Using UAV approach in monitoring of macrophytes and their habitats within small water bodies of pristine riparian wetlands: a case study of the Middle Danube Area (Serbia)

Abstract

Conservation of fragile riverine wetlands with pristine or near pristine hydro-morphological regimes has become imperative in this late Anthropocene era of severe biodiversity and habitat loss. Monitoring of wetland habitats provides necessary scientific information for adequate management of these ecosystems. The remote sensing capabilities of drones offer less invasive, non-hazardous, cost- and time-effective tools for nature monitoring and assessment. Opportunities offered by drones within the scope of macrophyte monitoring and habitat conservation assessment in riverine wetlands were tested and discussed in this paper. In order to explore the potential benefits of an unmanned aerial vehicle (UAV) approach against traditional fieldwork, data were collected using both approaches and compared using several data parameters: resolution of obtained information, applicability in conservational purposes and relevance. UAV imagery collected during drone flights was used for the production of orthomosaics, which were segmented and classified into digital orthomaps using an OBIA approach. Macrophyte plot data and digital orthomaps of the lake were assessed using various conservation frameworks (The Habitats Directive, The Bern Convention, The European Red List of Habitats and Serbian national conservation framework). UAV – GIS tools enabled successful delineation of aquatic habitat types following EUNIS habitat classification scheme and have also managed to distinguish all protected and conservationally important species for the area of the Republic of Serbia. High classification accuracy of digital orthomaps (average overall accuracy = 85%, average Кappa hat = 0.8) enabled precise mapping and calculation of the research area covered by each species or habitat type. These results indicated that UAV – GIS tools offer new insights into the domain of macrophyte research and aquatic habitat conservation assessment, and should be included into existing assessment frameworks.