This book presents a systematic framework for risk assessment and predictions of extreme climate impacts using big data analytics, artificial intelligence, and intelligent monitoring technologies. Central to this effort is the concept of a smart water grid, a "digital water network", capable of real-time monitoring, rapid transmission, accurate forecasting, optimized decision-making, precise allocation, and efficient management especially during floods and droughts.Building on case studies and original research from the Yangtze Delta — a region increasingly vulnerable to heavy rainfall, prolonged dry spells, sea level rise, and clustered extreme climate events that intensify saltwater intrusion, water shortages, ecological degradation, and disruptions to inland navigation — the book demonstrates how the construction of a high-quality, intelligent water grid advances climate adaptation, supports sustainable water governance, and contributes to national strategies of regional integration. Its interdisciplinary perspective spans hydrology, remote sensing, system dynamics, and machine learning, offering both theoretical foundations and applied methodologies.This text serves as a reference for researchers, engineers, and policymakers concerned with water resources engineering, environmental management, and disaster risk reduction in deltaic regions confronting climate change.