Floods are the most frequent type of natural hazards worldwide, and have caused significant loss of life and severe economic impacts on populations and property during the past two decades (CRED and UNDRR, 2020). To reduce the negative impact of floods, numerous types of flood defenses, such as levee systems, have been built to protect cities, towns, and farms in almost every country (Ubilla et al., 2008;Z. Wang & Liu, 2019). According to a report by the United States (U.S.) Army Corps of Engineers (USACE), approximately 11 million people and $1.3 trillion of property value existed in flood-defended areas in the U.S. as of 2018 (USACE, 2018). The number and standard of flood defenses continuously improve over time to meet societal needs and keep pace with rapid urbanization in floodplains (Leonard, 2008;T. Zhu et al., 2007). Flood defenses have significantly changed the regional flooding distribution and also residents' exposure (Di Baldassarre et al., 2009;Ludy & Kondolf, 2012), and this needs to be considered in flood hazard assessment.With the increase of computing power and advances in remote sensing techniques, it is now possible to map flood hazards on a large scale at high resolution (<100 m) (Ward et al., 2015). High resolution global hydrography datasets, such as MERIT Hydro (Yamazaki et al., 2019) and HydroBASINS (Lehner & Grill, 2013) have been released; however, information on detailed flood defenses for most rivers in the world is severely limited (Aerts et al., 2020;Sampson et al., 2015). Existing state-of-the-art global flood hazard models either assume a simplified high flood defense standard (FDS) or assume no protection when applied (Aerts et al., 2020;Scussolini et al., 2016;Ward et al., 2015). This assumption causes the misestimations of flood hazards when the flooded areas are actually protected by existing flood defenses, and therefore induces a distorted flood hazard and risk assessment. The first global flood defense database (called FLOPROS) was built by collecting FDS data worldwide at the sub-country scale (Scussolini et al., 2016). FLOPROS assumes that the FDSs in a vast area are the same (i.e., most states in the US or all of Australia have the same FDS) and ignores the heterogeneity of FDSs between rivers. The coarse resolution of the FDS data in FLOPROS cannot meet the requirement of large-scale flood hazard modeling at high resolution.