Abstract: Focusing on the core characteristics of water disaster scenes—extreme environments, rapid situational evolution, information sparsity, cascading risks, and spatial concealment—this study elucidates the essential connotations of water disasters and their on-site environments. Based on a generalized full-chain cognitive paradigm, a four-layer theoretical framework for thorough perception, "sensing-cognition-integration-feedback", is constructed. It involves four core technical pathways: multi-dimensional resilient sensing, intelligent fusion cognition, digital twin simulation, and precise collaborative feedback. The scientific issues underlying water disaster scenarios caused by naturally-driven and human factors are systematically examined. The two types of scenarios are distinguished by their respective technical emphases on "speed" and "depth." Three common key scientific and technological bottlenecks identified are information acquisition and transmission under extreme conditions, deep fusion of physics-based mechanisms with data-driven approaches, and real-time closed-loop regulation of complex systems. This framework achieves a full-cycle value transformation from data collection to operational action, providing systematic theoretical support for full-element, multiscale perception and rapid emergency response in water disaster scenarios.