Based on the flow characters of skew bridge crossing and the theory of wake spread as well as decay, the iterative calculating formulas of backwater and relation of bridge aperture design are deduced.

Using skillfully "the design path"to solve the increment of the state function in the course of irreversible phase transition;

The path designing of modernization of tourist industry is a directive assurance,control of modernizing course,base of coordination and criterion of effect evaluation.