A Fractal-Based Approach to Lightning Protection of Historical Buildings and Monuments: The Parthenon Case Study

A fractal-based approach to the lightning protection of historical buildings and monuments against direct lightning flashes is introduced. The proposed methodology is based on a stochastic lightning attachment model that considers physical criteria on downward and upward leaders’ inception and propagation. The model foresees multiple competing upward leaders incepting from vulnerable points of the monument under protection and considers the branching and tortuous behavior of the lightning attachment phenomenon. Applying the proposed methodology to the Parthenon has shown that the risk of direct lightning flashes per year that cause physical damage to the monument is not acceptable without an external lightning protection system (LPS); two different LPSs are evaluated in terms of lightning interception efficiency. Lightning risk assessment results are discussed and compared with those obtained by implementing the procedures of the International Electrotechnical Commission (IEC) 62305.