By analysis of the characteristics of the channal cross-sections of the Lower Yellow River, a new concept is presented that there exists a "secondary main channel" in the Lower Yellow River.

The two level schemes of master station of distribution automation are presented in this paper and the functions of a sub master station for distribution automation are emphatically described.

Flood volume required for keeping the main-channel from shrinkage in the lower Yellow River;

This paper shows that the flow for maintaining the capacity discharge of the main-channel in the lower reaches of the Yellow River should be larger than 4 000 m3/s, the flow for maintaining the capacity discharge of the main-channel in Inner Mongolia reaches should be larger than.

According to the flow state in flume for spur and experimental data, the formulas for the mean velocity of main channel varying with distance downstream were derived with momentum principle.

By using this method, the main channel and flood protection embankment are basically formed during construction.

Formulas used to determine the local head losses of single submerged dike and the mean velocity of main channel varying with distance downstreamare derived.