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.

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Rapid urbanization process is accelerating the dramatic transformation of urban land use, creating strong economic, social and environmental impacts in Hanoi (Vietnam). Improving the quality and optimizing the model of using ecological land in urban areas is very important to solving environmental issues and sustainable urban development. Using the Hanoi capital of Vietnam, an important and typical city in the Red River Delta, as in the case of the study, we applied the Minimum cumulative resistance model (MCRM) to calculate ecological land and constructed land meet the needs of socio-economic development and ecological protection. Results showed that the suitable ecological land area is about 2.090,298km2 (ecological land area 1.112,216km2, ecotones land area 978,082km2), which is 62% of the total urban area of Hanoi is mainly distributed in Bavi, Socson, Unghoa, Myduc, Chuongmy districts and Sontay town; and constructed land area is about 1.275,736km2, which accounts for 38% mainly distributed in the city center and urban areas. Study the ecological land space and construction land of Hanoi area and compare with the current land use status through simulation of MCRM model, we propose three types of land use. For urban ecological land, there must be measures to manage and protect the ecological environment and prohibit construction activities in the area. For ecotones land between urban construction land and ecological land, it is necessary to control and limit the construction to improve the quality of the ecological environment. For construction land, there must be a policy to promote construction along with reasonable and efficient land use development to improve urban living environment.