Spatiotemporal Variation of Extreme Precipitation in the Lixia River Basin, China, between 1960 and 2019 under Global Warming, Atmospheric Circulation, and Local Effects

As a consequence of global warming, extreme weather events are becoming more prevalent, which influences socioeconomic development. It is vital to reveal the variations of regional extreme precipitation for flood prevention and mitigation. This research presents a comprehensive analysis of spatiotemporal variation and segmentation trend of extreme precipitation indices (EPIs) from the spectrum of intensity, frequency, and duration in the Lixia River Basin (LRB), China, from 1960 to 2019. The influence of global warming [global mean near-surface temperature (GSTEMP)], atmospheric circulation [e.g., multivariate ENSO index (MEI), and East Asian summer monsoon index (EASMI)], and local effects (e.g., relative humidity and local temperature) are examined to explore the dominant driving factors on the trend of EPIs. Results show that the intensity and frequency of EPIs increase across the LRB, whereas the durations of extreme precipitation are decreasing. And the lower reach has more frequent extreme precipitation than the upper reach. And most stations in segmentation trend analysis of EPIs show UUD (i.e., increasing from 1960 to 1980, increasing from 1981 to 2000, and decreasing from 2001 to 2019). What is more, the intensity and frequency of extreme precipitation are more actively related to local temperature and relative humidity than others, with local temperature being the primary negative impact while other factors are positive. And relative humidity and GSTEMP have a greater impact on the duration of EPIs than others. The findings will help figure out how regional global warming affect the trends of extreme precipitation, and can be used on a regional scale for the development of socioeconomic activities.