Essential study on definition method and standard of designed navigable stage in tidal reaches;

The maximum navigable designed water level under bridge in the USA is analyzed,and the method for calculating the maximum navigable water level in China is appraised.

In view of the hydrographic feature of mountainous rivers, the shiplock designed highest navigable stage determined by flood frequency standard is hard to meet the demands of navigation flow condition in the entrance area of upper and lower approaches.

This paper introduces the definition of designed highest navigable water level of inland river, relevant standards and methods, and puts forward some suggestions on further research of the above-said fields based on the analysis and comparison with current national standards.

According to the variation law of the lowest navigation stage in the upstream channel of Xijin hydropower junction and the objective condition of upstream reservoir inflow adjustment,this paper puts forward suggestions on the calculation method and parameters of design lowest navigable stage in the upstream channel of Xijiang reservoir area.

Based on the in-depth analysis of the computation result of the design lowest navigable stage for the basic stations of Gong River in Guangdong Province, i.