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- Mapping wildfire vulnerability in Mediterranean Europe: testing a stepwise approach for operational purposesPublication . Oliveira, Sandra; Félix, Fernando; Nunes, Adélia; Lourenço, Luciano; Laneve, Giovanni; Sebastián-López, AnaVulnerability assessment is a vital component of wildfire management. This research focused on the development of a framework to measure and map vulnerability levels in several areas within Mediterranean Europe, where wildfires are a major concern. The framework followed a stepwise approach to evaluate its main components, expressed by exposure, sensitivity and coping capacity. Data on population density, fuel types, protected areas location, roads infrastructure and surveillance activities, among others, were integrated to create composite indices, representing each component and articulated in multiple dimensions. Maps were created for several test areas, in northwest Portugal, southwest Sardinia in Italy and northeast Corsica in France, with the contribution of local participants from civil protection institutions and forest services. Results showed the influence of fuel sensitivity levels, population distribution and protected areas coverage for the overall vulnerability classes. Reasonable levels of accuracy were found on the maps provided through the validation procedure, with an overall match above 72% for the several sites. The systematic and flexible approach applied allowed for adjustments to local circumstances with regards to data availability and fire management procedures, without compromising its consistency and with substantial operational capabilities. The results obtained and the positive feedback of end-users encourage its further application, as a means to improve wildfire management strategies at multiple levels with the latest scientific outputs.
- A common approach to foster prevention and recovery of forest fires in Mediterranean EuropePublication . Oliveira, Sandra; Laneve, Giovanni; Fusilli, Lorenzo; Eftychidis, Georgios; Nunes, Adélia; Lourenço, Luciano; Sebastián-López, AnaMost countries of Mediterranean Europe are strongly affected by forest fires, with major socio-economic and environmental impacts that can spread over several regions and countries. A transnational approach allows creating synergies regarding resource sharing and problem-solving strategies. The access to high quality and up-to-date information is critical to improve fire hazard mitigation measures and promote comparable appraisals between different regions. Several collaborative initiatives have been implemented in Europe to foster research and service development, focusing on common issues amongst countries. The PREFER project was one of these initiatives, with the purpose of contributing to protect human communities and forests from fire hazard, by providing cartographic products through the implementation of a new systematic framework. The participation of end users, such as civil protection organizations and forest services, covering the Euro-Mediterranean region, was crucial to ensure the operational application of the mapping products. Fuel classification, daily fire hazard indices, vulnerability assessment and damage severity levels were some of the mapping applications developed for several test areas in Mediterranean Europe. This chapter illustrates the potential enhancements for forest fire management offered by this framework, bearing in mind the benefits of applying shared and harmonized approaches for common issues.
- A common approach to foster prevention and recovery of forest fires in Mediterranean EuropePublication . Oliveira, Sandra; Laneve, Giovanni; Fusilli, Lorenzo; Eftychidis, Georgios; Nunes, Adélia; Lourenço, Luciano; Sebastián-López, AnaMost countries of Mediterranean Europe are strongly affected by forest fires, with major socio-economic and environmental impacts that can spread over several regions and countries. A transnational approach allows creating synergies regarding resource sharing and problem-solving strategies. The access to high quality and up-to-date information is critical to improve fire hazard mitigation measures and promote comparable appraisals between different regions. Several collaborative initiatives have been implemented in Europe to foster research and service development, focusing on common issues amongst countries. The PREFER project was one of these initiatives, with the purpose of contributing to protect human communities and forests from fire hazard, by providing cartographic products through the implementation of a new systematic framework. The participation of end users, such as civil protection organizations and forest services, covering the Euro-Mediterranean region, was crucial to ensure the operational application of the mapping products. Fuel classification, daily fire hazard indices, vulnerability assessment and damage severity levels were some of the mapping applications developed for several test areas in Mediterranean Europe. This chapter illustrates the potential enhancements for forest fire management offered by this framework, bearing in mind the benefits of applying shared and harmonized approaches for common issues.
- The cooling effect of green spaces as a contribution to the mitigation of urban heat: a case study in LisbonPublication . Oliveira, Sandra; Andrade, Henrique; Vaz, TeresaGreen areas in the urban environment can contribute to the mitigation of the Urban Heat Island. In a context of climate change, with the expected increase in temperature, dryness and intensity of heat waves, green areas assume even higher importance as they can create a cooling effect that extends to the surrounding areas. This study analyses the thermal performance of a small green space (0.24 ha) and its influence in the surrounding atmospheric environment of a densely urbanised area in Lisbon. Measurements of weather parameters (temperature, relative humidity, wind speed, solar and infrared radiation) were carried out along a selected path, starting from inside the green area to surrounding streets with different orientations and solar exposure. It was found that the garden was cooler than the surrounding areas, either in the sun or in the shade. These differences were higher in hotter days and particularly related to the mean radiant temperature (Tmrt). The highest difference found was of 6.9 °C in relation to air temperature and 39.2 °C in relation to Tmrt; in both cases this difference occurred between the shaded site inside the garden and the sunny site in an E–W oriented street in the southern part of the studied area. Besides the local weather conditions, particularly the low wind speed, the sun exposure and the urban geometry are the potential factors that explain these differences. The cooling effect of green areas on the surrounding environment can be enhanced by additional measures related to the urban features of each city.
- Rotas seguras e tempo de evacuação num cenário de ocorrência de escoadas de detritosPublication . Melo, Raquel; Zêzere, José; Oliveira, Sérgio; Garcia, Ricardo A C; Oliveira, Sandra; Pereira, Susana; Piedade, Aldina; Santos, Pedro PintoOs primeiros relatos, documentados, sobre a ocorrência de escoadas de detritos na região de Manteigas e do vale do Zêzere (Serra da Estrela, Portugal) remontam ao séc. XIX, numa altura em que as vertentes, que circundam a vila de Manteigas, se encontravam desprovidas de vegetação. Em 1804, a vila foi afetada por uma escoada de detritos que destruiu cerca de 20 casas e provocou a morte a um igual número de pessoas, tendo sido este o único evento, até à data, onde se verificaram vítimas mortais. Contudo, uma compilação de registos elaborada por Freitas (1989) sugere a recorrência de escoadas de detritos nesta área. O último evento de magnitude considerável teve lugar em outubro de 2005, apenas 2 meses após a deflagração de incêndios florestais no vale do Zêzere. Considerando este evento, Melo et al. (2018) aplicaram um modelo dinâmico, a 2D, com o objetivo de simular, por retroanálise, o comportamento reológico das escoadas de detritos desencadeadas em 2005 e, posteriormente, elaborar cenários de propagação, à escala da bacia hidrográfica, num contexto de ausência de vegetação. O referido modelo, que simula os processos de iniciação, erosão, propagação e deposição de fluxos de uma fase, sobre superfícies topográficas irregulares, permitiu a estimativa da velocidade do fluxo, do volume, da espessura dos depósitos e da extensão da propagação das escoadas de detritos. Adicionalmente, os cenários obtidos revelaram-se consistentes com os registos históricos de escoadas na área de estudo. Neste sentido, o presente trabalho teve como objetivo a comparação do resultado obtido no worst-case scenario (Melo et al., 2018) com o edificado atualmente existente e a população exposta. Pretende-se, assim, determinar as rotas seguras e o tempo de evacuação necessário, de acordo com as características dos residentes e com o declive encontrado ao longo do percurso, desde as suas habitações até aos locais definidos como ponto de encontro seguro.
- Land use/land cover change detection and urban sprawl analysisPublication . Viana, Cláudia M.; Oliveira, Sandra; Oliveira, Sérgio; Rocha, JorgeThis study presents a proposed application of the Time-Weighted Dynamic Time Warping (TWDTW) method for urban sprawl analysis. Four spectral indices were computed from a long time-series of Landsat satellite imagery, corresponding to 48 scenes acquired between 2006 and 2018. The spectral indices were the Normalized Difference Vegetation Index (NDVI), the Normalized Difference Built Index (NDBI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Bareness Index (NDBaI), which when processed resulted in 192 different images. The R package dtwSat was used for image processing, since it represents one of the few open source software programs available for processing large time-series datasets. The method was tested applied in the Alentejo Region of Southern Portugal; traditionally a rural region, where urban sprawl presents risks for the preservation of agricultural systems and for ecosystem sustainability. The sprawl analysis was integrated in a Geographic Information System (GIS), in which we computed an Expansion Index to quantitatively assess the three main urban land expansion types: infill, extension, and leapfrog. The results show that, between 2007 and 2012, the main changes are due to extension (50 ha), but with a significant amount of infill (36 ha) and leapfrog growth (4 ha), with this latter being the worst-case scenario. However, in the subsequent period, 2012-2017, urban growth decreased to about 10 ha, comprising both infill and extension, but notably leapfrog expansion disappeared. Our methodology proved to be flexible for managing irregular sampling and an out-of-phase time-series. The procedure offers a quantitative means of assessing urban sprawl dynamics and represents a potential strategy for defining sustainable urban development.
- Territorial resilience and flood vulnerability: case studies at urban scale in Torino (Italy) and Porto/Vila Nova de Gaia (Portugal)Publication . Ferrari, Stefano; Oliveira, Sandra; Pautasso, Giulia; Zêzere, JoséThis paper presents the implementation in QGIS of spatial informations for two case studies in Italy and Portugal by the conceptualization proposed in MOVE (Methods for the Improvement of Vulnerability assessment in Europe, www. move-fp7.eu). The chosen areas are in Turin (Italy) and Porto – Vila Nova de Gaia (Portugal). The conceptual model MOVE describes territorial vulnerability along three dimensions: exposure, susceptibility and lack of resilience. Each dimension can be described through a variety of indicators, such as physical, social, economic, cultural and others. A set of 59 variables to include in the analysis was drawn from the spatial informations available in publicly accessible databases. In addition to the indicators already presented in similar studies, the assets of cultural and historical heritage are introduced. Because of a rather complex measurement and research work, all indicators were standardized and mapped in the European grid (1 km x 1 km). Finally, maps of exposure, susceptibility and lack of resilience were obtained, from which it was possible to draw the maps of the local variation of flood vulnerability. The enphasis is on local variation because maps result from normalization of variables into a local range. Therefore, maps show local variability of vulnerability and can not be referred to either a national or European standard scale. The latter will be possible if further research identifies appropriate ranges for each indicator, representative for larger areas. The procedure, however, shows clearly how urban inequalities translate in inequalities in flood vulnerability and resilience. In this sense, if adopted to simulate the effects of planning, this procedure could help in designing more resilient territories.
- Definição de tempos de evacuação e áreas seguras num cenário de ocorrência de escoadas de detritosPublication . Melo, Raquel; Zêzere, José; Oliveira, Sérgio; Garcia, Ricardo A C; Oliveira, Sandra; Pereira, Susana; Piedade, Aldina; Santos, Pedro PintoOs primeiros relatos, documentados, sobre a ocorrência de escoadas de detritos na região de Manteigas e do vale do Zêzere (Serra da Estrela, Portugal) remontam ao séc. XIX, numa altura em que as vertentes, que circundam a vila de Manteigas, se encontravam desprovidas de vegetação. Em 1804, a vila foi afetada por uma escoada de detritos que destruiu cerca de 20 casas e provocou a morte a um igual número de pessoas, tendo sido este o único evento, até à data, onde se verificaram vítimas mortais. Contudo, uma compilação de registos elaborada por Freitas (1989) sugere a recorrência de escoadas de detritos nesta área. O último evento de magnitude considerável teve lugar em outubro de 2005, apenas 2 meses após a deflagração de incêndios florestais no vale do Zêzere. Considerando este evento, Melo et al. (2018) aplicaram um modelo dinâmico, a 2D, com o objetivo de simular, por retroanálise, o comportamento reológico das escoadas de detritos desencadeadas em 2005 e, posteriormente, elaborar cenários de propagação, à escala da bacia hidrográfica, num contexto de ausência de vegetação. O referido modelo, que simula os processos de iniciação, erosão, propagação e deposição de fluxos de uma fase, sobre superfícies topográficas irregulares, permitiu a estimativa da velocidade do fluxo, do volume, da espessura dos depósitos e da extensão da propagação das escoadas de detritos. Adicionalmente, os cenários obtidos revelaram-se consistentes com os registos históricos de escoadas na área de estudo. Neste sentido, o presente trabalho teve como objetivo a comparação do resultado obtido no worst-case scenario (Melo et al., 2018) com o edificado atualmente existente e a população exposta. Pretende-se, assim, determinar as rotas seguras e o tempo de evacuação necessário, de acordo com as características dos residentes e com o declive encontrado ao longo do percurso, desde as suas habitações até aos locais definidos como ponto de encontro seguro.
- Perception of thermal comfort by users of urban green areas in LisbonPublication . Oliveira, Sandra; Vaz, Teresa; Andrade, HenriqueGreen urban areas are a potential touristic attraction, providing opportunities for recreation and social interaction. In this study, two green areas in Lisbon were selected to investigate their influence on the thermal environment in and outside them and to analyse the usage of these parks in view of the perception of thermal comfort, the preferences and personal characteristics of the visitors. Measurements of temperature and relative humidity were carried out for several successive weeks in summer and in winter, in different locations around and inside the green areas. Temperature differences between the green spaces and the surrounding areas were greater in hotter conditions and reached up to 7ºC difference at certain times on particular days. This cooling effect provided by green areas has a potential role in mitigating climate change impacts. In order to analyse the perception of thermal comfort and users’ preferences, face-to-face interviews were carried out simultaneously with measurements of weather parameters. In summer, a positive correlation between the measured values of temperature and relative humidity with people’s perception was observed. A significant association between individual’s characteristics and type of usage of the parks was also revealed, particularly related to age and gender. Understanding the relationship between weather parameters, people’s perception and visitors’ preferences is paramount to create green areas more attractive and beneficial for the urban environment.
- Assessing the social context of wildfire-affected areas: the case of mainland PortugalPublication . Oliveira, Sandra; Zêzere, José; Queirós, Margarida; Pereira, José MiguelWildfires cause different impacts, depending on the conditions and resilience level of the exposed communities. Wildfire occurrence in mainland Portugal was assessed with regard to socioeconomic and demographic parameters, to identify the most distinctive conditions of fire-affected areas, without implying the existence of causal relationships. The latest population and agriculture census data were used to retrieve conditions at the civil parish level, regarding demographic patterns, social and labor conditions, physical structures and agricultural activities. To identify differences between parishes, two groups were created with the communities that showed the highest and lowest 20% of wildfire incidence between 2007 and 2014, separately for density of fire events and for burned area. A stepwise approach based on classification trees and random Forest methods was applied to identify the best discriminant variables between the groups. First, irrelevant variables were removed by an interactive process based on misclassification rates. The second step used random Forest analysis to the remaining variables to evaluate their importance in distinguishing the groups. In the final step, cluster analysis was applied to test the correspondence between the clusters created with the selected variables and the initial groups. Results showed that parishes with higher fire density have higher population density, higher proportion of young and educated people, larger families and more overcrowded buildings. On the contrary, parishes with larger burned area are less populated, less attractive to foreigners, have a higher proportion of elderly people, more degraded housing conditions and agricultural activities, visible in the density of sheep and goat and pastures, are still relevant. The cluster analysis demonstrated a better performance of the model for wildfire density, revealing a strong association with socioeconomic dynamics with an agreement above 0.85, much higher than for burned areas which is 0.29. Overall, the spatial distribution of wildfire impacts is framed by societal settings and particular conditions must be further understood to improve the coping capacity of affected communities.