Core Viewpoint - The article discusses the implementation of a digital twin system and decision support system in China's water management, focusing on the "Four Pre" functions which are essential for flood and drought disaster prevention [1][4]. Group 1: The "Four Pre" Functions - The "Four Pre" refers to forecasting, early warning, rehearsal, and contingency planning, which are the core functions of smart water management [4]. - Forecasting serves as the foundation, utilizing mathematical models to predict various water safety factors such as precipitation, water levels, and soil moisture, thereby providing valuable time for flood prevention efforts [3]. - Early warning acts as a frontline measure, delivering timely information to frontline water management teams to guide emergency responses like engineering inspections and personnel evacuations [6]. Group 2: Simulation and Planning - Rehearsal involves simulating typical historical events and future scenarios within a digital twin watershed to formulate risk mitigation measures [8]. - Contingency planning is based on rehearsals, taking into account actual engineering and social conditions to develop actionable engineering and non-engineering measures, ensuring the feasibility of the plans [10]. - The four components are interconnected and progressively build a safety defense line for smart water management [10].

Core Viewpoint - China is fully entering the flood season, with southern regions experiencing the main flood period, prompting various local measures to enhance flood prevention and disaster reduction capabilities [1][3][5] Group 1: Regional Flood Prevention Measures - Different regions in China are implementing tailored flood prevention strategies based on their specific geographical and climatic conditions [1][3] - In Beijing's mountainous areas, the focus is on ensuring rapid and safe evacuation of residents during emergencies, while the Pearl River Basin is developing a comprehensive safety monitoring network for informed decision-making [1][3] - The "one village, one policy" approach has been adopted in Beijing, dividing villages into multiple zones, each with designated personnel responsible for emergency tasks [3][7] Group 2: Technological Integration in Flood Management - The use of advanced technology is being emphasized in flood prevention efforts, with the integration of unmanned vessels, drones, and other innovative monitoring tools in Guangdong for emergency drills [11][13] - A digital platform for monitoring and early warning of mountain flood disasters has been established in Beijing, utilizing various hydrological monitoring devices to simulate rainfall and flood progression [9][15] - The Pearl River Water Resources Commission has developed an integrated monitoring system that combines satellite, radar, and hydrological data to enhance flood forecasting and risk assessment [15][17] Group 3: Current Weather Conditions and Predictions - The southern regions are currently experiencing heavy rainfall, with areas like Zhejiang, Jiangxi, and Guangxi facing significant flood risks [19] - The first typhoon of the year, "Butterfly," is expected to bring additional heavy rainfall to southern provinces, potentially leading to localized disasters [19][21] Group 4: Goals and Future Directions - The flood prevention strategy aims to achieve the "four no" goals: no casualties, no dam failures, no breaches in key levees, and no impacts on critical infrastructure [21] - Continuous investment in flood risk mapping and the application of cutting-edge technologies are enhancing the overall flood management system, making it more proactive and efficient [21]