Urban drainage system liquid level indirect monitoring analysis method based on directed topology network

The invention discloses an urban drainage system liquid level indirect monitoring analysis method based on a directed topology network. The method comprises the following steps that a drainage pipe network directed topology model and a drainage pipe network database are constructed; extracting numbers of upstream and downstream inspection wells and pipelines corresponding to the monitoring point positions; preliminarily estimating the liquid level; the pipe network is divided into an upstream area, a middle-upstream area and a downstream area; new liquid levels are calculated for all nodes and pipelines of an upstream area and a downstream area in the monitoring point; and the place with overlarge liquid level difference of the pipelines at the two ends is adjusted. According to the urban drainage system based on the directed topology network, the liquid level conditions of other pipe networks are indirectly monitored through pipe network initialization interpolation and follow-up smoothing processing in comb