# Formation Mechanism and Response Strategies for Urban Waterlogging: A Comprehensive Review
## 1 Introduction  
Waterlogging refers to the phenomenon of heavy rainfall or continuous precipitation exceeding the drainage capacity of the city, resulting in water accumulation disasters in the city. As the pace of urbanization accelerates and climate change intensifies [1, 2], urban waterlogging issues are becoming increasingly severe, posing significant challenges for numerous cities worldwide. Waterlogging not only threatens urban infrastructure and public safety but also raises new demands for urban economic development and resilience building. For instance, waterlogging events can lead to traffic paralysis and disruptions to commercial activities, consequently affecting residents' quality of life [3]. Furthermore, the environmental impacts of waterlogging cannot be overlooked, as they may lead to water pollution and the destruction of biological habitats. Previously, [PERSON] et al. [4] proposed a framework to analyze the driving factors of urban flood risk variation, emphasizing the need to develop long-term policies to address high-impact but low-manageable driving factors. Therefore, understanding the mechanisms and managementstrategies of urban waterlogging is crucial for enhancing urban resilience and achieving sustainable urban development. Heavy rainfall or extreme precipitation events within a short time often exceed the design capacity of urban drainage systems, making it difficult for rainwater to be discharged quickly and leading to water accumulation. Simultaneously, the accelerated urbanization process has increased the area of impervious surfaces, reducing natural infiltration and further exacerbating runoff. Additionally, the aging of urban drainage systems, inadequate design, and poor maintenance are also significant reasons for the frequent occurrence of waterlogging. The characteristics of urban microtopography, sunken areas, and unreasonable layout of drainage facilities can lead to water accumulation in specific regions. The combination of multiple factors makes urban waterlogging increasingly complex, affecting not only transportation and daily life but also potentially causing significant losses to urban economic activities, highlighting the importance of researching urban waterlogging management. Waterlogging mainly occurs in urban areas, usually caused by heavy rain or drainage system issues. It is related to hydrological disasters such as flooding, groundwater rise, and coastal inundation, focusing on the problem of water accumulation within the city. Currently, research on urban waterlogging mainly focuses on four aspects: theoretical analysis, experimental research, numerical simulation, and the application of artificial intelligence technology. At the theoretical level, researchers have deeply analyzed the formation mechanisms of waterlogging, revealing the complex interactions among precipitation, topography, land use, and drainage systems. Experimental research explores the mechanisms of waterlogging on urban streets, underground drainage systems, and buildings through physical models and hydrodynamic experiments. For example, [PERSON] et al. [5] conducted an idealized experiment using square blocks to represent buildings, exploring the effects of street width and direction on flow. Numerical simulation, as a key tool, utilizes one-dimensional, two-dimensional, and three-dimensional coupled models to predict and assess the processes and spatial distribution characteristics of urban waterlogging [6; 7; 8; 9; 10; 11]. The rapid development of artificial intelligence has breathed new life into waterlogging research; through deep learning, reinforcement learning, and data mining technologies, it has not only improved the accuracy of waterlogging predictions but also promoted the intelligent processes of emergency response and drainage scheduling [12; 13; 14; 15; 16].