Changes of meteorological parameter and lightning features after water impounded in three Gorges area

With the completion of Three Gorges Project and its water impounded, a big reservoir with water area of 1.08×10⁹ m² and volume of 3.93×10¹⁰ m³ has been formed, which causes the surrounding microclimate changed. This paper analyzed the changes of temperature and relative humidity between before and after water impounded, and variation trend of lightning current amplitude after water impounded, in three gorges area of west Hubei, China, by using of hydrological data, meteorological data and Lightning Location System data in the range of 2000 and 2009 in this area. The results show that after water impounded, the annual average Air Temperature presents rising trend in the entire Three Gorges Area of west Hubei, yet the annual average Relative Humidity presents descending trend. Meanwhile, lightning current amplitude presents rising trend, among which, the number of lightning current above 100kA is also increased. The correlation coefficient between median of lightning current amplitude and the annual average temperature is 0.75, which indicates that the changes of air temperature on earth surface is one of the reasons that lead to lighting activity enhancing.