Group 1 - The article discusses the varying perceptions of rainfall despite identical measurements, emphasizing that the impact of rainfall is closely related to its intensity and duration [1][2] - It explains that a rainfall amount of 70 millimeters can have drastically different effects depending on whether it falls in a short period or is spread out over a longer duration, with urban drainage systems playing a critical role in managing excess water [1][3] - The article highlights that regional climate differences affect how rainfall is perceived, with the same amount of rain being considered extreme in one area but normal in another, illustrating the subjective nature of weather events [2][3] Group 2 - The article notes that geographical factors, such as soil type and urban infrastructure, significantly influence the consequences of rainfall, with areas prone to flooding or landslides being particularly vulnerable [3] - It mentions that global warming is expected to increase the frequency and intensity of extreme rainfall events, necessitating adaptive strategies for disaster prevention and mitigation [3]

Core Points - The article discusses the types and significance of meteorological disaster warning signals issued by the meteorological department, including their classification and the actions the public should take upon receiving these warnings [2][3][4]. Group 1: Types of Warnings - Meteorological disaster warnings are categorized into three types: meteorological disaster warnings, meteorological disaster warning signals, and meteorological disaster risk warnings [2]. - Meteorological disaster warnings are aimed at government and relevant department officials, with a lead time of 12 to 72 hours [2]. - Meteorological disaster warning signals are designed for both government and the public, featuring a simplified icon and color-coded levels (red/orange/yellow/blue) with defense guidelines, typically issued with a lead time of 0 to 12 hours [2][3]. Group 2: Warning Levels - The warning signals are color-coded: blue (level 4, general), yellow (level 3, relatively serious), orange (level 2, serious), and red (level 1, particularly serious) [3]. - Special attention is required when orange or red warnings are issued for severe weather events such as strong winds or heavy rain [3]. Group 3: Public Response to Warnings - Upon receiving a warning, individuals should identify the type and level of the warning and act accordingly, as warnings are issued at the local level [4]. - In the event of a red rainstorm warning, the public is advised to minimize outdoor activities, and local authorities will implement emergency measures [5]. - Residents in vulnerable areas, such as mountains or near rivers, should evacuate to safe locations, and households in flood-prone areas should take precautions like placing flood barriers [5][6].