Studies On Temporal And Spatial Variations Of Lightning And Lightning Disaster In Chongqing

Based on data of lightning location system (LLS) from 1999-2008 in Chongqing, thunderstorm day from 1951-2008 and lightning disaster from 1997-2009 in Events Chongqing lightning disaster. This paper make a statistical analysis on temporal distribution of lightning in Chonging, the results show that the thunderstorm day show a decrease trend on the annual change but the lightning frequency's trend is the reverse; The lightning storms occur all the months, but mostly in a period from April to September, and the lightning activities have double-peak double-trough, the period from 22:00 to 03:00 and from 14:00 to 18:00 are the high incidence of lightning. The results from wavelet analysis show that the variation period of annual number of thunderstorm days in Chongqing is about the short periods of 6-9years and the long periods of about 30years.Studies on spatial distribution of lightning in Chongqing show that the western, especially near the main city is the high incidence of lightning, followed by the southeast and central regions, the northeast region is relatively low. The EOF analysis for thunderstorm show that there are three types of the spatial distribution of lightning in Chongqing:consistent change in the region; The Yangtze River as the boundary, reverse in south and north; reverse in east and west.The fitting expression format adopted by IEEE is better for cumulative probability curves gotten from lightning location system than that adopted by national power industry regulations. on the basis, get the cumulative probability formula of lightning current magnitude and steepness, which applicable to Chongqing.There are 572 times lightning disaster in Chongqing from 1997-2009, which have fluctuations in growth trend; The distribution of industry suffered lightning disaster is:the civilian facilities have the highest proportion of affected, followed by the electricity sector, transportation, broadcasting, communication industry has a relatively low proportion of affected; the lightning disaster mostly occurred in city, and the number of accident and economic loss in city was far more than that in country, but the casualties happened in country is much higher than in city.