Flood risk analysis under consideration of river system dynamics and spatial temporal scales

• Main Author: Oliver, Julien
• Other Authors: Qin Xiaosheng
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: DRNTU::Science::Physics::Meteorology and climatology; DRNTU::Engineering::Civil engineering::Water resources
• Online Access: https://hdl.handle.net/10356/89748; http://hdl.handle.net/10220/48040
• Institution: Nanyang Technological University

Due to rapid urbanization and climate change, the frequency of flood events has notably increased over the last decades, adversely impacting societal development and economic growth. The recent years have seen growing interests in devising risk-based solutions to support flood management. The risk-based approach, which quantifies both flooding frequencies and impacts, offers opportunities to design cost-efficient strategies to address all segments of the risk management cycle. While theoretically well established, current methods to quantify flood risks usually fail to capture adequately spatial and temporal dynamics of flood risks. This work presents novel and enhanced flood risk assessment frameworks designed to address three limitations of existing flood risk estimation methods, including: (i) the influences of morpho-dynamics and dike failure on risks patterns, (ii) the spatial coherency of regional flood events, and (iii) future flood risk adaptation at the regional scale. The frameworks proposed rely on modelling chains, with several or all of the following components: (i) long-term continuous and spatially coherent forcing events, (ii) a probabilistic river channel model, (iii) a stochastic structure failure model, (iv) an efficient inundation modelling strategy, and (v) a probabilistic damage simulation model. The risk modelling frameworks, applied in Nepal and India, highlight the benefits of using more advanced methods to address the complexity of flood hazard and risks dynamics. The research work demonstrates that integrated risk modelling approaches are nowadays applicable and should be considered to better inform risk management strategies.