Abstract:Based on the cloud-to-ground (CG) lightning data in Jinhua area from 2007 to 2018,we analyzed the climatic characteristics of CG lightning in Jinqu Basin and the corresponding relationship between CG lightning and topography or altitude.The results showed that:(1) The annual average times of lightning in Jinhua area from 2007 to 2018 is 45 481,and the average annual CG lightning density is 4.3 fl·km-2·a-1,which varies from 2.64 to 5.92 fl·km-2·a-1;(2)The difference in spatial distribution of annual CG lightning in Jinhua is rather big,and the CG lightning mainly occurred in the southwestern corner of Jinhua,specifically in Xianxia ridge area and along the Kuaiji mountain,as well as the Jinhua mountain at the junction of Lanxi city,Wucheng district and Jindong district.While in the southeast corner of Dapan mountain and in the north area of Longmen mountain,the total CG lightning density is relatively small;(3) Total CG lightning density has certain relation with topography and altitude.When the total flash density is above 80 times·km-2,it probably distributed in high-altitude mountainous areas;and 23 points out of the 25 points with strong lightning density (5-7 fl·km-2) distributed in the mountainous areas between 208 m and 989 m above sea level;(4) The CG lightning density in the Sanjiang River basin is the lowest,and it is barely close to the average along the Hangzhou-Changsha Railway and in its vicinity,which is inconsistent with other relevant research conclusions;(5) During the 12 years of 2007-2018,the number and total number of CG lightning increased with altitude in 41.7% years,and in the rest of 58.3% years,the average and total average CG lightning intensity increased with altitude,both of which have passed the significant test.