Probabilistic Risk Assessment of Bird-Turbine Collisions Using Flight Path Models

A hybrid probabilistic framework was developed to assess bird collision risk using stochastic flight path models based on Brownian motion and Brownian bridge processes. Species-specific flight parameters for itinerant and nesting birds were derived from field surveys and radar data collected in a remote outback region of Australia. Simulations were conducted to estimate the probability of birds entering the rotor-swept area of turbines and the expected number of collisions, accounting for turbine characteristics and flight variability. The results indicate that higher expected collision numbers were generally observed for itinerant birds than for nesting birds under similar avoidance rates. For nesting birds, collision estimates obtained from the Brownian bridge model were comparable to those from the Brownian motion model but corresponded to longer flight durations.

Keywords: Wind turbine, collision risk, CRM, Brownian motion, Brownian bridge process.