The aim of this study is to present the possibilities of thermal photogrammetry, carried out by an Unmanned Aerial System (UAS) in determining the Local Climate Zones (LCZ) in the city of Burgas, Bulgaria. This LCZ-based methodological approach has been used as one of the major standards in the research practices of mapping and assessment of the effects of the Urban Heat Island phenomenon (UHI). А complex methodological approach specifically designed for the purpose of the study was applied, which includes the use of a flying wing type UAS and a specialized integrated sensor with a thermal calibrated camera and a photogrammetric one, as well as a developed scheme for the collection, processing, and modeling of the data. As a result, the thermal characteristics of the surface of the individual types of LCZ on the territory of the city of Burgas were determined and specified. The latter was used as an information basis for modeling and mapping the effect of the UHI and determining its intensity. The data were collected according to a predetermined sampling scheme within a two-year period (2021-2022) during the hottest months of the year for the city (July and August) by the National University Center for Geospatial Research and Technology. All in-situ studies were carried out after sunset, in the time interval 20:30 - 22:00, in order to eliminate the effect of direct solar radiation on the recorded temperatures of the different land cover types. Subsequently, the collected and processed data were cataloged and integrated into geographic database of the LCZ, and the potential thermal load of each individual LCZ and individual land cover types was estimated. The results have been discussed with the Municipality of Burgas and will be used in the development of a series of urban planning measures focusing on energy efficiency, human health (regulating ecosystem services from green infrastructure) and the conservation of protected areas (falling immediately within the municipality).
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