Variation characteristics of different-level precipitation in Ningxia of Southwest China in 1962-2011

Based on the daily precipitation data from 9 meteorological stations in Ningxia in 1962-2011,and by using linear trend method,correlation analysis,Hurst trend analysis method,and IDW spatial interpolation method,this paper analyzed the variation characteristics of dif- ferent levels precipitation,precipitation days,and precipitation intensity,aimed to understand the structural characteristics of different levels precipitation in Ningxia. Overall,the annual pre- cipitation and the precipitations days showed a decreasing trend,while the annual precipitation intensity had a slight increase. In the future,the annual precipitation would be reversely persis-tent,while the precipitation days and precipitation intensity would be persistent. Spatially,due to the effects of different factors,the annual precipitation,precipitation days,and precipitation intensity decreased from southeast to northwest,and the spatial pattern of the precipitation and precipitation days was in consistency. Temporally,the precipitation in summer was abundant, precipitation days were more,and precipitation intensity was large,with the largest precipitation intensity of rainstorm. In winter,the precipitation was short,precipitation days were less,and precipitation intensity was small. The climate change trend analysis of different levels precipitation events on different time scales showed that the annual precipitation and precipitation days presented a decreasing trend,while the annual precipitation intensity,as affected by the light rain and storm rain in winter,summer and autumn,showed a slight increase.