Study on risk assessment method of ice disaster along transmission lines in Zhejiang province

Ice distribution and ice risk assessment map were mapped in Zhejiang province. First, based on icing numerical model, ice disaster analysis during 2005-2014 was carried out hourly on 0.01°× 0.01° grid. Then using the Gumbel function, the extreme value distribution of each grid was depicted, and Zhejiang province ice distribution was mapped. Secondly, based on the comparative analysis of multiple factors, tower ice downscaling scheme was established based on DEM data. Finally, based on the methodology of regional disaster risk assessment, vulnerability assessment model was selected to quantitatively evaluate the risk of ice disaster along transmission line in Zhejiang province on account of an index of failure rate of towers. The results showed that, in Zhejiang province, icing zones present zonal distribution, and the strongest ice zone is the middle one. In the current climate, if we ignore the human factor, ice disaster risk in the north and central zone of Zhejiang province is relatively high.