Flood-susceptibility-based building risk under climate change, Hyderabad, India

Urban floods have been highly prominent natural disasters occurring in catchments across the globe, causing financial loss and damage to buildings. This necessitates effective and sustainable mitigation mechanisms. In this context, flood-susceptibility-based building risk (FSBR), a combined index for evaluating flood susceptibility and building risk simultaneously to understand the impact of the flood, is proposed by fusing XGBoost (facilitates flood susceptibility) and Hydrologic Engineering Center River Analysis System 2D (enables building risk) in climate change situations. The methodology is applied to Greater Hyderabad Municipal Corporation, India. Six combinations of FSBR, namely, high building risk and high flood susceptibility (HH), high and medium (HM), medium and medium (MM), medium and high (MH), low and medium (LM), and low and high (LH) are employed to study the urban floods. The total affected areas for HH, HM, MH, MM, LH, and LM are 63.40 km2 (52.627%), 28.92 km2 (24%), 9.52 km2 (7.9%), 4.81 km2 (3.99%), 9.26 km2 (7.686%), and 4.56 km2 (3.79%) (totalling 120.47 km2). The number of corresponding buildings is 182,178, 84,136, 46,238, 22,691, 48,092, and 23,781. Waterproofing as a mitigation measure is considered. The total cost of waterproofing is Rs 4,964.60 cr. HIGHLIGHTS Machine learning and hydraulic modelling are complemented to derive an indicator, flood-susceptibility-based building risk (FSBR), for the urban catchment.; Six combinations of FSBR are employed to study urban floods.; Waterproofing as a mitigation measure is studied.;