Abstract
The hydraulic and morphological characteristics of the Lower Mekong River were investigated. A concept “segment division” was used in this study. Based on the concept, data analysis was conducted using existing data collected. The average bed elevation, average water depth, river width, representative diameter of riverbed material, friction velocity, etc at each cross section at average annual maximum discharge were obtained and their longitudinal changes in the whole Lower Mekong River were shown. As the results, in segment 3 from river mouth to downstream of Tan Chau, river was horizontal and average width was 1,239 m. In segment 2-2 from Tan Chau to Kratie, riverbed slope was 1⁄25700, representative diameter of riverbed material was 0.17∼0.76 mm (fine sand∼coarse sand), and average width was 1,645 m. The relationship between the non-dimensional tractive force and representative diameter in the Lower Mekong River in case of representative diameter 0.17∼0.76 mm was clarified.
