The ground flash density is the basic parameter of various lightning protection design

studying the difference of ground flash density in different terrains within a certain range of mountains can obtain more accurate lightning density maps in mountainous areas.In this paper

the concept of lightning distribution coefficient which characterizing the density of landmines in different mountainous terrain is defined.The theoretical calculation formula of the lightning distribution coefficient in the mountain top

valley and foothill is deduced by using striking distance theory of the electrical geometric model（EGM）.The difference of lightning distribution coefficients in the typical mountainous terrain is compared.The influence of different factors on the lightning distribution coefficient of typical mountainous terrain is studied

and use a province’s 10 years lightning positioning system data as an example to verify.The results show that the ground flash density of mountain top area is greater than it of the valley and foothills.The greater the slope of the mountain

the more obvious the difference in ground flash density in different regions.The difference in ground flash density is greater in regions with bigger 50% lightning current amplitudes.The difference in ground flash density with increasing terrain width gradually decreases and tends to be stable.