A study on regional extreme precipitation events and the exposure of population and economy in China

Based on daily precipitation data (1960-2014) collected at 771 meteorological stations over China，the 95th percentile of effective precipitation is selected to be the extreme precipitation threshold. A regional precipitation event is identified to be an extreme precipitation event if it exceeds the threshold over a continuous area at a given time scale. By taking into account the spatial and temporal continuity characteristics of extreme precipitation events，the Intensity-Area-Duration (IAD) method is applied to study the feature of regional extreme precipitation event at different durations and the population/GDP exposed to extreme precipitation events. The research results show that: (1) regional extreme precipitation events with maximum relative intensity mainly occurred in three periods：1960-1968,1991-1999 and 2006-2013; (2) the centers of extreme precipitation events are largely distributed in Northeast China and to the south of the Yangtze River，while single-day extreme precipitation events mainly occurred in the northern region and multi-day extreme precipitation events mostly occurred in the southern region; (3) the areal coverage of extreme precipitation events has increased significantly during 1960-2014，but no obvious change can be detected for the relative intensity of extreme events; (4) the population and GDP exposed to extreme precipitation events have shown a significant increasing trend. The population exposed to extreme precipitation events reached 24.08 million people/d in 1983, and the GDP exposed to extreme events reached 2 billion yuan/d in 1998.