Research On Urban Rainstorm Waterlogging Simulation Based On UAV Tilt Photogrammetry And SWMM

Urbanization is the inevitable result of economic and social development.With the acceleration of urban construction,the natural infiltration,runoff generation and confluence systems on the surface have been greatly changed by human beings.In addition to the lagging development of urban pipeline network system,serious waterlogging phenomena have occurred in many cities both at home and abroad when they encounter heavy rainstorms of recurrence period,which poses a great threat to the urban infrastructure and the lives,property and daily life of residents.Therefore,urban stormwater flood research has always been an important foundation in related fields such as water conservancy,disasters and management.At present,great progress has been made in the research of urban rainstorm water accumulation theory and the simulation of submergence process,but there are still many shortcomings,especially the low accuracy of urban underlying surface data,the lack of overall research on rainfall-runoff-pipeline water accumulation-submergence and the lack of research on multi-source submergence algorithm,which need to be further studied urgently.Based on the analysis of the research status of urban storm flood at home and abroad,this paper combines UAV,digital photogrammetry,geographic information science and hydrology,and carries out the simulation research of urban storm water based on UAV tilt photogrammetry and SWMM model according to the research idea of geographic data acquisition-model construction-case application-result test.Firstly,in order to overcome the inaccuracy of traditional satellite remote sensing and aerial remote sensing technology in obtaining urban underlying surface data,and to affect the accuracy of urban storm runoff calculation and water accumulation simulation,UAV tilt photogrammetry was used to construct urban high-precision DEM and TDOM models.Secondly,the SWMM model is selected to simulate urban rainfall-runoff,and the required parameters are extracted by highprecision DEM and TDOM obtained by UAV tilt photogrammetry,and the SWMM model is constructed and calibrated with urban pipeline network data.Finally,the simulation of urban storm runoff and pipeline network water conveyance process is completed.Then,a simulation model of urban rainstorm water accumulation is proposed,which takes the overflow volume of pipe network nodes simulated by SWMM as input and the highprecision DEM acquired by UAV oblique photogrammetry as data support.The model divides submergence calculation into three processes: subcatchment area overflow calculation,overflow direction calculation and water accumulation calculation,which can restore the process of urban rainstorm water accumulation to the greatest extent.Finally,a university campus in a city is selected as the research area.Based on the high-precision DEM and TDOM models constructed by UAV tilt photogrammetry,the SWMM model is used to simulate the rainstorm runoff in the research area,and the rainstorm water accumulation algorithm is used to calculate the submergence of the research area.The calculated results are compared with the measured water accumulation data in the research area,and the simulation accuracy of the model is verified.The model and method of urban stormwater accumulation based on UAV tilt photogrammetry and SWMM proposed in the paper can simulate the whole process of urban rainfall-runoff-pipe network water-submersion.It is not only of great scientific significance to the theory of urban rainstorm water research,but also of great application value in the practice of urban rainstorm water accumulation prediction.