北京6月1日上汛，雨水情监测预报“三道防线”持续优化完善

Group 1 - Beijing is preparing for the flood season starting June 1, with predictions of high-level flood warnings in the North Canal basin and risks in other areas [1] - High-risk areas for mountain floods include parts of Fangshan, Mentougou, Changping, Yanqing, Huairou, Miyun, and Pinggu districts [1] - Urban flooding risks are present in all central city districts, particularly in Fengtai, Shijingshan, Haidian, Chaoyang, and Tongzhou [1] Group 2 - The water authority has implemented responsibilities for flood defense across nine key areas, including reservoirs and river channels, with 128 revised emergency plans [1][2] - A total of 69,000 pieces of flood defense materials and over 3,600 specialized emergency response personnel have been mobilized [1] - New monitoring stations have been established, including 264 rain gauges and 90 hydrological stations, to enhance flood forecasting capabilities [2] Group 3 - Preparations include pre-positioning flood defense materials in key areas along the Yongding River, Chaobai River, and North Canal to ensure rapid response [3] - Comprehensive flood control drills are being conducted, focusing on responses to super-standard floods in the Chaobai River basin [3]