Temporal and spatial distribution of short-time heavy rain of Beijing in summer

By using rainfall dataset from 187 observation stations in Beijing during the period of 2006 to 2010, the short-time heavy rain (STHR) in summer is analyzed. The results show that STHR occurs mainly in the afternoon to mid-night with a rainstorm sustain time (Tsus) of mostly 20-35 minutes. The total precipitation (Rtot) is mostly 20-30 mm. Spatially, the piedmont region and the plains (region A) are the main locations of STHR. The front of Xishan, which is also near urban district, and urban district are regions with high incidences of STHR. The band from the piedmont in border region of Huairou County, Changping County, Shunyi County to Miyun Reservoir (region B) is another region with high incidences of STHR. In addition, the piedmont region in Pinggu County (region C) is also prone to STHR events. By comparing among the three high-incidence regions, region B, where has both favorable factors, i.e., the terrain and the water source, is more likely to presents shorter duration STHR (approximately 20 minutes) on one hand, and also is favorable to form long-maintained STHR (approximately 50 minutes) on the other hand. As a whole, the region B has a greater rainfall accumulation than the other two regions.