Lightning risk assessment at high spatial resolution at the residential sub-district scale: a case study in the Beijing metropolitan area

Abstract

Lightning risk indexes identifying the potential number of dangerous lightning events (NDLE) and ground sensitivity to lightning in residential sub-districts in the Beijing metropolitan area have been estimated on a 5 m resolution grid for the first time. The gridded cloud-to-ground (CG) lightning strike density was used in the NDLE calculation, on account of the multiple contacts formed by CG events with multiple lightning flashes. Meanwhile, in the NDLE estimates, the critical CG strike densities derived from the lightning location system data were corrected for network detection efficiency (DE). The case study for a residential sub-district indicates that the site-specific sensitivity to lightning, which is determined by the terrain factors related to lightning attachment and the lightning rod effects induced by nearby structures, differs greatly among types of underlying ground areas. The discrepancy in the NDLE, which is the numerical product of sensitivity and CG strike density, is dominated by the sensitivity to the relatively stationary CG strike density at the residential sub-district scale. Conclusively, the visualization of lightning risk sensitivity and NDLE differences in parts of a residential sub-district at a high spatial resolution makes this model useful in risk reduction and risk control for lightning risk management.

Keywords

• Lightning risk
• CG flash density
• lightning detection efficiency