Abstract: The reason for the hinder of navigation manipulating by the Manting water way of lan Chang-Mekon River is mainly because of the dammed water and flood detention effect due to the exist of san-dao-guai gorge range in the period of flood water.Based on the relationship between roughness and flow rate and the relationship between bed slope and water level.we calculated the different flowing abilities of Manting water way at various water levels.And obtained the flood detention rate of san-dao-guei gorge range at different water levels.

Key words: flood detention rate, roughness, bed slope

摘要： 澜沧江曼厅河段的碍航原因主要是三道拐峡谷段对洪水的壅水滞洪作用.在获得糙率流量关系和河床底坡水位关系基础上,计算出曼厅段在多种水位下的过水能力,最后获取三道拐不同水位的滞洪量.

关键词: 滞洪量, 糙率, 底坡