Research on the Effect of Topographic Factors on Extreme Rainfall in South China

The extreme rainstorms, along with the flood disasters, have been plaguing south China every summer. The reason for this phenomenon is not only because of its sub-topical monsoon climate, but the specific terrain character in south China also plays a role in the extreme weather. This essay delves into the extreme rainfall events in South China, highlighting the significant role of topographic factors in influencing precipitation patterns. The focus is on understanding how geographical characteristics impact rainfall intensity and subsequently lead to various natural hazards. The analysis employs a combination of historical precipitation data and topographic assessments to explore the forming mechanisms of extreme rainfall, specifically frontal rainstorms and warm-sector torrential rains (WSTRs). The roles are divided into the direct effects and the indirect effects, with the former taking the lead. The direct effects include the uplift of the moist air and the fraction of the ground contributing to the addition of turbulence. As for the indirect roles, key research questions emphasize the influence of low-level jets effects. The data of the precipitation figures comes from ERA5 reanalysis data of ECMWF, and the topography data is excerpted from GEBCO Gridded Bathymetry Data Download. In conclusion, extreme rainfall events are significantly intensified by South China's rugged topography, leading to increased risks of landslides and flooding. It emphasizes the need for improved disaster management strategies and long-term data collection to better understand and mitigate these impacts.