关键词: 急滩, 消滩水力指标, 成滩流量法, 消滩判数

Abstract: This article based on the measurement and research of several rapids shoal on Lancang river，by the shoal formation flows that we get the preliminary hydraulic index of representative ships． That preliminary hydraulic index is not systematic，and is not conducive to use in project． It needs systematization to get the series index． By force balance analysis on ship effective thrust and navigation resistance，export the reasonable expression of rapids shoal and away flow shoal hydraulic index，merge the flow and slope into a general． Away beach index that called the away beach distinguish number． Using the away beach distinguish number expression to curve fitting the preliminary hydraulic index，which can be simply identified that the systematic away beach hydraulic index is reasonable and easy for use．

Key words: riffle shoal, hydraulic parameter of rapids abating, rapids of flow method, rapid determination coefficients