Spatial-temporal analysis of precipitation variability in Qinghai Province, China

Rainfall is a key factor of hydrological variability in a changing climate. Based on daily precipitation dataset of 50 station records, spatial and temporal variations of annual and seasonal precipitation from 1962 to 2011 in Qinghai Province, China are investigated using four statistical methods. Moreover, rainfall is analyzed for different rainfall intensities using the innovative trend analysis (ITA) method and the double ratio statistic (DRS) method. The results indicate that the reduction of precipitation in the densely populated eastern and southeastern regions is closely related to human activities. And human activities primarily affect extreme precipitation. The decrease in summer and autumn precipitation plays a major role in the decrease in the annual total precipitation. Spring and winter rainfall exhibit significant increasing trends. The inhibition of autumn precipitation caused by human activities is the most obvious, and this inhibitory effect can cause drought. It is hoped that this study can provide support for water resources planning and for dealing with droughts and floods.