Abstract:
With the trend analysis, Morlet wavelet analysis and m-k test, the overall trend of precipitation in Longquanyi District from 1980 to 2018 are studied, including the interannual and seasonal trend of precipitation, characteristics of the number of precipitation days and the months, ten-day and daily precipitation. The results show that the annual precipitation in Longquanyi District has an obvious downward trend, accompanied by three-year and nine-year periodic fluctuations. The precipitation days have seven-year or eight-year and twelve-year periodic oscillation, and four-years sub periodic oscillation. The precipitation that can cause geological disaster in Longquanyi area are mainly in July and August, and the change trend of precipitation in the two months is opposite on decadal scale. Ten- day precipitation and daily precipitation show obvious quasi-normal distribution. Ten-day precipitation mainly concentrated in late July and mid August, and the larger value of daily precipitation also appeared in July and August.