianas, sendo possível a sua fixação numa matriz de poliuretano formando um compósito PU/npZnO, também ele com propriedades antibacterianas, com potencial interesse para tratamento localizado. Zinc oxide in the form of nanoparticles (npZnO) is currently a topic of high interest. However it is known that its properties and biological effects are highly dependent on the method of sunthesis. In that, context, characteristics such as the antibacterial performance and cytotoxicity are however still very little explored. Like other nanostructured materials, zinc oxide, when presented in the form of nanoparticles, can be potentially dangerous to the human body if their properties are not well controlled. Fixing these nanoparticles in a matrix of polyurethane (PU), forming a composite PU/npZnO is a possible way to control these properties. Preliminary work previously carried out in the Department of Materials Engineering and Ceramics of the University of Aveiro have established the necessary conditions for the synthesis of npZnO, and for the composite PU/npZnO, with promising characteristics for use as antibacterial agents. The present study aims to assess the antibacterial properties of nanostructured zinc oxide particles, and of the composite PU/npZnO. Specifically, the objective is to understand to what extent zinc oxide nanoparticles, synthetized with different physical and chemical characteristics, and their composites PU/npZnO, impact living organisms, paricularly bacteria. Zinc oxide nanoparticles were synthetized by a chemical precipitation method at room temperature, using diferent supersturation conditions. ZnO porous nanostructures with a high surface area were obtained, but mophological characteristics strongly influenced by the conditions of synthesis. In addition, the synthesized npZnO also showed different surface characteristics as reflected by their zeta potential curves which are different. Antibacterial studies were carried out with the bacterial strain E. Coli ATCC 25922. Although npZnO tendo to favor the bacterial growth when used in a low concentration, npZnO exhibit an antibacterial behavior that increases with the increasing concentration of npZnO. It should also be noted that npZnO with lower specific surface area and lower zeta potential showed the almost total reduction of bacterial viability for the highest concentration tested. The composites PU/npZnO prepared with the same npZnO mentioned above, also showed the same behavior. As conclusion, the npZnO synthesized in this work exhibit antibacterial properties. Furthermore it is possible to fix the npZnO in a polyurethane matrix, obtaining a composite with antibacterial properties which might offer a pontential interest for localized treatment.