Burned area mapping and post-fire monitoring of a Mediterranean forest using NDVI time-series of low resolution imagery and the BFAST method Mapeamento de área queimada e monitoramento pós-fogo de floresta na região Mediterrânea a partir de série

The Breaks For Additive Seasonal and Trend (BFAST) method was applied to NDVI composite series derived by MODIS and VEGETATION sensors in order to detect the rapid and gradual changes caused by fire in a typical Mediterranean ecosystem. This iterative approach identifies break points after decomposing time series into a trend, a seasonal and a noise component. The potential of this method was investigated for mapping a burned area and capturing the post-fire vegetation recovery trend and additionally assessment of the results from the analysis of the two datasets was performed. The spatial validation of the generated burned area maps revealed a better level of agreement for the MODIS NDVI derived perimeter compared to the VEGETATION outcome, but both results were considered quite promising. In addition, the post-fire vegetation trend was successfully captured from the analysis of these two datasets, although insufficient reference data did not permit a more thorough accuracy assessment. Still, the slope of the gradual changes observed in the trend component displayed post-fire vegetation recovery for both NDVI datasets.Resumo O método “Breaks for Additive Seasonal and Trend” - BFAST foi aplicado sobre uma série de imagens NDVI derivada dos sensores MODIS e do Vegetation com finalidade de detectar mudanças rápidas e graduais causadas pela ação do fogo num ecossistema mediterrânico típico. Essa abordagem iterativa identifica pontos de interrupções após a decomposição de séries temporais em uma tendência, uma sazonal e uma componente de ruído. O potencial deste método foi investigado para o mapeamento de uma área queimada, capturando a tendência de recuperação da vegetação pós-fogo e, adicionalmente, permitindo avaliar os resultados da análise dos dois conjuntos de dados temporais utilizados no presente estudo. A validação espacial dos mapas gerados sobre a área queimada revelou um melhor nível de concordância para o perímetro NDVI/MODIS comparado ao sensor Vegetation, mas ambos os resultados foram considerados bastante promissores. Além disso, a tendência de recuperação da vegetação pós-fogo foi capturado com sucesso a partir da análise dos dois conjuntos de dados-sensores, embora insuficientes dados de calibração temática não permitirem uma avaliação completa de melhor acurácia. Ainda assim, a inclinação que expressa as mudanças graduais observadas na componente de tendência mostra uma recuperação da vegetação pós-fogo em ambos os conjuntos da série de dados NDVI

Earth Observation for Forestry Applications in Cyprus

This paper presents an overview of how space-based and earth observation techniques can be used for forestry applications in Cyprus. Indeed, an example of how the Department of Forests in Cyprus can further promote the importance of using remote sensing techniques in Cyprus. Examples are shown of how mapping of burned areas is performed using remote sensing data (Landsat ETM, Sentinel) as well of how post-fire management is implemented. Examples of the Solea fire event occurred in Cyprus is presented. Finally, remote sensing is also used for risk assessment study for developing fire hazard index. Ground spectro-radiometric measurements are also used in combination with remote sensing imagery and burned severity measures to develop a simple, fast, accurate and reliable methodology for the assessment of the burn severity levels on a forest fire scar in Cyprus forests. The need to develop a national observatory of forests using earth observation and GIS is highlighted

Downstream Services for Rice Crop Monitoring in Europe: From Regional to Local Scale

The ERMES agromonitoring system for rice cultivations integrates EO data at different resolutions, crop models, and user-provided in situ data in a unified system, which drives two operational downstream services for rice monitoring. The first is aimed at providing information concerning the behavior of the current season at regional/rice district scale, while the second is dedicated to provide farmers with field-scale data useful to support more efficient and environmentally friendly crop practices. In this contribution, we describe the main characteristics of the system, in terms of overall architecture, technological solutions adopted, characteristics of the developed products, and functionalities provided to end users. Peculiarities of the system reside in its ability to cope with the needs of different stakeholders within a common platform, and in a tight integration between EO data processing and information retrieval, crop modeling, in situ data collection, and information dissemination. The ERMES system has been operationally tested in three European rice-producing countries (Italy, Spain, and Greece) during growing seasons 2015 and 2016, providing a great amount of near-real-time information concerning rice crops. Highlights of significant results are provided, with particular focus on real-world applications of ERMES products and services. Although developed with focus on European rice cultivations, solutions implemented in the ERMES system can be, and are already being, adapted to other crops and/or areas of the world, thus making it a valuable testing bed for the development of advanced, integrated agricultural monitoring systems

Geographical information systems and remote sensing in mapping and monitoring fire-altered forest

This work results from the urgent need to monitor the impact of forest fires on sensitive ecosystems such as the Mediterranean forest. It was done in order to examine forest vulnerability to global change and the extent to which changes in traditional land use patterns in Mediterranean Europe impact upon this vulnerability. These changes have recently affected the fire regime which in tum has led to an increase in the occurrence and destructiveness of wildfires in Southern Europe. The research aims to monitor the impact of fires upon the Mediterranean forest on the Greek island of Thasos and consequently, to estimate forest vulnerability to the changes mentioned above. The specific objectives of the research are: 1. To map recent and old burned areas accurately by using satellite images. 2. To accurately assess the area and wood volume affected by fire using a Digital Elevation Model (DEM) ofThasos and employing GIS analysis. 3. To monitor Pinus brutia forest and ecosystem regeneration using a combined approach involving GIS and Global Positioning System (GPS). 4. To understand the ways in which controlling factors influence existing patterns of Pinus brutia regeneration in Thasos. From the analysis the following were concluded : 1. Although different image processing techniques are necessary for the mapping of recent and old bums the use of satellite images ended in accurate burned area mapping. However, topographic correction of the satellite images prior to their use in the analysis improved the accuracy of mapping. 2. More than 70% of the area covered by Pinus brutia is estimated to have been affected by the fires. The Pinus brutia wood volume affected by the fires was 90% of the total. 3. Measurements of regeneration, eight to thirteen years after fire suggest that the Pinus brutia forest in Thasos is making a complete recovery. 4. Finally, controlling factors affect regeneration patterns in a complex hierarchical way. Understanding of critical values or thresholds in several of these factors is important to understand patterns of regeneration.Digitisation of this thesis was sponsored by Arcadia Fund, a charitable fund of Lisbet Rausing and Peter Baldwin

Assessing the Accuracy of MODIS MCD64A1 C6 and FireCCI51 Burned Area Products in Mediterranean Ecosystems

The catastrophic impact of wildfires on the economy and ecosystems of Mediterranean countries in recent years, along with insufficient policies that favor disproportionally high funding for fire suppression, demand a more comprehensive understanding of fire regimes. Satellite remote sensing products support the generation of relevant burned-area (BA) information, since they provide the means for the systematic monitoring of large areas worldwide at low cost. This research study assesses the accuracy of the two publicly available MODIS BA products, MCD64A1 C6 and FireCCI51, at a national scale in a Mediterranean country. The research period covered four fire seasons, and a comparison was conducted against a higher-resolution Sentinel-2 dataset. The specific objectives were to assess their performance in detecting fire events occurring primarily in forest and semi-natural lands and to investigate their spatial and temporal uncertainties. Monthly fire observations were processed and analyzed to derive a comprehensive set of accuracy metrics. We found that fire size has an impact on their detection accuracy, with higher detection occurring in fires larger than 100 ha. Detection of smaller (<100 ha) fires was favored by the 250 m FireCCI51 product, but not from MCD64A1 C6, which exhibited less than 50% detection probability in the same range. Their spatial estimates of burned area exhibited a fairly satisfactory agreement with the reference data, reaching an average of 78% in detection rate. MCD64A1 C6 exhibited a more consistent spatial performance overall and better temporal accuracy, whereas FireCCI51 did not substantially outperform the former despite its finer resolution. Additional research is required for a more rigorous assessment of the variability of these burned area products, yet this research provides further insight and has implications for their use in fire-related applications at the local to the national scale

Burned Area Mapping in Greece Using SPOT-4 HRVIR Images and Object-Based Image Analysis

The devastating series of fire events that occurred during the summers of 2007 and 2009 in Greece made evident the need for an operational mechanism to map burned areas in an accurate and timely fashion to be developed. In this work, Système pour l’Observation de la Terre (SPOT)-4 HRVIR images are introduced in an object-based classification environment in order to develop a classification procedure for burned area mapping. The development of the procedure was based on two images and then tested for its transferability to other burned areas. Results from the SPOT-4 HRVIR burned area mapping showed very high classification accuracies ( 0.86 kappa coefficient), while the object-based classification procedure that was developed proved to be transferable when applied to other study areas

Landscape fragmentation and the agro-forest ecosystem along a rural-to-urban gradient: an exploratory study

The present study investigates the transformations in the agro-forest landscape of Attica (Greece) along an urban-to-rural gradient over 20 years using landscape metrics and land-use indicators. This region experienced increasing human pressure reflected in the dispersed urban expansion stimulated by the 2004 Olympic Games. Based on the spatial distribution of nine land-use classes in 1987 and 2007 derived from comparable digital maps, a multi-temporal analysis was developed to assess ‘fast’ and ‘slow’ variables characterizing landscape changes in the area. Urban areas, bare land, and burnt areas expanded rapidly, fragmenting the agro-forest landscape. A principal components analysis carried out on selected landscape metrics in both 1987 and 2007 indicated that forests and cropland are moving toward patchiness and a higher fractal configuration. The multivariate approach applied to landscape metrics revealed how land fragmentation was dependent on both urban expansion and processes typically observed in rural areas, such as crop intensification, forest fires and clear-cutting, land abandonment, and shrubland expansion. These findings were confirmed by a local-level analysis of land-use changes (1945–2007) carried out on the fringe of Athens. By linking structural and compositional features of landscape, the approach developed in this study may inform policies promoting sustainable urban forms and protecting high-quality, relict agro-forest landscapes in peri-urban areas