Unmanned aerial vehicles and Geographical Information System integrated analysis of vegetation in Trasimeno Lake, Italy

This study examined the potential of using high-resolution image data acquired by micro-UAV (unmanned aerial vehicle) for analysing large-scale environmental and hydraulic parameters. A procedure based on image data acquisition and processing is discussed and applied to a test case, Trasimeno Lake. This lake was selected for this study because of its importance in cultural, environmental and social context. This study focused on the temporal and spatial scale extension of reed beds (Common Reed). The Common Reed can strongly influence the ecological balance of the lake and particularly its evapotranspiration levels, which significantly influence the lake's water balance. Moreover, the lake provides valuable ecosystem services, including phytoremediation water treatment and the absorption of carbon (carbon sink). A presentation of the study area from a geographical and morphological perspective is provided; then, the platform (UAV and sensors) and the processing system of the images are discussed. The results concerning the accuracy of the method for the construction of georeferenced orthophotographs, and the preliminary results obtained from flights performed at different times and growing seasons of reed beds of Trasimeno Lake, are presented. This study also provides convincing evidence that the orthophotographs obtained with a low-cost UAV system can be used to analyse changes in the extension of the Phragmites australis (Common Reed) of Trasimeno Lake, and the alteration of some environmental parameters of the vegetation, in a temporal and spatial scale. It also highlights that this system can be used to facilitate analyses performed by traditional remote sensing method.