Study on Difference of Ground Flash Density in Mountainous Areas and Presentation of mesoscopic terrain

Ground flash density is the basic parameter of various lightning protection projects. Obtaining a more accurate ground flash density can improve the precision of differential lightning protection for transmission lines. In this paper, the software Google Earth was used to select a grid area in the mountainous area of Guangdong Province, China. The software ArcGIS was used to make a statistical analysis of 10 years lightning localization system data in this selected area to obtain the 10 years average ground flash density distribution map of this area. The results show that there is a significant difference in ground flash density of mountainous areas. When calculating the lightning shielding failure trip-out rate of transmission lines, ignoring this difference will cause great errors. In order to further study this difference, this paper puts forward the concept of mesoscopic terrain and gives the definition of mesoscopic terrain.