Flood vulnerabilities in large watersheds, such as the Mahanadi Basin, result from a complex interplay of socioeconomic and physical factors. This chapter introduces a comprehensive framework for assessing vulnerabilities to riverine floods, leveraging Shannon Entropy and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The study evaluates vulnerabilities through a multi-indicator approach, integrating 24 socioeconomic and physical indicators to generate granular insights into spatial heterogeneity and sensitivity of flood-prone regions. The framework categorizes vulnerabilities into physical, socioeconomic, and composite dimensions, providing a nuanced understanding of the factors contributing to flood risks. Application of the framework to the Mahanadi Basin revealed that while physical indicators predominantly drive vulnerability in certain clusters, socioeconomic disparities significantly amplify risks in other areas. The analysis demonstrates the critical importance of comprehensive indicator selection and the use of robust statistical techniques to minimize subjectivity. Findings highlight the necessity of targeted interventions, such as infrastructure improvements and community-focused adaptation strategies, to mitigate vulnerabilities. This chapter provides a valuable reference for policymakers and researchers seeking to enhance flood risk management and develop sustainable solutions in multi-hazard environments.