Australian floodplain and wetland ecosystems are dynamic, diverse, and increasingly threatened by climate change and anthropogenic water diversion. Monitoring these ecosystems is critical for species conservation and improving water management policies. However, traditional vegetation assessment methods are often challenged by inclement weather, rough terrain, and logistical complications, which can limit sampling quantity and spatial coverage. Unpiloted Aerial Vehicles (UAVs) offer a rapid and efficient alternative for monitoring vegetation changes, particularly in remote floodplain and wetland environments.
This study aimed to compare the effectiveness of UAV imagery analysis with traditional field-based methods for rapid Plant Community Type (PCT) surveys in the lower Lachlan River floodplain, New South Wales, Australia. Approximately 1,000 plots, measuring 20 × 20 metres, were randomly selected within the ~670 km² Lachlan floodplain. UAV imagery was collected at varying altitudes, orientations, and resolutions across 187 sites and visually assessed by identifying vegetation species, coverage and condition to match existing PCT classifications within New South Wales. Traditional field-based surveys completed by researchers were conducted at 73 sites.
Field-based survey data was compared to that derived from UAV imagery and flight logs. Data was assessed for sampling quantity, spatial range, operational efficiency, identification confidence, species detection and economic expenditure. Analysis revealed that UAV-based survey methods provided advantages over traditional methods in sampling quantity, spatial range, operational efficiency, and economic expenditure. While species identification confidence was lower, genus level identification still provided adequate data to match a given PCT.
UAVs enhance vegetation assessment efficiency and enable surveys in otherwise inaccessible areas while minimizing environmental impacts associated with field-based surveys such as introduction of foreign biota While UAV sensor resolution presents a limitation where precise species identification is required, traditional surveying is limited by accessibility challenges. UAV’S provide a complementary method to traditional surveys, and effectiveness is expected to improve alongside advancements in sensor technology.