Long and short duration heavy rainfall spatio-temporal patterns change and its contribution to total heavy rainfall in China

Abstract

Recent studies have noted a worldwide increase in the occurrence of extreme-precipitation events. Here we use daily rainfall data from 1951 to 2010 of 659 meteorological stations in China and on the basis of duration days defined long duration heavy rainfall. Results indicate that: on the spatial distribution, short duration heavy rainfall shows gradually decreasing phenomenon from the southeast coastal to northwest inland in China from 1951 to 2010. And long duration heavy rainfall is concentrated in the southeast coastal areas, such as Guangdong, Guangxi and Hainan. On the temporal change, the interannual and interdecadal short and long duration heavy rainfall both show increasing trend. In precipitation contribution ratio, the proportion of total heavy rainfall amounts to total rainfall amounts and total heavy rainfall days to total rainfall days are 6.1%∼27.7% and 0.6%∼27.7% respectively from 1951 to 2010 in China. Short duration storm to occupy the dominant position that the proportion of short duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are 75.9%∼89.4% and 75.6%∼89.4% respectively in the same period. Long duration heavy rainfall occupy a secondary position that the proportion of long duration heavy rainfall amounts to total heavy rainfall amounts and short duration heavy rainfall days to total heavy rainfall days are only 10.6%∼24.1% and 10.8%∼24.4% respectively. On the trend of precipitation contribution, China’s the contribution rate of total heavy rainfall to the total rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 2.1%/10a and 0.2%/10a respectively. The contribution rate of short duration heavy rainfall to the total heavy rainfall show increasing trend with contribution of rainfall amounts and rainfall days trend are 0.5%/10a and 0.4%/10a respectively. On the contrary, the contribution rate of long duration heavy rainfall to the total heavy rainfall show decreasing trend with contribution of rainfall amounts and rainfall days trend are -0.5%/10a and -0.4%/10a respectively. The results suggest that the precipitation in China are changing to extremely accompanied by short duration storm increased significantly.