An Algorithm for Identifying Main and Slow Flow Channels of Yangtze River

Vessels which navigate on the main flow channel can save energy.In order to more accurately divide the main and slow channels of the Yangtze River,this paper proposed methods of k-nearest neighbor algorithm and P-tile method.The improved P-tile method can avoid the main stream being too small by dynamic selection of P values.The k-nearest neighbor algorithm partitions the main and slow streams with channel hydrology information,such as depths and flow velocities.With the 1 1 sections'data of Yueyang and Jinkou measuring stations in Yangtze River,this study com-pared the partition results of these two algorithms.The results showed that areas of main and slow channels at the 10 out of 1 1 sections were close.A further comparison with the waterways at Longkou and Yanglinyan of the Yangtze River indi-cated the difference of the mainstream zone width estimated from the proposed algorithms was within 12% comparing to the actual,which can meet the requirements of the ship navigation.