Changes in Extreme Precipitation Over Dry and Wet Regions of China During 1961-2014

Changes in extreme precipitation differ among regions (e.g., dry and wet regions), causing different adverse effects on human life, social economy, and natural ecosystems on a warming planet. In this study, we use the 95th percentile-based threshold to define extreme precipitation. The spatiotemporal changes in extreme precipitation and temperature-extreme precipitation scaling relationship between dry and wet regions of mainland China during 1961-2014 are analyzed using two gridded data sets of precipitation and temperature observations. Extreme precipitation increased faster in dry regions (3.9% frequency and 2.8% relative intensity per decade) compared to wet regions (2.5% frequency and 2.1% relative intensity per decade) over the past 54 years. Despite the negative regression relationship between mean precipitation and temperature in wet regions, extreme precipitation has a positive relationship with temperature. The regression coefficient in relative intensity against temperature change is 6% per °C in wet regions. The frequency increases significantly (p < 0.01) faster as temperature increases in wet regions (11.1% per °C) compared with dry regions (6.9% per °C). These results suggest that precipitation extremes increase for both dry and wet regions, and faster trends are observed in dry regions. However, the same magnitude of warming causes more extreme precipitation in wet regions. Therefore, more extreme precipitation in future may raise the risk of flooding in both dry and wet regions, particularly for wet regions, due to the stronger relative intensity and faster increases against warming.