The Yangtze River Basin and Huaihe River Basin in Southern China experienced severe floods 1998 and 2016. The reasons for the flooding hazards include the following two factors: hazardous weather conditions and degradation of the hydrological environment due to anthropogenic activities. This review work investigated the weather conditions based on recorded data, which showed that both 1998 and 2016 were in El Nino periods. Human activities include the degradations of rivers and lakes and the

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... ects caused by the building of the Three Gorges Dam. In addition, the flooding in 2016 had a lower hazard scale than that in 1998 but resulted in larger economic losses than that of 1998. To mitigate urban waterlogging caused by flooding hazards, China proposed a new strategy named Spongy City (SPC) in 2014. SPC promotes sustainable city development so that a city has the resilience to adapt to climate change, to mitigate the impacts of waterlogging caused by extreme rainfall events. The countermeasures used to tackle the SPC construction-related problems, such as local inundation, water resource shortage, storm water usage, and water pollution control, are proposed for city management to improve the environment. Due to rapid urbanization in China, a large number of people have migrated to coastal cities since the late 1990s, which has been identified as a factor contributing to global warming. Urbanization is another important factor responsible for land contamination in urban areas [10, 11] along with infrastructure construction [12] [13] [14] [15] [16] . Existing studies [17] showed that the urbanization rate ranged from 18% to 46% over 30 years, during the period of 1978 to 2008. In 2013, the urbanization rate increased to 58%, and it is expected that this rate will reach 80% in the near future. At present, more than 50% of cities are experiencing urbanization, as increasing numbers of people move to urban areas, especially to the coastal Chinese cities. Rapid urbanization triggers the construction of roads, bridges, and underground transit networks [18] [19] [20] [21] [22] , as well as the development of residential areas [23] . Increasing numbers of river banks and lakes are being reclaimed [24] [25] [26] . Due to the degradation of rivers and lakes, excess rainwater does not have sufficient drainage. Thus, the decrease in river bank and lake area intensifies flooding disasters. Many cities in the coastal regions of China have experienced land subsidence and flooding hazards induced by urbanization [27] [28] [29] . As a result, many researchers have focused on the impact of climate change caused by urbanization [30] [31] [32] [33] , as well as the risk of flooding caused by a combination of climate change and engineering activities [34] [35] [36] [37] .