In the year 2012 the Ministry of environment and waters (MOEW) in Bulgaria initiate the development of “Methodology for defining the adjoining lands and flooding rivers stripes in Bulgaria” based on Water Directive 2000/60/ЕС requirements and its transposing into national law. The methodology should be applied in cases when governmental bodies issue permits for use and water use of a water body upon art. 46 of the Water Act in Bulgaria. The methodology can be used also in the development of Flooding Risk Management Plans. The research investigates the possibilities of remote sensing as a tool for the verification of initial data for generating DEM and verification of data for the bedding surface of the studied watershed to the place of use or water use from the river section. The results show that remote sensing data from Sentinel-2 contribute for the timeliness of the data that have been used in different stages of the Methodology. The correlation among components water, vegetation and soil have been examined by estimating the indices NDVI, NDWI, SAVI, MSAVI 2. The interpretation of the analysis is useful when calculate the maximum runoff formed in the studied watershed. The probability of an increase in the water levels of the studied river section and flooding of the lands belonging to it can be predicted by applying the methodology.
According to Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora (Habitats Directive) each member state should maintain or restore at favorable conservation status natural habitats and species of wild fauna and flora. The study examines the possibilities for application of remote sensing in projects for improving the conservation status of habitats in NATURA 2000 network in Bulgaria. The research focuses on exploring the actual condition of certain habitats before and after implementing restoration measures like removing invasive or ruderal flora types. Sentinel-2 images and have been used to detect changes in plant species distribution and drone to verify that the invasive plant species have been removed. GIS database has been developed which can be used in future monitoring on surveyed area. The results can be used as a verification tool to measure the effectiveness of the restoration measures implemented and in long-term aspect to track the sustainability of similar projects in Bulgaria.
As a party to the United Nations Framework Convention on Climate Change (UNFCCC) and signatory of UN Paris Agreement Bulgaria has the obligation to submit annual Greenhouse Gas (GHG) inventory covering emissions and removals of GHGs from Land Use, Land-Use Change and Forestry (LULUCF). In particular, for calculation of GHG emissions and removals from LULUCF information about land area is needed for different land uses at yearly basis and at national level. This research focuses on tracking the changes in land cover and land use (Forest land, Cropland, Grassland, Wetlands, Settlements, Other land) for 2012-2021 period based on developed satellite database for the territory of selected test area - South-Eastern (Yugoiztochen) region for the needs of GHG reporting in Bulgaria. The main purpose of the study is to investigate how the application of remote sensing tools can contribute for the country to switch to a higher Tier and Approach 3: spatially explicit land-use and land use change data. The results can be considered by the decision- makers to overcome the challenges they face in improving Transparency, accuracy, consistency, comparability and completeness of GHG emission estimates.
The general idea of the study is to emphasize the necessity of Interim Ecological Monitoring application based on remote sensing tools for effective monitoring on water bodies used to supply drinking water to urban areas. The aim of the study is to identify the changes in the water surface of the “Studena dam” for a period of three years (2018-2020) and in different seasons. The investigation is made based on Sentinel 1 and Sentinel 2 (MSI optical) data for different time intervals. Orthogonalization of Sentinel 2 data has been applied. Correlation between the obtained data from Sentinel 1 and Sentinel 2 has been defined. The results have been verified by additional data generated by analyzing the inflow and outflow in watershed and alluvial outflow based on officially published information by the Ministry of Environment and Water in Bulgaria (e.g. monthly schedules for water usage from dams with great importance for Republic of Bulgaria, calculations, etc.) and the influence of climate factors (precipitation and temperature). The final results from IEM application based on remote sensing data could be applied to generate tendency for changes in dam water volume in different time periods and gives opportunity for decision-makers to undertake preventive actions or effective actions in case of a water crisis.
The aim of the study is to obtain a quantitative assessment of soil type impact on the soil-vegetation system through the respective models. To achieve this goal, the vegetation cover of a habitat under Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora (Habitats Directive) for the 2016-2019 time period and the influence of climatic factors (precipitation and temperature) on the vegetation cover by applying Interim Ecological Monitoring (IEM) based on remotely-sensed data. Multispectral satellite data (MSI) from Sentinel-2 have been used for quantification of the soil-vegetation system. Various types of Vegetation Indices like Normalized Differential Vegetation Index (NDVI), Soiled-adjusted Vegetation Index (SAVI), Modified Soil-Adjusted Vegetation Index (MSAVI2), Normalized Difference Infrared Index (NDII), have been estimated to determine the actual state of the vegetation cover. For tracking the “soil-vegetation” relation Normalized Differential Greenness Index (NDGI) has been applied based on orthogonalization of satellite data from Sentinel-2. The results obtained are validated by interim ecological monitoring methodology (MIEM) for habitats and are expected to review habitat(s) trends for the indicated period and such for a near - future period. The study will demonstrate the benefits of IEM application for the purposes of reporting under art. 17 from Habitats Directive.
Wildfires are recurring in many terrestrial ecosystems all over the world. Accurate assessment of the forest ecosystem, affected by fire is of great importance for the fires spread predicting and modelling of the post-fire activities for recovery of the affected territories. High spatial and spectral resolution satellite data were used to evaluate the vegetation variation on a fire-affected territory, located on the northwest slopes of the Rila mountain, considering its spatial heterogeneity. The forest fire was spread on the area of deciduous forests Turkey oak (Quercus cerris L.), and coniferous: Scots pine (Pinus sylvestris L.) and European larch (Larix desidua, Mill.). Different spectral indices like Disturbance index (DI), Normalized difference greenness indices (NDGI) and Normalized Difference Vegetation Index (NDVI) and derived from remote sensing methods (satellite data from different sensors Landsat and Sentinel) as well as the Geographical Information System (GIS) were applied for the forest disturbance assessment in two periods after forest fire occurrence. The results of the applied integrated model provide a quantitative information about the fire effects for distinct forest types. The documented spatial distribution of the territory based on the obtained DI values shows clear differences between the fire-affected forest types, thus demonstrating the usefulness and accuracy of the approach followed.
Forest fires are among the most dangerous natural threats that cause significant changes in forest ecosystems. For the better management of the wildfire-prone territories, the fire weather components like temperature, precipitation and evapotranspiration predictions and monitoring within the extreme fire seasons are of great importance. Remote sensing has been identified as an effective tool for better understanding how forest ecosystems respond to these components. Respective spectral indices, like Normalized difference greenness indices (NDGI), Normalized Difference Vegetation Index (NDVI), Improved Modified Chlorophyll Adsorption Ratio Index (MCARI2) and Moisture Stress Index (MSI), derived from remote sensing methods (satellite data from different sensors - Landsat and Sentinel) as well as the Geographical Information System (GIS) were applied for the monitoring of the climatic parameters in forest fire vulnerable regions in Bulgaria. The climatic parameters dataset from 2008 consisting of the ten-day period mean temperature and precipitation data were collected. The NDVI trends for the studied periods exhibited significant correlations with the mean precipitation and weak or no correlation with the temperature recorded. These results are largely linked to the relative air humidity. Different vegetation types were found to show distinct spatial responses to climatic changes.
This research presents the results of a survey on the extent of the affected areas in the municipality of Bregovo from the flood of the Timok River, which occurred on 11.03.2018. The application of SAR and optical data for assessment of the spatial and temporal characteristics of the occurred flood is the objective of this paper. This methodology applies orthogonal transformation of different multispectral images from Sentinel 2 mission combined with SAR data from Sentinel 1. The assessment was made on the basis of the orthogonal transformation’ components of the bands from different multispectral Sentinel 2 imagery: Tasseled Cap Transformation TCT-brightness, TCT-wetness, TCT-greenness. Indicators of quantitative changes in areas affected by the floods have been obtained. Satellite images from Sentinel 1- SAR and Sentinel 2-MSI satellite missions, orthophotography, terrestrial and in-situ terrain data from the Bregovo municipality affected by flooding were used. The processed satellite images are from different sensors and are selected by different dates before and after the day of the natural disaster. Pseudocomposite radar images with different polarization (vv,vh) were used to clarify and more precisely visualize the territorial coverage of the flood in the surveyed area. Various normalized quantitative differentiation indices (vegetation, humidity, vapors, etc., NDGI,) are generated after image processing. Results are presented for correlation between the values obtained for the different data types. On the basis of the obtained data and results, a comparative analysis of the dynamics of the changes occurred as a result of the disaster was carried out and a quantitative assessment of the changes occurred and respectively the registered negative environmental impacts in the territorial extent of the flood.
Nowadays, the ecosystem service framework can be accepted for designing and completion of different management strategies to preserve and restore ecosystems. The present study will contribute to increase the stakeholders’ interest to wetlands condition and possibilities for better management aiming at improving the ecosystems services they provide. For the research of the wetland in the area of quarry lakes in Negovan village interim ecological monitoring (IEM) using remote sensing data after restoration measures have been implemented. The aim of IEM is to obtain results for the wetland actual condition and restoration process efficiency for ecosystems services assessment. Based on the generated data an interim ecological monitoring methodology (MIEM) implying different remote sensing data (different temporal intervals, spectral and spatial resolution) has been designed. The model functions entirely within Geographical Information System (GIS). It generates data for the actual environmental condition of the wetland in different temporal intervals. The obtained results for the wetland actual condition have been used for defining the values of Disturbance Index (DI), which in turn is defined based on orthogonalization of multispectral satellite data from Sentinel 2 - Multi Spectral Instrument (MSI) and Landsat for different temporal intervals. DI rates are determined through Wetness component and Greenness component. Ecosystem services are assigned based on the correlation between vegetation and water surface area that is connected to water balance/budget. The space distribution of vegetation is specified on the base of Normalized Differential Vegetation Index (NDVI), Normalized Differential Greenness Index (NDGI) for different temporal intervals of the research. This paper presents results for evaluation the potential for delivery of ecosystem services taking into consideration the environmental and ecological processes behind the services that have been assessed at a relevant scale generated.
Forest fires continue to burn large territories, both within and outside Europe. It is suitably to assess fire-induced changes in the vegetation, which in turn affects infiltration, runoff, and erosion potential. Therefore it is important to identify potential areas of concern and prioritize field reconnaissance. The development of a burn severity map will facilitate quantifying of the post-fire assessment phase. In this study the potential of Normalized Burn Index (NBR), Normalized Difference Vegetation Index (NDVI) and normalized difference greenness indices (NDGI) derived from remote sensing methods (satellite data from different sensors Sentinel and Landsat) and Geographical Information System (GIS) have been analyzed for forest fire severity assessment. For more accurate assessment of the fire severity, a hybrid model was developed, using satellite data from different sensors - Sentinel and Landsat. For this purpose, the area, affected by fires occurred in august 2017 on the northwest slopes of the Ajtovska Mountain (East part of the Stara planina mountain) in the Eastern part of Bulgaria was studied. The forest fire events were spread on the area of (508.5 ha) and the affected vegetation was composed by deciduous forests (309.4ha), coniferous (62.4ha), mixed forests (61.4 ha) and grass and shrubs (75.3ha). Through the model developed, results applicable to the actual forest ecosystem conditions for different time intervals have been obtained. These results provide quantitative information about fire severity for distinct forest types, thus allowing for designing relevant fire severity maps.
In recent years on the territory of Bulgaria it has been observed the existence of events with extreme character – floods, forest fires, etc.- that have a negative effect on ecosystems and ecosystem services. The purpose of the present research is the application of remote sensing for ecological monitoring implementation for the ecosystems upon the appearance of natural hazards. In this paper a methodology for ecological monitoring in different temporal intervals has been proposed and additionally the results from the application of remote sensing for the purpose of ecosystem monitoring and risk assessment in case of events that induce negative effect on ecosystems have been presented. The methodology and criteria have been implemented in observing different types of ecosystems. For the purpose of the present investigation satellite data with different spatial, temporal and spectral resolution from Sentinel 2, Landsat and air photo images have been used. Terrestrial data have been used for results verification and validation. The introduced results have been obtained for different temporal intervals from ecological monitoring, on which base criteria for optimization of the temporal characteristics of the ecological monitoring have been suggested. The present research is with conformance of Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora and Directive 2009/147/EC on the conservation of wild birds. The results from the completed research can be of benefit for defining concrete actions for the implementation of measurements appointed in the Action Plan for nature, people and the economy of 27.4.2017 COM(2017) 198.
In Earth observations the reference spectra of well-described objects are required for better object-oriented interpretation of remotely sensed data from laboratory, field, airborne, and satellite sensors. For this purpose measurements of spectra using laboratory and field spectrometers are performed. The acquired spectra are used in creating a thematic spectral library. The used spectral instruments work in the wavelengths (0.4 to 2.5 microns) covering the spectral ranges from the visible /VIS/ to the shortwave infrared /SWIR/. Two different spectrometers are used to measure spectra included in the library: (1) Thematically oriented multichannel spectrometer covering the spectral range 0.4 to 0.9 microns and (2) high resolution NIRQuest spectrometer covering the range from 0.9 to 2.5 microns, both models of Ocean Optics Inc. Spectrometric measurements of representative samples of minerals, rocks, related soils, vegetation, and their natural mixtures are made in laboratory and field conditions. In some cases, samples were purified, so that the unique spectral characteristics of the studied objects could be related to their typical structure. The relations between the spectra and the structures are important for interpreting remotely sensed data acquired in the field or from an air- or space-borne platform. In some cases for making easy wide use of the spectra in the library the obtained spectra have to resample to selected broadband multispectral sensors for example those based on the satellites Landsat and Sentinel. The obtained spectral data with the metadata and additional information are planned for including in files for better interpretation of images with different spatial resolution.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.