Study on urban waterlogging risk identification model based on cellular automata
[Objective]At present,the urban waterlogging simulation model faces many challenges,such as high data require-ments,large amount of calculation,small applicable scale and so on.Exploring a simple,efficient and operational waterlogging simulation model can provide a powerful tool for cities lacking information to identify waterlogging risks and improve disaster pre-vention level.[Methods]The ability of cellular automata to simulate complex systems and the spatial data processing ability of GIS platform are integrated,cells and their rules are defined according to the principles of hydrology and hydraulics,the risk identification model of urban waterlogging is established.Using open source data,the model is applied to the eight districts of Hangzhou main city.The applicability and limitations of the model are discussed by comparing the existing studies.[Results]The results show:(1)The simulation result of the model are best when the cell side length is 60 meters and the time step is 4 min.The Nash-Sutcliffe efficiency coefficients of parameter calibration and model verification are 0.969 3 and 0.971 4.(2)Un-der the condition of once-in-a-century short-term heavy rainfall in the study area in 2021,the waterlogging risk area accounts for 6.94％of the construction land.When the design recurrence period of rainwater pipes is increased from once every five years to once every ten years,the proportion of waterlogging risk area is reduced to 6.30％.(3)The model does not need to divide the catchment area and requires less data,so it has good practicability and operability in the waterlogging simulation of short-term heavy rainfall in plain cities.However,there are also some limitations,such as weak physical mechanism and imprecise simula-tion result.[Conclusion]The risk identification model of urban waterlogging based on CA is not an improvement of the numerical model of hydrology or hydraulics,but a simplified model established after weighing many factors such as data requirements,mod-el operation efficiency,accuracy of identification result and so on,which has good applicability to the prevention and control of waterlogging in plain cities.
万方数据
维普
