A Preliminary Risk Assessment Model Considering UAV Operations Over Land and Sea

The rapid expansion of the low-altitude economy has highlighted a critical gap in safety evaluation. To bridge this gap, this work proposes a preliminary risk assessment framework for unmanned aerial vehicles (UAVs) operations. First, we delineate the risk assessment requirements for urban low-altitude routes and introduce a core framework. Subsequently, the operational volume of these routes is quantiffed. Risk evaluation then proceeds in two parallel streams: ground and air. For ground risk, a two-tiered process is employed, comprising an initial coarse assessment and a subsequent reffned, granular analysis. For air risk, two distinct scenarios are examined: mid-air collision over land and gust interference over sea. To demonstrate its application, a case study of Shenzhen is conducted. Ground risk is assessed at both the region and grid levels, while air risk analysis separately addresses mid-air collision over land and wind gusts over sea. In summary, the proposed methodology provides cities with a structured, preliminary tool to systematically evaluate the safety of low-altitude UAV operations across land and sea environments.