持续超147小时的北京强降雨，为何山区更猛烈？

Group 1 - The core viewpoint of the article highlights the severe impact of the recent heavy rainfall in Beijing, which peaked on July 28, 2025, leading to significant flooding and the displacement of over 80,000 residents [1][2][3] - The rainfall lasted for 147 hours, with an average precipitation of 210.4 mm across the city, and the maximum recorded in the Miyun District reached 573.5 mm, which is significantly higher than the average annual rainfall for that area [2][3] - The heavy rainfall has been attributed to the geographical features of Beijing, particularly the mountainous regions that occupy about 62% of the city's area, which create conditions for intense rainfall through orographic lift [13][15] Group 2 - The Miyun Reservoir, a critical water source for Beijing, has been releasing water to manage the flood situation, with a total discharge of 1.2 billion cubic meters, equivalent to the volume of 8.5 West Lakes [3][11] - The article emphasizes the importance of Miyun District, which serves as a key geographical and hydrological point for the city, with historical significance reflected in its long-standing infrastructure, including the Great Wall [4][11] - The interaction between the mountainous terrain and water systems is crucial for understanding the historical and current hydrological dynamics of Beijing, as many rivers originate from the surrounding mountains [21][22]