APPLYING UAV PHOTOGRAMMETRY DATA FOR HIGH-RESOLUTION GEOMORPHOLOGICAL MAPPING OF A PART OF THE LOM RIVER VALLEY NEAR THE VILLAGE OF VASILOVTSI (BULGARIA).

Floodplains are complex systems which include a wide number of socio-economic activities like agriculture, freshwater fisheries, electricity from power plants and others. They have often highly dynamic property, due to the alternation of fluvial processes, floods, and ongoing sediment transport, as well as of environmental specifics and natural or anthropogenic processes. In the context of the investigation of soil pollution with heavy metals in the riverine floodplains, the availability of geomorphological maps at large scale is of great importance. The rapid development of new remote sensing and computer technologies offers nowadays the possibility for acquisition of high-resolution topographic and land surface data which can serve as basis for digital terrain analysis and geomorphologic mapping. This paper outlines the preliminary results of applying unmanned aerial vehicle (UAV) data for geomorphological mapping of the study area. The methodological approach is based on the two key data products of UAV photogrammetry − the digital terrain model (DTM) and the orthophoto mosaic. The digital terrain model is used for calculation of terrain derivatives such as altitude above the channel network and topographic ruggedness index (TRI), using Geographic Information Systems (GIS). The orthophoto mosaic, on the other hand, is used to calculate local statistical measures, enabling detection of textural and structural properties, as well as for differentiation of features with similar spectral responses but different surface structures. The obtained results show that UAV photogrammetry is a powerful and inexpensive tool for fluvial remote sensing analysis and has the potential for high-resolution geomorphological mapping. [ABSTRACT FROM AUTHOR]