In the context of climate change and rapid urbanization, urban waterlogging risks due to rainstorms are becoming more frequent and serious in developing countries. One of the most important means of solving this problem lies in elucidating the roles played by the spatial factors of urban surfaces that cause urban waterlogging, as well as in predicting urban waterlogging risks. We applied a regression model in ArcGIS with internet open-data sources to predict the probabilities of urban waterlogging risks in Hanoi, Vietnam, during the period 2012–2018 by considering six spatial factors of urban surfaces: population density (POP-Dens), road density (Road-Dens), distances from water bodies (DW-Dist), impervious surface percentage (ISP), normalized difference vegetation index (NDVI), and digital elevation model (DEM). The results show that the frequency of urban waterlogging occurrences is positively related to the first four factors but negatively related to NDVI, and DEM is not an important explanatory factor in the study area. The model achieved a good modeling effect and was able to explain the urban waterlogging risk with a confidence level of 67.6%. These results represent an important analytic step for urban development strategic planners in optimizing the spatial factors of urban surfaces to prevent and control urban waterlogging.

In developing countries, rapid urbanization reduces the natural land area and increases the impervious surface. At the same time, urban rainstorm waterlogging is also becoming more frequent and serious. Therefore, one of the important works to be done is to elucidate the relationship between impervious surface expansion and waterlogging frequency (WF) causes of urban waterlogging. To move forward, we used ENVI to classify land cover types and applied the spatial analysis methods integrated in ArcGIS with internet open data to explore these relationships in Hanoi, Vietnam in 2018. The results show that waterlogging frequency was positively related to impervious surface percentage (ISP), indicating that if the median values of ISP increased then the waterlogging frequency would increase as well with a confidence level of 63.2%. This study demonstrates the importance for controlling the impervious surface expansion in urban waterlogging risk management and urban planning.