IOP Conference Series: Earth and Environmental Science
In this work we perform an initial assessment of the accuracy of two publicly available MODIS bur... more In this work we perform an initial assessment of the accuracy of two publicly available MODIS burned area products, MCD64A1 C6 and MODIS FireCCI51, at national scale in a Mediterranean region. The research focused on two fire seasons for the years 2016 and 2017 and comparison was performed against a higher resolution Sentinel-2 dataset. The specific objectives were to assess their capabilities in detection of fire events occurring primarily in forest and semi-natural lands and also to investigate their spatial uncertainties. The analysis combined monthly fire observations and accuracy metrics derived from error matrices. Satisfactory performance was achieved by the two products in detection of larger fires (> 100 ha) whereas their spatial performance exhibited good agreement with the reference data. MCD64A1 C6 exhibited a more consistent performance overall and the 250 m FireCCI51 product exhibited relatively higher sensitivity in detection of smaller (<100 ha) fires. Although...
The catastrophic impact of wildfires on the economy and ecosystems of Mediterranean countries in ... more 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 an...
The significance of forest ecosystems in terms of ecosystem processes and services and impacts on... more The significance of forest ecosystems in terms of ecosystem processes and services and impacts on humanity is fully acknowledged. The constant exploitation of natural resources and the increasing anthropogenic pressure on ecosystems continue to put a strain on and irretrievably threaten global forest ecosystems. Global forest health is declining due to climate change, air pollution and increased human activities. Protecting and monitoring the health of forest ecosystems is a vital resource management function. The technological development in the field of remote sensing provides new tools and automated solutions for forest health monitoring. An effective web-based forest health monitoring platform can contribute to ecological, social, and economic aspects. This study aims to design rapid and automated workflows (Spatial Models-SMs) for time-series forest health monitoring with flexible parameterization and user-friendly interfaces ready for feeding WPS web-GIS platforms. Those inclu...
Proceedings of the 11th EARSeL Forest Fires SIG Workshop held in Chania, Crete, Greece, 25-27 Sep... more Proceedings of the 11th EARSeL Forest Fires SIG Workshop held in Chania, Crete, Greece, 25-27 September 2017. The 11th EARSeL Forest Fire SIG workshop was co-organised by the Mediterranean Agronomic Institute of Chania, of the International Centre for Advanced Mediterranean Agronomic Studies, the School of Forestry and Natural Environment, Aristotle University of Thessaloniki, and the National Aeronautics and Space Administration (NASA). The focus of the event was on global systems for monitoring wildfires, as well as the missions providing data for this purpose, and the modelling endeavours about climate change, considering the contribution of forest fires. As a result, a good number of high quality scientific works were presented during the three days of the workshop covering the following topics: • Studies on the impact of climate change on forest fires occurrence and severity • Contribution of the current and upcoming Sentinel missions on forest fire research • Exploitation of B...
In the Mediterranean region, many types of forests are non-productive or degraded, although they ... more In the Mediterranean region, many types of forests are non-productive or degraded, although they could substantially contribute to growth of local economies. In Greece, 30% of the total area is covered by forests, however their contribution to the GDP is almost non-existent. An example is the chestnut production in Thessaly region of Greece, and especially in Mouzaki municipality, which is almost abandoned due to insufficient agricultural policies concerning establishment of alternative crops, and consequently leads to loss of potential income for the rural economy. The ARTEMIS project, funded by the Greek Secretariat for Research and Technology, aims at delivering an innovative information platform providing systematically high quality Earth Observation based products and services for monitoring forest health and supporting eventually the growth of forestry related economy and market. The architecture of the proposed platform will incorporate new OGC/ISO technologies, while the app...
H παρούσα διατριβή πραγματεύεται τη χρησιμότητα και την αξιοποίηση οπτικών δορυφορικών δεδομένων ... more H παρούσα διατριβή πραγματεύεται τη χρησιμότητα και την αξιοποίηση οπτικών δορυφορικών δεδομένων με διαφορετική χωρική και χρονική διακριτική ικανότητα για την αποτίμηση των άμεσων και μακροχρόνιων επιπτώσεων των πυρκαγιών σε Μεσογειακά οικοσυστήματα. Στην έρευνα συνδυάζεται η ανάπτυξη αυτοματοποιημένων τεχνικών χωρικής και χρονικής κατάτμησης χρονοσειρών εικόνων, με την χωρική ανάλυση γεωγραφικών δεδομένων και δεδομένων πεδίου για την χαρτογράφηση καμένων εκτάσεων και την παρακολούθηση της μεταπυρικής ανάκαμψης της βλάστησης. Το πρώτο μέρος της έρευνας επικεντρώθηκε στην αξιοποίηση των δεδομένων υψηλής χωρικής ευκρίνειας Landsat, μέσω αυτοματοποιημένων μεθόδων χωρικής κατάτμησης εικόνων, για τη διαχρονική χαρτογράφηση πυρκαγιών. Ειδικότερα, διερευνήθηκε η δυνατότητα της αντικειμενοστραφούς προσέγγισης (OBIA) να αξιοποιεί ιστορικά και σύγχρονα δεδομένα Landsat που έχουν συλλεχθεί από διαφορετικούς αισθητήρες για την παραγωγή διαχρονικών χαρτών καμένων εκτάσεων. Στη συνέχεια προτείνε...
Land cover is one of the key terrestrial variables used for monitoring and as input for modelling... more Land cover is one of the key terrestrial variables used for monitoring and as input for modelling in support of achieving the United Nations Strategical Development Goals. Global and Continental Land Cover Products (GCLCs) aim to provide the required harmonized information background across areas; thus, they are not being limited by national or other administrative nomenclature boundaries and their production approaches. Moreover, their increased spatial resolution, and consequently their local relevance, is of high importance for users at a local scale. During the last decade, several GCLCs were developed, including the Global Historical Land-Cover Change Land-Use Conversions (GLC), the Globeland-30 (GLOB), Corine-2012 (CLC) and GMES/ Copernicus Initial Operation High Resolution Layers (GIOS). Accuracy assessment is of high importance for product credibility towards incorporation into decision chains and implementation procedures, especially at local scales. The present study build...
Fourth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2016), 2016
During the past decades, forest fires have increased both in frequency and severity thus, increas... more During the past decades, forest fires have increased both in frequency and severity thus, increasing the life threats for people and environment and leading countries to spend vast amounts of resources in fighting forest fires. Besides anthropogenic activities, climatic and environmental changes are considered as driving factors affecting fire occurrence and vegetation succession. Especially in the Mediterranean region, the development and existence of effective tools and services is crucial for assisting pre-fire planning and preparedness. The collaborative project NFOFRAS aims at introducing an innovative and effective system for rating forest fire risk, and is based on existing technology and standards that have been developed by countries with a long and a very successful involvement in this field. During the first phase of the project a detailed documentation of the proposed methodology was composed. In addition, Earth Observation (EO) and meteorological datasets were utilized for producing accurate pre-fire measurements over a selected study area in Greece.
2014 IEEE Geoscience and Remote Sensing Symposium, 2014
The performances of a novel salinity retrieval strategy by means of Support Vector Regression (SV... more The performances of a novel salinity retrieval strategy by means of Support Vector Regression (SVR) have been studied. The SMOS satellite brightness temperatures measurements and additional auxiliary parameters have been co-located with salinity data collected by Argo buoys, which represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR with a combination of features and at two polarizations are in good agreement with the ground-truth data. A critical additional feature that was studied was the TB/emissivity incidence angle dependency, analyzing the possible performances improvements due to the multi-angular information content. The robustness and versatility of this approach are under further assessment over wider areas and time lags, and in various combinations of SMOS features.
A sounding of the capabilities of a novel salinity retrieval strategy by means of Support Vector ... more A sounding of the capabilities of a novel salinity retrieval strategy by means of Support Vector Regression (SVR) has been performed. SMOS brightness temperatures measurements and additional auxiliary parameters have been co-located with salinity data collected by ARGO buoys, which represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR are in good agreement with the ground-truth, suggesting that the chosen approach can be promising, despite its robustness and versatility are under further assessment over wider areas and time lags, and in various combinations of SMOS features.
A prospective sounding of the capabilities of a novel salinity retrieval by means of Support Vect... more A prospective sounding of the capabilities of a novel salinity retrieval by means of Support Vector Regression has been performed. Co-located SMOS measurements and additional auxiliary parameters have been considered, whilst salinity data collected by ARGO buoys represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR are in good agreement with the ground-truth, suggesting that the chosen approach can be promising, despite its robustness and versatility needs to be assessed over wider areas and time lags, and in various combinations of SMOS features.
IOP Conference Series: Earth and Environmental Science
In this work we perform an initial assessment of the accuracy of two publicly available MODIS bur... more In this work we perform an initial assessment of the accuracy of two publicly available MODIS burned area products, MCD64A1 C6 and MODIS FireCCI51, at national scale in a Mediterranean region. The research focused on two fire seasons for the years 2016 and 2017 and comparison was performed against a higher resolution Sentinel-2 dataset. The specific objectives were to assess their capabilities in detection of fire events occurring primarily in forest and semi-natural lands and also to investigate their spatial uncertainties. The analysis combined monthly fire observations and accuracy metrics derived from error matrices. Satisfactory performance was achieved by the two products in detection of larger fires (> 100 ha) whereas their spatial performance exhibited good agreement with the reference data. MCD64A1 C6 exhibited a more consistent performance overall and the 250 m FireCCI51 product exhibited relatively higher sensitivity in detection of smaller (<100 ha) fires. Although...
The catastrophic impact of wildfires on the economy and ecosystems of Mediterranean countries in ... more 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 an...
The significance of forest ecosystems in terms of ecosystem processes and services and impacts on... more The significance of forest ecosystems in terms of ecosystem processes and services and impacts on humanity is fully acknowledged. The constant exploitation of natural resources and the increasing anthropogenic pressure on ecosystems continue to put a strain on and irretrievably threaten global forest ecosystems. Global forest health is declining due to climate change, air pollution and increased human activities. Protecting and monitoring the health of forest ecosystems is a vital resource management function. The technological development in the field of remote sensing provides new tools and automated solutions for forest health monitoring. An effective web-based forest health monitoring platform can contribute to ecological, social, and economic aspects. This study aims to design rapid and automated workflows (Spatial Models-SMs) for time-series forest health monitoring with flexible parameterization and user-friendly interfaces ready for feeding WPS web-GIS platforms. Those inclu...
Proceedings of the 11th EARSeL Forest Fires SIG Workshop held in Chania, Crete, Greece, 25-27 Sep... more Proceedings of the 11th EARSeL Forest Fires SIG Workshop held in Chania, Crete, Greece, 25-27 September 2017. The 11th EARSeL Forest Fire SIG workshop was co-organised by the Mediterranean Agronomic Institute of Chania, of the International Centre for Advanced Mediterranean Agronomic Studies, the School of Forestry and Natural Environment, Aristotle University of Thessaloniki, and the National Aeronautics and Space Administration (NASA). The focus of the event was on global systems for monitoring wildfires, as well as the missions providing data for this purpose, and the modelling endeavours about climate change, considering the contribution of forest fires. As a result, a good number of high quality scientific works were presented during the three days of the workshop covering the following topics: • Studies on the impact of climate change on forest fires occurrence and severity • Contribution of the current and upcoming Sentinel missions on forest fire research • Exploitation of B...
In the Mediterranean region, many types of forests are non-productive or degraded, although they ... more In the Mediterranean region, many types of forests are non-productive or degraded, although they could substantially contribute to growth of local economies. In Greece, 30% of the total area is covered by forests, however their contribution to the GDP is almost non-existent. An example is the chestnut production in Thessaly region of Greece, and especially in Mouzaki municipality, which is almost abandoned due to insufficient agricultural policies concerning establishment of alternative crops, and consequently leads to loss of potential income for the rural economy. The ARTEMIS project, funded by the Greek Secretariat for Research and Technology, aims at delivering an innovative information platform providing systematically high quality Earth Observation based products and services for monitoring forest health and supporting eventually the growth of forestry related economy and market. The architecture of the proposed platform will incorporate new OGC/ISO technologies, while the app...
H παρούσα διατριβή πραγματεύεται τη χρησιμότητα και την αξιοποίηση οπτικών δορυφορικών δεδομένων ... more H παρούσα διατριβή πραγματεύεται τη χρησιμότητα και την αξιοποίηση οπτικών δορυφορικών δεδομένων με διαφορετική χωρική και χρονική διακριτική ικανότητα για την αποτίμηση των άμεσων και μακροχρόνιων επιπτώσεων των πυρκαγιών σε Μεσογειακά οικοσυστήματα. Στην έρευνα συνδυάζεται η ανάπτυξη αυτοματοποιημένων τεχνικών χωρικής και χρονικής κατάτμησης χρονοσειρών εικόνων, με την χωρική ανάλυση γεωγραφικών δεδομένων και δεδομένων πεδίου για την χαρτογράφηση καμένων εκτάσεων και την παρακολούθηση της μεταπυρικής ανάκαμψης της βλάστησης. Το πρώτο μέρος της έρευνας επικεντρώθηκε στην αξιοποίηση των δεδομένων υψηλής χωρικής ευκρίνειας Landsat, μέσω αυτοματοποιημένων μεθόδων χωρικής κατάτμησης εικόνων, για τη διαχρονική χαρτογράφηση πυρκαγιών. Ειδικότερα, διερευνήθηκε η δυνατότητα της αντικειμενοστραφούς προσέγγισης (OBIA) να αξιοποιεί ιστορικά και σύγχρονα δεδομένα Landsat που έχουν συλλεχθεί από διαφορετικούς αισθητήρες για την παραγωγή διαχρονικών χαρτών καμένων εκτάσεων. Στη συνέχεια προτείνε...
Land cover is one of the key terrestrial variables used for monitoring and as input for modelling... more Land cover is one of the key terrestrial variables used for monitoring and as input for modelling in support of achieving the United Nations Strategical Development Goals. Global and Continental Land Cover Products (GCLCs) aim to provide the required harmonized information background across areas; thus, they are not being limited by national or other administrative nomenclature boundaries and their production approaches. Moreover, their increased spatial resolution, and consequently their local relevance, is of high importance for users at a local scale. During the last decade, several GCLCs were developed, including the Global Historical Land-Cover Change Land-Use Conversions (GLC), the Globeland-30 (GLOB), Corine-2012 (CLC) and GMES/ Copernicus Initial Operation High Resolution Layers (GIOS). Accuracy assessment is of high importance for product credibility towards incorporation into decision chains and implementation procedures, especially at local scales. The present study build...
Fourth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2016), 2016
During the past decades, forest fires have increased both in frequency and severity thus, increas... more During the past decades, forest fires have increased both in frequency and severity thus, increasing the life threats for people and environment and leading countries to spend vast amounts of resources in fighting forest fires. Besides anthropogenic activities, climatic and environmental changes are considered as driving factors affecting fire occurrence and vegetation succession. Especially in the Mediterranean region, the development and existence of effective tools and services is crucial for assisting pre-fire planning and preparedness. The collaborative project NFOFRAS aims at introducing an innovative and effective system for rating forest fire risk, and is based on existing technology and standards that have been developed by countries with a long and a very successful involvement in this field. During the first phase of the project a detailed documentation of the proposed methodology was composed. In addition, Earth Observation (EO) and meteorological datasets were utilized for producing accurate pre-fire measurements over a selected study area in Greece.
2014 IEEE Geoscience and Remote Sensing Symposium, 2014
The performances of a novel salinity retrieval strategy by means of Support Vector Regression (SV... more The performances of a novel salinity retrieval strategy by means of Support Vector Regression (SVR) have been studied. The SMOS satellite brightness temperatures measurements and additional auxiliary parameters have been co-located with salinity data collected by Argo buoys, which represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR with a combination of features and at two polarizations are in good agreement with the ground-truth data. A critical additional feature that was studied was the TB/emissivity incidence angle dependency, analyzing the possible performances improvements due to the multi-angular information content. The robustness and versatility of this approach are under further assessment over wider areas and time lags, and in various combinations of SMOS features.
A sounding of the capabilities of a novel salinity retrieval strategy by means of Support Vector ... more A sounding of the capabilities of a novel salinity retrieval strategy by means of Support Vector Regression (SVR) has been performed. SMOS brightness temperatures measurements and additional auxiliary parameters have been co-located with salinity data collected by ARGO buoys, which represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR are in good agreement with the ground-truth, suggesting that the chosen approach can be promising, despite its robustness and versatility are under further assessment over wider areas and time lags, and in various combinations of SMOS features.
A prospective sounding of the capabilities of a novel salinity retrieval by means of Support Vect... more A prospective sounding of the capabilities of a novel salinity retrieval by means of Support Vector Regression has been performed. Co-located SMOS measurements and additional auxiliary parameters have been considered, whilst salinity data collected by ARGO buoys represented the ground-truth to be matched by the algorithm. Salinity fields estimated by the SVR are in good agreement with the ground-truth, suggesting that the chosen approach can be promising, despite its robustness and versatility needs to be assessed over wider areas and time lags, and in various combinations of SMOS features.
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