Group 1 - The core period for flood prevention in China is "July to August," characterized by the highest rainfall in northern regions, accounting for about one-third of the annual precipitation in just one month [1] - The concentration of rainfall in northern China during this period is influenced by the subtropical high pressure in the western Pacific, which acts as a "moisture conveyor belt," transporting moisture northward [2] - The geographical features, such as the Taihang Mountains, significantly impact weather systems and rainfall patterns in northern China, contributing to the occurrence of heavy rainfall events [3] Group 2 - The active typhoon season during "July to August" can lead to significant rainfall in northern regions, as typhoons carry large amounts of moisture [3] - Northern regions have a lower capacity to handle heavy rainfall compared to southern regions, necessitating preparedness for disaster prevention and mitigation [3] - Experts warn of potential secondary disasters, such as flash floods and mudslides, due to the strong rainfall events already occurring in northern areas [3]