The invention relates to an urban inland
river water level forecasting and early warning method comprising the steps of: firstly, obtaining the urban historical waterlogged point distribution, and setting a waterlogged
point set of {M1, M2,..., Mn}; according to a regional
pipe network topological structure, searching out an outlet of a rainwater
pipe network through which the accumulated water at the waterlogged points is discharged to an inland river, and setting a warning section at the outlet location; then, based on a urban rainwater
pipe network design method and a urban drainage
physical law, calculating the warning water levels of different warning sections by a warning
water level calculation method, and using an inland
river water level as an early warning
critical condition for urban inland inundation disasters; determining a warning section
water level unit line; in a real-time forecasting and warning process, calculating a warning section
water level process, based on a rainfall forecast and the warning section water level unit line, as a water level forecast result under the corresponding rainfall process; when the forecasted or actually-measured warning section water level reaches the warning water level, determining the moment as an inland water level warning moment. The method provides a warning water level calculation method for an inland inundation early warning program, and reduces the urban inland inundation losses.