Conceptual model for justifying a rational engineering protection system for transport infrastructure against systematic floods

The article addresses the urgent problem of ensuring the resilience of transport infrastructure to the increasing frequency and intensity of systematic floods. Analysis of events in the Russian Federation for the period 2020–2025 revealed a key systemic contradiction between the need for comprehensive protection of extensive, structurally complex facilities and the limitations of available material, technical, and financial resources. As a solution, a shift from the concept of absolute protection to the justification of a rational engineering protection system is proposed. The aim of the work is to develop a conceptual model that formalizes the process of transforming initial data on the state of transport infrastructure and flood hazards into a project for an optimal protection system under given resource constraints. The model, based on the principles of systems analysis, represents a structure of interconnected abstract operators, each solving a specific task: from diagnosing the condition of objects and assessing hydrological threats to forming and comparing protection options and selecting a final solution with its verification. Particular attention is paid to the application of fuzzy logic methods for operating under conditions of significant uncertainty in the initial data. The developed model serves as a formalized research algorithm, providing a structured approach to diagnostics, design, and justification of rational parameters for an engineering protection system, which is a necessary condition for enhancing the resilience of critically important facilities in the context of escalating climate risks.